IDENTIFICATION, CLASSIFICATION, AND INVENTORY OF CRITICAL NURSERY HABITATS

FOR COMMERCIALLY AND RECREATIONALLY IMPORTANT FISHES IN THE MANATEE RIVER ESTUARY SYSTEM OF TAMPA BAY

Submitted to:

Submitted by :

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ni NOV 13 1992 :'" br~:rGLJlTI]E

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FINAL PROJECT REPORT

Southwest Florida Water Management Di strict Tampa Bay Surface Water Improvement and Management Program 2379 Broad St reet Brooksville, FL 33512-9712

Mote Marine Laboratory 1600 Thompson Parkway Sarasota, FL 34236

November 9, 1992

MOTE MARINE LABORATORY LIBRARY 1600 THOMPSON PARKWAY SARASOTA, FLORIDA 34236

Mote Marine Laboratory Technical Report No . 276

TABLE OF CONTENTS

Table of Contents i List of Figures ii List of Tables iv Participants v

Executive Summary 1

Introduction 3

Importance of Nursery Habitats to Fisheries 3 Importance Estuari ne-Dependent Spec i es in the Tampa Bay and

Southwest Florida Region 4 The Manatee River Estuary System 6 The Manatee River Estuary System Nursery Habitat Problem 8 General Project Description 10

Methods 12

Study Area Habitat Classification, Survey and Mapping Habitat Sampling

Results and Discussion

Habitat Classification System Development Habitat Survey and Mapping Habitat Sampling -- Fall Sampling Period Habitat Sampling -- Winter Sampling Period

12 12 13

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16 18 19 23

Conclusions and Recommendations 26

Snook Nursery Habitat 26 Spotted and Sand Seatrout Habitat Relationships 28 Red Drum and Striped Mullet Nursery Habitat Relationships 28 Possible Differences Between the Manatee and Braden Rivers 29 Possible Braden River Environmental Problems 29 Possible Manatee River Environmental Problems 30 Monitoring and Management of the MRES 31

Literature Cited 32

Appendices:

A. Habitat Map and Sampling Station Cross Reference List B. FLAFS Abstract

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

LIST OF FIGURES

Simple input-output model diagram of estuarine nursery habi tat.

Study area locator map.

MRES study area map, showing zones and subzones .

MRES study area maps, showing sampling stations.

Schematic diagram of a "typical" marsh island in the MRES, showing all geomorphic categories used in the classification system.

Figure 6. Schematic examples of intertidal morphological categories used in the classification system.

Figure 7. Schematic plan view examples of linear upland shorelines with patchily-distributed marsh vegetation (L-2) and of upland shorelines with continuous marsh fringe (L-3). ·

Figure 8. Locations of EJ spotted seatrout catches during the fall sampling period.

Figure 9. Locations of EJ sand seatrout catches during the fall sampling period.

Figure 10. Distribution, relative to salinity, of EJ snook, spotted seatrout and sand seatrout collected in the Manatee River Estuary System during the fall sampling period.

Figure 11. Distributions of sal inities at fall sampl ing period stations.

Figure 12. Relative abundances of EJ snook, spotted seatrout and sand seatrout collected in the Manatee River Estuary System during the fall sampling period.

Fi gure 13. Locations of EJ snook catches duri ng the fall samp 1 i ng period.

Figure 14. Salinity in the MRES on 2/8/90 .

Figure 15 . Locations of EJ red drum catches during the winter sampling period.

Figure 16. Adjusted length frequencies of red drum collected during the winter sampling period.

i i

Figure 17. Locations of EJ striped mullet catches during the winter sampling period .

Figure 18. Catch distribution by salinity of red drum and striped mullet collected during the winter sampling period.

Figure 19 . Total flow (spillway plus toe drain discharges) from the Lake Manatee Dam during July through October, 1989 .

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LIST OF TABLES

Table 1. Habitat classification nomenclature.

Table 2. Tabulated results of seine collections (September-November , 1990) -- target species.

Tabl e 3. Tabul ated results of sei ne coll ect ions (September-November, 1990) -- other species.

Table 4. Tabulated result s of seine collection s (January/ February, 1990) -- target species.

Table 5. Tabulated re sults of seine collections (January/ February, 1990) -- other species.

Table 6. Tabulated results of seine collections (January/ February, 1990) for all stations where red drum were collected.

Table 7. Tabulated results of seine collections (January/February , 1990) for all stations where striped mullet were collected.

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PARTICIPANTS

Dr. Randy Edwards, Staff Scientist -- Principal Investigator Mr. T. Duane Phillips, Senior Biologist Ms. Cathy L.P. Palmer, Staff Biologist -- Habitat Mapping Coordinator Mr. Andrew P. McAllister, Staff Biologist -- Fish Sampling Coordinator Ms. Shelly Heidelbaugh, Staff Biologist Mr . Paul Dufault, Technician

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EXECUTIVE SUMMARY

(1) The Manatee River Estuary System (MRES), which includes the tidal Braden River as well as the Manatee River, is extremely important to Tampa Bay fisheries. This large system probably ha s more estuarine habitat for recreationally and commercially valuable fish than any other river subsystem of Tampa Bay. Because of this habitat, the MRES supports

-valuable commercial fisheries in the immediate area and probably subsidizes or contributes to fisheries throughout Tampa Bay.

(2) The MRES is particularly important as a nursery ground for early­juvenile (EJ) stages of estuarine fishes that are dependent upon availability of suitable shallow-water, estuarine habitat for survival and production. However , prior to this study, there were many important unanswered ecological questions about the MRES including: which types of habitats are important for the various valuable fish species, where are prime nursery habitats located, and what are the relationships between nurseries and salinity patterns?

(3) Since answers to these and other questions are essential to effective development and implementation of programs designed to improve and manage Tampa Bay, a study was conducted as part of the Tampa Bay Surface Water Improvement and Management (SWIM) Program.

(4) A classification system was developed to allow shallow estuarine habitats of the MRES to be categorized. A trinomial system was developed to classify all shallow-water habitats in the upper MRES in terms of their geomorphology , intertidal morphology, and vegetation .

(5) The upper MRES was surveyed and mapped with regard to this habitat classification system, and detailed habitat maps were provided as a final work product.

(6) The habitat categories were sampled on a replicated basis throughout the study area by seining (203 stations) during September-November , 1989 to identify the nursery habitat relationships of early-juvenile stages of important spring and summer spawners like snook (Centropomus undecimalis) , spotted seatrout (Cynoscion nebulosus), and sand seatrout (Cynoscion arenarius), whose early juveniles use shallow nurseries during the late summer and fall. Habitats were sampled again (204 stations) in January and February, 1990 to identify nurseries of early-juvenile red drum (Sciaenops ocellatus) and striped (=black) mullet (Mugil cephal us) that spawn in the fall and winter. Data on other fish species and environmental parameters were also collected and assembled into an extensive data set.

(7) EJ snook were found to be restricted to specialized habitats that included or were near small tidal creeks or other sources of freshwater inflow.

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(8) Snook were never colI ected from common 1 y-occurri ng and area lly­abundant habitats like linear mangrove or needlerush marsh shorelines.

(9) Snook were found to be restricted to low salinity environments. All snook were collected at stations with salinities ranging from 0 to 11 ppt, and 95% were collected at less than 7 ppt. However, snook were not found in freshwater reaches of the MRES far from saline areas.

(10) The MRES was found to be an important nursery for EJ spotted seatrout and sand seatrout. These two species heavily utilized common and abundant habitats like linear mangrove and needlerush marsh shorelines. The two seatrout species were found to exhibit SUbstantial habitat partitioning, in that they were rarely collected from the same station. Normally spotted and sand seatrout did not appear to normally utilize habitats with salinity less than about 5 ppt.

(11) EJ red drum, like snook, were found to utilize specialized habitats, · particularly tidal creeks and creek mouths, most heavily. However, they were also found to utilize common and abundant types of linear shoreline habitat, Red drum were collected from stations with salinities ranging from 0 to 21 ppt and were most abundant at stations with salinities in the mid to upper portion of this range.

(12) EJ striped mullet were found to utilize habitats like tidal creeks, creek mouths and other speci ali zed habitats almost excl us i ve ly. They were almost never collected from common and abundant habitats like linear mangrove and marsh shorelines. EJ mullet were restricted to salinities of 5 ppt or greater.

(13) Abundances of EJ red drum, striped mullet, spotted seatrout and sand seatrout were found to be substantially and statistically sign i fi cantl y lower in the Braden Ri ver, as compared to the Manatee River. Possible causes, including effects of the Braden River impoundment, are proposed.

(14) The types of ecological relationships observed in the study indicate that there is high potential for substantial losses of estuarine functioning and productivity the Manatee River Estuary System, and therefore that the MRES must be carefully monitored and managed.

(15) The results of the study indicate that with respect to snook, red drum and striped mullet, it is insufficient for programs that aim to protect, manage, improve, or restore estuari ne systems to protect, manage, improve or restore generall y. Instead, they must consider estuarine habitat in a more-detailed, discriminating and specific manner. This means that for these and other important fish, specific nursery habitats must be protected, managed, improved or restored.

(16) The results of this study can be used to identify and locate specific nursery habitat throughout Tampa Bay and can be used to guide habitat restoration projects and resource management programs so that the fishery productivity of Tampa Bay can be sustained and improved.

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INTRODUCTION

Importance of Nursery Habitats to Fisheries

It is now generally accepted that many recreationally and commerci a 11y- important fi sh speci es are estuari ne dependent (Gunter, 1957) in as much as estuaries are essential to all or part of their life cycles. It is also recognized that for many species, estuaries are most important as nurseries for juveniles (Sykes and Finucane, 1966), and fisheries ecologists know that certain general types of habitat, such as saltmarshes and seagrass meadows . provide nursery habitat for many important species (Lewis et ~., 1985). Therefore, a general approach toward natural resources management and fisheries protection has been to seek to preserve, conserve, protect, and, in some cases, to restore, create or enhance these general habitat types.

What is not so widely appreciated is the fact that these general habitat types themselves are not uniformly valuable as nurseries , but instead, subhabitats and structural components of these general habitat types provide the specific nursery habitat for early-life stages of many species. For example, mangroves are widely thought of as being important as nursery habitat for snook (Centropomus undec i ma 1 is), when in fact early- juven i 1 e snook are almost never found with inc 1 ass i cal mangrove prop-root communities. Instead, early-juvenile snook have been collected almost exclusively from small basins, tributaries, pocket marshes, and other subhabitats within mangrove habitats (Gilmore, Cooke and Donohoe, 1983; Gilmore, 1987; Mote Marine Laboratory, 1987; E. Rutherford (Everglades National Park Research Center, personal communication).

Habitat requirements of estuarine fishes are closely tied to life history patterns. Many important estuarine fishes have a life history starting with spawning in open coastal waters, followed by movement of planktonic larval stages to very shallow estuarine habitats as larvae approach metamorphosis at an age of about three to four weeks. In order for these newly-metamorphosed juveni 1 es to survi ve, they must find specific nursery habitats--they almost never survive or are found in other habitats. For such species, the entire recruitment or year-class strength may be determi ned by avail abil ity of suitable early-j uven il e habitat (Edwards, 1989).

Not only must proper habitat be available in sufficient quantity, conditions within the habitat must also be suitable for early juvenile growth and survival. In estuaries, freshwater inflow/ salinity regime is a pri mary factor that often determi nes if the structural habi tat is suitable. Browder and Moore (1981) developed this idea into a conceptual model (Figure 1) in which production (recruitment) occurs in an area which is the intersection of stationary (structural) habitat and dynamic habitat (often sal inity regime). Another way of conceptual izing this idea is to consider an estuary as a stationary or structural habitat over which a salinity gradient is superimposed. Only the portion of

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structural habitat that is within suitable sal inity ranges is highly productive in terms of recruitment production. Another feature of this concept is that generally a relatively large area of stationary habitat is required to ensure that sufficient areas of productive habitat are available. For this reason larger estuarine systems are probably very valuable as areas of consistently productive nursery habitat.

In some regions, for example the Louisiana/Mississippi Gulf Coast, protect i on of 1 arge areas of e"stuari ne marshes and wetl ands can be an effective resource management strategy vis-a-vis fisheries, because these large areas are almost certain to include substantial areas of critical nursery subhabitat. In Florida in general, and in the Tampa Bay system ~pecifically, protection of these kinds of large expanses of estuarine marshes and wetl ands is not often a vi abl e opt i on. In some cases, marshes have already been destroyed or altered. In many other situations extensive marshes never naturally occurred, and a narrow fringe provides (or provided) all nursery habitat and supports (or supported) all juvenile fish recruitment.

Therefore, in Tampa Bay and many other areas of Florida. resource management must focus on protect i ng rem a in i ng nursery habi tats (as opposed to generally protecting estuarine systems). If sufficient nursery habitat is not maintained, a biological bottleneck will exist, and other improvement, enhancement or management will not be effective in ma i nta i ni ng fi shery resources. Increas i ng water clarity, reduci ng nutrient loading, elevating dissolved oxygen levels, and creating additional adult habitat (e.g., seagrass beds, reefs, etc.) will not enhance or even susta ina fi shery if there are not enough young fi sh being produced and recruited to take advantage of the improved subadult and adult conditions and habitats. Therefore, for species with special nursery requirements, nursery habitat identification, characterization, protection, and in some cases enhancement, should have high priority in improvement and management programs.

Important Estuari ne-Oependent Speci es in the Tampa Bay and Southwest Florida Region

Many commercially and recreationally-important fish of Tampa Bay and the Florida Gulf coast fall within the category of species which have life histories that subject them to the possibility of nursery habitat-l i mited recru itment and product i on. Three notable speci es in this category are snook (Centropomus undecimalis), red drum (Sciaenops ocellatus, locally called redfish) and striped (black) mullet (Mugil cephal us). The importance, general life histories and present states of knowledge about the nursery habitat relationships of these three species are discussed below.

Snook.--Snook is an important gamefish in the Tampa Bay and Southwest Flori da regi on. Adult snook ut i 1 i ze a wi de divers i ty of habitats ranging from freshwater tributaries to high-sal inity coastal environments (Seaman and Collins, 1983).

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The 1 i fe history and habi tat requi rements of snook have only recently began to be understood. Gilmore et £1. (1983) documented an early-life-history with spawning occurring in summer (May through September) in near-coastal waters adjacent to ocean inlets (or Gulf passes on the Flori da West Coast), and in whi ch newl y-metamorphosed juveniles (about 3 to 4 weeks old, about 20 to 30 mm SL) move to shallow, low-salinity or freshwater reaches of estuarine headwaters. The young snook remain in these oligohaline nursery areas for about 3 to 4 months and then move to deeper, more-saline regions of bays and estuaries. In southeastern Florida, snook populations are probably limited by insufficient recruitment resulting from destruction and unavailability of juvenile nursery habitat (Edwards, 1983) . Similar limitation may occur in other areas, including Tampa Bay.

Red drum.--Red drum are commercially and recreationally important in the Tampa Bay and Southwest Florida region. About three-fourths of the Florida inshore commercial harvest (1980-1984 average = 621,000 lb) of red drum came from Southwest Florida. Although exact regional data for recreational landings are not available, it is likely that a similar portion of the recreational harvest (1980-1984 estimate = 3,132,000 lb (NMFS, 1986)} came from Southwest Florida. Recently, red drum stocks in the Gulf of Mexico have been found to have declined to critical levels, with much of the decline attributable to decreased recruitment (Goodyear, 19B9).

Red drum spawn in the open Gulf of Mexico or in the open portions of Tampa Bay during late fall and early winter, and larvae begin to move from the open bay to backwater areas as they start to metamorphose at an age of about 17 days and a size of around 8 mm SL (Peters and McMichael, 1987). Early juvenile red drum are known to be restricted to shallow backwaters in other regions as well (Mansueti, 1961). Peters and McMichael (1987) pointed out that small juvenile red drum were never collected in open portions of Tampa Bay, even though small juveniles of other sci aen i d speci es were collected there. Peters and McMi chael s (1987) also pointed out that more than 90% of their small juvenile (15-59 mm) red drum were coll ected from what they termed "backwaters" and that 98% of 7,536 juven i 1 es smaller than 100 mm were collected from backwaters. However, Peters and McMi chae 1 (1987) di d not attempt to characterize, describe or otherwise relate habitats to juvenile distribution. None of their collections were made in the Manatee River Estuary.

For regions of the Gulf outside of Florida, early-juvenile red drum habitats and ecological relationships have been at least partially studied, identified and understood, particularly in Texas (e.g., Breuer, 1973; Holt and Arnold, 1982) and Louisiana (e.g., Sabins" 1973; Bass and Avault, 1975; Rogers and Herke, 1985). However, with the exception of the life history study by Peters and McMichaels (1987), there have been no previ ous di rect studi es of juvenil e red drum nursery habitat requirements and relationships in Florida. Although recent Mote Marine Laboratory (MML) observations of juvenile red drum distributions in the Braden River generally agreed with published habitat suitability index

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(HSI) models (Buckley, 1984), these models were in sufficient to explain the distributional patterns of red drum collected in the Braden River.

Striped (black) mullet . --A very large and economically important commercial fishery for striped mullet is centered in Cortez in Manatee County. In 1986, the county-wi de 1 and i ngs of stri ped mull et totalled more than three mi 11 i on pounds (3,117,128 1 b) and had a docks i de value of more than one million dollars ($1,028,652). Although the landing statistics are not delineated with respect to where the catch was made, a major portion of the Manatee County mullet catch comes from the Manatee River and surrounding, connected waters. Each winter, commercial mullet boats wait for spawning migrations of mullet as they move downstream on the Manatee River. A large portion of the local annual catch is taken directly from the river, and large portion of those mullet caught from surrounding Tampa Bay waters may have earlier grown up in nurseries in the Manatee River Estuary System.

Striped mullet spawn offshore during late fall and winter, with a peak spawning period of November-December (Collins, 1985). Planktonic larvae migrate toward inshore waters and estuaries where early juveniles almost invariably utilize extremely shallow habitats (Major, 1978). Metamorphosing juveniles arrive at the shallow estuarine nursery habitats at an age of about four to six weeks and a size of around 20-25 mm SL. However, early-juvenile habitat requirements of striped mullet may be different than those of red drum due to the fact that mullet do not acquire the osmoregulatory ability to withstand extremely low salinities until they reach a size of about 40 mm SL (Nordl ie et il., 1982). Relationships between habitat j subhabitat types and early-juvenile mullet presence had not been previously evaluated for Tampa Bay or the Florida Gulf coast, except for the early descriptive work by Kilby (1949) which pointed out the importance of small-scale habitat features to juvenile mullet.

The Manatee River Estuary System

In many urbanized areas of Tampa Bay, the point of recruitment limitation of important fisheries due to insufficient juvenile nursery habitat avail abi 1 ity probabl y has already been reached for important species. In some other parts of Tampa Bay, sufficient nursery habitat for normal recruitment still exists. It is 1 ikely that bay-wide recruitment and fishery production is sustained and subsidized by these areas that still have good early-juvenile nursery habitat. The Manatee River Estuary System is one such area that still has large areas of potentially productive nursery habitat.

The term Manatee Ri ver Estuary System (MRES), as used in thi s report, refers to the estuarine system which includes the Manatee River and its estuarine tributary, the Braden River. The Manatee River Estuary extends from Tampa Bay upstream approximately 25 miles (40 km) to the Lake Manatee Reservoir impoundment. The Braden River is also impounded, with its estuarine portion extending approximately five miles upstream from its confluence with the Manatee River at a point approximately 7.8

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miles (12.6 km) from Tampa Bay. The annual flow of the Manatee River is estimated at 6.87 x 10" gal yr·' (2.60 x 108 m'/yr), which ranks it third among Tampa Bay rivers (behind the Hillsborough and Alafia Rivers) with respect to flow (Dooris and Dooris, 1985). The flow of the Braden River has not been measured, but based upon total drainage basin area for the two rivers (Estevez and Edwards, in prep.), total annual discharge of the MRES is probably second only to that of the Hillsborough River.

An important feature of the Manatee and Braden rivers is that along much of their reaches they are wide, shallow and relatively un­channelized. This results in broad estuarine mixing zones which include large areas with diverse geomorphology and vegetational habitats. This situation contrasts with the two Tampa Bay rivers with larger flow, the Hillsborough and Alafia, which are relatively narrower, more channelized and have smaller mixing zones (compressed salinity gradients) and smaller areas of estuarine habitat. Lewis and Whitman (1985) estimated that the Manatee River subdivision of Tampa Bay included 5.92 mi ' of emergent wetlands and was surpassed only by the Old Tampa Bay and Middle Tampa Bay subdivisions with 7.21 and 6.55 mi ' , respectively. Lewis and Whitman (1985) did not include the "Braden River and the upper 11 miles of the Manatee River Estuary, which if included would certainly result in the MRES containing more emergent wetlands than any other subdivision of Tampa Bay. Even as calculated by Lewis and Whitman (1985), the Manatee River had an areal ratio of wetlands to open water of 0.47, which is far greater than the ratios for other subdivisions which, with the exception of nearby Terra Ceia (ratio = 0.30), ranged only from 0.03 to 0.10.

The portion of the system included in this study covers a very large area . The Manatee River study area (as defined below) extends more than 25 linear kilometers, and the Braden River study area extends more than 8 km. The actual lengths (length along the main channels) are much greater. In some places the Manatee River estuary approaches 2 km in width. The smaller Braden River approaches 1.5 km in width.

The portion of the MRES studied in this project spans salinity ranges from mixohaline (up to about 30 ppt) to freshwater conditions. The system experiences large seasonal salinity transitions, which in some areas may exceed 25 to 30 ppt. Sal inity changes are probably amplified by the existence of the dams / reservoirs on both the Manatee and Braden Rivers.

Morphologically, the system is very complex and ranges from narrow riverine channels with firm , clean, sandy bottoms and steep banks, to broad estuari ne shall ows wi th soft, organ i c-ri ch, muddy sedi ments and without well-defined banks. The system includes countless irregularly­shaped islands, meanderi ng marsh creeks and interconnected channels . The system is fed by numerous tributaries ranging from rivulets that drain immediately-adjacent uplands , to major tidal tributaries with watersheds extending tens of kilometers from the rivers.

Much of the system is natural and relatively unaltered, while significant portions of the system are highly altered and / or surrounded

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by res i dent i a 1 development or i ntens i ve agri culture. Land use in the immediate area is in a dynamic state of transition. Several very large residential developments bordering the estuary or in the watershed are under construction or in final stages of planning .

The shorel ine and marsh vegetation in the system ranges from freshwater species and communities to classical estuarine saltmarshes. Saltmarshes range from well-developed mangroves typical of tropical and subtropical regions, to marshes vegetated by species such as Spartina alterniflora and Juncus roemerianus, more typical of temperate regions. The MRES is located at or near botanical / zoological cl imatological boundaries and zoogeographic ranges. The system exists in a state of dynamic succession that occurs in response to episodic climatic events (e.g., freezes, droughts and tropical storms).

A high degree of complexity also occurs within major habitats.Almost every habitat has its own set of unique conditions, in terms of geomorphic configurations, elevations, sediments, and vegetation. Even monospecific marshes (e.g., Juncus marshes) include a diversity of subhabitats and geomorphic conditions, with conditions changing rapidly over distances as small as a meter or so.

Ichthyofauna of the MRES ranges from freshwater species, such as largemouth bass (Micropterus salmoides) and shiners (Notropus sp . ), to estuarine species, like red drum (Sciaenops ocellatus) and spot(Leiostomus xanthurus), to occasional marine species, like cobia (Rachycentron canadum) and Spanish mackerel (Scomberomorus maculatus) . Fishes range from species 1 ike tarpon (Megalops atlanticu s) that are normally found in tropical regions , to species like menhadens (Brevoortia sp.) that are more typical of temperate regions.

The Manatee River Estuary System Nursery Habitat Problem

Because of its broad salinity gradient and large area of wetlands, the Manatee River Estuary System is probably extremely important as a nursery for estuarine fishes , but prior to the present project, it has never been assessed in this regard. Comp (1985) reviewed the literature on fishes of Tampa Bay but was unable to find any reports of ichthyological studies or collections in the Manatee River, whereas all other areas of Tampa Bay had been sampled and studied. Perhaps the only ichthyofaunal study of the MRES was the cursory 1957 survey by the Florida Board of Conservation (Murdoch, 1957) that concl uded that the area was an important nursery for striped mullet, red drum, snook and other fishes, and which stated:

"The areas provided by rivers, bays and adjacent lowlands are undoubtedly important nursery grounds for most of the fi sh found in this region."

For Tampa Bay in general, and for the Manatee River Estuary System specifically, there is a serious need to protect and manage important estuari ne nursery habitats. However, nursery habitats are not well

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understood, known or identified. Comp's (1985) BASIS review included the following recommendations (p. 413):

"It is recommended therefore, that an indirect approach be taken toward monitoring fish stability an / or production within the Bay . Such an approach will involve locating, then monitoring the community structure (and perhaps, relative abundance) within the major nurseries in Tampa Bay. Information on seasonal use of several nurseries in the Bay is provided in this report; however, to best understand the extent of utilization the location of all nurseries should be identified. Once the locations of the major nurseries have been established, steps can be taken to insure that these areas are preserved since, as shown in previous reports, a loss of crit i cal estuari ne habitat can result ina loss of fi shery resources."

These recommendations are parti cularly apropos to the MRES for a number of reasons. In addition to its aforementioned large size, large area of wetlands and other habitats valuable as nurseries , and its broad estuarine mixing zone, the MRES has several other features that justify ecological and ichthyological studies.

Both the Manatee and the Braden Rivers are impounded to provide reservoi rs for dri nki ng-water supp 1 i es. An extens i ve survey of the Manatee River was conducted in 1982-1983 by the Manatee County Utilities Department and Camp, Dresser and McKee , Inc . (MCUDCDM, 1984) to identify factors contro 11 i ng the salt profil e and to quant ify the effect of proposed changes in Lake Manatee releases (due to proposed increased drinking water withdrawal from the reservoir) on the salt profile. Terminology for zonation of the MRES are adapted from this survey. This survey included water quality monitoring, benthic surveys and a vegetational survey , as well as salinity models. However, the MCUDCDM (1984) survey did not address, in any way, the potential effects of the reservoir on the fishery resources of the area. The effects of construction and operation of the Braden River dam and reservoir (Lake Evers-City of Bradenton reservoi r) on fi sheri es resources and general eco 1 ogi ca 1 funct ion i ng have never been assessed. However, anecdotal information from long-time residents and fishermen strongly indicate that great fisherie s decl ines corresponded in time with dam and reservoir construction events .

The Manatee County area is rapidly growing in population and will have greater demands for drinking water in the very near future. Manatee County has recently commissioned an engineering study to evaluate feasibility and alternatives for increasing consumption of Manatee River freshwater and expanding the Lake Manatee reservoir. Not only do the existence and operation of the two reservoirs in the MRES directly affect the system through alterations of the quantity and timing of freshwater i nfl ow, they may affect the quality of the freshwater i nfl ow. The effects of such impoundment s on transport of estuarine organic detritus and sediments and on the overall energy and nutrient budgets i s unknown.

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The possible effects of extremely large amounts of copper sulfate applied to the two re servoirs is unknown. Recently, more than half of the copper sulfate brought into Flori da ha s been goi ng into the Lake Manatee reservoir for control of algal blooms (Don Moores, FDER--presented at Tampa Bay Agency for Bay Management-Goals and Strategies for Tampa Bay, December 8, 1989). Copper sulfate is also frequently used to control algae blooms in the Evers Reservoir.

In addition to demanding more potable water , regional population growth will likely lead to other significant anthropogenic alterations of the MRES. In view of all the possible impacts on the MRES, it is essential that all ecological and natural resource implications of future changes be understood and properly managed . The effects of past and future impacts on the MRES are particul arly important from a fi shery resource standpoint . The upper MRES includes extensive areas of natural habitat associated with relatively-unaltered saltmarshes and mangroves, making the MRES an important and productive nursery ground for snook , red drum and striped mullet and other important fishes. The MRES is a system that supports 1 arge commerci al and recreational fi sheri es and that probably supplements recruitment to fisheries throughout much of Tampa Bay . In terms of nursery habitat area , the MRES is perhaps the largest existing nursery in Tampa Bay. Therefore, this project was undertaken as an important first step in fishery resource impact assessment, and was focused on identifying and inventorying the areas and specific habitats of the MRES that function as nurseries for important fishes .

In addition to providing the direct benefits of better understanding of the MRES and the ultimate benefits of sustained or improved fishery recruitment to Tampa Bay, the MRES study was designed to assist overall Tampa Bay management/improvement efforts by providing a model in which techniques and procedures could be developed and evaluated, prior to eventual appl ication to nursery habitat assessment / inventory in other areas of Tampa Bay . The project was also designed to provide information about nursery habitats that could be used to guide habitat re storation and enhancement efforts in Tampa Bay. New restoration / creation projects should be designed to incorporate features that will result in additional nursery habitat. Since the difference between unproductive or unsuitable nursery habitat and good nursery habitat is often subtle and physically minor, an understanding of important subhabitat parameters can be used to modify existing natural or altered habitats in ways that would make them much more suitable and productive for important species.

General Project Description

The goal of the study was to identify t ypes of environments within the Manatee Ri ver Estuary System (MRES) that are uti 1 i zed by, and therefore presumably important as habitat to, recreat i ona lly or commercially valuable juvenile fishes. The project had three phases: 1) habitat classification and . mapping phase, 2) fall 1989 habitat sampl ing phase, and 3) winter habitat sampl ing phase. In the first phase, a habitat classification system was developed and used to map the MRES with respect to habitat categories of the system. The fall field

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sampling phase was designed to sample habitats (as defined and mapped in the fi rst phase) duri ng the peri od of maximum abundance of early­juvenile snook in nursery habitats. Similarly, the winter sampling phase was des i gned to sample MRES habitats duri ng the peri od of maxi mum abundance of early-juvenile red drum and striped mullet in nursery habitats.

The main hypothesis of the study was that specific types of habitats in the MRES (and other systems) are more important (in terms of degree of utilization and total [system-wide] numbers of fish supported) as early-juvenile nurseries for snook, red drum, striped mullet and other important species. A subordinate hypothesis of the study was that the importance of habitat types as early-juvenile nurseries is quantitatively related to position (upstream/downstream) along the river and/or position along the estuarine salinity gradient. A second subordinate hypothesis was that within habitat types, subhabitats or structural components exist such that they are even more important than the general habitat type.

11

METHODS

Study Area

The general location of the study area is shown in Figure 2. The study area included the entire tidal Braden River downstream of the Evers Reservoi r dam and the t i da 1 Manatee Ri ver downstream from the Lake Manatee dam to the U.S. 301/41 bridge (Desoto Bridge) . The MCUDCDM (1984) zonation system was adopted for this study , resulting in the Manatee River being divided into four zones (1-4, starting upstream) . Each of which was subdivided into three (upper, middle, lower) subzones. Only Zones 1, 2 and the upper subzone of Zone 3 of the Manatee River were i ncl uded in the study area. Be low thi s poi nt, the Manatee Ri ver is highly altered, and shorelines are seawalled or filled , with little or no natural shoreline existing outside of a few areas near the river's confl uence with Tampa Bay. The Braden Ri ver was di vi ded into three subzones (upper, middle, lower). In order to utilize physically­recognizable landmarks during the field study, the precise delineation of zones and subzones was modified sl ightly from the MCUDCDM (1984) system. This revised zonation is shown in Figure 3.

Habitat Classification, Survey and Mapping

In order to accomplish the project goal, it was first necessary to categorize and classify habitats within the MRES. Unfortunately, classification systems appropriate for this application were unavailable. Therefore, an important first step in this study was the development of a habitat classification system that was meaningful relative to distribution and ecology of juvenile estuarine fishes , while at the same time was practical relative to the scope and budget for the field studies to be conducted.

The development and implementation of a workable (meaningful and practical) habitat classification system wa s made difficult by the great extent and geomorphological and ecological complexity of the MRES. The classification system developed for this project and presented below must be viewed in this light. A high degree of abstraction and simplification was necessary because of the system complexity and because of the budgetary limitation of this study, which was designed and funded as a short-term research project of the Tampa Bay Surface Water Improvement and Management (SWIM) Program . Although more-detailed and more­complicated classification systems are possible , they would not be practical or useful for ecological studies unless the duration, scope, effort and funding level s of the studies were much greater than that possible in this short-term study.

Many possible classification systems could be developed and applied to complex estuarine systems such as the MRES . The system that was deve loped and app 1 i ed for our study of the MRES was ori ented toward classifying early-juvenile fish habitat relationsh i ps. The system was developed from the perspective of the juvenile fish. Since the species

12

of primary interest in this study (snook, red drum and striped mullet) are usually associated with intertidal and subtidal shoreline habitats, the classification system emphasized shoreline habitats.

The classification system (described below) was used to classify and map habitats during a field survey (7/12/89-9/5/89) of the entire MRES system upstream from the Desoto Bridge (US 301) on the Manatee River to the Braden River dam (Evers Reservoir) and the Manatee River dam (Lake Manatee). A team of two biologists surveyed all shorelines in the study area from a small boat. Major tributaries were mapped to at least 500 m upstream from thei r confl uence wi th the Manatee or Braden ri vers, moderate tri butari es for at 1 east 200 m and mi nor tri butari es for at least 100 m, with a minor tributary being defined as at least 2 m in width. Habitat classifications were recorded directly onto Florida DOT aeri al bl ueprints purchased through the Manatee County Tax Assessor's Office. Map scales included 1" - 100', 1" - 200' and 1" - 400'. This type of map was not available in the same scale for all areas of the MRES, since avail ab 1 e scale (determi ned by DOT) is dependent on the degree of urbanization in the area. The smallest scale (most detailed) available for any area was generally used. Field mapping was later copied onto identical aerial blueprint maps to make the field notes more legible, neater, and uniform in format and nomenclature.

Habitat Sampl ing

Station identification and ·selection.--The distribution of sampling effort (number of samples) within the MRES study area was based on zonation (Figure 3). Stations were selected and distributed with the intent of sampling the major habitat types in each subzone and zone on an approximately equal basis. The study was designed to sample representative habitat types, with significant replication of sampling for important (areal extent or frequency of occurrence) types, throughout the MRES study area. However, the number of habitat types present in the MRES and classifiable with the trinomial system (eight geomorphic descriptors, five intertidal morphological descriptors, nine vegetational descri ptors) is much greater than coul d be sampled (on a rep 1 i cated basis) within the effort available in this project. Therefore, an effort was made to sample the habitat categories that were most important (in terms of areal extent or frequency of occurrence) in each of the zones and subzones. Not all categories were present in each subzone, and their importance (as defined above) was not the same for all zones in which they were present. The sampling was temporally distributed such that subzones and habitat types within the subzones were sampled throughout the sampling periods. The location of all sampling stations is shown in Figure 4.

The necessary decisions about selection and distribution of selected habitat categories were subjective and were influenced by initial sampling results. An example is the decision to limit sampling in the upper subzone of Zone 1 (I-U - subzone nearest to the Lake Manatee dam). This decision was based on the fact that marine fish species were almost never collected in the first samples and on the fact that the water was

13

completely fresh in the entire subzone. The Lake Manatee Dam began (for the first time in several months) to discharge large amounts of freshwater on around August 19, 1989. This pulse and high flow of freshwater may have flushed marine species out of that portion of the river. In any event, by the beginning of sampling (September 22, 1989), the high flow had resulted in an almost total absence of marine species in U-1. Therefore, some of the effort that would have been expended in that subzone was transferred to other subzones, so that they could be more thoroughly sampled. Similarly, the bight (B) habitat descriptor was found to be difficult to distinguish from 1 inear (L) descriptor and therefore was de-emphasized in the final allocation of sampling effort.

Sampling technigues.--Each station was sampled with a 4.6 m (15 ft), 9.2 m (30 ft), 30.5 m (100 ft), or 61.0 m (200 ft) seine. All seines were 1.8 m (6 ft) deep and constructed of 0.3-cm (1/8-in) mesh knotless nylon netting. The 30.5-m and 61.0-m seines had a 1.8-m square bag sewn into the middle of the seine. The largest seine that could be effectively deployed at the station was used. Stations were sampled during tidal states that would not affect the effectiveness of sampling or the abundance of fish at the station. For example, marsh shorelines were not sampled during extremely high tides that could allow fish to escape into the marsh, and tidal creeks were not sampled during extremely low tides that would be expected to force fish out of the creeks. All juveniles of commercially or recreationally important fish species were enumerated and measured (SL) in the field. Other species collected were subjectively classified as present, common or abundant, and so recorded. To the extent possible, fish were released alive at the collection site.

Environmental data (temperature, salinity, dissolved oxygen concentrat i on, sedi ment type, tide condit ions) were also collected. Dissolved oxygen was measured with a YSI Model 54 oxygen meter that was air calibrated (sea level, ambient temperature, freshwater saturation) daily. Sediments at the station were subjectively classified as firm sand, muddy sand, mud or soft mud, and numerically recorded as 1-4, respectively. Tidal state (flooding or ebbin9; low, 1/4, 1/2, 3/4, high) was estimated visually. All data were immediately recorded onto field data sheets. Stations were marked by tying plastic flagging to existing vegetation or to wooden stakes driven into adjacent shorel ine. Some stations also were marked with aluminum station number tags. All station locations were immediately recorded onto maps. Habitat classifications of stat ions where target speci es were collected were assessed with particular care, and if it was deemed necessary, the stations were revisited an re-evaluated at low tide so that associated features such as small marsh creeks (rivulets) could be detected. When such features were discovered, the station was reclassified.

Sampling periods--In order to assess habitat utilization by early­juveniles of the three target species (snook, red drum and striped mullet), two different sampling periods were required. Half of the field sampling effort was allocated to sampling the MRES habitats during the fall when EJ snook and EJ's of other summer spawners utilize estuarine

14

nurseries, and the other half was allocated to sampling during the winter when EJ red drum and striped mullet utilize nursery habitat .

Fall sampling period .--Stations were sampled (by seining) during the fall sampling period in order to identify which habitat categories were important as nurseri es for commerc i ally and recreat i ona lly important summer-spawning fishes. This period of sampling was primarily focused on juvenile snook, although other impo rtant species were collected. During the fall sampling period, a total of 203 stations was sampled from 9/ 22 / 89 through 11/2/ 89.

Winter samPling period (red drum and striped mulletl . --The primary purpose of thi s period of sampling was to determine habitat relationships of early-juvenile red drum, striped mullet and other fall/winter spawning fish in the MRES during the period of their peak abundance in southwestern Florida. The same stations as sampled during the fall, with the exceptions of deletion of stations 57 and 61, and the addition of stations 204, 205 and 206 (total of 204 stations) were sampled from 1/ 8/ 90 through 2/ 8/ 90.

15

RESULTS AND DISCUSSION

Habitat Classification System Development

The classification system developed and employed in the study is presented in Tabl eland is shown schemat i ca 11 yin Fi gures 1-3. The trinomial classification system included terms for general geomorphic, intertidal morphological, and intertidal vegetational descriptors.

Geomorphi c descri ptors . --The class i fi cat i on categori es for thi s term were based on the geomorphology of shorelines in the MRES. Classification categories used in this study included:

A -- Altered Shorelines. This categorization was applied to any unnatural habitats, including seawalls, rip-rapped shoreline, dredged canals, etc. In order to emphasize natural habitat relationships in the limited amount of mapping and sampling effort budgeted in this project, altered shorelines were not mapped in detail (beyond being denoted as "A") or sampled, except for few special instances.

B -- Bights. This categorization was applied to indentations in linear shorelines . An indentation was classified as a bight if its opening was generally at least one-half the width of its major axis. If the opening was more restricted, the embayment (E) categorization was applied. Bights were further categorized with regard to size. Small bights with major axis less than about 2 m were categorized as B1. Larger bights were assigned the B2 descriptor. Overall, a continuum between linear shorelines (see below) and bights exists. Therefore, this categorization may not be as distinct or as valuable as the other descri ptors. Eva 1 uat ion (mappi ng and samp 1 i ng) of habitats with regard to this category was limited in order to conserve available effort so as to be able to fully evaluate other categories.

C -- Tidal Creeks. Tidal creeks were subcategorized as C1 rivulets (less than 1 m wide), C2 small creeks (generally less than 2 m wide), and C3 1 arge creeks (wider than 2 m). Creeks were not subdivided with regard to being intertidal (creek bottom exposed at low tide) or subtidal (creek bottom submerged at low tide) because of the relatively small tidal range in the area. Generally, however, rivulets were intertidal, some areas of small creek bottoms were exposed at MLW, and large creeks were subtidal.

E -- Embayments. Shorel ines were described as embayments if the connection to open waters was restricted compared to the overall size (major axis). Embayments were subcategorized as El, small embayments less than 5-m wide, or E2 large embayments.

16

L -- Linear Shorelines. This category was used to denote relatively straight or smoothly-curving shorelines. This is the dominant geomorphic category, in terms of areal extent, in the MRES.

M -- Creek Mouths. Most creeks widen at their confluence with their recei vi ng water body. Such mouths were denoted as Ml, M2 or M3, corresponding to their respective creek size (see above). In instances in which significant confluent widening did not exist, the ent ire creek was categori zed as C, and the confl uence was not designated as M.

o -- Open-Water Shoals. Shallow (less than 0.5 m on MLW) shoals in open water were included because their depth range being comparable to shoreline habitats suggest the possibility of their being utilized as early-juvenile habitats.

S n SPit Shoals. Shoals, usually in the f.orm of sandy spits accreting at the downstream terminus of an island or a peninsula, are common components of the system. Depth of these shoals normally is such that portions of the shoal are exposed at MLW and almost all of the shoal is exposed at LLW .

Intertidal morphological · descriptors.--Intertidal morphological descriptors were developed by considering morphological characteristics of the i ntert i da 1 zone. These descri ptors can be app 1 i ed to further categorize many of the geomorphic descriptors described above, although some geomorphic categories, by definition, do not include intertidal vegetation or uplands that are the basis of this group of descriptors. These descriptors are discussed below and are shown diagrammatically in Figures 5-7.

1 -- Upland Shorelines. Upland shorelines are characterized by having limited intertidal areas that interface directly with uplands (or non-intertidal flood plains). Such shorelines normally have no significant intertidal vegetation. In freshwater reaches of the Manatee River, upland vegetation (e.g., grasses and sedges) grows to the waters edge and is inundated during high water (high tide or high river stage). Such vegetation is not considered as intertidal in this categorization system.

2 -- Upland Shorelines with Patchily-Distributed Marsh Vegetation. This category pertains to cases in which the intertidal zone includes patches of vegetation ranging from a few to up to around 10 m in width (alongshore dimension). Vegetation does not form a continuous fringe or a marsh of extensive depth (less than about 5 m deep shoreward).

3 -- Upland Shorelines with Continuous Marsh Fringe. This category includes all shorelines with a continuous marsh fringe (>10 m width along shore, <5 m in depth shoreward).

4 -- Fringed Solid Marsh. Areas of extensive (>5 m deep shoreward) intertidal marsh are usually either solid (a dominant species of

17

vegetation with or without a significant intermix of other species) or consist of a narrow fringe of one species nearest open water interfacing an extensive zone of marsh dominated by another species. The former case is designated as 5 -- Solid Marsh (see below), and the latter case is designated as a fringed solid marsh. Many fringed solid marshes in the MRES may reflect successional states of marsh vegetational communities.

5 -- Sol id Marsh. This category includes a·ll marshes deeper than 5 m that do not have a distinct band or fringe of plants different from the main portion of the marsh.

Vegetation Oescriptors.--Marshes were categorized according to dominant vegetation. The following species were present in sufficient abundance or dominance to merit separate descriptors:

Common Name

Needlerush Red Mangrove Bl ack Mangrove White Mangrove Saltmarsh Cordgrass Smooth Cordgrass Catta il s Brazilian Pepper Leather Fern

Scientific Name

Juncus roemerianus Rhizophora mangle Avicennia germinans Laguncularia racemosa Spartina alterniflora Spartina bakeri ~sp. Schinus terebintifolia Acrostichum sp.

Habitat classification nomenclature.--A system of nomenclature for classification of habitats was developed using the descriptors described above. Since three categories of descriptors were developed , a trinomial system resulted. The format of the trinomial nomenclature is: Geomorphi c Oescri ptor - Shore 1 i ne Oescri ptor - Vegetat ion Oescri ptor. In some cases the vegetation descriptor includes more than one term to identify co-dominant, sub-dominant or spatially-separate vegetation. The system is explained in Table 1.

Habitat Survey and Mapping

The Manatee River Estuary habitat mapping is provided in the accompanyi ng set (44 i ndi vi dual map sheets) of Flori da Department of Transportation aerial blueprints. Shoreline habitat classification is recorded for all unaltered habitats. Sampling stations are also recorded onto the maps. Sampling stations and map sheets are cross referenced in Appendix A. Classifications shown on the maps are those recorded during habitat surveys. In a few border-line instances, mapped habitat classification at a seine-sampling station differs slightly from the classification assigned to the station during the sampling phase . These slight differences were due to the fact that stations could be examined more closely and in more detail during the sampling.

The habitat maps are a valuable product of the study, as they provide a baseline from which habitat changes can be assessed in the

18

future. This is particularly important in the MRES because both the Manatee and Braden Rivers are impounded for public water supply, and future increases in water use and diversion could result in significant ecological changes in the MRES. The maps should be carefully archived by the District. Original field-note maps will be archived by MML. The maps should be protected from light because the diazo-process aerial blueprints are subject to fading when exposed to light. Ultimately, the habitat mapping data would be most useful and most secure if it were to be entered into the Southwest Florida Water Management District (SWFWMD) geographic information system (GIS). The GIS would facilitate quantification of habitat distribution in the MRES.

Habitat Sampling -- Fall Sampling Period

Recreationally or commercially valued species collected (as early juveniles) during this period were: snook, Centropomus undecimalis (43 individuals , 19 stations), spotted seatrout, Cynoscion nebulosus (221 individuals, 53 stations), sand seatrout (Cynoscion arenarius (326 individuals, 34 stations), and sheepshead, Archosargus probatocephalus (three individuals , three stations). A total of 27 larger (>100 mm) juvenile snook was collected at 20 stations. A total of 85 EJ mullet was collected and were all identified (field 1.D.) as white mullet (Mugil curema). The data for all recreationally or commercially valued species collected and habitat type are given in Table 2. Data on other fishes collected during this sampling period are presented in Table 3.

Spotted and sand seatrout.-- Although not originally a target species, large numbers of spotted seatrout and sand seatrout were collected during the period, indicating that the MRES is an important nursery for these species. The locations of stations where spotted seatrout and sand seatrout were collected are shown in Figures 8 and 9. Juvenile spotted seatrout were collected at stations with salinities ranging from 0 to 22 ppt, and EJ sand seatrout were collected at stations with salinities ranging from 0 to 22 (Figure 10). However, examination of Figure 10 shows that spotted seatrout were more abundant at stations with low salinities , with more than 90% (200/ 221) collected at stations with salinities lower than 12 ppt and 62% (137/221) at 7 ppt or lower. On the other hand, silver seatrout were most abundant at stations with higher sal inities, with more than 90% (295 / 326) collected at stations with salinities greater than 7 ppt and 38% (123 / 326) at stations with salinities of 12 ppt or higher. With respect to salinity, niche overlap (MacArthur and Levins, 1967) was evident only over the range of 8 to 11 ppt, within which 29% (63/221) of the spotted seatrout and 48% (155/ 326) of the sand seatrout were collected.

Although the data and Figure 10 show that spotted seatrout and sand seatrout catches exhi bi ted different abundance patterns rel at i ve to salinity, the overall salinity pattern in the MRES and the number of sampling stations falling into each salinity range must be taken into account. Salinities were generally very low during the fall sampling period. The distribution of salinities for the 204 sampling stations is shown in Figure 11 . The maximum sal inity encountered at sampl ing

19

stations was 22 ppt. Salinity greater than 15 ppt was encountered only at seven stations. Because of the low salinities, it is not proper to directly interpret Figure 10 as indicating preferred or optimal salinities for seatrout. Figure 12 shows estimates of adjusted abundance calculated by dividing the total catch for each species for each salinity range by the number of stations sampled within that salinity range. The adjusted abundances indicate that to the extent that otherwise suitable habitats are available at higher salinities, the early-juveniles of the two~peties utilize a broad range of salinities, with spotted seat rout showing a higher degree of penetration into low-salinity habitats. This penetration contributes to niche partitioning between the two species.

Ni che part it i on i ng between the two seat rout speci es was further evidenced by the fact that only 4% (12/326) of the sand seat rout were co 11 ected at stat ions where more than three spotted seat rout were collected. Similarly, only 12% (26/221) of the spotted seatrout were collected at stations where more than three sand seatrout were collected. The niche partitioning did not appear to be a function of habitat classification, although it is possible that the partitioning was based on parameters not considered in the. classification system. Both spotted seatrout and sand seatrout were collected from linear shorelines primarily, with 62% (137/221) and 83% (279/326), respectively, collected from habitats classified as having the L (linear) geomorphic descriptor. Spotted seatrout also were frequently collected from medium (M2) creek mouths, with thi s two category account i ng for 26% (57/221) of the individuals collected. Together the linear shoreline and medium creek mouth habitat categories accounted for 88% (194/22 1) of the spotted seatrout collected during this phase. Only a few spotted seatrout (6) or sand seatrout (14) were collected from creeks proper.

Juvenile spotted seatrout were most abundant at stations with sediments classified as sand (38% of all spotted seatrout collected), or muddy sand (30%), although they were also collected at stations with mud (17%) or soft-mud (15%) bottoms. Relative to spotted seatrout, juvenile sand seatrout were more abundant at stations with softer bottoms, with stations with muddy sand (32%) and mud (62%) sediments accounting for most of the individuals collected, and only a few were collected at stations with sand (1%) or soft-mud (5%) bottoms. Of all the stations sampled during the period, 26% were classified as having sand sediments, 32% as muddy sand, 25% as mud, and 17% as soft mud.

Juvenil e spotted seatrout were often coll ected at stati ons where snook were collected. Significant niche overlap is suggested by the fact that 42 of the total of 221 spotted seatrout juveniles collected during the fall period came from stations where snook juveniles were collected. On the other hand , strong niche partitioning between juvenile snook and juvenile sand seatrout is indicated by the fact that only three of the 461 sand seatrout were collected at stations where snook were collected. No corre 1 at ions between juvenil e snook and other speci es collected (Table 3) were obvious. Of the other species that were frequently collected during this phase, only Fundulus seminolis, Lucania parva, Membras martinica, and Leiostomus xanthurus were not collected at

20

stations where juvenile snook were collected. The first two species were generally restricted to predominantly freshwater environments.

Snook.--A total of 43 early-juvenile «100 mm SL) snook was collected during the first sampling period (September-November). Snook were collected at 19 stations. The 1 ocat ions of these stat ions is plotted in Figure 13.

Relationships between juvenile snook and environmental parameters (Table 2) other than salinity were not discernable. Dissolved oxygen concentrations ranged from 6.5 to 12'.0 ppm (unadjusted for sal inity). DO measurements were inadvertently overlooked early in the study, but all subsequent DO measurements indicated that DO was not a determining factor in snook distribution. The fact that all juvenile snook, except one, were collected over a relatively narrow temperature range of 26-30 ' C probably only reflects typical conditions during this period. Most snook were collected at low or one-quarter tides, but some were collected at three-quarter or high tides. Snook were collected on ebbing and flooding tides. Sediments at stations where snook were collected ranged from firm sand to soft mud, although only two of the 43 juvenile snook were collected at stations with soft mUd.

Only 14 EJ snook were collected in the Manatee River, and all were caught either at creek (C) or creek mouth (M) stations (Stations 21, 35, 54,58,66,87,91). Juvenile snook were collected at salinities ranging from 0 to 6 ppt. It is very important to note that no EJ snook were collected in the most common and extensive (areally) habitats such as 1 i near shorel i nes along mangrove or Juncus marshes. These results support the hypothesi s that EJ snook ut i 1 i ze on 1 y certain speci ali zed nursery habitats.

No EJ snook were collected in the Braden River until midway into the study period (10/16/89). Until this time, snook were absent even at locations at which they had been found to be common or abundant in the past three years of MML informal sampling. Based on these observations, it was suspected that 1 arva 1 /EJ snook recru i tment to Braden Ri ver habitats was extremely low in 1989. Finally, during a period of four days (10/ 16-10/19/ 89), a total of 27 EJ snook was collected (25 at 0 ppt, one at 5 ppt, one at 9 ppt) . All but two of the EJ snook collected in the Braden River during the sampling period were taken during this time, and these two were collected in creek habitats (0 ppt and 11 ppt).

The mid-October period in which most EJ snook were collected in the Braden River coincided with the first extremely low tides of the fall. Low tides (NOAA tide table 'predictions for St. Petersburg) of -0.3 ft, -0.4 ft, -0.4 ft and -0.3 ft occurred during 10/ 15-18/ 89. By comparison , lowest low tides (predicted) in August and September were 0.0 and +0.1 ft, respectively. During the extremely low tides of mid October, large areas of marsh embayments and creeks became totally exposed for the first time in about three months (based on predicted tides and field observations). Therefore, it was inferred that the 27 snook collected at creek mouths or along shorelines close to creek mouths probably

21

represented a few snook in the system that had been concentrated and forced to the main river channel by the low tides. This was substantiated when the stations at which EJ snook were collected were revisited during November low tides. Stations that were found to include or were adjacent to marsh creeks that were not detected during surveys at higher tides are denoted in Table 2 as /el, /e2 or /e3. Redistribu­tion of EJ snook from primary nursery habitats following the first extremely low spring tides in the fall may be a natural feature of snook early life history (Edwards, 1990) and may explain the migration out of primary nursery habitat at around 100 mm SL described by Gilmore et ~. (1983) .

Examination of the habitat classification of stations at which EJ snook were collected (Table 2) shows that EJ snook were collected only at stations associated closely with creeks. Snook were collected adjacent to creeks (/e), in creek mouths (M), or within creeks (e). Five snook were collected at two stat ions cl ass ifi ed as 1 i near shore 1 i nes (Station 102 = L-3-T, Station 110 = L-2-T), but with cattail (~sp.) vegetation . Presence of ~ in the saline portions of the MRES almost always indicates freshwater inflow that allows the ~ to survive during high salinity periods. Therefore, snook collected at the stations with ~ also represent associations with creeks or freshwater inflow.

The distribution of salinities at which EJ snook were collected in the MRES (Figure 10) and the relative (based on number of stations sampled within each sal inity range) distribution (Figure 12) indicate that EJ snook in the MRES are concentrated in low salinity «11 ppt) habitats. However, the stations where they were collected at 0 ppt were all close to areas of salinity; EJ snook were not collected in the purely freshwater reaches of the MRES.

The extremely low salinity conditions in the MRES during the fall of 1989 (Figure 11) probably reflect sudden freshwater flows from the Lake Evers and Lake Manatee as these reservoirs, which were at extremely low levels prior to onset of the wet season, became filled to capacity and began to overflow or flood gates were opened (Lake Manatee) in late August. The upper (upstream, nearest the dam) subzone (8-U) of the Braden River stayed fresh (0 ppt) for the entire study period. The upper two subzones (l-U and I-M) of the Manatee River also stayed completely fresh during the entire study period (with the exception of one reading at the extreme lower end of I-M on the next to last day of the study). Subzone l-L was al so fresh (0 ppt) almost until the end of the study period, increasing to up to 7 ppt on 10 / 31 / 89. In Manatee Zone 2, salinities also were low, but increased slightly during the study period. In 2-U, salinities of 0-3 ppt were measured early in the study, with salinities increasing up to 10 ppt by the middle of the period. Similarly, salinities in 2-M were low (0-5 ppt) early in the study period, but increased significantly to 8-13 ppt at the end of the period. The same pattern applied to 2-L, in which salinities were 1-10 ppt early in the study period, 10-15 ppt towards the middle of the period, and increased to 11-18 at the end of the period. The farthest downstream

22

zone (3-U) included in the study area had salinities of 14-22 ppt when it was sampled near the end of the study.

Habitat Sampling -- Winter Sampling Period

The entire data set for the winter sampling is presented in Tables 4 and 5. A total of 338 EJ red drum and 716 EJ striped mullet was collected during the period. With the exception of six early-juvenile snook, one early-juvenile spotted seatrout and one early-juvenile sand seatrout, no other juveniles of commercially or recreationally-important species were collected. Numerous post-larval «20 mm SL) striped mullet were also collected early in the period, but they were not quantified due to their small size (which made precise field sorting and enumeration extremely difficult) and due to the project's scope including only juveniles (>20-25 mm SL). Data for other species collected during the period are presented in Table 5.

Environmental data measured at the sampling stations are also presented in Table 4. During the period, salinity at the stations ranged from 0 to 26 ppt, and DO was always high, ranging from 5.6 to 14.5 ppm. Sal inity was measured semi-synoptically throughout the study area on 2/8/ 90 (Figure 14).

Red drum.--A total of 338 EJ red drum was collected at 43 stations (Table 6). The locations of stations where EJ red drum were collected are shown in Figure 15.

Red drum was the only target species for which length data provided distinct insights into early juvenile ecology in the MRES. Differences in lengths of EJ red drum collected during the period suggested that more than one cohort was present in the MRES. This conclusion is supported by the results of an analysis in which the length of each red drum was adjusted to the estimated length (SL) that the fish would have been on 1/1 / 90. These conversions were based on growth rate estimates (Peters and McMichaels, 1987) of 0.632 mm (SL) per day for juvenile red drum in Tampa Bay. A plot of these adjusted length frequencies (Figure 16) indicates that two distinct modes around 19 and 35 mm were present on 1/1 / 90 and suggests that two other modes at 55-60 mm and 75-80 mm were poss i b 1 e. Based on the above growth rate est imates , these modes closely corresponded to sizes of fish that would have been spawned (probably in the Gulf or lower Tampa Bay) one month apart in the fi rst week of December, first week of November, first week of October and first week of September , 1989. These periods correspond to new moons during the fall and early winter of 1989. Peters and McMichaels (1987) also suggested that there was a lunar periodicity to red drum spawning, but their data indicated that peak spawning occurred around full moons during the years of their study. During 1989-1990 , juvenile red drum, which attain a size of around 20 mm (SL) after one month , were probably recruiting into the MRES from October through January. Continued sampling might have detected even later recruitment.

23

Striped mu11et. - -A total of 716 EJ striped mullet was collected at 28 stations (Table 7). Juvenile striped mullet were not collected until 1/ 17/90, although post1arvae were collected as early as 1/9/90. Locations of stations where EJ striped mullet were collected are shown in Fi gure 17. Duri ng the study peri od, the size of the co 11 ected juvenile mullet ranged from 20 to 40 mm SL, with more than 95% ranging from 20 to 30 mm SL (most were 25-30 mm). Although no accurate growth estimates are available for striped mullet juveniles and post1arvae , based on estimated growth rates of 0.6-0.8 mm SLId typical for estuarine fishes, it is likely that most of the mullet were spawned in December and were recruited to the MRES starting in early January.

Only 16 mullet from four stations were collected in the Braden River (67 total stations). The remainder were collected in the Manatee River. The reason for the low number of mullet collected from the Braden River is unknown but , considering MML studies which also collected few mullet in the Braden in prior years, these results may reflect real differences between the two rivers. Continued sampling might have detected continued recruitment (some possibly into the Braden River) and movement of juveniles into lower salinity habitats as they grew.

The data indicate that striped mullet and red drum exhibited a high degree of niche partitioning. Although the red drum and mullet were similar in size, making red drum predation on mullet at this stage unlikely, mullet were not collected in abundance at stations with numerous red drum , and vice-versa. At stations where more than one mullet was collected (total of 708 mullet) , only 13 red drum were collected. Similarly, at stations where five or more red drum were collected (total of 305 red drum) only one mullet was caught.

Juvenile red drum were most abundant at stations with sediments classified as muddy sand (50% of all red drum collected), although they were also collected at stations with sand (16%), mud (19%) or soft-mud (15%) bottoms. Relative to red drum, juvenile striped mullet were more abundant in habitat as with softer bottoms, with stations with mud (62%) or muddy sand (18%) sediments accounting for most of the individuals collected, although quite a few were collected at stations with sand (8%) or soft- mud (i2%) bottoms. Of all the stations sampled during the period , 20% were classified as having sand sediments, 34% as muddy sand, 35% as mud, and 11% as soft mud.

Salinity relationships . --Salinities at the MRES stations during the winter sampling period ranged from 0 to 26 ppt. Red drum were collected at stations with salinities ranging from 0 to 21 ppt, and striped mullet from stations with salinities from 5 to 21 ppt. A histogram of number of red drum and striped mullet collected versus station sal inity is presented as Figure 18 and indicates that red drum and striped mullet EJ's were substantially and significantly (Chi-squared, p <0.01) more numerous in collections at stations with salinities ranging from 16 to 20 ppt. Slightly more than half (53%) of the red drum and 83% of the EJ mullet were collected over this salinity range, despite the fact that on ly 25% of the stations fell wi th in thi s range. The fi ndi ngs that

24

striped mullet were caught only at stations with salinity of 5 ppt or more, and that they were more abundant in stations with higher salinities conform to results of physiological studies (Nordlie et ll., 1982) that showed that juvenile striped mullet do not develop the osmoregulatory capacity necessary to tolerate low salinity until they attain a size of around 40 mm SL. None of the mullet collected from the MRES in January and February were larger than 40 mm SL.

Habitat relationships.--Red drum and striped mullet appeared generally, but not quite as rigorously, to exhibit habitat utilization patterns similar to that found for early-juvenile snook. This is based on the fact that most EJ red drum and mullet were collected in habitats other than linear marsh shorelines (L-4 or L-5). Only 45 of the 338 red drum were collected from L -4 or L-5 stations. Red drum were collected at 11 L-4 or L-5 stations out of a total of 43 stations with red drum. This fraction (11/43 = 26%) is actually higher than the fraction of L-4 and L-5 stat ions i ncl uded ina 11 stations sampled duri ng the peri od (42/205 = 21%), but in terms of numbers, the L-4 and L-5 stations accounted only for 45 of the 338 (13%) red drum collected. Some of the L-4 or l-5 stations where red drum were collected may have undetected features that could explain the presence of red drum. Overall. the results indicate that although EJ red drum, 1 ike snook, may be more abundant in special ized habitats, they are also distributed at lower abundances throughout most of the shoreline habitats in the MRES.

Not including the large catch (360 individuals--estimated by subsampl ing) at Station 117 (L-5-J) only 15 mullet from only three stations were caught at L-4 or L-5 stations. Station 117 is located less than 100 m away from a large creek (C3) and less than about 30 m away from a small creek (Cl), and was sampled on a low falling tide. Therefore, the hi gh abundance of mull et at thi s station cannot be attributed to a normal linear (L) shoreline. Overall, most mullet were collected at stations in or closely associated with tidal creeks, creek mouths and other spec i ali zed habitats. Ki 1 by (1948) noted that small poo 1 sin marshes along the northern Flori da Gulf coast were pri mary juvenile mullet habitat. The results of the present study indicate that a similar situation occurs in the MRES, with small creeks, creek mouths and other specialized habitats being particularly important as striped mullet nursery habitat.

25

CONCLUSIONS AND RECOMMENDATIONS

Snook Nursery Habitat

The results of the study are consistent with the hypothesis that certain specific types of habitats in the MRES (and other systems) are more important (in terms of degree of util ization and total [system­wide] numbers of fish supported) as early-juvenile nurseries for snook, red drum, striped mullet and other important species. This was particularly true with regard to EJ snook , which were found to utilize a very 1 imited suite of habitats and a 1 imited range of sal inities. Almost all snook were found to be associated with small tidal creeks, and no EJ snook were found in the most common and extensive habitats like linear Juncus marsh shorelines or linear mangrove-fringed shorelines.

The snook habitat relationships were based on a data from relatively small number (43) of EJ snook that were collected during the study at a few (19) stations. More-detailed understanding of EJ snook habitat requirements would require a study in which larger numbers of snook were collected. However, the results of the present study should not be minimized because of the 1 imited number of snook that were coll ected during the period. The inverse fact that snook were not collected at 184 of the 203 stations provides substantial evidence that EJ snook are not distributed generally or randomly throughout MRES shoreline habitats.

Based on these results, efforts to preserve or enhance snook juvenile recruitment in MRES, Tampa Bay or other estuarine systems should focus on insuring that specific types of habitats are preserved, protected, and if necessary, created. The fact that the types of habitat utilized by juvenile snook are very delicate, and are susceptible to physical or functional alteration or destruction, needs to be carefully considered by any program attempting to manage estuarine systems like the MRES and other subcomponents of Tampa Bay. Given the specialized nature of EJ snook habitat relationships, additional study focusing on characterizing these habitat relationships in more detail is warranted. The results of the present study would facilitate such research, since expenditure of large amounts of effort in sampling many of the common and extensive habitats that have now been shown to not serve as primary nurseries for snook would be eliminated or reduced.

A subordinate hypothesis of the study was that the importance of habitat types as early-juvenile nurseries is quantitatively related to position (upstream/downstream) along the river and/or position along the estuarine salinity gradient. The results of the early-juvenile snook sampling show a strong relationship with salinity. However, since snook are primarily associated with creeks and tributaries, the relationship between position along the river is more complex. Salinity regime within a creek is probably often related as much to freshwater input into the tributary as to the large-scale salinity conditions in the estuary. As a result, with respect to snook nursery habitat, it is essential that

26

estuarine management consider freshwater inflow into small tributaries or subsystems whose summed contributions to system inflow may be minor, although their summed contributions to snook recruitment is very large.

This is not to say that overall salinity regime within the system is not important to EJ snook. The annual production of juvenile snook in the MRES is dependent on the existence of a salinity regime ranging from around 10 ppt to near-freshwater conditions throughout certain large areas of the estuary that have large amounts of physical habitats that are suitable for EJ snook. Using the analogy shown in Figure 1, production of juvenile snook is a function of the degree to which the dynamic habitat (area with 0. 5-10 ppt salinity) intersects with the stationary habitat (area with suitable physical habitat). In the MRES, there is great potential for occurrence of adverse salinity conditions that can significantly reduce juvenile snook production. If too little or too much freshwater inflow occurs in late summer and early fall, very little of the stationary habitat will intersect with the dynamic habitat, and snook production will be low. In fact such condit ions may have occurred in 1989 . Snook were not collected from the middle subzone of Zone 1 (Zone 2M--approximately defi ned as upstream from confl uence of Mill Creek and Gamble Creek) despite the fact that the available habitats in this subzone physically appear very suitable for snook. It is likely that EJ snook would have utilized this subzone were it not for the very high flows and resultant freshwater conditions following sudden releases from the Lake Manatee spillway (Figure 19). The possibility of juvenile snook penetration into the upper subzone of the Manatee River should be examined during a year with more "normal" flow and salinity conditions.

The findings of this study indicate that freshwater inflow, in terms of its resultant general effect on sal inity regime within estuarine subsystems and its specific effect within tributaries and sub­tributaries, is of critically important to juvenile production. Therefore, the primary application of the results should be the i dent ifi cat ion, 1 ocati on and quant ifi cat i on of snook nursery habitat throughout the Tampa Bay system, so that these essential nurseries can be protected, managed, and, where possible or appropriate, enhanced or created. The results of this study provide the information necessary for inventorying snook nursery habitats in Tampa Bay. They also could be used to guide habitat restoration efforts in Tampa Bay.

It is important to note that the types of habitats that are valuable as snook nursery habitat, due to their relatively small size, usually do not receive much attention from resource managers. Also, due to their small size, such habitats are easily destroyed or altered. A very small sub-tri butary creek can provi de nursery habitat to 1 arge numbers of juvenile snook each year. However, in Tampa Bay and throughout southern Florida, many small sub-tributaries have been filled, channelized, or have had their normal freshwater inflow drastically altered (quantity and quality) by activities associated with development and population growth. Continued loss of snook nursery habitat can be avoided only if resource managers specifically focus on this type of habitat and develop measures for protecting and restoring it.

27

Spotted and Sand Seatrout Habitat Relationships

The fact that considerable numbers of spotted and sand seatrout were collected in the study indicates that the MRES is an important nursery area for these two species. Juvenile spotted seatrout and sand seatrout are generally known to utilize shallow estuarine areas as nursery habitat (lassuy, 1983, Sutter and McIlwain, 1987), but little detailed information about their habitat and salinity requirements and relationships is available. Based on the results of the MRES study, it is clear that EJ spotted seatrout and sand seatrout, in contrast to EJ snook, are very abundant in the more-open habitats along linear (l) marsh shorelines and do not appear to utilize creeks to any great extent.

In general, it probably can be concluded from the 1 iterature and from the resul ts of thi s study that EJ' s of both seatrout species normally do not greatly utilize habitats with extremely low salinities, but instead prefer intermediate salinities. Although Peebles and Davis (1989) captured (plankton net) highest numbers of EJ spotted and sand

-seatrout at low «6 ppt) salinities in the little Manatee River during 1988, Tabb (1966) indicated that juvenile spotted seatrout are unable to tolerate salinities lower than 5 ppt for protracted periods and must reach areas with higher salinity in order to survive post-storm freshets. More than 20% of the spotted seatrout collected in the MRES came from stations with salinities of 3 ppt or less. However, most of these were collected during a period (first five days of October) which immediately followed a period of about a week in which there was extremely high freshwater inflow (Figure 19) into the MRES. Similarly, all of the sand seatrout collected at salinities less than 5 ppt were collected following this period of rapid freshening. Therefore, the fact that seatrout were collected at such low salinities probably does not reflect a normal utilization of or preference for such extremely low-salinity conditions. Instead, the presence of significant numbers of EJ seatrout in MRES and little Manatee River (Peebles and Davis, 1989) areas with very low sal inities may reflect concentration of juvenile seatrout as they are forced downstream duri ng peri ods of increased freshwater i nfl ow and attendant rapid salinity declines.

Red Drum and Striped Mullet Nursery Habitat Relationships

Like snook nursery habitat, red drum and striped mullet nursery habitat consists special habitat components that are far less common and less aerially extensive than some of the more abundant habitat categories. Therefore, with respect to red drum and striped mullet, it is not sufficient for habitat protection, management and restoration programs to generally protect estuari ne habi tat. As is requi red for snook habitat conservation, such programs ought to consider estuarine habitat in a more-detailed, and discriminating manner. The fact that EJ red drum and striped mullet distributions were found to be significantly related to salinity, with both species being much more abundant in the salinity range of 16-20 ppt and EJ mullet never penetrating into salinities less than 5 ppt, indicates that maintenance of proper salinity

28

reg~mes in the areas of the MRES where these habitats is also critically important.

Possible Differences Between the Manatee and Braden Rivers

The combined results of the fall and winter sampling suggest that there may be significant differences between the Manatee River and Braden River sub-estuaries in terms of early-juvenile fish productivity. Except for snook, important juveniles were much less abundant in the Braden River. For example, only ten of the 416 EJ spotted seatrout collected during the fall period came from the Braden River. Similarly, only 31 of the 221 sand seatrout (fall), 16 of the 716 striped mullet (winter), and 72 of the 338 red drum (winter) were collected from the Braden River. The catches of these four species from the Braden departed significantly (Chi-squared, p <0.01) from the expected catch for 66 (fall) or 67 (winter) samples taken from the Braden River. The disparity is even greater than indicated, because the Manatee River stations included several that were predominantly freshwater and not suitable for these species. EJ snook abundance appeared to be abnormally depressed in 1989 in both sUbsystems . Therefore, the fact that only 12 snook were collected from the 137 Manatee River stations, as compared to 31 from 66 Braden River stations, may not be meaningful. On the other hand, it is possible that the disparity may truly reflect the extremely abnormal salinity and flow conditions that occurred in the Manatee River during late summer and early fall of 1989. The present study did not provide any direct explanation for the disparity in abundance of seatrout, red drum and mullet between the two rivers. No obviou s differences in terms of types of habitats available were detected, and similar salinity ranges were available in each river (Figure 14).

Possible Braden River Environmental Problems

In addition to the study results discussed above, observational and anecdotal information suggests that the Braden River may be suffering from cumulative impacts of the original construction and modifications of the Evers Reservoir dam . The Braden River appears to have extensive deposits of fine-grained organic-rich sediments that seem to be accumulating rapidly. There are several ways that construction of the dam could have accelerated sediment accumulation. Physically, the dam probably attenuates high flow events that otherwise would tend to flush fine sediments from the system. Also, the dam, by changing freshwater inflow patterns and salinity regimes, may have resulted in the estuarine drop zone (the area in which colloids and other fine particles sediment due to increased ion i c strength (Edzwa 1 d, Upchurch and 0' Me 1 i a, 1974» being contained within the Braden River. Such a change could dramatically affect an estuarine sediment budget. Finally, changes in salinity regime could have caused decreased sediment metabolism, decreased remi neral i zat i on of sediment organi c matter and increased organic accumulation (Edwards, 1981) . Hydrological changes related to construction of a new bridge (Highway 64) and alteration of the natural channel at the river mouth (around 1957) may have exacerbated the problem . Flow and salinity have not been monitored in the Braden River,

29

so the extent to which present conditions differ from those prior to construction of the dam and reservoir is unknown.

Several individuals have volunteered anecdotal observations that the Braden River has changed drastically since the dam was originally built and after the reservoir and dam were made larger . Mr . Ernie Marshall (deceased), proprietor of Marshall's Boat Rental at Highway 70 and the Braden River, reported that most of his business had been due to the very high abundance of snook in the Braden River, but that snook were no longer abundant. Captain Scott Moore, a noted guide who specializes in snook fishing in the Tampa Bay area, related experiences of tremendously high snook abundance and catches from the Braden River in the early 1960's. Murdock's (1957) Braden and Manatee rivers survey, which alluded to excellent and productive recreational fisheries, corroborates these anecdotal reports. Murdock (1957) estimated that up to 250 anglers per day fished the Manatee and Braden rivers. Today, recreational fishing in the Braden River would have to be rated as generally poor, the number

. of anglers fi shing the Braden River is very small, and far fewer recreational fishermen now use the Manatee and Braden Rivers than were reported by Murdock (1957).

Factors other than the dam al so may have negatively impacted the Braden River. Two public landfills were formerly operated along the banks of the Braden River , one just downstream of the Highway 70 bridge and one along the southern shore about 1 km upstream of the river mouth. The tidal Braden river also receives large amounts of agricultural runoff. Copper sulfate is frequently appl i ed to control phytopl ankton blooms in the Evers Reservoir, but the degree to which it copper reaches the estuary and negatively impacts it is unknown. Stormwater is re 1 at i ve 1 y unmanaged along much of the t ida 1 Braden , present i ng an increasing problem as land use in the area has changed and continues to change from rural res i dent i a 1 and extens i ve agri culture to hi gher­density residential and more-intensive agriculture.

Possible Manatee River Environmental Problems

At present, most of the Manatee River upstream of the 175 bridge can be considered to be relatively unaltered in terms of physical destruction or alteration of habitat . The largest alteration that has occurred is the construction of the Lake Manatee reservoir and dam. The potential for the dam to negatively impact fisheries habitat and productivity by affecting flow and salinity conditions is high, but these effects have never been directly assessed in this regard. The addition of large amounts of copper to the reservoir also poses a potential problem to the downstream river and estuary. In the future, more shoreline and adjacent upland habitat in the MRES will be altered for residential development, and habitat loss may significantly impact fisheries. The Manatee River has many tributaries ranging in size from small creeks with drainage basin areas of only a few hectares , to large creeks like Gamble and Mill creeks that have large and extensive drainage basins. Future alterations of these and smaller tributaries, particularly with regard to quantity

30

and quality of inflow, could have significant negative impacts on the Manatee River.

Monitoring and Management of the Manatee Riv er Estuary System

The Manatee River Estuary System needs more study and monitoring if it is to be properly managed and protected. This large and important system is unusual relative to most other areas of Tampa Bay in that it

--still can benefit most from protection and management because it has not deteriorated to the point that it needs extensive improvement or enhancement. However, the effects of construction and operation of the Lake Manatee and Braden River dams on fishes, habitats and estuarine functioning of the MRES should be quantified, analyzed and evaluated to determine the extent to which management measures are needed. To the extent possible, the negative effects of the two impoundments and other anthropogenic alterations should be identified, rectified or ameliorated. Overall, the MRES, by virtue of its large area of productive wetlands and shallow estuarine environments, and by virtue of the its importance to the productivity and health of Tampa Bay, should receive high priority in any efforts to improve and manage Tampa Bay.

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LITERATURE CITED

Bass, R.J. and J.W. Avault. · 1975. Food habits, length-weight relationships, condition factor and growth of juvenile red drum, Sciaenops ocellatus, in Louisiana. Trans. Amer. Fish. Soc. 104:35-45.

Breuer, J.P. 1973. A survey of the juvenile and adult food and game fish of the Laguna Madre. Texas Parks and Wildl. Dept. Coastal Fish. Proj. Rept.

Browder, J.A. and D. Moore. 1981. A new approach to determining the quantitative relationship between fishery production and the flow of freshwater to estuari es. pp. 403-430 in R. D. Cross and D. L. Williams (eds.), Proceedings of the National Symposium on Freshwater­Inflow to Estuaries , Vol.!. U.S. Fish and Wildl ife Service, Office of Biological Services. FWSjOBS-81j04.

Buckley, J. 1984. Habitat suitability models larval and juvenile red drum. U.S. Fish and Wildlife Service FWSjOBS-82jl0.74. 15 pp.

Collins, M.R. 1985. Species profiles life histories and environmental requirements of coastal fishes and invertebrates (South Florida)-­striped mullet. U.S. Fish Wildl. Servo Biol. Rep. 82(11.34}. U.S. Army Corps of Engi neers, TR EL -82- 4. 11 pp.

Comp, G.S. 1985. A survey of the distribution and migration of the fi shes in Tampa Bay. pp. 393-425 in S. A. Treat et il. (eds. ) Proceedings, Tampa Bay Area Scientific Information Symposium. Bellwether Press, 663 pp.

Dooris P.M. and G.M. Dooris. 1985. Surface flows to Tampa Bay: Quantity and qual ity aspects. pp. 88-106 in S.A. Treat et il. (eds.) Proceedings, Tampa Bay Area Scientific Information Symposium. Bellwether Press, 663 pp.

Edwards, R.E. 1990. Estuarine nursery habitats of early-juvenile fishes in the Manatee River Estuary System of Tampa Bay: habitat classification and snook habitat relationships. Florida Chapter, American Fisheries Society Annual Meeting, 26-28 February, 1990. (Abstract).

Edwards, R.E. 1989. The importance of early-juvenile habitat to Florida fi shery recruitment. p. 38 in G. S. Kl eppe 1 and W. S. Seaman, Jr. (eds.). Fishery recruitment in Florida waters. Florida Sea Grant Technical Paper No. 57.

Edwards, R.E. 1983. Experimental marine fish propagation. Second Snook Sympos i urn Summary of Proceedi ngs. Flori da Department of Natural Resources and International Game Fish Association.

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Edwards, R.E. 1981. The influence of salinity transition on benthic nutrient regeneration in estuaries. pp. 2-16 in R.D. Cross and D.L. Williams (eds.). Proceedings of the National Symposium on Freshwater Inflow to Estuaries. Fish and Wildl ife Service, u.S. Dept. Int., Wash. 528 pp .

Edzwald, J.K., Upchurch, J.B. and C.R. O'Melia. 1974. Coagulation in estuaries. Environ. Sci. Technol. 8: 58-63.

Gilmore, R.G. 1987. The microhabitat and niche of juvenile snook. p. 3 in Third Snook Symposium Proceedings , Florida Department of Natural Resources . (abstract).

Gilmore, R.G. , Cooke, D.W., and C.J. Donohoe. 1983. Observations on the distribution and biology of east-central Florida populations of the common snook, Centropomus undecimalis (Bloch). Florida Sci. 46:313-336.

Goodyear , P.C . 1989. Stock assessment for Gulf of Mexico red drum. Project (Grant No. 89NMFS01) to MARFIN.

Gunter, G. 1957. Some relationships of estuaries to the fisheries of the Gulf of Mexico. pp. 621-638 in G.H. Lauff (ed.), Estuaries. American Association for the Advancement of Science, Publ. No. 83, Washington, D.C.

Holt, S.A. and C.R. Arnold. 1982. Distribution and abundance of eggs, larvae and juveniles of redfish (Sciaenops ocellatus) in seagrass beds in a south Texas estuary. p. 86 in C.F. Bryan, J .V. Connor and F.M. Truesdale (eds.), Proceedings of the Fifth Annual Larval Fish Conference. Louisiana Cooperative Fishery Research Unit, Louisiana State Univ., Baton Rouge .

Kilby, J.D . 1949. A preliminary report on the young striped mullet (Mugil cephal us L i nneaeus) in two Gulf coastal areas of Flori da. Q. J. Fla. Acad. Sci. 11:7-23.

Lassuy , D.R. 1983. Species profiles: life histories and environmental requirements (Gulf of Mexico)--spotted seatrout. U.S. fish Wildl. Servo FWSjOBS-82j11.14. U.S. Army Corps of Engineers, TR EL-82-4. 14 pp.

Lewis, R.R. , III, Gilmore, R.G., Jr., D.W. Crewz and W.E. Odum . 1985. Mangrove habitat and fishery resources of Florida. pp. 281-336 in W. Seaman, Jr. (ed.) Florida aquatic habitat and fishery resources. Florida Chapter of the American Fisheries Society.

Lewis, R.R., III and R.L. Whitman, Jr. 1985. A new geographic description of the boundaries and subdivisions of Tampa Bay. pp. 393-425 in S.A. Treat et li. (eds.) Proceedings, Tampa Bay Are? Scientific Information Symposium. Bellwether Press, 663 pp.

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Major, P.F. 1978. Aspects of estuarine intertidal ecology of juvenile striped mullet, Mugil cephalus, in Hawaii. U.S. Natl. Mar. Fish. Servo Fish. Bull. 76:299-313.

Manatee County Utilities Department and Camp Dresser & McKee, Inc. 1984. Downstream effects of permitted and proposed withdrawals from the Lake Manatee Reservoir. Report submitted to Southwest Florida Water Management District.

Mansueti, R.J. 1960. Restriction of very young red drum , Sciaenops ocellata , to shallow estuarine waters of Chesapeake Bay during late autumn. Chesapeake Sci. 2:207-210.

McMichael, R.H., Jr., K.M. Peters and G.R. Parsons. 1989. history of the snook, Centropomus undecimalis, in Florida. Northeast Gulf Sci. 10: 113- 125.

Early 1 ife Tampa Bay,

Mote Marine Laboratory. 1987. Fish stock enhancement annual report--1986-87. Final report submitted to Florida Department of Natural Resources . 150 pp.

Murdoch, J.F. 1957. Report on the sport and commercial fisheries of the Braden and Manatee Rivers . Florida State Board of Con servation Report 57-23. 22 pp.

National Marine Fisheries Service (NMFS). 1986. Final secretarial fishery management plan regulatory impact review, regulatory flexibility analysis for the red drum fishery of the Gulf of Mexico.

Nordlie, F.G., W.A. Szelistowski, and W.C. Nordlie. 1982. Ontogenesis of osmotic regulation in the striped mullet, Mugil cephal us L. J . Fish . Biol . 20 :79-86.

Peebles, E.B. and S.E. Davis. 1989. Riverine discharge and estuarine fish nurseries: Annual report for the ichthyoplankton survey of the Little Manatee River, Florida.

Peters, K.M. and R.H. McMichael , Jr. 1987. red drum, Sciaenops ocellatus (Pisces Florida. Estuaries 10:92-107.

Early life history of the Sciaenidae), in Tampa Bay,

Rogers, B.D. and W.B. Herke. 1985 . Temporal patterns and size characteristic s of migrating juvenile fishes and crustaceans in a Louisiana marsh. School of Forestry, Wildl ife and Fisheries, La. Agricul. Exp. Sta., LSU Agricul. Ctr., Res . Rept. 5. 81 pp.

Sabins , D.S. Laminada 163 pp.

1973. Diel studies of larval and juvenile fishes of the Pass area, Louisiana. M.S. Thesis , Louisiana State Univ.

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Seaman, W., Jr. and M. Collins. 1983. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (South Florida)--snook. U.S. Fish Wildl. Servo FWSjOBS-82j11.16. U.S. Army Corps of Engineers, TR EL-82-4. 16 pp.

Sutter, F. C. and T.D. McIlwain. 1987. Species profiles: life histories and environmental requirements (Gulf of Mexico)--sand seatrout and s i 1 ver seatrout. U. S. fi sh Wi 1 dl. Serv. FWSjOBS-82/ll. 72. U. S. Army Corps of Engineers, TR EL-82-4. 16 pp.

Sykes, J.E. and J.H. Finucane. 1966. Occurrence in Tampa Bay, Florida of immature species dominant in Gulf of Mexico commercial fisheries. U.S. Fish Wildl. Servo Fish. Bull. 65:369-379.

Tabb, D.C. 1966. The estuary as a habitat for spotted seatrout (Cynoscion nebulosus). Am. Fish. Soc . Spec. Publ. No. 3:59-67.

35

Table 1. Habitat classification nomenclature.

FORHAT: Geomorphic-Shoreline-X(Fringing Vegetation)-Y(Interior Vegetation)

HAP AND STATION HABITAT SYMBOLS:

Geomorphic Symbol Description

Shoreline Symbol Description

A B1 B2 C1 C2 C3 E1 E2 L Ml M2 M3 o S

Altered 1 Bight«2m) 2 Bight(>2m) 3 Creek(Rivulet) 4 Creek«2m wide) 5 Creek(>2m wide) Embayment«Sm) Embayment(>Sm) Linear Shoreline Mouth(Creekl) Mouth(Creek2) Mouth(Creek3) Open-water Shoal Spit Shoal

UL=Upland

Notes:

Unveg . . UL Patchily Veg. UL Fringed(2-4m) UL Fringed Marsh Solid Marsh

Vegetation Symbol Description

J Juncus R Red Mangrove W White Mangrov€ B Black Mangrove F Fern(Leather) P Brazilian Pepper S Spartina alterniflora Sb Spartina bakeri T I:t.Qb.£ M Mixed

(1) If the marsh is a solid marsh (Fringing=Interior), the Interior designation (Y) is not written (e.g., L-S-J-J written as L-S-J). Similarly, if only a fringe exists (e .g., L-3-J), there will be no Interior designation.

(2) X may be designated as X.a, which indicates significant presence of vegetation a i n X. X may also be designated as X/a, which indicates approximately equal dominance of X and a in the fringe.

(3) Y may be designated as Y/ b, which indicates approximately equal dominance of Y and b in the interior . To avoid excessive complexity, the notation Y. b was not used, and only dominants or co-dominants (Y/b) were noted for interior marshes.

Table 2. Tabulated results of seine co l lections (September - November, 1989) _. target species. Species abbr eviations -- target speci es: snook (Centropomus undecimalis) . SNK, snook larger than 100 mm SL SNK+, spotted seatrout (Cynoscion nebulosus) . SPT, sand seatrout (Cynoscion arenarius ) . SST, striped mu l let (Mugil ~) . MUL, r ed drum (Sciaenops ocellatus) . ROD, and sheepshead (Archosargus probatocephal us) . SHOo The number of each target species collected at each station is indicated. Total number of each target species colleted dur i ng the per iod is given. Tide conditions ar e presented as 1 = low, 2 = 1/4, 3 = 1/2, 4 = 3/4, 5 = h igh, and e = ebbing or f = flooding . Habitat descr i ptors follow the trinomial habitat classification system and use the same nomenclaut ure and abbreviat ions.

No . Zone . Habi tat TOTAL SNK SNK+ SP T SST MUL ROD SHD Date Time Sal. DO T efTll . Tide Sed. Seine Z Sub 1 2 3 NO. 43 27 221 326 85 1 4 (ppt)(ppn ) (oC ) Type (tt)

- - ----- - -- - - - - -- --- - -- ---- - -1 B L El 5 R 09/22/89 08:15 5 29 4 e 4 60 2 B L C2 5 J 09/22/89 09:1 5 5 30 3 e 4 15/B 3 B L E2 5 R 1 41 09/ 22/89 10:15 5 30 3 e 4 200 4 B L C3 5 R 2 09/22/89 11:30 10 31 2 e 4 15 5 B L C2 5 R 09/22/89 12:00 8 31 2 e 4 15 6 B L Cl 5 J 10/17/89 13:45 10 30 f 3 30 7 B L L 5 R 10/02/89 09:00 5 30 e 2 30 8 B L Ml 5 R 10/02/89 09:50 5 30 1 e 3 30 9 B Ml 5 R 10/02/89 10: 12 4 31 1 e 3 30

10 B L 5 R 7 10/02/89 10:45 3 31 1 e 2 100 11 B M L 4 J . R 4 10/02/ 89 11:50 0 32 1 f 2 100 12 B M L 4 J . R 6 10/02/89 12:10 0 32 2 f 2 100 13 B M L 5 J 10/02/89 12:40 0 31 2 f 2 100 14 B M L 5 J 10/02/89 12:55 0 31 3 f 2 100 15 B M Ml 2 J.R 10/02/89 13 : 20 0 32 4 f 1 100 16 B U E2 3 2 10/02/89 14:00 0 31 4 f 2 100 17 B M C2 5 10/02/89 15:00 0 31 5 f 3 100 18 2 M L 5 1 10/03/89 10 :00 4 28 2 e 1 100 19 2 M L 5 R 3 10/03/89 10:30 4 28 2 e 2 100 20 2 M L 5 R 10/ 03/89 10:30 4 28 2 e 2 100 21 2 M /L 5 J 2 1 2 6 10/03/89 12:00 0 30 1 e 1 100 22 2 M /L 4 J . R 3 1 10/03/89 12:00 0 30 1 e 1 100 23 2 M /L 5 38 10/03/89 12 :00 0 30 1 e 1 100 24 2 M L 5 2 10/03/89 12:50 1 30 1 f 1 100 25 2 M 5 J 1 10/03/89 12:50 1 30 1 f 1 100 26 2 U L 5 J 10/03/89 13:40 0 31 2 f 3 100 27 2 U L 5 J 10/03/89 13: 40 0 31 2 f 3 100 28 2 U L 2 J 10/03/89 14:00 1 31 3 f 1 100 29 2 U L 2 10/03/89 14:00 1 31 3 f 1 100 30 1 M L 5 10/03/89 14:50 2 31 4 f 4 100 31 1 '1 Ml 5 10/03/89 15 :00 0 31 4 f 1 100 32 2 U C2 5 10/04/89 10:00 3 27 3 e 4 15/B 33 2 U M2 5 10/04/89 10:45 0 31 3 e 4 30 34 1 L C3 5 10/04/89 11 : 15 0 29 2 e 4 30 35 L c3 5 J 10/04/89 11: 15 0 29 2 e 4 30 36 M Ml 5 J 10/04/89 12 :00 0 27 2 e 4 30 37 M S 5 10/04/89 12:00 0 27 e 4 30 38 M 5 5 10/04/89 12:00 0 27 e 2 30 39 M 5 5 T 10/04/89 12:30 0 27 e 2 30 40 M L 3 T 10/04/89 13 :00 0 27 e 1 100 41 M 1 10/04/89 13 :30 0 27 e 1 100 42 M Ml 5 10/04/89 13:40 0 29 e 2 100 43 M L 5 10/04/89 14 : 00 0 29 e 2 100 44 1 M L 5 10/04/89 14:00 0 29 e 2 100 45 2 U M2 5 2 10/04/89 14 :40 1 30 1 f 2 100 46 2 L L 7 10/05/89 09:00 10 29 2 e 1 100 47 2 L 1 5 10/05/8909: 15 . ) 29 2 e 1 100 48 2 L L 2 S 25 10/05/89 09 :30 10 29 2 e 1 100 49 2 L L 2 24 10/05 / 89 10:30 5 28 e 2 ' 100 50 2 L L 1 7 10/05/89 10: 40 5 28 e 2 100 51 2 L 5 II . R. B 10/04/ 89 11:40 4 30 f 2 100 52 2 L L 5 II.R . B 10/04/89 12:00 4 30 f 2 100

Table 2. Cont i nued .

No. Zone. Habitat TOTAL SNK SNK+ SPT SST MUL RO D SHD Date Time Sal. DO Temp. Tide Sed. Seine Z Sub 2 3 NO. 43 27 221 326 85 1 4 (ppt )(ppn) (oC) Type (ft)

------- ------------- --- ------

53 2 L L 5 IJ . R 10/05/89 12:30 5 30 1 f 1 100 54 2 L M2 5 IJ.R 19 10/05/89 12 :40 5 30 1 f 3 100 55 2 L S 5 R 9 10/05/89 13:15 1 31 1 f 4 30 56 2 L L 5 1 7· 10/05/89 13:30 1 32 2 f 4 30 57 2 M Cl 5 10/09/89 12:05 5 26 4 e 3 15/8 58 2 L C2 5 4 2 10/09/89 12:50 6 26 4 e 1 15/8 59 2 M Ml 5 10/09/89 13:30 3 28 3 e 2 30 60 2 M Cl 5 10/09/89 13:45 5 27 3 e 3 30 61 L S 3 10/09/89 14:10 1 27 2 e 1 30 62 L S 3 J 10/09/89 14:20 1 27 2 e 1 30 63 L C3 3 JfT 10/09/89 14:40 0 28 2 e 1 30 64 L S 10/09/89 14:40 0 28 1 e 1 30 65 L S 5 J 10/09/89 14:40 0 28 1 e 1 30 66 1 L C3 5 T 2 10/09/89 15:10 0 28 1 e 2 30 67 1 U L 3 MIX 10/11/89 12:10 0 27 4 f 1 30 68 1 U L 3 MIX 10/11/89 12:20 0 27 4 f 1 30 69 1 U Ml 3 MIX 10/11/89 12:30 0 27 5 f 1 30 70 1 U Cl 10/11/89 12:40 0 27 5 e 1 30 71 1 U L 1 10/11/89 13:00 0 27 4 e 1 30 72 1 U L 3 MIX 10/11/89 13:15 0 27 4 e 1 30 73 1 M Ml 1 10/11/89 13:30 0 27 4 e 1 30 74 1 M L 3 MIX 10/11/89 13: 45 0 27 4 e 1 30 75 1 M L 3 MIX 10/11/89 14:30 1 27 4 e 30 76 1 M L 3 MIX 10/11/89 14:50 0 28 3 e 30 77 1 M S 2 MIX 10/11/89 15:15 0 27 3 e 30 78 1 M H2 2 MIX 10/11/89 15 :30 0 27 3 e 1 30 79 1 L L 1 10/12/89 10: 14 0 26 2 f 1 200 80 2 U L 2 10/12/89 10:50 0 26 2 f 1 200 81 2 U C3 5 10/12/89 11:12 1 26 3 f 4 30 82 2 U M2 5 10/12/89 11:47 4 26 3 f 3 30 83 2 U M2 5 10/12/89 12:30 7 26 4 f 2 30/8 84 2 U Ml 5 4 10/12189 12:50 7 26 4 f 2 30 85 2 U Ml 5 10/12/89 13:17 7 5 f 4 30 86 2 U Hl 5 J 10/12/89 13:25 6 5 f 4 30 87 2 U M2 5 J 2 17 10/12/89 14:50 6 27 4 e 2 30 88 2 U H2 5 J . R 11 10/13/89 10:00 3 27 3 f 1.5 30 89 2 U H2 5 1 10/13/89 10:30 3 27 4 f 2 30 90 2 U Hl 3 10/13/89 10:50 4 26 4 f 2 30 91 2 U Hl 5 2 10/13/89 11:30 5 26 5 f 4 30 92 2 U H2 5 R.J 10/13/89 12:30 9 27 5 e 4 30 93 2 U H2 5 1 10/13/89 13:30 8 30 4 e 4 30 94 2 U Ml 3 3 10/13/89 14:30 7 29 3 e 1.5 30 95 2 U Hl 5 10/13/89 14:30 12 29 3 e 30 96 8 U C2 5 10/16/89 09:00 0 26 1 e 4 30 97 8 U C2 3 10/16/89 09:45 0 26 1 e 2 30 98 B U 0 10/16/89 10:15 0 27 1 f 2 30 99 B U /L 5 6 10/16/89 10:45 0 28 1 f 3 100

100 B U L 1 10/16/89 11 :00 0 27 1 f 2 100 101 B U C2 2 10/16/89 11:45 0 28 1. f 2 30 102 B M L 3 T 4 10/16/89 12:30 5 29 2 f 3 100 103 B M C2 5 10/16/89 13:30 3 30 2 f 2 30 104 B M 07 5 R 10/16/89 14:15 3 31 3 f .1 30 105 B H /L 5 1 2 10/17/89 08:45 0 27 2 e 3 100 106 B H /L 5 3 1 10/17/89 09: 15 0 27 1 e 3 100 107 B M /L 5 2 3 10/17/89 09:45 0 27 1 e 3 100 108 B U /L 5 13 2 10/17/89 10: 15 0 28 e 2 100 109 B u /L 5 1 10/17/89 10:46 0 28 1 e 3 100 110 B U L 2 AfT 1 10/17/89 11 :00 0 29 1 e 3 100 111 B L 4 R.J 10/17/89 12:30 4 30 1 f 3 100

Table 2. Continued.

No . Zone. Habi tat TOTAL SNK SNK+ SPT SST MUL ROD SHo Date Time Sal. DO Temp. Tide Sed . Seine Z Sub 1 2 3 NO. 43 27 221 326 85 1 4 (ppt)(ppn) (oC) Type (tt)

------- ------------- --- -------

112 B L L 5 10/17/89 13:35 10 30 1 t 2 100 113 B L L 3 J . R 10/17/89 14:20 10 31 2 t 3 100 114 B L L 5 J 3 10/18/89 08:20 9 28 3 e 3 100 115 B L /L 5 J 2 2 10/18/89 09:00 9 28 2 e 3 100 116 2 M L 5 J 1 12 10/18/89 10:30 5 28 2 e 3 100 117 2 U L 5 J 1 2 10/18/89 11:00 5 29 2 e 3 100 118 2 U L 3 J 4 10/18/89 11:45 7 30 1 e 4 100 119 2 U L 2 10/18/89 13:10 2 29 1 e 4 100 120 2 U M2 5 10/18/89 13:40 0 29 1 f 2 30 121 2 U Ml 5 10/18/89 14:05 2 29 1 f 3 30 122 2 U C2 3 10/18/89 14 :35 2 29 1 f 4 30/B 123 2 U C2 5 10/18/89 15 : 00 1 32 2 f 4 30/B 124 2 L M2 3 J . R 4 10/19/89 09:00 10 27 3 e 2 30 125 2 L C2 3 S 10/19/89 10:00 15 27 3 e 1 30/B 126 B M Cl 5 10/19/89 10:45 5 29 3 e 3 30 127 B M Cl 5 J 10/19/89 11 :19 7 27 2 e 4 30 128 B M C2 5 J 10/19/89 12:00 3 27.5 2 e 3 30/B 129 B M M3 5 J 10/19/89 12:30 0 27 2 e 3 30 130 1 L L 5 J 10/23/89 09:45 0 8. 7 19 5 f 3 100 131 L M2 2 J 10/23/89 10:20 0 8.7 21 5 e 2 30 132 L Cl 5 J . F 10/23/89 10:40 0 9 . 4 19.8 5 e 3 30 133 L L 2 10/23/89 12:25 1 9.5 21 5 e 3 100 134 B L A 1 10/23/89 14:00 10 9.3 20.8 4 e 3 100 135 B M L 2 10/23/89 14:45 10 9.7 22 4 e 2 100 136 B U L 2 J 10/23/89 15:00 1 9 . 7 23 . 9 3 e 2 100 137 B M C3 5 R 10/24/89 11:45 8 8.3 21.3 4 e 4 30/B 138 B M L 5 R 10/24/89 12:30 10 8.3 21.8 3 e 3 100 139 B L L 2 R. J 10/24/89 13:15 11 8.8 22.5 3 e 2 100 140 B L L 2 SIR 3 4 10/24/89 14:00 11 9.0 22.9 3 e 2 100 141 B L C3 5 10/24/89 14 :45 10 8.2 22.8 2 e 4 30/B 142 B L L 2 R.J 10/24/89 14:50 9 8.6 23 2 e 2 100 143 B M L 2 J 2 10/24/89 15: 15 2 9.3 24 2 e 3 100 144 B U L 3 J/F 10/25/89 08:30 0 7 . 0 20.5 1 f 2 laO 145 B U L 3 10/25/89 09:15 0 7.7 20.5 1 f 3 100 146 B U L 2 T.J 10/25/89 09 :45 0 6 .5 20.7 1 f 2 100 147 B M C3 5 J 10/25/89 10:15 0 7.7 20.3 2 f 3 30/B 148 B M Ml 5 10/25/89 11 : 15 0 8 . 2 21.5 2 f 3 30 149 B M L 3 10/25/89 11:45 1 7 .8 21 2 f 2 100 150 B M L 2 10/25/89 12:30 2 8 . 3 21.8 3 f 2 100 151 B M A 1 10/25/89 13:20 4 8.1 21.8 3 f 3 100 152 B ~ C3 5 R. \.1 10/25/89 14:00 6 7.7 22.9 3 f 2 30/B 153 B M L 4 R. J 10/25/89 14:30 10 7. 6 23.2 4 f 3 100 154 B L C3 5 R 10/25/89 15: 15 10 7. 9 24.2 4 f 4 30/B 155 2 L L 5 R/B 1 2 10/26/89 09: 16 12 7 . 7 19.5 1 f 2 100 156 2 M 5 R.B 4 10/26/89 09:50 11 7.8 20.6 2 f 4 100 157 2 M L 4 R.J 62 10/26/89 10 :30 9 7. 3 20.7 2 f 3 100 158 2 M L 4 R.J 3 15 10/26/89 11:30 10 7 . 721.1 3 f 3 100 159 2 M M2 5 R 6 10/26/89 12:21 11 8.4 21.6 3 f 4 30 160 2 L L 3 23 10/26/89 13:00 11 8.6 22 4 f 2 100 161 2 M L 3 2 11 3 10/26/89 14:.10 12 8.8 22.5 4 f 3 100 162 2 M L 2 J.R 15 10/26/89 14:45 11 8.6 23.5 5 f 3 100 163 2 L A 1 10/26/89 15:40 18 10.0 22 5 f 3 100 164 M L 3 J . F 10/27/89 09: 15 0 8.8 21 1 f 2 100 165 L L 2 10/27/ 89 09: 45 0 10. 3 21.8 1 f 2 100 166 1 L 0 10/27/89 10:30 0 10 . 7 21.8 1 f 1 100 167 2 M L 2 J 14 10/27/89 11:30 8 8.3 22 .1 2 f 2 100 168 2 M L 3 J/R 61 10/27/ 89 12:30 13 8.3 21.5 3 f 3 100 169 3 U L 3 R/B 4 5 10/27/89 13:30 20 9.8 23 3 f 2 100 170 3 U Ml 3 R/B 2 19 10/27/89 14:1 0 22 10 . 3 23 . 1 4 f 2 30

Table 2. Continued.

No. Zone. Habitat TOTAL SNK SNK+ SPT SST MUL ROO SHO Date Time Sal. 00 Temp. Tide Sed. Se ine Z Sub 1 2 3 "NO. 43 27 221 326 85 1 4 (ppt)(ppn) (oC) Type <ft)

------- ------------- --- - -- ------171 3 U C2 3 R/B 10/27/89 14:40 22 9.8 23.9 4 f 2 30/B 172 B L S 10/30/89 09:00 10 7.2 21.6 1 f 1 100 173 B L 0 10/30/89 09:20 10 6.6 21.5 1 f 1 100 174 3 U L 3 R/B 10/30/89 10:30 14 7.7 21.2 2 f 2 100 175 3 U L 2 R/B/II 5 4 10/30/89 11:15 18 10.5 22 2 f 2 100 176 3 U L 5 R/B/II 4 10/30/89 12:00 22 10 . 3 22.9 3 f 1 100 177 2 L M3 3 J/II.R 1 10/30/89 12:35 12 7.8 23 3 f 2 30/B 178 2 L L 3 J .II/R 2 10 10/30/89 13:15 16 7.5 22 . 5 4 f 2 100 179 2 L M3 5 J 7 10/30/89 14:00 12 8.5 23.8 4 f 2 30 180 2 L C3 5 J 1 10/30/89 14:30 11 7.5 24 4 f 3 30/B 181 2 L C1 5 12 10/30/89 15:00 11 7.7 23.5 4 f 3 30 182 2 L a 8 10/31/89 09:00 12 7.1 22 1 e 1 100 183 1 L L 2 T/J 10/31/89 10:00 2 7.5 22 1 e 2 100 184 1 L S 10/31/89 10:45 1 9.1 22.4 f 1 100 185 1 L C3 5 10/31/89 11:15 a 9.3 23 1 f 3 30 186 1 L C2 5 10/31/89 11:45 4 7.6 24 .5 1 f 4 30 187 1 L C2 5 10/31/89 12:00 5 7.6 24.5 2 f 4 30/B 188 1 L L 5 J 9 10/31/89 12:30 7 7.8 23.5 2 f 3 100 189 2 M C2 5 J 10/31/89 13 : 00 11 6.7 22.8 3 f 3 30/B 190 1 M C2 3 MIX 11/01/89 10:00 0 9.9 23 1 e 1 30/B 191 1 M C1 2 MIX 11/01/89 10:20 o 10.3 23.5 1 e 1 30 192 1 M C1 3 MIX 11/01/89 10:30 o 12 .0 23 1 e 1 30 193 1 M L 3 T 11/01/89 10:50 o 12.0 22 1 e 1 100 194 1 M C2 5 11/01/89 11:30 7 9.4 22.8 1 f 3 30 195 1 L L 5 J .F 11/01/89 12 : 00 5 7.6 23.9 1 f 3 100 196 1 L C2 5 J.F 11/01/89 12:30 5 7.8 24.5 2 f 4 30/B 197 1 L L 2 J.R 5 11/01/89 13:00 5 10.2 25 3 f 2 100 198 2 L L 5 R 6 11/01/89 14:15 12 8.2 25.8 3 f 2 100 199 B L C1 5 J 11/01/89 15:15 12 9.3 26.5 4 f 3 30 200 B L C1 5 J 11/01/89 15:45 11 10.0 29 4 f 4 30 201 1 U L 2 MIX 11/02/89 13: 15 0 8 . 0 23 1 f 1 100 202 M M1 1 11/02/89 14:00 0 8.6 22 2 1 30 203 M C2 2 MIX 11/02/89 14:30 0 10.9 24 . 2 2 2 30/B

Table 3. Tabulated results of seine collections (September· November , 1989) .. other species: threadfin shad (Dorosoma patenense) . SHAD, menhaden (Brevoortia sp.) . MENH, bay anchovy (Anchoa mitchilli)· A-BAY, striped anchovy (Anchoa hepsetus) - A-STR, hardhead catfish (Arius felis) - CATF, diamond killifish (Adinia xenica) . K-DIA, sheepshead killifish (Cyprinodon variegatus) - K·SHD, goldspotted killifish (Floridichthys carpio) - K·GSP, marsh killifish (Fundulus confluentus) - K-MRS, gulf killifish (t. grandis) - K-GUL, Seminole killifish (~seminoli s) - K-SEM, striped killifish (~majalis) - K-STR, longnose killifish (t. similis) - K·LNG, rainwater killifish (Lucania parva) K-RNY, mosquitofish (Gambusia affinis), sailfin mollie (Poeceilia latipinna) - MOLL, inland silverside (Menidia beryllina) - SLV-I, rough silverside (Membras martinica) - SLV-R, striped mojarra (Diapterus plumieri) - S-MOJ, mojarras (Eucinostomus sp.) . MOJA, pinfish (Lagodon rhomboides) - PINF, spot Leiostomus xanthurus)-SPOT, hogchoker (Trinectes maculatus) - HOGC, bluegill (Lepomus macrochirus) - BLUE, gobies (Gobiedae) - GOBY. Qualitative estimates of relative abundance was recorded as: present (P), common (C), or abundant (A).

Station Number SHAD MENH A·BAY A-STR CATF K-DIA K-SHD K·MRS K-GUL K-SEM K-STR K-LNG K-RNY MSQF MOLL SLV-I SLV-R MOJA S-MOJ PINF SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----- ---- --- ---- ---- ----- ---- ---- ---- ---- ---1 A P P A A 2 P 3 A A A P 4 P P P 5 P P P 6 P A C P P 7 P P P P C C P 8 A P P P P P 9 A P

10 P A P P A A P 11 A P A A A 12 A P A A A 13 A A 14 A A 15 A A 16 P A P 17 P A P 18 C A C A P C 19 A A 20 A A 21 A C C A 22 A C C A 23 A C C A 24 P P c 25 P P C 26 C C C C 27 C C C C 28 A A C 29 . A A C 30

, P P P 31 A A P C A c 32 c A P 33 A P 34 A C

Tabl e 3. Continued.

Sta tion Number SHAD MENH A- BAY A- STR CATF K- DI A K- SHD K-MRS K-GUL K- SEM K- STR K- LNG K-RNY MSQF MOLL SLV - I SLV-R MOJA S- MOJ PIN F SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----- ---- --- ---- ---- ------ ---- ---- ---- ---- --- ---35 A C 36 C A A P P P 37 C A A P P P 38 C A A P P P 39 A A A P C P 40 C C A A A P 41 C C A A A P 42 P A A A P P P P 43 P A A A P P P 44 P A A A P P P 45 A A A C 46 C A A C 47 A A C 48 A A C 49 C A A A 50 A A A 51 A C A A 52 A C A A 53 C P 54 P P A A A 55 C C A C 56 C C 57 A A A C 58 A C C C C C 59 A A 60 C C 61 C A A P 62 A A P P 63 C C C A P 64 C C C A P 65 C C C A P 66 P P 67 C P 68 C C P 69 C C P P 70 p P 71 C or C A P P 72 P C P 73 C A C 74 C A P P 75 C C C

Table 3 . Continued.

Station Number SHAD MENH A-BAY A- STR CATF K-DIA K-SHD K-MRS K-GUL K- SEM K-STR K-LNG K-RN~ MSQF MOLL SLV-I SLV-R MOJA S-MOJ PINF SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------ ---- --- ---- ---- ----- ---- ---- ---- ---- ---76 C A A P C 77 P A A C P 78 A P A A C P 79 P P P A A C 80 A A A 81 P P 82 P P P 83 C A P 84 C P P P 85 C C P 86 P P P 87 C C C 88 A C A P 89 A P P 90 C P P 91 P P P P 92 A P 93 P P P 94 P P P P 95 P P P P P 96 P C A A P A P 97 C A A A P 98 P A A P A 99 C P A P

100 A A A C C P 101 P P P P P 102 P P A P A A P A C 103 P A A A C C C 104 P A C A A A 105 C P C P A C P 106 P C P P P A A C 107 A P C P A P C C 108 A A C C A C A 109 P A A P A P C 110 P P P P A P C 111 C A A A P 112 C A A A P P P P C 113 A C C A A C C P 114 A P A A A C P 115 P A A C C 116 A P P A A P P

Table 3. Continued.

Station Number SHAD MENH A-BAY A-STR CATF K-DIA K-SHD K-MRS K-GUL K-SEM K-STR K-LNG K-RNW MSQF MOLL SLV-I SLV-R MOJA S-MOJ PINF SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----- ---- --- ---- ---- ----- ---- ---- ---- ---- --117 A C C P P P P P P 118 C P P P C C A A C P 119 C C P C C A C P P 120 A A A C A C P 121 A C C P P C 122 A A P C P 123 P P A P P P 124 P P A A A 125 A P A P A C 126 P A A A A 127 A A C A C C 128 A P A A P 129 P A A C A C P P P 130 A A 131 C P A C C C 132 A P 133 P P C P A A P P 134 C P 135 C C C 136 A A P A A C P 137 P C P A A P 138 P P A A P 139 A P P P P A A P 140 P P P P P P P P 141 A P P P P P P 142 C P A A 143 P P A C C P 144 C A C A C 145 P A A A P 146 A P A C P 147 C P A C A C 148 A C P C 149 P P P A A P C 150 P C C A A C C 151 A P 152 P C A P P 153 C C A C C 154 A A C 155 A C A C P 156 C C A A C C P 157 C C C C P C P P

Table 3. Continued .

Station Number SHAD MENH A·BAY A- STR CATF K- DIA K-SHD K-MRS K-GUL K- SEM K-STR K-LNG K-RN~ MSQF MOLL SLV-I SLV-R MOJA S-MOJ PINF SPOT HOGC BLUE GOBY

-- -- --- -- -- --- --- --- --- -- -- ---- -- -- -- -- --- --- --- --- ----158 C C C C C P P 159 A C 160 P P P P P P 161 P P P A C 162 P P P C C P P P 163 A+ P P 164 P P A A 165 P A A 166 C P P A A C 167 P C C C P 168 P A A P P 169 A C P A C P 170 A P P C A A C P 171 P C C A A C A 172 A P P 173 P 174 A A A 175 A C A A C P 176 A C P A A P P 177 A C A A C 178 A A P C A A P C 179 A A A A 180 A A A P P 181 A A A 182 183 A P 184 A P C A 185 A C C P 186 A C A 187 A A A 188 P A A 189 C A A C 190 A A 191 A A C C 192 A A 193 . A A A A P 194 ,

A A C 195 C A A C P P 196 A A P P 197 C A A C C P C P 198 P C C P P

Table 3. Continued.

Station Number SHAD MENH A-BAY A-STR CATF K-DIA K-SHD K-MRS K-GUL K-SEM K-STR K-LNG K-RNW MSQF MOLL SLV-I SLV-R MOJA S-MOJ PINF SPOT HOGC BLUE GOBY

199 200 201 202 203

A A A

A

A A A

A A

Table 4. Tabulated results of seine collections (January/February) -- target species . Species abbreviations -- target species : snook (Centrooomus undecimalis) SNK. snook larger than 100 mm SL SNK+. spotted seat rout (Cvnoscion nebulosus) - SPT. sand seatrout {Cynoscion arenarius} - SST. striped mullet (~ ceohalus) HUL . red drum (Sciaenops ocellatus) - ROD. and sheepshead {Archosargus probatoceohalus} -SHD. The number of each target species collected at each station is ind icated . Total number of each target spec i es colleted during the period is given. Tide conditions are presented as 1 = low . 2 = 1/4 . 3 = 1/2. 4 = 3/4. 5 = high. and e = ebbing or f = flooding. Habitat descriptors follow the trinom i al habitat classification system and use the same nomenclature and abbreviations.

No. Zone. Hab i tat TOTAL SNK SNK+ SPT SST HUL ROD Date Time Sal . DO Temp. Tide Sed. Seine Z Sub~ 1 2 3 NO . 6 2 1 1 716 338 {ppt){ppm} {OC} Type {ft}

1 B M El 5 R 2 8 L C2 5 J 3 8 L E2 5 R 4 8 L C3 5 R 5 8 L C2 5 R 6 8 L Cl 5 J 7 8 L L 5 R 8 8 L HI 5 R 9 B L HI 5 R

10 8 L L 5 R 118M L 2 J .R 128M L 2 J . R 13 B H L 5 J 14 8 H L 5 J 15 B M HI 2 J.R 16 8 U E2 3 J 17 B M C2 5 J 182 M L 5 J 192M L 5 R 202M L 5 R 21 2 H /L 5 J 222M /L 5 J . R 232M / L 5 J 24 2 H L 5 J 252M L 5 J 26 2 U L 5 J 27 2 U L 5 J 28 2 U L 2 J 29 2 U L 2 J 301M L 5 J 31 1 H HI 5 J 32 2 U C2 5 J 33 2 U M2 5 J 34 1 L C3 5 J 35 1 L C3 5 J 361M Ml 5 J 371M S 5 J 381M S 5 J 391M SST 40 1 M L 3 T 41 1 H L 1 42 1 L HI 5 J 43 1 H L 5 J 44 1 M L 5 J 45 2 U H2 5 J 46 2 L L 1 47 2 L L 1 48 2 L L 2 S 49 2 L L 2 J 50 2 L L 1 51 2 L L 5 W.R B 52 2 L L 5 W. R.B 53 2 L L 5 W. R 54 2 l H2 5 W.R 55 2 L S 5 R 56 2 l L 5 J 57 SAME AS STATION 58 58 2 _ C2 5 J

4 2

3 11

15

12

10

5 32 10

2 1

10

42 10 16 10 6

14

2

1 9 1

6 35

1 93 30

1

2

-------01/30/90 09 :35 01/31/90 15 : 05 02/01/90 12 : 15 02/01/90 14 : 15 02/01/90 14 : 25 01/22/90 15:30 01/30/90 10:00 02/01/90 13 :25 02/01/90 13: 00 02/01/90 12 :30 01/24/90 09:00 01/24/90 09 : 30 01/29/90 09 :00 01/29/90 09 : 15 02/01/90 11 : 30 01/24/90 09 :50 02/08/90 Og : 15 01/10/90 09:40 01/22 .' 30 12 : 15 01/22190 12:40 01/22/90 14 :00 01/22/90 14:20 01/17/90 12:45 01/17/90 13 : 10 01/17/90 13:35 01/16/90 11 :35 01/16/90 11:50 01/23/90 09 : 15 01/23/90 09 :30 01/23/90 14 :00 01/23/90 13 :35 01/16/90 10 :30 01/29/90 12 : 15 01/24/90 13:30 01/25/90 09:00 01/23/90 11 : 15 01/23/90 11 :45 01 / 23/90 10:45 01 / 23/90 12 : 15 01/23/90 12 :45 01 / 23/90 13: 10 01/11/90 12 : 40 01/29/90 10:00 01/29/90 10 : 15 01/24/90 14: 10 01 / 22/90 09:00 01 / 22/90 Og: 30 01 / 22/90 09:50 01 / 22/90 10: 15 01 / 22/90 10 :40 01/ 22/ 90 11: 20 01/ 22/ 90 12:00 01/15/90 12: 25 01/16/90 08 :25 01/30/90 16:20 01130 / 90 15 :40

15 7.1 20 .3 13 7. 2 25 .0 20 8 .0 23.3 20 6.6 23.5 20 7.2 29 .9 19 8 . 1 23.0 20 7.3 20 .3 20 7. 1 22.5 19 7. 7 4.8 19 8 .3 25.0 8 6. 4 20 . 2 8 6.3 20 .0

11 7. 2 19 . 5 11 7. 2 19 . 5 13 7.9 23 . 5 4 6.2 21.0 7 10 .0 22 . 0

14 6.3 18 . 5 15 8.6 22 .6 15 8 .6 22 . 6 16 7. 2 22 . 0 16 7. 2 22 . 0 15 11.3 19 . 1 13 11.4 19 .0 13 11. 4 19 . 0 11 9 .3 17 . 2 11 9 .3 17.2 5 8 . 0 19 . 2 5 8 . 0 19 . 2 3 10 . 5 21.8 4 11.0 21.6 8 9. 2 16.8 8 10.8 21. 2 6 6.8 21.9 6 7.6 21.0 2 9.2 20 . 1 2 9. 2 20 . 1 2 9 .2 20.1 2 9.2 20.1 3 10 . 1 21. 2 3 10.1 21.2 o 8.8 19 .0 5 8 . 3 19 .0 5 8.3 19 .0

10 6 .3 22 .0 20 8 .3 20 .1 20 8.3 20.1 20 8 .3 20. 1 20 8.3 20.8 20 8 .3 20.8 187 .6 21. 8 187 . 621.8 15 10 .8 16 .1 17 9 .3 ~ 5 . 5 20 8 .3 22 . 2 21 9 . 2 23 2

01 / 16/90 08:40 17 9 6 15 . 5

1 e 3 f 1 f 3 f 3 f 3 f 1 e 2 f 2 f 1 f 1 e 1 f 2 f 2 f 1 e 1 f 1 e 1 f

1. 5 f 1. 5 f

2 f 2 f 1 e 1 f 1 f 1 e 1 e 1 e 1 e 3 f 3 f 2 e 1 f 2 f 1 e

. 5 f 2 f

1. 5 f 2 f

1. 5 f 1. 5 f 2. 5 f

1 e 1 e 3 f 1 f 1 f 1 1 f 1 f

. 5

.5 f 1 3 e 3 f 3

3 e

3 4 4 4 4 3 3 3 3 3 2 2 2 2 1 3

3.5 3 2 2 2 2 1 1 1 3 3 3 3 2 1 2 2 2 3 3 3 3 3 2 2 1 1 1 2 1 1 2 2 2 2 2 3 3 4

3

100 30

100 30 30 30

100 30 30

100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 30 30 30 30 30 30

100 100 100 100 30

100 100 100 00

100 100 100 100 100 100 100 ' : 00 100 100

30

Table 4. Continued.

No. Zone. Habitat SNK SNK+ SPT SST HUL ROD Date Time Sal. DO Temp. Tide Sed. Se ine TSub 1 2 3 (ppt)(ppm) (OC) Type (ft)

------- ------ ---- -- ------

59 2 H HI 5 J 01/24/90 15:00 14 6. 7 22.0 3 f 2 30 60 2 H C1 5 J 01/11/90 14:55 14 8 .7 19.0 3.5 f 3 30 61 NOT SAMPLED DURING THIS PERIOD 62 1 L S 3 J 01/31/90 1l:0-L 9 7.3 21.0 1 f 2 30 63 1 L C3 3 JfT 12 01/24/90 13:00 6 7.821.5 2 f 1 100 64 1 L S 10 01 / 31/90 10:40 11 7. 2 20 .9 1 e 1 30 65 1 L S 5 J 1 01/29/90 10 : 40 9 8 .9 20.5 1 f 1 30 66 1 L C3 5 T 01/10/90 12 : 00 6 6.6 19.1 1. 5 f 2 100 67 1 U L 3 HIX 01/25/90 12:00 0 7. 2 20.5 1. 5 f 1 30 68 1 U L 3 HIX 01/25/90 12 : 15 0 7. 2 20 . 5 1.5 • 1 30 I

69 1 U HI 3 HIX 01/25/90 12 :30 0 7.2 20.5 1.5 f 1 30 70 NOT SAHPLED DURI NG THIS PERIOD 71 1 U L 1 01/25/90 12:50 0 7.3 20 .0 2.5 f 30 72 1 U L 3 HIX 01/25/90 13 : 00 0 7.3 20.0 2. 5 f 30 73 1 U HI 1 01/25/90 13 : 15 0 7.2 20.0 3 f 30 74 1 M L 3 HIX 01/25/90 10: 10 0 7. 5 19 . 1 1 • 100 I

75 1 M L 3 HIX 01/25/90 10: 15 0 7. 7 20 .5 1 f 1 30 76 1 H L 3 MIX 01/25/90 10:30 0 7. 7 20.5 1 f 1 30 77 1 H S 2 HIX 01/25/90 13 : 45 0 8 . 2 21.8 3 f 1 30 78 1 t~ H2 2 HIX 01/25/90 14: 15 0 3.2 21.8 3 f 1 30 79 1 L L 1 01/10/90 11: 40 7 5.3 18.7 1 f 2 100 80 2 U L 2 J 01/10/90 11:00 5 6.8 19 .8 1 f 1 100 81 2 U C3 5 J 1 01/31/90 12: 40 7 6.3 23 . 1 2 f 4 30 82 2 U H2 5 J 1 02/01/90 16 :30 15 9 .0 23 .9 4 f 3 30 83 2 U H2 5 J 5 01/29/90 14:20 15 8.5 22.0 3 f 3 30 84 2 U HI 5 J 01/29/90 14:00 12 8.0 23 . 0 3 f 3 30 85 2 U HI 5 J 16 01/29/90 15:00 15 8 .8 22 . 1 3 f 3 30 86 2 U HI 5 J 3 01/29/90 15 :30 15 8 .8 22 . 1 3 f 3 30 87 2 U H2 5 J 01/22/90 14:45 15 8 .0 22.0 2.5 f 2 30 88 2 U H2 5 J . R 01/16/90 11:00 10 8.8 16.8 1. 5 e 3 30 89 2 U H2 5 J 14 01/29/90 13:45 12 9 . 1 22. 1 2. 5 f 3 30 90 2 U HI 3 J 01/29/90 12:40 12 8 . 5 21.2 1 f 3 30 91 2 U HI 5 J 01/29/90 12:55 15 6.6 23 . 2 2 - 3 30 92 2 U H2 5 R.J 14 01/29/90 13:20 15 8 . 6 20 . 2 2 f 3 30 93 2 H H2 5 J 2 01/24/90 15 : 15 15 8 .3 25 . 1 3 f 4 30 94 2 M HI 3 J 8 01/31/90 12:00 15 8 . 5 21.0 1 f 3 30 95 2 H HI 5 J 01/31/90 11:30 12 7.6 21.0 1 f 2 30 96 B U C2 5 J 01/12/90 08 : 30 2 7. 1 14 . 5 1. 5 e 4 30 97 B U C2 3 J 01/12/90 08 : 45 2 5. 6 15 .3 1 e 2 30 S8 B U 0 01/12/90 09:00 0 7.8 15. 1 1 e 2 100 99 B U /L 5 J 01/12/90 09:25 4 8 .8 16 .8 1 e 3 100

100 B U L 1 01/09/90 11 : 45 0 6 .8 19.0 1.5 f 2 100 101 B U C2 2 J 01/09/90 12 : 55 2 8 .8 20 .0 1. 5 f 2 30 102 B H L 3 T 01/15/90 10 : 15 6 9 .3 15 .8 1. 5 e 2 100 103 8 M C2 5 J 01 / 31 / 90 17:00 14 8 . 1 23 . 2 4 f 3 30 104 B H 07 5 R 01/15/ 90 10:55 7 9 . 1 15.0 1 e 1 100 105 B H / L 5 J 01/09/90 09:00 4 6. 1 16 . 7 1 f 1 100 106 B H / L 5 J 01/15/90 10: 30 8 9 .3 16 .0 5 e 3 00 107 B M /L 5 J 01/09/90 10 : 25 2 7. 1 16 .2 1 f 2 100 108 B U / L 5 J 01 / 09/90 10: 50 0 6.9 17. 5 1 f 2 100 109 B U / L 5 J 38 01/1 5/90 08 : 55 4 9 .8 lJ . 2 2 e 2 100 110 8 U L 2 AfT 01 / 09/90 11 : 15 2 7.9 17. 2 . 5 f 2 100 111 B L L 4 R.J 01/09/90 13 : 50 15 6 . -+ 20 .9 3 f 3 100 112 B L L 5 J 01/18/ 90 10:50 17 8 .3 19.1 2 5 e 2 100 113 a L L 3 J .R 01/1 5/90 15 : 15 18 9 . S 9 .9 2 f 3 100 114 B L L 5 J 01/15/90 15 :40 18 9 . 1 21. C 2. 5 f d 100

15 B L / L 5 J 01/17 / 90 08 : 20 15 6 .0 16 .6 3 e 3 100 116 2 M 5 J 01 / 10/90 10:30 12 6. -+ 19 .0 1 f 3 100 117 2 U L 5 J 360 3 01/17 / 90 10:45 16 10 .8 19 .0 2 e 3 100

18 2 U L 3 J 2 02 / 08/90 13 :00 16 9 .3 21.0 <; : • J I 3 1 0

119 2 U L 2 J 5 01/17/90 14: 00 12 2.J 20 .C . 5 f -l 100 120 2 U M2 5 J 01/16/ 90 11 : 25 9 8 .B 16.8 5 e 2 30

21 2 U Ml 5 J 01 / 17 / 90 15:00 10 1.3 19 .0 3 3 30 122 2 U C2 3 J 01/24/90 13 : 50 9 7.2 23.0 2 5 f 3 30 123 2 C2 5 J 01/ 31 / 90 12 : 25 12 8 .3 21.2 1 4 30

Table 4. Continued.

No. Zone. Hab i tat SNK SNK+ SPT SST HUL ROD Date Time Sal. DO Temp . Tide Sed . Seine --zsub 1 2 3 (ppt )( ppm) (OC) Type (ft)

- ------ ----------- -- - - -- ------

124 2 L H2 3 J .R 51 01/30/90 13:35 16 9 .3 22 . 4 2. 5 f 2 30 125 2 L C2 3 S 01/12/90 13:30 20 9 . 1 19 . 5 3 f 2 30 126 B H Cl 5 J 01/12/90 14:20 17 8 . 0 19 .0 3.5 f 3 30 127 B H C1 5 J 01/16/90 14 : 45 16 8 . 0 20 .5 2 f 4 30 128 B H C2 5 J 01/08/90 13: 20 16 6. 5 20 . 5 3 f 4 30 129 B H H3 5 J 01/18/90 09 : 50 5 8 . 5 18 .5 3 e 3 30 130 1 L L 5 J 01/10/90 12:20 5 6. 6 17 .8 1. 5 f 3 100 131 1 L H2 2 J 01/11/90 13 : 30 2 7.6 18 .2 3 f 3 30 132 1 L Cl 5 J . F 01/11/90 14: 30 6 7.2 23 .0 3. 5 F 4 30 133 1 L L 2 J 01/30/90 12:00 9 8.1 21.2 2 f 3 100 134 B L L A 01/12/90 10 :00 14 8 .0 18 .0 1 e 3 100 13 5 B H L 2 J 01/08/90 13 :05 19 6.3 20 . 5 1 f 1 100 136 B U L 2 J 01/15/90 09 :30 3 7. 6 16.0 1. 5 e 2 100 137 B H C3 5 R 01/12/90 14 : 00 16 8 . 2 19. 0 3. 5 f 3 30 138 B H L 5 R 01/09/90 08: 15 9 5.8 19 .0 1 f 4 100 139 B L L 2 R. J 01/12/90 11 :00 18 8 .8 17 . 2 1 f 2 100 140 B L L 2 SIR 01/1 5/90 14:40 17 10.7 20 .0 2. 5 f 2 100 141 B L C3 5 J 01/31/90 14 :00 18 7. 5 23 . 0 3 f 4 30 142 B L L 2 R.J 01/08/90 12:45 16 8 .8 20 .9 3 f 2 100 143 B H L 2 J 01/09/90 09: 15 6 7. 4 17. 0 1 f 2 100 144 B U L 3 J/ F 01/09/90 12: 15 0 8 .3 18 .8 2 f 2 100 145 B U L 3 J 2 02/08/90 09:4 5 13 9 .3 19 . 5 1 f 3 100 146 B U L 2 T.J 01/09/90 12 :05 1 7.9 17 . 5 2 f 2 100 147 B H C3 5 J 01/1 5/90 08 : 20 5 8 .6 14 .2 2. 5 e 2 30 148 B H M1 5 J 01/15/90 08: 40 3 8 .3 15.2 2. 5 e 3 30 149 B M L 3 J 01/09/90 10:00 4 6. 5 17.0 1 f 2 100 150 B M L 2 J 6 01/09/90 09 :30 2 6. 7 16 .9 1 f 2 100 151 B H A 1 SEAIIALL 01/18/90 09 : 20 9 8 . 6 17 .8 4 e 3 100 152 B M C3 5 R. 'J 01/31/90 16:40 15 7. 0 22 .9 4 f 3 30 153 B M L 4 R.J 01/18/90 08: 25 15 6 .4 18 .0 5 e 3 100 154 B L C3 5 R 02/01/90 14 : 45 20 6.8 22 . 5 3 f 1 30 155 2 L L 5 R/B 01 / 15/90 12 :00 15 9 .0 15. 5 1 f 2 100 156 2 H L 5 R. B 01/17/90 09:40 18 10 . 7 18 .0 2 e 2 100 157 2 .'1 L 4 R. J 2 01/30/90 12 :40 13 8 .8 227 2.5 f 3 100 158 2 H L 4 R. J 01/16/90 12 : 30 13 9 . 4 17. 5 1 e 3 100 159 2 M M3 5 R 56 02/08/90 12 : 20 18 9 .3 23 .0 1.5 f 4 30 160 2 L L 3 J 01/15/90 13 : 20 19 10 .2 17.0 2 f 1 100 161 2 H L 3 J 01 / 24/90 14 :35 15 8 . 0 24.0 3 f 2 100 162 2 H L 2 J.R 01/10/90 14:25 8 7.6 19.4 3.5 & 3 100 . 163 2 L A 1 01 / 15/90 14 :20 16 8 .9 17. 5 2 f 3 100 164 1 H L 3 J .F 01/11/90 10:05 3 7. 7 17 .8 1 f 1 00 165 1 L L 2 J 01/11/90 09 : 50 5 9 .3 18.8 1 f 2 100 166 1 L 0 01/11/90 09:20 3 7.2 17 .8 1 e 1 100 167 2 M L 2 J 01/22/90 13 : 20 16 6 .8 22.6 2 f 2 100 168 2 H L 3 J/R 01/16/90 13 : 20 18 9 .8 18 . 5 1 & 3 1CO , 169 3 U L 3 R.II 01/12/90 12:00 22 8 .4 18 .0 1. 5 f 2 100 170 3 U HI 3 R/B 02/01/90 15:30 20 8 . 2 21.5 <1 f 1 30 171 3 U C2 3 R/ B 01/12/90 13 : 00 24 8 .8 18 .3 2 f 2 30 172 B L S 01 /1 0/90 08: 30 13 5 .8 18 .0 1 e 2 100 173 B L 0 01/10/90 08: 15 12 5.9 17 .9 1 e 2 100 174 3 U L 3 R/ B 01/17 / 90 08 : 55 10 8 .0 17 o 2 5 e 3 100 175 3 U L 2 R/II 01/12/90 12: 45 26 9 . 4 19 6 2 f 2 10' 176 3 U L 5 R/B / II 01/16/90 14: 10 23 10 . 4 19 2 2 - 2 100 177 2 L H3 3 J/ II .R 21 01 / 30/90 14 : 10 18 8 .3 22 . 1 3 2 30 178 2 L L 3 J .II / R 01/15/ 90 12 : 50 20 11.0 :8 . 0 . - 2 100 179 2 L H3 5 J 01/3 0/ 90 14 : 30 20 9 .3 Z3 0 2 30 180 2 L C3 5 J 22 01/30/90 15 :20 21 8 .3 25 .0 .1 30 181 2 L Cl 5 J 01 / 30/ 90 15 :00 20 8 . 7 2.1 . 2 3 3C 182 2 0 01/10/90 09 :00 14 7.2 17 .8 lOa 183 1 L L 2 T/J 01/10/90 13: 10 4 6 . 1 17 . a 5 00 184 L S 01/10/90 13: 40 4 6.8 10 . 7 2 lGG 185 L C3 5 J 01 / 11 / 90 13: 45 3 8.9 19 . 2 3 f 3 30 186 L C2 5 J 01 / 23 /9 0 14:35 3 4. 5 22.0 3 .y.: 187 L C2 5 01/ 23 / 90 14 :1 5 4 14 . 5 22 . 2 f 3 ~-188 L L 5 J 01 / 23 / 90 09: 50 5 10.6 19 .1 f 3 GO

Ta ble 4. Continued.

No. Zone . Habitat SNK SNK+ SPT SST MUL ROD Date Ti me Sa 1. DO Temp. Ti de Sed . Seine TSlJb 1 2 3 (ppt)(ppm) (OC) Type (ft)

------- ----------- ---- - -- ------189 2 M C2 5 J 01/31/90 13 :30 11 7.7 21.5 3 f 3 30 190 1 M C2 3 MIX 01/11/90 12:00 0 8 .6 19 .0 2 & 2 30 I

191 1 M Cl 2 MIX 02/08/90 14 : 15 0 9.3 21.0 2. 5 f 1 30 192 1 M Ml 3 MIX 02/08/90 14:00 0 9 .0 22.0 2 f 1 100 193 1 M L 3 T 01/11/90 11 :00 0 8 . 7 18 . 5 1.5 f 1 100 194 1 L C2 5 J 01/31/90 13:00 7 7.5 20 .·6 2 f 4 30 195 1 L L 5 J.F 01/10/90 14 : 00 4 6.3 18 .6 3 f 2 100 196 1 L C2 5 J . F 01/11/00 14 : 10 3 8 .2 19. 3 3 f 3 30 197 1 L L 2 J.R 01/10/90 12 : 45 4 6.5 17.8 1.5 f 2 100 198 2 L L 5 R 01/30/90 16 :00 20 8 .3 22 .9 3 f 4 100 199 B L Cl 5 J 01/31/90 14 :25 18 7 . 5 23 . 0 3 f 3 30 200 B L Cl 5 J 01/31/90 16 : 00 15 8.7 25 .0 4 f 4 30 201 1 U L 2 MIX 01/25/90 11 : 15 0 7. 7 20 .5 1. 5 f 1 30 202 1 M Ml 1 01/25/90 11: 00 0 7.1 19 .0 1. 5 f 1 30 203 1 M C2 2 MIX 01/11 / 90 11:35 0 8 .2 18.0 1. 5 f 2 30 204 2 U E2 1 1 Z7 2 01/17/90 14: 40 10 1l .S 18 . 5 2.5 f 3 100 205 B L 0 02/08/90 11:21 14 7. 7 21 .0 1 f 1 100 206 2 L /0 02/ 08/90 11: 50 18 10 .9 21 .0 1 f 1 100

Table 5. Tabulated results of seine collections (January/february, 1990) -- other species: threadfin shad (Oorosoma patenense) - SHAD, menhaden (Brevoortia sp.) - MENH, bay anchovy (Anchoa mitchilli) - A-BAY, striped anchovy (Anchoa hepsetus) - A-STR, hardhead catfish (Arius felis) - CAlf, diamond killifish (Adinia xenica) -K-OJA, sheepshead killifish (Cyprinodon variegatlls) - K-SHO, goldspotted killifish (floridichthys carpio) - K-GSP, marsh killifish (fundulus confluentus) - K-HRS, gulf killifish (~ gr andis) . K-GUl, Seminole killifish (f. seminoli s ) - K-SEH, striped killifish (f. majalis) - K-STR, longnose killifish (f. similis) - K-lNG, rain~ater killifish (lucania parva) -K-RNIoI, mosquitofish (Gambus ia affinis), sailf.in mollie (Poeceilia latipinna) - HOll, inland silverside (Henidia beryllina) - SlV-J, rough silverside (Hen~ras martinica) - SlV -R, striped mojarra (Oiapterus plumieri) - S-HOJ, mojarras (Eucinostomus sp.) - HOJA, pinfish (lagodon rh~oboides) - PJNf, spot leiostomus xanthurus) - SPOT, hogchoker (Trinectes maculatus) - HOGC, bluegill (lepomus macrochirus) - BLUE, gobies (Gobiedae) - GOBY. Qualitative estimates of relative abundance ~as recorded as: present (P), common (el, or abundant (A).

Station Number

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

HENH A-BAY A-STR K-SHO K-GSP K-MRS K-GUl K-SEM K-lNG K-RNIoI MSQf MOll SlV-J SlV-R S-MOJ MOJA PJNF SPOT HOGe BLUE GOBY

A

A P

A

P P

A A

A e

A

A A

P

e C P P

A A A

A A

P A

A C

A

P A A

P

A A A A e P A

P

P P

2

A P

A P P C

A P A P C A A A

A A

P C

P P C P A

C P A A e

P A P

P A P A A C A P

e A C A A A e

e C A

A e A A C A P C

e A A P e A A A A P C A A A A A A e e P A C A C A A A

P A A

C P P

A

A A A

P P

e

P P P

P P P

P

c

P

A

P

A P

A

Tabl e 5. Continued.

St ati on Number MENH A-BAY A-STR K- SHD K-GSP K-MRS K-GUL K-SEM K- LNG K-RNU HSQF HOLL SLV - I SLV -R S-MOJ HOJA PINF SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----33 P C 34 P P A P 35 A A A A A C 36 A A P P 37 A P C 38 P C 39 A C C C A A C 40 A P A A P P 41 A P A A P P 42 A P A P 43 A A A 44 A A A A P 45 C C C A C A 46 A A A A P 47 C C A P 48 A A A C P 49 C A A C C P 50 P A P P 51 P 52 A 53 C P P P C C 54 P 55 C A A P 56 A A P 57 58 A P 59 60 P P 61 NOT SAMPLED 62 P P P 63 P P A 64 P A 65 C P A P 66 P C P C 67 A C 68 A P 69 A 70 71 P A 72 P A

Table 5. Continued.

Station NlSIiJer MENH A·BAY A·STR K-SHD K-GSP K-MRS K-GUL K-SEH K-LNG K-RNU MSQF MOLL SLV-I SLV-R S-MOJ HOJA PINF SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----73 A A A 74 75 A P P 76 A C 77 A P 78 A P P A 79 A A C 80 C P A P A 81 C P A A 82 p P C C 83 C P C P 84 A C A 85 P C C 86 A A 87 A A P A C A 88 A P P C 89 C C C A 90 A P P A A 91 A P C P 92 C A C C 93 A P C 94 P c 95 C P P P 96 C P P A A 97 P P 98 C P A P 99 C A A C P

100 P C P A C P A P P 101 P P P 102 P p A P P P 103 A A A C 104 P P A A C P P C P 105 C P C P C C 106 C P P A P C C P 107 A P A A P 108 A P P A C P p

109 p p A C P P P 110 C p C P P 111 A C C C 112 C P P P

Tabl e 5. Continued .

St a ti on NUlt>e r MENH A-BAY A- STR K-SHD K- GSP K- MRS K-GUL K- SEM K-LNG K-RNY MSQF MOLL SLV-I SLV-R S-MOJ MOJA PINF SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----113 A P A A 11 4 A P P A C 11 5 A A P 11 6 A P C C P 11 7 P A P C P 118· P C P 11 9 P C C A A 120 A P C P 121 C P P 122 P C P A C C 123 C 124 A C C A A 125 A A C C 126 P P 127 P P P P 128 C P P P 129 p P P 130 C P P C P A A 131 A P C A 132 A P C 133 P 134 A P 135 P C P P P 136 A C P P 137 A A P 138 P P C P P C P 139 A A P 140 P P C A P 141 A 142 A P P 143 P C C P 144 A C C A C 145 P A C A A P 146 P P P P P 147 P 148 P A P 149 P P A P 150 A A C A P 151 P P C C 152 11 P P

Table 5 . Continued.

Stat i on Nl.t1Der MENH A-BAY A-STR ( - SHD (-GSP ( -MRS (-GUL (-SEM (-LNG (-RNY MSQF MOLL SLV-) SLV-R S-MOJ MOJA P)NF SPOT HOGC BLUE GOBY

---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----

153 P P C A 154 P A A 155 p C C A 156 A P A C 157 P P 158 A P P A A A 159 P A 160 P C A 161 P C A A 162 C C A A 163 P C A 164 A A P P 165 C p A A P 166 C A P P 167 A 168 C A 169 C A P 170 A P A A 171 P P 172 A 173 p p P A C P 174 P P 175 A A P A 176 A A C P 177 C P P C p

178 C P A A P 179 A A 180 P C C 181 P A A A 182 A P 183 A P P P A 184 C P A P C C C 185 p p

186 A C 187 p C P C C P 188 P C P A P 189 C A C 190 p P 191 C C A P 192 A C A C P P

Tabl e S. Continued.

St at ion Number HENH A- BAY A-STR K-SHD K-GSP K-HRS K-GUL K-SEH K- LNG K-RNY HSQF HOLL SLV - l SLV -R S-HOJ HOJA PINF SPOT HOGC BLUE GOBY

193 194 195 196 197 198 199 200 20 1 202 203 204 205 206

C

A P A

A

C

P C

P

P

C

A C P A C

P A A A A

A

C

P C C C P C C P C A P

A P P

A C C

P P

A P

Table 6. Tabulated result s of seine collections (January/February, 1990) sorted in decl i ning order of red drum abundance for a ll s t ati ons where red drum where coll ected . Spec ies abbrevi ations - - target spec ies: snook (Cent ropomus undecimal is ) - SNK, snook larger than 100 mm SL SN K+ , spot t ed sea t rout (Cynoscion nebulosus ) - SPT, s and seat rout (Cynoscion arenarius ) - SST , s triped mullet (Mugil cephalus ) - MUL , red drum (Sciaenops ocellatus ) - ROD, and sheepshead (Archosargus probatocephal us ) - SHOo The number of each t arget species collected at each sta t i on i s indicated .

No . Z Sub 2 3 SNK SNK+ SPT SST MUL ROD Date Time Sal. DO Temp. Tide Sed. Se ine TOTAL 4 2 0 1 437 338 (Coll ection) (ppt) (ppm) (C) Type ( f t)

-- ---- ----48 2 L L 2 S 93 01/22/90 09:50 20 8.3 20. 1 1 f 2 100 21 2 M /L 5 42 01/22/90 14:00 16 7.2 22.0 2 f 2 100 17 B M C2 5 4 2 32 02/08/90 09: 15 7 10.0 22.0 1 e 3.5 100 23 2 M / L 5 J 16 01/17/90 12:45 15 11.3 19.1 1 e 1 100 31 1 M Ml 5 J 14 01/23/90 13:35 4 11.0 21.6 3 f 1 100 89 2 U M2 5 14 01/29/90 13:45 12 9.1 22.1 2. 5 f 3 30 92 U 2 M2 5 R.J 14 01/29/90 13: 20 15 8 .6 20 . 2 2 f 3 30 3 B L E2 5 R 12 02/01/90 12 : 15 20 8 . 0 23 . 3 1 f 4 100

24 2 M L 5 J 10 01/17/90 13 : 10 13 11.4 19.0 1 f 1 100 18 2 M L 5 J 10 01/10/90 09 :40 14 6.3 18.5 1 f 3 100 14 B M L 5 10 01/29/90 09 : 15 11 7.2 19.5 2 f 2 100 22 2 M /L 5 J.R 10 01/22/90 14 :20 16 7.2 22 . 0 2 f 2 100 46 2 L L 1 6 01/22/90 09 : 00 20 8 . 3 20 . 1 1 f 1 100

150 B M L 2 J 6 01/09/90 09:30 2 6.7 16.9 1 f 2 100 25 2 M L 5 6 01/17/90 13 :35 13 11. 4 19.0 f 1 100 16 B U E2 3 J 5 01/24/90 09: 50 4 6 . 2 21.0 1 f 3 100 83 2 U M2 5 J 5 01/29/90 14:20 15 8.5 22. 0 3 f 3 30

117 2 U L 5 J 360 3 01/17/90 10 :45 16 10.8 19.0 2 e 3 100 204 2 U E2 1 27 2 01/17/ 90 14:40 10 11 . 8 18 . 5 2. 5 f 3 100 118 2 U L 3 2 02/08/90 13: 00 16 9 .3 21.0 1. 5 f 3 100 145 B U L 3 2 02/ 08/ 90 09:45 13 9. 3 19.5 1 f 3 100 39 1 M S 5 T 2 01/23 /90 12:1 5 2 9.2 20 .1 2 f 3 100 55 2 L S 5 R 2 01/30/90 16:20 20 8.3 22 .2 3 f 4 100

100 B U L 1 01/09/90 11 :45 0 6.8 19 . 0 1. 5 f 2 100 50 2 L L 1 01 / 22/ 90 10:40 20 8 .3 20 .8 1 f 2 100

206 2 L / 0 1 02/08/90 11 :50 18 10.9 21. 0 1 f 1 100 192 1 M Ml 3 MI X 02/08/90 14:00 0 9 . 0 22. 0 2 f 1 100 178 2 L L 3 J .\J/R 01/1 5/90 12:50 20 11 .0 18 .0 1. 5 f 2 100 158 2 M L 4 R. J 01/16/90 12:30 13 9 .4 17. 5 1 e 3 100 44 1 M L 5 01/29/90 10: 15 5 8. 3 19. 0 1 e 1 100

180 2 L C3 5 22 01/30/90 15:20 21 8.3 25 . 0 3 f 4 30 7 B L L 5 R 01/30/90 10:00 20 7.3 20 .3 1 e 3 100

20 2 M L 5 R 2 01/22/90 12:40 15 8 . 6 22 .6 1. 5 f 2 100 66 1 L C3 5 T 01 /1 0/90 12:00 6 6 .6 19.1 1.5 f 2 100

Table 6. Continued.

No. Z Sub 2 3 SNK SNK+ SPT SST MUL ROD Date Time Sal. DO Temp. Tide Sed. Seine TOTAL 4 2 0 1 437 338 (Collection) (ppt) (ppm) (C) Type (it)

-- ---- -----

198 2 L L 5 R 01/30/90 16:00 20 8 . 3 22.9 3 f 4 100 59 2 M Ml 5 J 01/24/90 15:00 14 6.7 22.0 3 f 2 30 10 B L L 5 R 11 02/01/90 12:30 19 8.3 25.0 1 f 3 100

154 B L C3 5 R 02/01/90 14:45 20 6.8 22.5 3 f 4 30 82 2 U M2 5 J 02/01/90 16:30 15 9.0 23 .9 4 f 3 30 34 1 L C3 5 J 01/24/90 13:30 6 6.8 21.9 2 f 2 30 81 2 U C3 5 J 01/31/90 12:40 7 6.3 23.1 2 f 4 30 9 B L Ml 5 R 3 02/01/90 13:00 19 7. 7 4.8 2 f 3 30

45 2 U M2 5 9 01/24/90 14: 10 10 6.3 22.0 3 f 2 100

Figure 1. Simple input-output model diagram of estuarine nursery hab i tat.

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Figure 3. MRES study area map, showing zones (1-3) and subzones (U upper, M = middle, L = Lower).

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~ Uplands

t~~;i Shoals

____ ~~ __________ ih~~~~~ __________ ~~~M~;;angroves

Figure 6. Schematic examples of intertidal morphological categories used in the classification system. All examples, except for the altered (A) case , are shown for linear (L) shorelines. Vegetational descriptors are not written out on the f igures. The L-2 example is L-2-R and the L-S example is L-S-J . Dashed and solid lines represent approximate MHW and MLW, respectively.

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Figure 7. Schematic plan view examples of linear upland shorelines with patchily-distributed marsh vegetation (L-2) and of upland shorelines with continuous marsh fringe (L-3) . Dashed and solid lines represent approximate MHW and MLW, respectively.

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Figure 8 . Locations of EJ spotted seatrout catches during the fall sampling period. Number of spotted seatrout collected at each station is indicated by the follow i ng symbols:

0=1, e = 2-3, EB = 4-10, • = 11-30. Maps are presented only for those areas where EJ spotted seatrout were collected. Match lines for adjoining, overlapping sheets are provided, and only those stations falling within the match lines are plotted on each sheet.

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Figure 9. Locations of EJ sand seatrout catches during the fall sampl ing period. Number of sand seatrout collected at each station is indicated by the following symbols: o = 1-3, e = 4-10, EB = 11-20, • = 21-150. Maps are presented only for those areas where EJ sand seatrout were collected. Match lines for adjoining, overlapping sheets are provided, and only those stations falling within the match lines are plotted on each sheet.

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Figure 10. Distribution, relative to salinity, of EJ snook (SNK), spotted seatrout (SPT) and sand seatrout (SST) collected in the Manatee River Estuary System during the fall sampling period.

100

90

80

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Vers us Coil ectio n Sa Iinity

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Sa linity ( ppt) tZ:Zl SPT

12-15 1 6-1 9

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20- 23

Figure 11. Distributions of salinities at fall sampling period stations. Total number of stations within each range is indicated above each bar.

Sampling Station Salinity Fall. 1989

100

90

80

70 <Il C 0 :;:; 60 .B 106 (f)

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0 V/~//I V/ ~//l V/-<//1 V/{//l ? 2 I

0-3 4-7 8-11 12-15 16-19 20-23

Salinity (PPT)

Figure 12. Relative abundances of EJ snook (SNK), spotted seatrout (SPT) and sand seatrout (SST) collected in the Manatee River Estuary System during the fall sampling period. Relative abundances were calculated by dividing the number of individuals collected in a salinity range by the number of stations sampled in a salinity range, and expressing the results for each range as a percentage of the total . .

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8-11

Sal inity (PPT) ~ SPT

12-15 16-19 20-23

~ SST

Figure 13. Locations of EJ snook catches during the fall sampling period. Number of snook collected at. each station is indicated by the following symbols:

() = 1, E1 = 2-3, E9 = 4, tt = 15 . . Maps are presented only for those areas where EJ snook were collected. Match lines for adjoining, overlapping sheets are provided, and only those stations falling within the match lines are plotted on each sheet.

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Figure 14. Salinity in the MRES on 2/8/90. Mid-river salinity was measured at the surface and bottom (i n parentheses) between 1400 hrs and 1545 hrs, starting upstream in the Manatee River. High tide (37 cm at St. Petersburg» was at Redfish Point was predicted (NOAA Tide Tables) to occur at 1514 hrs on this date.

Figure 15. Locations of EJ red drum catches during the winter sampling period. Number of red drum collected at each station is indicated by the following symbols: . 0 = 1-3, 8 = 4-10, EB '" 11-20, • '" 21-93.

Maps are presented only for those areas where EJ red drum were collected. Match lines for adjoining, overlapping sheets are provided, and only those stations falling within the match lines are plotted on each sheet.

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Figure 16. Adjusted length frequencies of red drum collected during the winter sampling period.

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ADJUSTED LENGTH FREOUENCY RED DRUM

Call eet e d Jon .. - Feb .. , 1990

r-r-

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10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 ADJUSTED STANDARD LENGTH (rnm)

Figure 17. Locations of EJ striped mullet catches during the winter sampling period. Number of striped mullet collected at each station is indicated by the foll owi ng symbol s: .

0=1-3, e = 4-10, .E9 = 11-20, • = 21-360. Maps are presented only for those areas wiiere EJ snook were collected. Match lines for adjoining, overlapping sheets are provided, and only those stations falling within the match lines are plotted on each sheet~

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Figure 18. Catch distribution by salinity of re"d drum and striped mullet collected during the winter sampling period.

0

~ L..) UJ ---.l ---.l

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CATCH DISTRIBUTION BY SALINITY

800 .---, ----,-------------------..,---.. tL1 RED DRUM g STRIFED MULLET ID STAT10NS

600 1-571

400

200

o V",'1'1=====I !t"1~Lt-=---t II I I///~ II II I///l=-J II ~ I ~~ I ,'I j!

o to 5 6 to 10 11 to 15 16 Lo 2J 21 to 26 5 AL1NITY RA NGE (PPTl

Figure 19. Total flow (spillway plus toe drain discharges) from the Lake Manatee Dam during July through October, 1989. Source: Manatee County consumptive use permit reports to SWFWMD.

(f) LL o

Lake Manatee Discharge (Spillway + Toe Drain)

260

240

220

200

180

160

140

120

100

80

60

40

20

o III I I II I I TI I I II I I II I I II I I II I I II I I II T I II I II I I I II r I II I I I I I II I I n I I II I I II I I I I I I' I I II I I I I II I II I I I I I". I (I I Y I I I {I I III I TI I I I I I I I I I I

July August Sept. October

Date

APPENDICES

APPENDIX A.

HABITAT MAP AND SAMPLING STATION CROSS REFERENCE LIST

SAMPLING MAP SAMPLING MAP STATION NO. SHEET NO. STATION NO. SHEET NO.

001 51C4 049 50B4 002 4204 050 5084 003 41C2 051 50B3 004 51C2 052 50A3 005 51C2 053 50A4 006 4201 054 50A4 007 51C2 055 5002 008 51C2 056 5001 009 51C2 057 5001 010 51C2 058 5001 011 51C4 059 59A4 012 51C4 060 59A4 013 5103 061 68A 014 5103 062 68A 015 52A 063 68A 016 53A 064 68A 017 520 065 68A 018 58C3 066 68A 019 5982 067 860 020 5982 068 860 021 58C4 069 860 022 58C4 070 860 023 58C4 071 860 024 59A2 072 860 025 59A2 073 868 026 688 074 868 027 688 075 868 028 688 076 868 029 688 077 868 030 778 078 868 031 778 079 68A 032 59A4 080 86A 033 688 081 688 034 68A 082 59A4 035 68A 083 67C 036 778 084 67C 037 778 085 59A2 038 778 086 59A2 039 778 087 59A2 040 778 088 688 041 778 089 5901 042 778 090 59A4 043 778 091 59A4 044 778 092 59A3 045 59A4 093 58C3 046 50C3 094 58C4 047 50C3 095 58C4 048 50C3 096 53A

SAMPLING MAP SAMPLING MAP STATION NO. SHEET NO. STATION NO. SHEET NO.

097 53A 145 520 098 53A 146 520 099 520 147 520 100 520 148 520 101 520 149 520 102 52A 150 52A 103 52A 151 52A 104 5103 152 52A 105 52A 153 52A 106 52A 154 50A3 107 520 154 51Cl 108 520 155 50A3 109 520 156 5984 110 520 157 5984 111 SIC 1 158 59A3 112 5201 159 5981 113 51C2 160 58C4 114 51C3 161 58C4 115 51C3 162 58C4 116 67C 163 5903 117 59Al 164 778 118 59Al 165 778 119 688 166 778 120 688 167 58C4 121 688 168 58C3 122 688 169 41C2 123 68B 170 41C1 124 50A4 171 41C1 125 50C1 172 42A4 126 51C1 173 42A4 127 51C1 174 3201 128 51C4 175 41Cl 129 520 176 41A3 130 68A 177 50A4 131 77B 178 50A4 132 68A 179 5001 133 68A 180 5001 134 42A4 181 5001 135 51Cl 182 SOB 1 136 520 183 68A 137 51C4 184 778 138 51C4 185 77B 139 4201 186 68A 140 4204 187 68A 141 4204 188 68A 142 51C2 189 59A2 143 52A 190 77A 144 53A 191 77A

SAMPLING MAP STATION NO. SHEET NO .

192 77A 193 77A 194 778 195 68A 196 68A 197 68A 198 4204 199 4204 200 51C3 201 868 202 77A 203 77 A

MAP SAMPLING MAP SAMPLING SHEET NO. STATION NO. SHEET NO. STATION NO.

3201 174 50C3 046 047

41A3 176 048

41Cl 170 5001 056 171 057 175 058

179 41C2 003 180

169 181

42A4 134 5002 055 172 173 51Cl 111

126 4201 006 127

139 135 154

4204 002 140 51C2 004 141 005 198 007 199 008

009 50A3 052 010

154 113 155 142

50A4 053 51C3 114 054 115 124 200 177 178 51C4 001

011 5081 182 012

128 5083 051 137

138 5084 049

050 5103 013 014

50C1 125 104

MAP SAMPLING MAP SAMPLING SHEET NO. STATION NO. SHEET NO. STATION NO.

52A 015 59Al 117 102 118 103 105 59A2 024 106 025 143 085 150 086 151 087 152 189 153

59A3 092 520 017 158

099 100 59A4 032 101 045 107 059 108 060 109 082 110 090 129 091 136 145 59B1 159 146 147 59B2 019 148 020 149

5984 156 5201 112 157

53A 016 5901 089 096 097 5903 163 098 144 67C 083

084 58C3 018 116

093 168 68A 034

035 58C4 021 061

022 062 023 063 094 064 095 065 160 066 161 079 162 130 167 132

MAP SAMPLING MAP SAMPLING SHEET NO. STATION NO. SHEET NO. STATION NO.

133 86A 080 183 186 868 073 187 074 188 075 195 076 196 077 197 078

201 688 026

027 860 067 028 068 029 069 033 070 081 071 088 072 119 120 121 122 123

77A 190 191 192 193 202 203

778 030 031 036 037 038 039 040 041 042 043 044 131 164 165 166 184 185 194

APPENDIX B.

FLAFS ABSTRACT

***Abstract -- 1990 Ann. Meeting FL Chapt. AFS***

Estuarine nursery habitats of early-juvenile fishes in the Manatee River Estuary System of Tampa Bay: habitat classification and snook habitat relationships.

R.E. Edwards, Mote Marine Laboratory, 1600 City Island Park, Sarasota, FL

Shoreline and shallow-water habitats of the Manatee River Estuary System (MRES) were studi ed with regard to habitat characteri st i cs and utilization by early juveniles «100mm) of commercially and/or recreationally important fishes. A trinomial habitat classification system involving shoreline geomorphology, intertidal morphology, and intertidal vegetation was developed, and the MRES was surveyed and mapped with regard to this system.

Representative examples of important (areal extent and/or frequency of occurrence) habitats were sampled throughout the MRES during late summer and early autumn to determine habitat utilization patterns of early-juvenile (EJ) snook and other important species present during that season. Over 200 stations covering more than 25 major habitat categories were sampled (seine), but snook were collected from only a very few habitat categories.

EJ snook appear to utilize specialized habitats almost exclusively and do not generally utilize some of the most extensive habitat categories (e.g., Juncus-fringed or mangrove-fringed linear shorelines). EJ snook probably are displaced from their primary nursery habitats and at least temporarily redistributed by low-water conditions occurring during mid-autumn spring tides.