New York

Report #7 September 2002

RECENT BROWN TIDE ACTIVITYFollowing are the current results of the Suffolk County Departmentof Health Services monitoring for the year 2002 on Long Island.

The Peconic Estuary has shown no indication of bloomconditions this year. Aureococcus anophagefferens cell numbersat stations analyzed have not exceeded 2,000 cells per milliliter.

Relatively high numbers (80,000 – 90,000 cells per milliliter) forJanuary through early March 2002 at several Great South Bay(GSB) stations suggested the possibility that there would be anoccurrence of a major brown tide event during the summermonths. However, cell numbers decreased to less than 15,000cells per milliliter by late March and have not exceeded 17,000cells per milliliter to date. Special phytoplankton samples col-lected at a hatchery in GSB revealed that the poor shellfish growthnoted there was not related to high numbers of Aureococcus.

A bloom occurred in Quantuck Bay beginning in early June. Cellnumbers rose to 160,000 cells per milliliter, reached over 730,000cells per milliliter in late June, and then declined to about325,000 per milliliter in mid-July (the last date for which data are

Figure 2: Mapshowing sampling sitesacross Long Island.

Continued on page 2Figure 1:Hugh MacIntyre andAlison Coe set up amesocosm containing asediment core.Photo by Todd Kana

Brown Tide Research Initiative2

Report #7

New York Sea Grant StaffDirector: Dr. Jack MatticeAssociate Director: Dale BakerAssistant Director: Cornelia SchlenkCommunicator: Barbara BrancaProject Assistant & BTRIOutreach Specialist: Patrick Dooley

For a complete staff listing visitwww.nyseagrant.org

Continued from page 1

Writer: Patrick Dooley

Editors: Barbara BrancaCornelia Schlenk

Designers: Loriann CodyBarbara BrancaSharon O’Donovan

BTRI Steering Committee:Cornelia Schlenk, Chair, NYSG

Richard Balla, US EnvironmentalProtection Agency, representing thePeconic National Estuary Program (PEP)

Susan Banahan, NOAA CoastalOcean Program

Kenneth Koetzner, NYS Dept. ofEnvironmental Conservation,representing New York State

Dr. Robert Nuzzi, Suffolk CountyDept. of Health Services, representingSuffolk County

Roger Tollefsen, NY Seafood Council,representing SSER and PEP CitizensAdvisory Committees

William Wise, Marine SciencesResearch Center, SUNY Stony Brook,representing the South Shore EstuaryReserve (SSER) CouncilVacant, Representative, Town level

New York

New York Sea Grant is part of anational network of universitiesmeeting the challengingenvironmental and economic needsof the coastal ocean and Great Lakesregions. Unique among the 30Sea Grant programs nationwidebecause it has both marine and GreatLakes shorelines, New York Sea Grantengages in research, education, andtechnology transfer to promote theunderstanding, sustainabledevelopment, utilization, andconservation of our diverse coastalresources. NYSG facilitates thetransfer of research-based informationto a great variety of coastal usergroups which include businesses,federal, state and local governmentdecision-makers and managers, themedia, and the interested public.

presently available). Cell numbers in west-central Shinnecock Bay reachedalmost 200,000 cells per milliliter in June, declining to less than 30,000 permilliliter in July.

The State of New Jersey Department of Environmental Protection reportedthat Barnegat Bay and Little Egg Harbor Bay in New Jersey experiencedbrown tide in April and May 2002. Aureococcus concentrations ranged from200,000 – to greater than 851,000 cells per milliliter causing a local hatcheryto relocate juvenile seed clams to waters free of brown tide. Brown tideblooms have recurred in these bays since 1995 and have occurred every yearsince 1999 at specific locations.

To find out more about regional brown tide activity, please visit the BrownTide Clearinghouse website at: http://www.seagrant.sunysb.edu/browntide.

Editor’s Note: BTRI Report Number 7 builds on the preceding 6 BTRIReports and follows a similar format as the previous issues for easy projecttracking. Boldfaced terms are defined under Key Terms adding to thosedefined in the earlier reports.

RECENT BROWN TIDE ACTIVITY

What’s NextSynthesizing the results of the past five years of lab and fieldwork is the nextpriority for present and past BTRI and other brown tide researchers, New YorkSea Grant and the BTRI Steering Committee. In the coming months, we will bespearheading efforts to synthesize all the new results and knowledge for presen-tation in a technical document and an executive summary report that will alsoinclude any possible brown tide mitigation recommendations.

Five years ago, the first set of eight BTRI projects began. Building on earlyresults of these efforts, three BTRI projects were added in September 1999.While the first projects have been completed, the second set are still windingdown and finishing data analyses. Accordingly, conclusions and possiblemitigation recommendations are not presented in this report.

Photo by Todd Kana

3Report #7

BTRI Projects 1999-2001

Kana, MacIntyre, Cornwell & Lomas:Benthic-Pelagic Coupling and Long IslandBrown Tide

This research team continues its investigation into thecontrol of brown tide by nutrients. A significantaspect of this project is the documentation of theimportance of nutrient exchange between the sedi-ments and water column and the interaction betweenbenthic and pelagic processes. Quantuck andFlanders Bays were sampled to represent variousLong Island embayments. During the 2000 fieldseason, a single brief brown tide event occurredbetween field sampling periods in Quantuck Bayonly. Accordingly, modifications were made duringthe 2001 field season to account for the possibility ofanother “non-brown tide year,” or missed bloomevent. The investigators included mesocosm experi-ments to directly test the effects of selected nitrogennutrients and a sediment interface on biologicalprocesses in the water column. Four treatments ofinorganic and organic nitrogen combinations plus acontrol were tested over the course of two ten-daymesocosm experiments (see Figures 1 and 3).

The first experiment encountered a natural fluctuationin available light. During the first 5 days of thisexperiment, the weather was overcast or rainy whilethe weather was sunny during the second 5 days.These weather conditions had the effect of loweringthe entire mesocosm system’s “metabolism” duringthe first half of the experiment, followed by a “grow-out” period in the second half.

The water column uptake rates of the various nitrogenforms (inorganic forms: nitrate & ammonium, organicforms: glutamic acid & urea) were measured in themesocosm experiment. The uptake rates of theinorganic nitrogen forms did not change significantlyover time in any of the treatments. The uptake ratesof the organic nitrogen forms showed a more complex

pattern. The organic nitrogen treatments showedsignificant increases in either glutamic acid or ureauptake. Of the total nitrogen uptake in themesocosms (inorganic + organic), the organic nitro-gen forms had a higher uptake relative to the inor-ganic nitrogen forms.

Associated with the nitrogen uptake differences, therewere corresponding changes in Aureococcus densi-ties. All treatments started with roughly the sameAureococcus densities (3,000 – 12,000 cells permilliliter), but by day 6, densities dropped to less than1,000 cells per milliliter in all treatments most likelydue to the overcast weather conditions. During thesecond half of the experiment when it was sunny(days 6-9), Aureococcus populations grew in all theorganic nutrient treatments to greater than 10,000cells per milliliter. There remained less than 1,000cells per milliliter in the control (no added nutrients)and inorganic (nitrate) treatment. The increase inAureococcus density during the second half of theexperiment was concurrent with the increase in therelative uptake of organic nitrogen forms. Theseresults support the hypothesis that Aureococcusgrowth is enhanced under organic rather than inor-ganic nitrogen conditions.

Field studies focused on the shallow Quantuck Bay(see Figure 2) for the benthic-pelagic coupling experi-ments detailing the flux of nutrients into or out of thebottom sediments. The rationale is that the nutrientexchange (or flux) across the sediment-water interfacewould be important in providing supportive nutrientsto Aureococcus growth. Both inorganic and organicnitrogen forms can be released or taken up by thesediments. For 2000 and 2001, large temporal andspatial differences were seen in the flux of dissolvedorganic nitrogen (DON) across the sediment-waterinterface. On average DON was released from thesediment (3-4 µmol per liter per day: this is equivalentto approximately 10% of the DON standing stock perday). There were some high rates of DON uptake bythe sediments, however, uptake rates varied across thebay (e.g., lower flux rates were observed in the centerand southern sampling sites). So far the resultssuggest that the sediments appear to have had only asmall impact on the water column DON concentra-tion in Quantuck Bay. In terms of brown tide, exceptfor a brief event in late June of 2000, Quantuck Bayhad low DON concentrations which may have causedit to remain relatively free of a major brown tide bloom.

Figure 3: (Opposite page)Kana’s mesocosms were deployed off a floatingdock at the Marine Science Station ofSouthampton College. Treatments includedinorganic nitrogen, organic nitrogen, heatdegraded green algae, sediment plus a control.

Brown Tide Research Initiative4

Lonsdale, Caron & Cerrato:Causes and Prevention of Long IslandBrown Tide

During the summer of 2001, this research teamcontinued its mesocosm investigation intohow hard clams (suspension-feeding bivalveMercenaria mercenaria) impact brown tide andthe structure of the rest of the plankton com-munity.

Two eight-day mesocosm experiments wereconducted to test the effects of varyingconcentrations of hard clams on brown tidebloom dynamics. The hard clam treatmentswere designed to approximate higher hardclam population densities in Great South Bayduring the 1970’s and lower present dayconcentrations. The clam treatments consistedof 2, 4, 8 and 16 clams per mesocosm. Toencourage brown tide growth, nutrients wereadded to the mesocosms. These included urea,an organic nutrient source, and phosphate(PO4) as a phosphorus source.

Brown tides developed in mesocosm tankstreated with pumps and nutrients, reachingmaximum concentrations of 400,000 cells permilliliter in experiment #1 and approximately600,000 cells per milliliter in experiment #2.Nutrients alone enhanced brown tide growthonly until day 3 during experiment #1 whereasin experiment #2, concentrations peaked at600,000 cells per milliliter by day 6 (seeFigure 4).

Although plankton community structuresamples from these experiments are still beingenumerated, preliminary results suggest thathard clams in mesocosms have a significantimpact on both brown tide and the entireplanktonic food web structure. Previousexperiments conducted in 1997 and 1998showed that as hard clam clearance rates wentup, copepod abundance decreased. However,the ciliate population increased in the presenceof clams. It is plausible that without copepodpredation pressure, the ciliate populationincreased in mesocosms with clams. Addition-ally, the ciliate population may have increasedbecause brown tide abundance was alsoreduced. By the end of both mesocosmexperiments, the hard clam clearance rateexperiments showed that clams in the two-clam treatment were not feeding (Table 1). Thehigh concentrations of brown tide (greater than400,000 cells per milliliter for both experi-ments) in the tanks could have inhibited theirfeeding. The degree of brown tide control withfour clams per mesocosm differed betweenexperiments. After day 3 during experiment#1, Aureococcus declined to less than 10,000cells per milliliter. By day 8, the clams wereclearing the water at a mean rate of 0.55 litersper clam per hour or a water turnover rate of19% per day. This water turnover rate is higherthan that estimated for current hard clampopulations in Great South Bay but lower thanthat estimated for the 1970’s prior to the onsetof brown tides. In contrast, after day 3 duringexperiment #2, the concentration ofAureococcus gradually increased in the four-clam treatments, reaching 179,000 cells permilliliter on day 8 and the clams had ceasedfeeding. Brown tides did not develop in

Figure 4:Water color and transparency in mesocosms differing inthe number of hard clams (about 20-60 millimeters long)in an experiment conducted during 2001. A = no clams,B = 2 clam-treatment, C = 4 clams, D = 8 clams, and E =16 clams). Aureococcus anophagefferens reached anaverage concentration of 400,000 cells per milliliter in the‘A’ no clam treatment.Photo by Darcy Lonsdale

A B

C

D E

5Report #7

Continued on page 6

mesocosms containing eight or sixteen clamsduring either experiment. For experiment #1,water turnover rates on day 8 were estimatedas 66% and 95% per day for the eight- andsixteen-clam treatments,respectively, and for experiment #2, 27%and 74% per day (see Table 1).

A review of hard clam results from all themesocosm experiments conducted between1997 and 2001 (Table 1) strongly suggests thata water turnover rate by hard clams of approxi-mately 30% per day is sufficient to prevent theformation of brown tide in controlledmesocosms even when the Aureococcuspopulation is growing at near-maximumgrowth rates (1.0 population doubling per day).These results match the estimates of hard clamgrazing impacts in the Great South Bay duringthe 1970’s. This finding supports the hypoth-esis that the significantly reduced density ofthis benthic suspension feeder in Long Islandembayments over the last 30 years may be animportant factor contributing to the mid-80’sappearance and continual reoccurrence ofbrown tide.

Sieracki & O’Kelly:The Effects of MicrobialFood Web Dynamics onthe Initiation ofBrown Tide Blooms

While examining growth and grazing ofAureococcus within the context of themicrobial plankton community, this team’sresearch includes studying picoplankton com-munity dynamics such as bacteria and proto-zoan grazers. One focus under investigation isthe ‘picoalgae niche’ hypothesis (see BTRIReport #6).

Four bays were sampled in 2001 (4/2001-7/2001): Flanders, Quantuck, Shinnecock andWest Neck Bays (see Figure 2). Only QuantuckBay experienced a brown tide. This occurred inthe beginning of July and peaked at greater than800,000 cells per milliliter. The 2000 and 2001field results for Quantuck Bay and West NeckBay are consistent and demonstrate a picoalgaeniche in the late spring. During the short 2001brown tide bloom in Quantuck Bay,Aureococcus dominated the picoalgae sizeclass. Synechococcus was present, but atreduced population numbers during the brown

Mesocosm Experiment(yr-exp #)

Hard Clam Clearance Rate

(liters per clam per hour)

Water Turnover Rate

(%/day)

Hard Clam Treatment

1997-1

1998-1

1998-2

1998-2

2000-1

2001-1

2001-1

2001-1

2001-1

2001-2

2001-2

2001-2

2001-2

0.15

0.52

0.51

0.48

0.61

0.55

0.96

.70

0.39

0.53

25

140

65

145

99

0

19

66

95

0

0

27

74

20-clam*

30-clam

15-clam

35-clam

19-clam

2-clam*

4-clam

8-clam

16-clam

2-clam*

4-clam*

8-clam

16-clam

Table 1:Hard clam mean clearancerates (liters per hour perclam) summarized formesocosm experimentsbetween 1997-2001. *Indicates treatments inwhich mesocosms devel-oped an Aureococcusanophagefferens bloom.

Brown Tide Research Initiative6

Continued from page 5

tide bloom. West Neck Bay’s picoalgae nichewas dominated by a short bloom ofOstreococcus tauri (greater than 500,000 cellsper milliliter, June 2001), a species not previ-ously identified in Long Island bays and thesmallest eukaryotic organism known to science(see Figures 5 and 6).

This research team previously reported apositive correlation between Aureococcus andbacteria populations based upon samples takenduring a brown tide bloom in its initiationphase (see BTRI Report #3, March 1999). Thisinformation led to the hypothesis that underbloom conditions Aureococcus could outcompete the bacteria for DON. With newinformation and further analysis of past data,no strong correlation exists betweenAureococcus and bacteria abundance, biomassor cell size. Large amounts of mucopolysac-charide produced at the bloom onset sustains alarge bacterial population leading to thehypothesized brown tide – bacteria correlation.Data are now available for the entire bloomperiod and the relationship between browntide and bacteria seems clearer. During thebloom initiation period, Aureococcus producesmucopolysaccharides that fuel bacteria popula-tions. After a lag period, protozoa that feed onbacteria (called bacterivores) respond to theelevated bacteria populations and also in-crease. As the brown tide bloom progressesthe combination of less mucopolysaccharideproduction and grazing by bacterivores causethese two populations to balance out and stabilize.

Plankton community studies showed commu-nity-wide changes during the summer of 2000.The microphytoplankton populations shiftedfrom low abundances dominated by dinoflagel-lates to high abundances dominated by pen-nate diatoms. For comparison, flagellates andthe dinoflagellate Prorocentrum dominatedWest Neck Bay during June. Heterotrophicdinoflagellates (Gyrodinium/Gymnodinium)dominated the week prior to the brown tidebloom and may have effectively grazed com-peting phytoplankton. In West Neck BaySynechococcus (similar in size to Aureococcus)bloomed the same week as the Aureococcusbloom in Quantuck Bay.

Although analysis is still underway, preliminarygrowth and grazing rates of total phytoplank-ton, nanoalgal and picoalgal cell populationsindicate a tightly coupled system betweenmicrograzers and algal prey during the browntide initiation period (usually May). Very highgrowth rates (one doubling of the populationper day) were commonly observed. Growthand grazing were closely balanced, withgrazing removing virtually all phytoplanktonproduction. Addition of organic nutrientschanged the picoalgal cell populations, but didnot stimulate any blooms of Aureococcus.Figure 5:

Ilana Hobson, of Sieracki’s research team, fills experiment incuba-tion bottles at Quantuck Bay May 2001, Long Island, New York.Photo by Mike Sieracki

Figure 6:Mike Sieracki fills experimental incubationbottles at Quantuck Bay May 2001, Long Island,New York.Photo by Sieracki team member

7Report #7

Other Brown TideProjects

Greenfield:Ph.D. Dissertation:The Influence of Variability inPlankton Community Composition onthe Growth of Juvenile Hard ClamsMercenaria mercenaria (L.)

Dianne Greenfield worked on her doctoralresearch with Dr. Lonsdale, addressing theinfluence of Aureococcus anophagefferens onthe growth and feeding physiology of juvenilehard clams (Mercenaria mercenaria). Fieldstudies conducted during 1999 and 2000compared clam growth and plankton commu-nity composition between Oyster Bay, anembayment where Aureococcus has neverbloomed, and West Sayville where brown tidefrequently recurs (see Figure 2). Hard clamsgrew better at Oyster Bay than West Sayvilleregardless of Aureococcus levels at WestSayville. The phytoplankton community atOyster Bay generally consisted of centricdiatoms both years. West Sayville typicallysupported pennate diatoms, dinoflagellates,and small flagellates. A brown tide in 2000caused 67% clam mortality at West Sayville,but survivors grew rapidly within weeks.During the brown tide at West Sayville, clamsdid not exhibit an increase in whole animalbiomass. Then, after the brown tide subsided(7/17/00), clams that survived brown tideexhibited recovery and a rapid increase inbiomass. After a 4-week rapid growth spurt,clam growth rates were equivalent to OysterBay, a site that had no bloom of Aureococcus.Clams that survive brown tide recover and mayeventually grow at rates comparable to clamsthat never experienced a bloom ofAureococcus (see Figure 7.)

Since the field component involved raising twodifferent clam stocks in their nativeembayments, a study was conducted to deter-mine if genetics were responsible for growthdifferences between Oyster Bay and WestSayville. Though Polymerase Chain Reaction (PCR)

amplification demonstrated genetic differences,common garden experiments revealed nosignificant growth differences between popula-tions. Thus, clam growth was likely moreheavily influenced by environmental factorsthan heritability.

To determine if hard clams are sensitive toAureococcus when concentrations are too lowfor toxicity to inhibit feeding, carbon absorp-tion rates and clam growth were comparedbetween clams fed unialgal diets of phy-toplankton common to Long Islandembayments to diets mixed with brown tide.Flagellates and centric diatoms promoted thehighest absorption rates and fastest growth.Pennate diatoms resulted in poor absorptionrates and growth. Mixed diets generally causeda decrease in absorption rate and a minornegative influence on growth. Since centricdiatoms were typical in Oyster Bay, the higherabsorption rates possibly explained the rapidclam growth in the field. Conversely, theslower hard clam growth at West Sayville wasprobably associated with the abundance of

Figure 7:Mean (n = 5 ± SE) ash-free dry weight or biomassof Mercenaria mercenaria at Oyster Bay and WestSayville during the 2000 growing season. Notethat during the West Sayville brown tide (Maythrough July ending on July 17th) hard clams didnot grow but started growing again after browntide subsided.

Continued on page 8

06/27/00 7/11/00 7/25/00 8/8/00 8/22/00 9/5/00 9/19/00

1

2

3

4

5

6

AFDW

(m

g)

OBWS

No biomass increase during brown tide at WS

Rapid biomass increase/ recovery following brown tide

Brown Tide Research Initiative8

pennate diatoms, a poor food source. Thesefindings suggest that clams suffer subtle,chronic effects of brown tide at low levels, andin general, brown tide is not solely responsiblefor the poor hard clam growth in West Sayville.[Text written by Greenfield and modified byDooley]

Gobler:The Impact of Bottom-Up and Top-Down Processes on the Abundance ofAureococcus anophagefferens During theSummer 2000 Brown Tide Bloom inGreat South Bay, NY, USA

During the summer of 2000, the most intenseNew York brown tide bloom (Aureococcusanophagefferens) in fifteen years occurredthroughout Great South Bay. During thebloom, light and dissolved inorganic nitrogen(DIN) levels were low (1% light depth less than1.5 meters, mean DIN = 0.6 µM), indicatingthat obtaining carbon and nitrogen by standardautrophic means was likely difficult for mostphytoplankton species. However, dissolvedorganic carbon and nitrogen levels were high(mean = 600 µM and 45µM, respectively) inGreat South Bay, potentially giving a nutritionaladvantage to the brown tide which can useorganic nutrients. Although the growth of mostphytoplankton in Great South Bay was limitedby nitrogen during the summer of 2000, browntide growth is frequently not limited by nutri-ents. Instead, the brown tide seemed to utilizethe high levels of organic nutrients for growth,as DOC and DON concentrations in GreatSouth Bay decreased as the brown tide grew.During the Great South Bay 2000 brown tide,microzooplankton, which consume phy-

Continued from page 7 toplankton, grazed Aureococcus cells at aslower rate than they grazed other phytoplank-ton in western Great South Bay (Bay ShoreCove). In contrast, microzooplankton con-sumed Aureococcus and the total phytoplank-ton community at nearly equivalent rates ineastern Great South Bay (Patchogue Bay).Since the brown tide ended more quickly ineastern Great South Bay, the results couldindicate that microzooplankton grazing canplay a key role in regulating blooms. Insummary, the results indicate that both organicnutrients and lowered microzooplanktongrazing rates can contribute toward the forma-tion of brown tides in Long Island bays. [Textwritten by Gobler and modified by Dooley]

Mulholland:Pathways of DON Mobilization byAureococcus anophagefferens:Peptide Hydrolysis, Amino AcidOxidation and Uptake

Dissolved organic nitrogen (DON) has beenimplicated as a causative agent in the forma-tion of brown tides. It was determined thatAureococcus has several unique attributes thatmay allow it to out-compete co-occurringspecies in systems with high organic nutrientlevels. A newly tested fluorescent compoundwas used to measure rates of peptide hydroly-sis. Stable isotopes were also used to traceboth carbon and nitrogen uptake from aminoacids to test hypotheses regarding the ability ofAureococcus to recycle and use organicmaterial to support their growth. Peptidehydrolysis was high during blooms ofAureococcus enabling it to rapidly break downand recycle proteins and peptides. If so, browntide cells might not become nutrient deprivedso long as there is high in situ production to

9Report #7

supply reactive organic material. In addition toDON uptake, Mulholland directly determinedthat brown tide organisms subsidize photosyn-thetic carbon acquisition by using dissolvedorganic carbon to support net growth. Theability to take up organic material to providecells with both nitrogen and carbon may givecells a competitive advantage in organicallyenriched environments where light levels may below. Peptide hydrolysis can fuel both carbon andnitrogen acquisition because peptides are nitro-gen-rich organic compounds. These studies arethe first to employ dually labeled organic com-pounds to trace both carbon and nitrogen uptakefrom dissolved organic material and they are thefirst studies investigating seasonal changes inrates of organic material utilization and cycling.[Text written by Mulholland and modified byDooley]

BIBLIOGRAPHYPublished papers and graduate student theses from BTRI and otherNYSG funded brown tide projects since BTRI #6 October 2001.For a complete bibliography, please visit the BTRI web pagehttp://www.seagrant.sunysb.edu/BTRI

Boissonneault-Cellineri, K.R., M. Mehta, D.J. Lonsdale and D.A. Caron.(2001). Microbial food web interactions in two Long Island embayments.Aquat. Microb. Ecol. 26:139-155.

Gobler, C.J., J.R. Donat, J.A. Consolve III, and S.A. Sañdo-Wilhelmy. (2002).Physicochemical speciation of iron during coastal algal blooms. MarineChemistry, 77:71-89.

Gobler, C.J., M.J. Renaghan, and N.J. Buck. (2002). Impacts of nutrients andgrazing mortality on the abundance of Aureococcus anophagefferens during aNew York brown tide bloom. Limnol. Oceanogr., 47(1):129-141.

Greenfield, D.I. (2002). The influence of variability in plankton communitycomposition on the growth of juvenile hard clams Mercenaria mercenaria (L.)Ph.D. Dissertation Stony Brook University, 189 pages.

Lomas, M.W. (2002). Temporal and spatial dynamics of urea uptake andregeneration rates and concentrations in Chesapeake Bay. Estuaries 25(3):469-482.

Lomas, M.W., P.M. Glibert, D.A. Clougherty, D.R. Huber, J. Jones, J. Alexander,and E. Haramoto. (2001). Elevated organic nutrients ratios associated withbrown tide algal blooms of Aureococcus anophagefferens (Pelagophyceae).J. Plankton Research. 23(12):1339-1344.

Mulholland, M.R., C.J. Gobler, and Lee C. (2002). Peptide hydrolysis, aminoacid oxidation, and nitrogen uptake in communities seasonally dominated byAureococcus anophagefferens. Limnol. Oceanogr. 47(4): 1094-1108.

VIRUSES

BACTERIA

PHYTOPLANKTON& SMALL ZOOPLANKTON

Plankton Size and Associated Group Names

0.1 micr

omete

r

"femtop

lankto

n"

"picop

lankto

n"

"nanop

lankto

n"

"micr

oplank

ton"

"meso

plankt

on"

"macr

oplank

ton"

"mega

plankt

on"

1 micr

omete

r

10 micr

omete

rs

100 micr

omete

rs

1 milli

meter

1 centi

meter

10 centi

meters

1 mete

r

VISIBLETO THE

UNAIDEDEYE

Figure 8:Diagram depicts typical size ranges for somecommon marine groups (micrometer = micron = µm).Figure from Bigelow Laboratory

1999-2001 BTRI INVESTIGATORS

Bermuda Biological Station for Research, BermudaDr. Michael W. Lomas

Bigelow Laboratory for Ocean Sciences, MEDr. Charles O’Kelly Dr. Nicole PoultonDr. Michael Sieracki Mr. Ed Thier

Horn Point Environmental Laboratories, MDDr. Jeffrey Cornwell Dr. Todd M. KanaDr. Hugh L. MacIntyre

Long Island University, Southampton College, NYDr. Christopher Gobler

Stony Brook University, Marine Sciences Research Center, NYDr. Robert Cerrato Ms. Dianne GreenfieldDr. Darcy L. Lonsdale

Old Dominion University, VADr. Margaret Mulholland

University of Southern California, CADr. David A. Caron

Brown Tide Research Initiative10

KEY TERMSFor a complete list of Key Terms, access http://www.seagrant.sunysb.edu/BTRI/btriterms.htm.See Figure 8 on page 9 for plankton size ranges.

bacterivores

Organisms such as protozoa that eat bacteria.

benthic-pelagic coupling

The interaction that links the benthos or bottom with thewater column or the pelagic ecosystems. In particular, thisterm refers to how the dynamics in one ecosystem influencethe dynamics of the other. In other words, how benthicsystems affect pelagic systems, and how pelagic systemsinfluence benthic systems.

centric diatoms

Round shaped cylindrical single-celled algae,mostly photosynthetic, that form silica cell wallsand can be solitary or chain-forming, ranging insize from 2 microns to several millimeters. They

are found in marine and aquatic systems, up in the watercolumn or on/in the bottom sediments.

ciliate

Single-celled protozoa (1.0 microns indiameter and range up to about 250 microns)often found in plankton that move by beatinghair-like structures called cilia. Ciliates are

especially important trophic links in microbial food websbecause they are the major consumers of bacteria, pico- andnano- plankton, diatoms, dinoflagellates, and amoebae, andthey are eaten in turn by animals such as copepods in thezooplankton. Because of their “keystone” role in microbialfood webs, they are important indicators of the conditionsand health of the environment at the microbial level.

clearance rates

As used in this Report Series, the rate at which filter-feeders,such as shellfish, remove particles (including plankton) fromwater by passing the water through their systems.

copepod

A small crustacean that is important as a foodsource for higher trophic organisms such as fish(typically 1-2 millimeters in length; oceanic speciescan reach over 1 centimeter).

dinoflagellates

Unicellular protists, which exhibit a greatdiversity of form including photosynthetic(autotrophic), heterotrophic, or parasitic andrange in size from up to about 250 microns).

Many harmful algae blooms are caused by dinoflagellates.

eukaryotic

A cell with a distinct membrane-bound nucleus.

flagellate

Flagellates are single-celled protista with oneor more flagella, a whip-like organelle oftenused for propulsion.

growth rate

Increase in the number of individuals in a population per unittime (e.g., population doubles once per day).

heterotrophic

Organisms that obtains nourishment from the ingestion andbreakdown of organic matter such as plants and animals.

in situIn the original location (e.g., water column or within theorganism).

microflagellate

Small protists that can be photosynthetic or heterotrophic.

micrometer (µµµµµm) or micron

One millionth of a meter (1 inch = 25,400 µm).1 millimeter = 1000 micron

microphytoplankton

Small, plant planktonic organisms in a size range 20 - 200 µm.

microzooplankton

Small, animal planktonic organisms in a size range 20 -200 µm.

mucopolysaccharide

Complex polysaccharides containing an amino group; occurchiefly as components of connective tissue. Mucopolysaccha-rides are quite similar structurally to the more well-knownanimal and plant polysaccharides such as glycogen andstarch. Chitin is a particularly plentiful mucopolysaccharideand serves as a structural polysaccharide for many phyla oflower plants and animals such as lobsters, crayfish, crabs,insects, and many other invertebrate organisms.

nanoplankton

Small, single-celled planktonic organisms ina size range 2.0 - 20 microns. Can be animals –nanozooplankton or plants – nanophytoplankton.

pennate diatoms

Elongated single-celled algae, mostlyphotosynthetic, that form silica cell walls;

can be solitary or chain-forming, range in size from 2 micronsto several millimeters and are found in marine and aquaticsystems, up in the water column or on/in the bottom sediments.

11Report #7

peptide

A compound of two or more amino acids joined bypeptide bonds. Proteins are formed by the linkage ofmany peptides.

peptide hydrolysis

The splitting of a peptide compound molecule (protein orpolypeptide) by the addition of water.

picoalgae

Very small, single-celled planktonic algae in a size range0.2 – 2.0 µm.

picoalgae niche hypothesis

Between April and May, there is a succession from largerto smaller algal cells in Long Island bays. Typically,Synechococcus dominates the smaller picoalgae sizeclass. If, however, Synechococcus is selectively removedor its density is reduced, the picoalgae niche opens forsome other similar sized algae, such as Aureococcusanophagefferens.

picoplankton

Very small, single-celled planktonic organisms (plants oranimals) in a size range 0.2 - 2.0 µm.

Polymerase Chain Reaction (PCR)

PCR is used in classification to help show evolutionaryrelationships among organisms on the molecular level. Ithas the advantage of being useful even when only verysmall samples, such as tiny pieces of preserved tissuefrom extinct animals, are available.

polysaccharide

Polysaccharides are carbohydrates, such as starch andcellulose, formed from many connected sugar units.

protist

A group of simple single celled eukary-otic organisms (e.g., protozoa andeukaryotic phytoplankton) not distin-guished as animals or plants, though

having some characteristics common to both.

SynechococcusA group in the genus of cyanobacteria(also called blue-green algae) thatcontain chlorophyll; are coccoid inshape and are within the same size

range as Aureococcus.

The Brown Tide Research Initiative (BTRI) is fundedby the National Oceanic and AtmosphericAdministration’s Coastal Ocean Program and admin-istered by New York Sea Grant. The first (1996-1999) three-year $1.5 million BTRI program wasdeveloped to increase knowledge concerning browntide by identifying the factors and understanding theprocesses that stimulate and sustain brown tideblooms. Continued funding for BTRI (1999-2001), asa second $1.5 million three-year effort, comes onceagain from NOAA’s COP. The COP, National SeaGrant Office, National Science Foundation, Environ-mental Protection Agency, Office of Naval Research,and National Aeronautics and Space Administrationare jointly sponsoring research on Harmful AlgalBlooms (HAB) ecology and oceanography in theinteragency research program, Ecology and Ocean-ography of Harmful Algal Blooms (ECOHAB).

There were eight projects in the first three-year effort,then three projects in the next three-year effort. AllBTRI projects were selected through national calls forproposals. The research projects chosen for BTRIfunding were selected following peer review andevaluation by a technical review panel. To involveconcerned parties and aid in decision-making, NewYork Sea Grant formed the BTRI Steering Committeeas an advisory group of invited state, local andgovernment agency representatives, and citizen’sgroups.

This Report Series will aid in the dissemination ofgeneral brown tide information. The results and con-clusions of the projects will help determine the direc-tions of potential management and future research.

BTRI researchers continue to work closely with theSuffolk County Department of Health Services whichhas provided brown tide and water quality data, andhas collected samples for various investigators.Suffolk County has also provided funds to BTRI andother researchers studying the brown tide phenom-enon including: Drs. Boyer, Lonsdale, Caron andGobler (BTRI researchers), J. LaRoche (University ofKiel), D. Repeta (WHOI), G. Taylor, S. Sañudo-Wilhelmy (MSRC), and J. Giner (SUNY ES&F, Syra-cuse). The work from these and others has beenintegrated into the brown tide story, assisting in theefforts to understand this phenomenon. For a listingof BTRI Investigators, please see page 9.

BACKGROUND

Brown Tide Research Initiative12

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Bringing Science to the Shore

If you have any questions about brown tide,would like a copy of Report #1, 2, 3, 4, 5 or 6,or would like to be added to our mailing list,please contact Patrick Dooley at New YorkSea Grant (patrick.dooley@stonybrook.edu or631-632-9123) .

You may also read these reports by visiting ourwebsite: www.seagrant.sunysb.edu

This publication may be made available in analternative format and is printed on recycledpaper.

© Copyright 2002

INSIDE

Recent Brown Tide Activity .......................... 1

Editor’s Note................................................. 2

What’s Next .................................................. 2

BTRI Projects 1999-2001 .............................. 3Kana, MacIntyre, Cornwell & Lomas ... 3Lonsdale, Caron & Cerrato .................. 4Sieracki & O’Kelly ............................... 5

Other Brown Tide Projects ........................... 7Greenfield ........................................... 7Gobler ................................................. 8Mulholland .......................................... 8

Bibliography ................................................. 9

BTRI Investigators ......................................... 9

Key Terms ................................................... 10

Background ................................................ 11