WHAT MUST BE DONE TO PROTECT ROCKFISHES?_____________________

Priorities for management of West Coast rockfishes

The following are actions that must be taken if the future existence of West Coast rockfish species is to be secured in perpetuity.

I. INCREASE BOTH THE QUALITY AND QUANTITY OF INFORMATION ON ALL COMMERCIAL AND SPORT FISHED ROCKFISH SPECIES, THEIR ASSOCIATED FISHERIES AND HABITAT.

Many species of rockfishes harvested in the commercial and recreational fisheries have never been assessed and the total numbers caught are not tracked. At a minimum, biomass estimates and accurate numbers of removals should exist for all rockfishes taken in these fisheries.

Habitat destruction is a threat to rockfish populations. Not only does healthy habitat provide structure for protection against predation, complex habitats foster niches that support a great diversity of organisms, some acting as essential prey for the rockfish species covered in this report. "One of the greatest long-term threats to the viability of commercial and recreational fisheries is the continuing loss of marine, estuarine, and other aquatic habitats. Habitat considerations should receive increased attention for the conservation and management of fishery resources in the United States" (Section 2 (a)(8) MSFCMA 1996).

Habitat requirements for rockfishes are many and vary between species and life stages. Currently, all of the essential fish habitat information in the "Essential Fish Habitat West Coast Groundfish Appendix" developed by NMFS is classified as level one. This level contains the least amount of information of four possible levels. It includes information only on "presence/absence distribution available for some or all portions of the geographic range of the species" (NMFS 1998). Of immediate concern are the many species of unassessed rockfishes residing in the nearshore area (sometimes defined as the area within a mile from shore). This area has experienced marked increases in fishing pressure within recent years as a result of displaced effort from other declining fisheries as well as increases in gear technology allowing for areas and habitats to be exploited that had previously functioned as defacto reserves. Listed below are specific actions that would lead to an increase in data on and habitat protection for West Coast rockfishes and their associated fisheries.

a. Require increased sorting of landed catches of rockfish to the species level. Lumped market categories are unacceptable and valuable data is lost.

b. Develop an assessment for nearshore rockfish species.

c. Perform an economic and biological analysis on the livefish fishery.

d. Develop gear performance standards in terms of the impact of fishing gear on habitat.

e. Investigate and develop an appropriate timeline for the implementation of marine refugia for habitat protection.

f. Completely implement the Essential Fish Habitat (EFH) document for West Coast groundfish

II. DEVELOP A MANDATORY WEST COAST OBSERVER PROGRAM.

The numbers utilized to calculate bycatch rates in West Coast groundfish fisheries are only estimates. Accurate bycatch information is critical to managing a fishery in a sustainable and efficient manner. One effective mechanism to get this data, utilized in other areas of the United States as well as the world, is on-board observers. The West Coast groundfish fishery is in critical need of a mandatory fleet-wide observer program to account for bycatch and allow for the implementation of certain incentive programs.

III. REDUCE TOTAL MORTALITY OF ROCKFISHES.

Because the current numbers utilized to estimate bycatch rates of West Coast rockfishes are only estimates, an accurate picture of total removals (landings + discard) from the system does not exist. If actual bycatch numbers are higher than the current estimates, then the amount of fish permitted to be caught and sold may be exceeding the maximum sustainable yield (MSY). This could contribute significantly to the decline of certain species of rockfish. One way to approach this issue is to establish and enforce gear selectivity standards aimed at reducing the amount of bycatch in a fishery. Other actions taken could include:

a. Analysis and deviation from the year-round fishery/trip limit management problem as it relates to the production of bycatch (trip limit management has been addressed by Pikitch et al. 1988 and found to result in increased amounts of discard).

b. Development of incentive programs to facilitate bycatch reduction by rewarding vessels with lower bycatch levels.

c. Analysis of gear selectivity and utilization of this analysis in the management process.

IV. REDUCE OVERALL EFFORT AND STOP OVERFISHING.

During the 1980s the West Coast groundfish fishery expanded from a relatively small fishery harvesting surplus production to one with excess capacity and limited potential for long-term sustainability, which unfortunately, continue to be the characteristics of the fishery today. Investments into greater horsepower, and larger boats and gear have been made consistently over time by people hoping to equate this increase in capacity with more fish and greater economic returns. This has resulted in an overcapitalized fleet, requiring operating costs to increase as people struggle to catch enough fish to make boat payments on more technologically advanced boats, gear, etc. What this translates into is more stress placed on the resource to fulfill the needs of the investments made and the growing number of people participating in the fishery. Management changes such as those listed below would begin to address the excess effort and overfishing problems existing in the fishery for West Coast rockfishes.

a. Assign separate Allowable Biological Catches (ABC) and Harvest Guidelines (HG) to the nearshore, slope, and shelf rockfish complexes.

b. Apply recommended ABCs where they already exist to species in the categories of "other rockfish" and "remaining rockfish". In cases where a recommended ABC does not exist further investigation is necessary.

c. The issues of fleet reduction and re-evaluation of the current limited entry program need to be seriously investigated for the fishery on West Coast rockfishes.

d. Mechanisms must be developed to facilitate the management of mixed-species assemblages, more in-line with the concept of "weak stock" management, where the weaker stocks are protected to some degree instead of overexploited.

e. Identify the appropriate level of effort and technology for the fishery on West Coast rockfishes.

f. Quantify the economic losses to communities as a result of losses in fishing opportunity or changes in man- agement and regulations over the years. This data is critical background information that will allow for edu- cated decisions regarding the short versus long-term economic losses/gains associated with management decisions such as annual harvest levels

g. Challenge and develop alternatives to the current harvest policy. Analysis has shown that the current level of exploitation is too aggressive for many rockfish species.

h. Develop a conservative and appropriate default harvest policy for commercially fished rockfish species for which we have little or no information.

i. Manage stocks identified to be in decline in an appropriate manner. Allowing overfished species to continue to be taken and landed or discarded as bycatch in order to allow access to other species is an unacceptable method of management.

j. Develop reporting mechanisms for bycatch levels and stock levels by area for the commercial and sport fishing fleets.

k. Develop mechanisms for data collection based on where rockfish species are caught rather than landed. This will allow for the development of area specific management.

V. IN THE FACE OF UNCERTAINTY UTILIZE PRECAUTIONARY MANAGEMENT.

The need for precautionary management is immediate and critical. The luxury of time no longer exists for developing new ways of management and increased data collection for some rockfish species. In the face of this ever-present uncertainty, the Council, NMFS, all management entities, and the fishing industry must begin to utilize the precautionary approach in the management of West Coast rockfish stocks. It is intuitive in the face of doubt to err on the side of caution. Time and time again federal and state management entities have gambled with the health of the rockfish resource and erred on the side of risk. Actions representing the precautionary approach to fisheries management include the following.

a. Set standards for impacts of gear on habitat as well as gear selectivity.

b. Minimize bycatch through the use of more selective gear.

c. Protect and restore essential habitat.

d. Place a cap on both fishing capacity and total fishing catch rate.

This report is meant to take a proactive approach for the purpose of preventing further rockfish declines by providing an educational tool and background information to those interested and willing to become integral voices in the management process for these species. It will hopefully provide the catalyst for numerous conversations between the many and diverse factions of people interested and concerned for this public resource, and these conversations will begin to move the management process in the direction of better stewardship and actions resulting in the development of sustainable fisheries.

 WHAT ARE ROCKFISHES?___________________

Three genera under the family Scorpaenidae are represented in the commercial fisheries off the West Coast. One genus Scorpaena, the scorpionfishes, forms only a small fishery off southern California and will not be dealt with here. The thornyheads, genus Sebastolobus, included in this report, are occasionally referred to as rockfish. However, the genus of this family most commonly referred to as rockfish is Sebastes, and is a very diverse group. See Table 1 for a listing of West Coast rockfishes and thornyheads (Love et al. 1998b). The word "Sebastes" comes from the Greek word "sebastos" meaning "magnificent" (Grant et al. 1996). The biomass and stock status of only eight of these has ever been fully assessed (Rogers et. al. 1996).

Rockfishes are characterized by primitive viviparity (Wourms 1991). Fertilization is internal and the female retains the eggs until they hatch, then gives birth to live young. Although the females of many species only produce a single brood annually, some produce multiple broods (Haldorson and Love 1991). There is evidence for the occurrence of multiple matings by males, and the sperm can be retained and survive in the ovaries of the female possibly for many months, usually resulting in a period of about one month between fertilization and parturition (release of the young) (Echeverria 1987). The duration of the larval period for rockfish lasts about a month and is followed by metamorphosis into the pelagic juvenile stage, the duration of varies, but averages three to six months. It is during the larval and juvenile stages that year-class strength is determined (Ralston and Howard 1995). Rockfish are characterized by relative longevity; the age of one specimen of rougheye rockfish was estimated at over 147 years (Grant et al. 1996). Longevity estimates can be found in Table 2.

Sebastolobus, is a second important genus within the family Scorpaenidae. These are the "thornyheads," represented by three species along the West Coast, the longspine and shortspine thornyheads, which are commercially fished, and the broadbanded thornyhead, which is relatively rare (Love et al. 1998b). Thornyheads are oviparous, meaning the eggs are released and hatch outside the body of the female. Females exhibit multiple spawnings. It is assumed fertilization is internal (J. Butler SWFSC pers comm.). Females release pelagic, bilobed gelatinous hollow egg masses, which can sometimes be seen floating at the surface. After hatching, juvenile short and longspine thornyheads spend 14-20 months in the water column before transforming and settling to a benthic environment (NMFS 1998). Both species are long-lived with estimates for longspines of up to 45 years and shortspines of up to 158 years (Rogers et al. 1997).

In general, sexual dimorphism occurs commonly among rockfish with females growing larger than males (Pearson and Ralston 1990). Length at maturity increases at higher latitudes and is probably due to delayed maturation. It has been suggested that sexual size dimorphism may result in a selective advantage if fecundity is related to size of females but not males for the species. Maximizing reproduction is best accomplished by females through increased size, while for males it is maximized by early onset of sexual maturity, so that energy is expended on reproduction rather than growth. (Pearson and Ralston 1990). The life history model that appears to fit rockfishes the best dictates that if juvenile mortality increases relative to adult mortality, then the optimum size of maturity increases. Conversely, if adult mortality increases relative to juveniles, the size at maturity should decrease (Haldorson and Love 1991). Growth, maturity, and fecundity, which are interrelated life history parameters, can be influenced by external conditions such as temperature, abundance of prey, and predation. Observing a shift in either age or size at maturity can be an indication of a change in the density of the population. The reproductive strategy of Sebastes reflects K-type characteristics, which include later maturity, slower growth rates, and some amount of parental care. This strategy allows rockfish to minimize the effects of a poor reproductive year. However, the late age at maturity, as seen in rockfish, potentially can be a disadvantage for a heavily fished K-type species. The advantage of late maturity and a long life-span, which normally would allow for the occurrence of many reproductive seasons, must be balanced against the size of the spawning population in the formulation of a safe level of harvest (Escheverria 1987).

Ocean current systems and larger oceanographic regimes can have a strong impact on the overall health of rockfish stocks and the strength of individual year-classes. The oceanographic regime off southern California including temperature, upwelling, and offshore transport, appears to undergo long-term cycles. The waters of the southern California Bight began warming in the late 1970s and have remained warmer than the previous four decades. During fall and winter, the 1997 El Nino warmed the waters off the coast of California to their highest temperatures in 40 years, and scientists from the Scripps Institution of Oceanography reported in 1995 that within this 40-year time period, the ocean temperature off the coast of San Diego had warmed by 0.8 degrees Celsius. They also reported that zooplankton biomass had declined by 70 percent during the preceding two decades (McGinn 1998). These conditions can potentially impact rockfish populations by limiting the amount of upwelling and consequently decreasing part of their food supply, the associated zooplankton biomass. Long-term declines in local recruitment and population density of shallow-water rockfishes are described by Ralston and Pearson (1997), and Love et al. (1991), as occurring simultaneously at sites tens of kilometers apart and corresponding with El Nino events.

While there is a general understanding that many species of juvenile rockfishes move into deeper water as they age, and that seasonal movements appear to be related to changes in water temperature and turbulence, there has been proportionately very little attention paid to the juvenile period of rockfishes in general, and especially those dwelling in deeper water (> 40m) (Love et al. 1991, Singer 1985). Understanding the recruitment process that occurs from the pelagic larval stage to the substrate dependent juvenile stage is critical to understanding how local populations are replenished (Love et al. 1991) and, therefore, how they should be managed.

What characteristics of rockfishes predispose them to

overfishing vulnerability?

1. Low mobility of adults.

2. Extreme longevity of some (rougheye rockfish can live up to 147 years).

3. Low natural mortality (M generally less than 0.15).

4. Aggregation in multispecies complexes. Rockfish tend to aggregate with other species which makes singling out a species for capture sometimes an impossible task. This especially becomes a problem when the species aggregating differ markedly in life history traits such as maximum age and natural mortality rate.

5. Fecundity increases with age. Not only do rockfish continue to reproduce as they age, evidence exists to show that older females actually produce more young. Seventy-seven percent of total widow rockfish spawning output comes from age 10+ females (Ralston and Pearson 1997).

6. Infrequent recruitment success.

7. Comparatively low productivity/biomass.

8. Specific habitat requirements varying with age and species.

The characteristics of being long-lived and slow growing predispose rockfishes, according to fisheries scientists, to being unable to indefinitely support large sustained removals. The traits of rockfishes of long life and slow growth in combination with their viviparity (live-bearing) and increased fecundity as they age may have evolved to allow them to deal with environmental variability. In other words, rockfishes ability to live a long time and produce more young as they age increases the odds that they will be able to "wait out" poor environmental conditions and/or perhaps produce enough young that the probability is good that a few will survive.

How do the characteristics of long-life, slow growth, low natural mortality, etc. relate to the fact that many of the older rockfishes have already been removed from populations and the current oceanographic regime of warmer water does not favor good recruitment levels for rockfishes? The loss of highly fecund, older fishes can result in declines in recruitment. This conclusion is borne out by the results of ten years of SWFSC midwater trawl recruitment surveys (S. Ralston SWFSC pers. comm.). Trends in recruitment for nine rockfish species can be seen in Figures 2-10.

Feeding and Trophic Interactions

In addition to changing habitats as the mature, rockfish species change their diets. this may be due to the changes in habitat,size, and/or metabolism (Singer 1985). Juvenile Sebastes are primarily diurnal (daytime) feeders (singer 1985), and rely heavily on crustaceans in thier diet, shifting to larger crustaceans and fish as they grow (Love et al. 1991). Many species that feed in the water column as juvineniles also feed in the water columns as audlts (Singer 1985). Information on the feeding and topic interaction for the majority of rockfish species on the West Coast (including those listed below) can be found in the EssentialFish Habitat West Coast Groundfish Appendix (NMFS 1998). This discussion will be limited to detailed infermation on eight commonly fished species.

Shortspine thornyhead (SST)

SST are benthic sit-and-wait predators remaining motionless on the bottom for extended periods of time. They feed on a variety of invertebrates such as shrimps, crabs, and amphipods as well as fishes and worms. Longspine thornyheads are commonly found in SST stomachs. Cannibalism of newly-settled juveniles is important in the life history of thornyheads.

Widow rockfish

These animals primarily feed in the water column, pursuing nektonic prey and probably hunting by sight. They feed in the upper levels at night and in deeper water during the day. Juveniles are opportunistic feeders on various life stages of calanoid copepods and sub-adult euphausids. Adult feeding is most intense in the spring after spawning, and prey consists mostly of salps. Fishes become more prominent in the diet during the fall. In the winter their prey consists of sergestid shrimps.

Yellowtail rockfish

Yellowtail rockfish are primarily pelagic feeders, but are known to be opportunistic and occasionally prey on benthic animals as well. Most feeding occurs during the night or early morning hours and is on such fishes as small whiting, Pacific herring, smelt, anchovies, and lanternfishes as well as squid, euphausids, and other planktonic organisms for both juveniles and adults.