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Rockfish Conservation Areas

Michael Maguire

ENVS 120

June 5, 2015

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Concise Summary

Increased fishing pressure on rockfish populations off the west coast of the United States

has drastically reduced rockfish fishery stocks since the 1960s. Rockfish Conservation Areas

were established in 2002 to restrict rockfish catch and protect rockfish habitat by implementing

seasons, catch limits, prohibited species retention lists, fishing depth limits, and gear restrictions.

NOAA Fisheries and the California Department of Fish and Wildlife established dockside and

charter outreach programs to educate fishermen on RCA zone regulations and to provide

descending devices to anglers so that rockfish bycatch could be returned to depth. The

implementation of RCA zone regulations have proven to be moderately successful at reducing

rockfish bycatch and have deterred anglers from retaining prohibited species.

Stock assessments have provided valuable data towards developing effective

management strategies in RCA zones for overfished and healthy stocks. However, recent data

suggests that older and larger females contribute disproportionately more offspring to the

population as a function of body size and sexual maturity in comparison to smaller and younger

females. RCA regulations permit a maximum retention of 10 rockfish per day, and as a result

larger fish are typically selected by anglers (commercial and recreational) as the preferred catch

to retain. These fishing practices are inhibiting the recovery of overfished and vulnerable

rockfish populations. Stricter size restrictions for retainable catch need to be implemented in

RCA zones in order to protect the larger females that overwhelming contribute more offspring to

their populations.

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Introduction

In response to growing concerns over declining marine fishery stocks, conservation has

become a very powerful platform within the environmental movement in recent decades. As a

result of increased fishing pressure around the globe, certain coastal species such as rockfish

have become greatly overfished. In particular, the potential for the collapse of rockfish fisheries

off the U.S. west coast has increased awareness for the need of conservation efforts.

Increased dependence on ocean resources has imposed significantly larger fishing

pressure on rockfish fisheries that have never before been experienced as a result of human

activity. In order to ensure the sustainability of rockfish fisheries for future generations,

significant conservation efforts must continue to be made to restrict bycatch and over-harvesting.

Over the duration of this report, I will refer to stock assessment data and discuss effective

management strategies that have been implemented in the Rockfish Conservation Area (RCA)

along the west coast of the United States.

Background

Since the late 19th century, as a result of the high demand that rockfish carry, several

rockfish species off the California coast have become greatly overfished. According to the

California Department of Fish and Wildlife, “yelloweye, canary, cowcod, bocaccio, widow,

pacific ocean perch and darkblotched rockfish have been federally designated ‘overfished

species’, which means that less than 25 percent of their estimated pre-fishery population now

exists” (California Department of Fish and Wildlife, 2015). The target biomass for overfished

species to reach in order to no longer be designated overfished, is 40 percent of their estimated

pre-fishery population (California Department of Fish and Wildlife, 2015). To reach target

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biomass (40%), many rockfish species require anywhere from 3-11 years and occasionally 20-30

years to fully mature and reach maximum reproductive capacity (Beyer et al., 2015).

In response to declining rockfish populations along the west coast of the United States,

the Rockfish Conservation Area (RCA) displayed in figure 1 below, was enacted in September

of 2002, to restrict recreational and commercial fishing from identified rockfish habitat.

According to NOAA Fisheries, “The locations of the RCA boundaries are set primarily to

minimize incidental catch of overfished rockfish by eliminating fishing in areas where and times

when those overfished species are likely to co-occur with more healthy target stocks of

groundfish” (NOAA, 2015). Since the enactment of the Rockfish Conservation Area, the stock

assessments of several rockfish species indicate that they

have rebounded to near or above the 40 percent target

biomass (NOAA, 2015).

(Figure 1: Map of the RCA Boundary Along Central California Coast.

Source: Beyer, 2015)

Findings

The RCA established depth restrictions (varying between 37-

180 meters) all along the California, Oregon, and

Washington coastlines in order to prevent fishing at depths

that rockfish inhabit (Beyer et al., 2015). Within each

specified RCA zone, fishermen are only allowed to fish above a specified depth in order to

prevent rockfish bycatch. The RCA also established gear restrictions, catch limits, seasons, and

restricted species that are illegal to retain. Gear was restricted to one line per fishermen, with a

maximum of two hooks per line. Seasons begin as early as April 1 and end as late as December

31. Bag limits were set at 10 per day, with a maximum retention of five (5) black rockfish, three

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(3) bocaccio rockfish, and three (3) cabezon rockfish (NOAA, 2015). However, there are four

species in Monterey Bay that are specifically prohibited to retain, which are: the canary rockfish,

the yelloweye rockfish, the bronzespotted rockfish, and the cowcod rockfish (NOAA, 2015).

As part of conservation efforts, fishermen are not only encouraged to prevent catching

rockfish, but to also return them to depth using any one of several descending devices such as a

Shelton descending device. Often when rockfish are caught, even unintentionally, fishermen are

unaware that they can return the fish back to its appropriate depth in order to reverse the

barotrauma that it suffers from at the surface. Barotrauma can be defined as, the physical damage

to body tissue that occurs as a result of significant and rapid change in ambient pressure, which

again occurs when the fish is caught and brought from great depth to the surface.

When suffering from barotrauma, a rockfish’s swim-bladder fills with gas as it ascends

towards the surface, and the expanding swim-bladder displaces the internal organs, typically

forcing the stomach and esophagus to protrude out from the fish’s mouth. These fish appear to

look dead according to most fishermen, and they usually just throw them back into the ocean.

Unfortunately, the excess gas in their bodies due to low-pressure conditions makes descending

on their own very difficult, if not impossible because of their very high buoyancy. However,

studies by John Hyde and Nick Wegner at NOAA Fisheries Southwest Fisheries Science Center

show that if a rockfish is returned to its appropriate depth with the use of a descending device

within just a few minutes of reaching the surface, it has roughly a 92.7 percent survival rate

(Hyde & Wegner, 2014).

These studies were conducted off the coast of southern California, where fifty (50)

rockfish of five (5) different species were caught, tagged, and recompressed at depth. Hyde and

Wegner monitored fish movement using an accelerometer and a pressure sensitive acoustic tag to

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determine short-term and long-term survival after being re-submerged to depth using a

descending device. The data indicated that 92.7 percent survived up to 2 days and 76.7 percent

survived more than four months, which was the battery power lifespan of the tags (Hyde &

Wegner, 2014).

(Figure 2: Displays the Fecundity of four Rockfish species relative to Female Fork Length. S ource: Beyer, 2015)

Illustrated in figure 2, recent rockfish fecundity

analysis conducted locally at the NOAA Fisheries

SWFSC this spring indicated that, older and larger

females experienced a disproportionately greater

reproductive output than smaller and younger females

(Beyer, 2015). Also, “greater maternal investment by

older and larger females may further promote larval

survival and contribute significantly to recruitment” (Beyer et al., 2015). Older and larger

females have also been found to release larvae earlier in the season, which lengthens the

reproductive season, providing the opportunity to release multiple broods (Beyer et al., 2015).

These were important finding for several reasons, but most importantly the implications of these

findings suggest that the retention of highly desired, older and larger fish that are primarily

selected by recreational and commercial fishermen, can severely inhibit population growth and

stock recovery. This is a major concern for conservationists since the stocks of several of these

species are currently designated overfished by the California Department of Fish and Wildlife.

Recommendations

While rockfish populations are on the rise, many more years lie ahead until rockfish

fishery stocks can safely be designated sustainable. So far, dockside and charter outreach efforts

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to both recreational and commercial fishermen have been moderately successful at introducing

descending devices and supplying regulation handbooks for fishermen to use and follow while at

sea. However, further outreach at California’s marinas is certainly needed in order to provide the

foundation for conservation efforts to be more successful. Future stock assessments will also

continue to serve as an essential component to adequately quantify the success of current and

future conservation efforts in Rockfish Conservation Areas. With further input from data

acquired in future stock assessments, I believe that significant gains can continue to be made

towards restoring rockfish populations to historical levels.

However, my greatest concern resides with the retention of older and larger females.

Though rockfish catch has been greatly reduced due to RCA zone regulations, outreach efforts

should be adjusted to address this area of concern. I believe that rockfish conservation efforts can

be enhanced substantially by just reducing the catch of these individuals that contribute

disproportionately more to the population. Stricter size restrictions should be implemented into

RCA regulations to prevent the loss of these fish that are essential to continued population

growth and fishery stock health.

Despite the concerns mentioned above, I can conclude that the overall efforts that have

been made since the enactment of the Rockfish Conservation Area has certainly been successful.

Dockside and charter outreach programs have certainly achieved their objectives in providing

fishermen with descending devices and educating them on rockfish conservation and the RCA

zone regulations. Stock assessments, monitoring programs, and fecundity analysis have also been

very successful at projecting population growth and providing the necessary data to calculate

catch limits and harvest restrictions. I am hopeful that future efforts will continue with further

success.

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Reference List

Beyer, Sabrina. G., Sogard, Susan. M., Harvey, Chris. J., Field, John. C. (2015). Variability in

rockfish (Sebastes spp.) fecundity: species contrasts, maternal size effects, and spatial

differences. Springer Science. Environ Biol Fish (2015) 98:81-100

Beyer, Sabrina (2015). Rockfish Early Life History Project and Fecundity Analysis. Intern

Summary Spring Quarter 2015. NOAA Fisheries Southwest Fisheries Science Center,

Fisheries Ecology Division.

California Department of Fish and Wildlife (2015). Yelloweye, Canary, and other Rockfish

Species of Concern. Marine Conservation. Retrieved from:

https://www.dfg.ca.gov/marine/groundfishcentral/yelloweye.asp

Hyde, John. Wegner, Nick (2014). Barotrauma. NOAA Fisheries Southwest Fisheries Science

Center. Retrieved From:

https://swfsc.noaa.gov/textblock.aspx?Division=FRD&id=17814

National Oceanic and Atmospheric Administration (2015). Rockfish Conservation Areas:

Management, Law & Policy. NOAA Fisheries Southwest Fisheries Science Center.

Retrieved From:

http://www.westcoast.fisheries.noaa.gov/fisheries/management/groundfish_closures/rock

fish_areas.html