7. National Marine Fisheries Service-SWFSC

Groundfish-related research and management support is conducted by three major components of the NMFS Southwest Fisheries Science Center (SWFSC): the Coastal Fisheries Research Division (La Jolla), directed by Dr. John Hunter; the Pacific Fisheries Environmental Laboratory (Pacific Grove), directed by Dr. George Boehlert; and the Tiburon Laboratory (Tiburon), directed by Dr. Alec MacCall.

a. Coastal Fisheries Resources Division (La Jolla)

The SWFSC Coastal Fisheries Resources Division (Coastal Division) is involved in a large number of research studies that support management of groundfish by the Pacific Fishery Management Council and California Department of Fish and Game. These studies address short and long term problems in biology, economics and management of groundfish. Work in the Coastal Division is focused primarily on Pacific hake and the deep water complex (sablefish, Dover sole and thornyheads), but work on rockfish (Sebastes spp.) and California halibut (Paralichthys californicus) in shallow water is increasing.

An ongoing program to describe the distribution and abundance of groundfish eggs and larvae is being conducted in connection with the CalCOFI program and groundfish research cruises. A definitive identification guide for fish eggs and larvae in the California Current, including groundfish was published in 1996. The identification guide, which contains 1,505 pages and 182 citable articles, is a major scholarly work that will serve for decades as a key reference for scientists all over the world.

Now that the identification guide has been finished, Coastal Division staff are sorting and identify ichthyoplankton (including several species of groundfish) collected in CalCOFI samples since the mid-1980's. The updated CalCOFI database will be of considerable use for groundfish. For example, cooperative work between the Coastal Division and Tiburon Laboratory indicates that CalCOFI data for bocaccio rockfish (Sebastes paucispinis) larvae can be used to track trends in spawning biomass during 1951-1984. CalCOFI data are particularly important for bocaccio rockfish because they are the only fishery independent data available for the 1950's to early 1980's. An index of spawning biomass based on CalCOFI data was used in the 1996 stock assessment for bocaccio and a report describing the index was published during 1996. Ongoing work with scientists at the Northwest Fisheries Science Center in Newport, Oregon, indicates that CalCOFI data will also prove useful for tracking trends in spawning biomass of Dover sole.

CFRD staff devoted a great deal of time during 1996 and 1997 to establishing a PFMC review process for groundfish stock assessments. The goals were to increase confidence in groundfish stock assessments by improving technical review of assessment work and increasing public participation.

b. Pacific Fisheries Environmental Laboratory (Pacific Grove)

Pacific Fisheries Environmental Laboratory (PFEL) develops methods to address the linkages between natural environmental variability and fish populations dynamics. Data series developed within the PFEL research program are made available to scientific collaborators. Close association with the U.S. Navy's Fleet Numerical Meteorology and Oceanography Center provides access to ocean and atmospheric data on a global scale. Major categories of scientific activity at PFEL include: (1) Development of environmental index time series, (2) ocean anomaly diagnostic studies, (3) identification of environmental-biological causal linkages through interregional comparative studies, exploratory data analysis, empirical modeling etc., (4) development of appropriate environment-dependent fishery modeling methodologies, (5) development of biological time series for calibration, verification and parameter estimation. The potential effects of climate change on marine ecosystems and resources is a major focus of PFEL research activity at the present time. In addition, PFEL personnel are increasingly involved in inter-institutional collaborative field studies of coastal groundfish habitat off the U.S. west coast.

c. Tiburon Laboratory (Tiburon)

Field and laboratory research on groundfish is cooperatively conducted at the Tiburon Laboratory by three interrelated Branches: Groundfish Analysis, Coastal Communities, and Physiological Ecology.

The Groundfish Analysis Branch develops methods to predict rockfish recruitment, estimate spawning biomass, sample groundfish landings and age groundfish; staff members also study rockfish life histories, develop new management models and conduct stock assessments. In addition, staff participates on the Pacific Fishery Management Council's Groundfish Management Team, principally in stock assessments and exploring management alternatives.

Rockfish landings have been sampled since 1977 in a cooperative program with the California Department of Fish and Game. The data from the port samples are compiled with software developed by project members and routinely used in stock assessments. The staff recently improved the software and is collaborating with the California Department of Fish and Game to improve expansion of port samples to total landings. A report describing the statistical methodology is in press (1997). An extensive groundfish database is maintained at the Tiburon Laboratory, and is available to researchers.

The Physiological Ecology Branch has been reprogrammed to work on estuarine salmon issues, and terminated its groundfish sampling activity. Staff are finishing up laboratory analyses and manuscript preparation based on a decade-long study of yellowtail rockfish physiological ecology at Cordell Bank.

The major objective of the Coastal Communities Branch is to determine how changes in the environment affect the distribution, abundance and the relative success of recruitment in groundfish species. Changes considered include regular seasonal transformations of the habitat, as well as changes associated with irregular environmental events like El Niños. Emphasis is on how these changes affect interspecific relationships, particularly those between predator and prey. Because prey populations fluctuate widely in response to habitat transformations, the ability of specific predators to accept alternate prey in the absence of preferred prey is a major topic of study. Information from these studies should help managers anticipate not only the effects of environmental change on the relative availability of prey, but also the impact of fisheries for such important prey as shortbelly rockfish and anchovies. In addition, recruitment strength is thought to correlate with certain elements of environmental change, and so is another topic of study.

The investigation coordinates sampling of commercial and recreational lingcod landings in California and Oregon and contributes to assessments of the lingcod stock for the Groundfish Management Team of the Pacific Fisheries Management Council.

b. National Marine Fisheries Service - SWFSC

Coastal Division scientists, in cooperation with the Southwest Fisheries Science Center Tiburon Laboratory, NOAA's National Undersea Research Program, and the Monterey Bay Aquarium Research Institute continue to develop technology and procedures for estimating abundance of fish stocks using remotely operated underwater vehicles (ROV's). A paper comparing ROV estimates of fish abundance and traditional swept area estimates from bottom trawl surveys is in press. It appears that traditional swept-area methods may underestimate fish abundance and are more variable than ROV surveys in many cases.

2. Shelf Rockfish

b. National Marine Fisheries Service - SWFSC

New genetic studies of rockfish (Sebastes) are being initiated by the Coastal Division in three areas: 1) determination of phylogenetic relationships among species, 2) development of genetic techniques for identification of eggs and early stage larvae, not identifiable by other means (by amplification and sequencing of larval DNA followed by comparison to adult sequences from phylogenetic studies), and 3) analysis of rockfish population structure based on microsatellite DNA allele frequencies.

A molecular genetic approach, based on the sequencing of the cytochrome b gene, is being used to identify rockfish larvae. There are over 70 species of rockfish along the west coast of North America. Identification of early life stages is a recurrent problem because of their morphologic similarity. Phase one is to sequence genes from adults of each species to obtain species-specific genetic signatures. Larvae from samples will then be positively identified based on their genetic sequence. This approach can not be applied to large numbers of samples but will help taxonomists identify useful physical characteristics useful for species identification. Phase two is to examine the DNA sequences for species-specific restriction sites that will be, in effect, a "bar code" for each species. This method could potentially be automated to identify larger numbers of larvae in plankton samples.

The Coastal Division of the SWFSC is beginning an analysis of commercial rockfish fisheries in the Conception management area. Preliminary analysis revealed an important commercial fishery for blackgill rockfish in this area. Landings of blackgill peaked in the mid-1980's and then declined. Biological data including age structure and longevity are being collected. A preliminary stock assessment is being prepared.

PFEL conducts research to identify the impacts of fishing activity on rockfish community structure and to assess species-habitat relationships using geophysical and in situ submersible techniques. Their research includes evaluating deepwater fish and habitat resources in a marine protected area; PFEL also is convening a workshop to evaluate marine protected areas as a means to manage and conserve rockfish populations on the west coast. Additionally, PFEL is describing changes in the recreational rockfish fisheries of the Monterey Bay area using multi-decadal time series of landings and size data collected by CDFG. PFEL personnel are also examining the influence of environmental variability on recruitment in four species (chilipepper, widow, canary, and yellowtail rockfish).

Tiburon Laboratory's recruitment work, which aims to detect differences in relative strength of rockfish year-classes prior to their entry into the fishery, continues. Annual surveys using midwater trawls determine the relative abundance and distribution of first-year juvenile rockfishes off the coast of central California. In this work, staff members are evaluating interannual variation in oceanographic conditions, plankton abundance, juvenile rockfish diet, time of spawning, and growth rate. Oceanographic data are collected with a CTD and an acoustic Doppler current profiler. Staff members collaborate with staff of the SWFSC-PFEL in analyses of the oceanographic data that are published in Technical Memoranda. Staff members also collaborate with scientists of UC Davis to study the nearshore recruitment process.

4. Thornyheads

b. National Marine Fisheries Service - SWFSC

A publication during 1996 by Coastal Division scientists includes a description of relationships between depth and length of short- and longspine thornyhead. Results indicate that deep water refuges (where maximum shortspine thornyhead and Dover sole spawning biomass occurs) could be used to manage the valuable commercial fisheries on the continental slope. Coastal Division and scientists at the Northwest Fisheries Science Center in Newport are using results to estimate fishery selectivities based on trawl survey and logbook data. This ongoing work will be incorporated into stock assessments during 1997 for shortspine and longspine thornyhead, Dover sole and sablefish.

A report describing use radioisotope ratios to validate criteria for ageing shortspine and longspine thornyhead was completed in 1995. The work was a joint effort involving scientists at Scripps Institution of Oceanography, Moss Landing Marine Laboratory and the University of Hawaii. A report has been published. Results, though uncertain, indicate that shortspine thornyhead is very long-lived and the report will be used in stock assessment work during 1997.

5. Sablefish

b. National Marine Fisheries Service - SWFSC

The SWFSC Tiburon Laboratory is collaborating with the AFSC on an OTC-based study of sablefish age determination, with the intent of developing criteria that will improve reader agreement which has been poor for sablefish captured off California, Oregon and Washington. About 2500 fish were released in 1991. About 325 fish have been recovered, and otoliths from those fish are being examined by Tiburon and AFSC scientists.

The SWFSC Tiburon Laboratory assisted scientists from the Alaska Fisheries Science Center on an assessment of the sablefish fishery that was published in the PFMC Status of Stocks document.

6. Flatfish

b. National Marine Fisheries Service - SWFSC

In 1996, Coastal Division scientists published a description of the growth and duration of Dover sole as planktonic larvae. Dover sole may remain in the planktonic larval stage for as long as two years. This surprising result has strong implications for interpreting stock structure and population definition in Dover sole because larvae may be dispersed over great distances.

7. Pacific whiting

b. National Marine Fisheries Service - SWFSC

The 1996 California Cooperative Oceanic Fisheries Investigations (CalCOFI) conference was devoted entirely to a symposium on Pacific hake. Twenty papers, presented at the symposium or submitted afterward, are being considered for publication in a special symposium section of the 1997 volume of CalCOFI Reports.

The Coastal Division continues an ongoing research program dealing with reproductive biology and early life history of Pacific hake. This work is part of a broad and comprehensive cooperative research effort by the Southwest, Alaska and Northwest Fisheries Science Centers. In 1996 and 1997, cruises aimed at collecting spawning adults were carried out. The cruise during 1997 was particularly successful because ripe and running adults were captured and eggs were spawner artificially and held in incubators to collect information about temperature dependent development rates. These preliminary data will be augmented in 1998. In addition, the size of the spawning aggregation of hake was measured and drogues were set in spawning schools at depth. After the drogues had drifted north along the coast beyond Point Conception, ichthyoplankton samples detected high concentrations of larval hake and verified that the patch of spawning products had persisted.

During 1996, an adaptive approach for sampling hake eggs and larvae was evaluated based on data from cruises during 1995. Results, which have been submitted for publication, indicate that considerable increases in precision are possible but with the added complication of some bias.

A joint project with Canadian scientists (Department of Fisheries and Oceans, Nanaimo) and scientists at the Alaska Fisheries Science Center concerning reproductive histology of hake is currently underway. Preliminary data prove that hake spawn repeatedly during the spawning season. Samples from several hundred hake gonads are being worked up for detailed histology studies.

The CalCOFI database is now complete for hake larvae sampled during 1951-1996. The updated time series is being used to construct a time series of larval production estimates, with corrections for mortality and growth.

During 1996, Coastal Division scientists published a review of the population biology of hake along with life table models. Results indicate that effects of adjacent year classes may prevent sequential strong recruitments. Work to identify oceanographic features associated with years of strong hake recruitment is underway. It appears, in particular, that strong recruitment tends to occur when hake spawn in northern areas and eggs and larvae drift northward along the coast.

Coastal Division scientists have completed a research project that used daily growth rings in otoliths to measure growth rates in the larval population after spawning and in fish that actually survived the larval phase and became juveniles. Comparison of growth rates in the larval population with those in survivors indicates that survivors had higher growth rates, on average, than the bulk of the population. Results have been submitted for publication.

9. Lingcod

b. National Marine Fisheries Service - SWFSC

Port sampling of Oregon and California commercial landings of lingcod fin rays for aging was initiated in January 1992. Sampling is conducted by Oregon Dept. of Fish and Wildlife and California Dept. of Fish and Game, but is coordinated through Tiburon. Aging of the lingcod fin rays also occurs at Tiburon. The target is to sample two trips per month per gear category. The eventual goal is to obtain enough years for an age structured analysis. Sampling of the California recreational catch also began in 1992 with length-sex sampling in all ports and fin ray sampling for age analysis in the San Francisco-Princeton ports. In 1993, this program was expanded to age sampling statewide. Age structure sampling of Oregon's recreationally-caught lingcod began in 1994, and included state of maturity. Currently, Tiburon staff is comparing lingcod age and growth patterns from California waters with observations from Washington and Canada.

b. National Marine Fisheries Service - SWFSC

Coastal Division scientists, in cooperation with the Southwest Fisheries Science Center Tiburon Laboratory, NOAA's National Undersea Research Program, and the Monterey Bay Aquarium Research Institute have developed technology and procedures for estimating abundance of fish stocks using remotely operated underwater vehicles (ROV's). A paper comparing ROV estimates of fish abundance and traditional swept area estimates from bottom trawl surveys was published during 1995. It appears that traditional swept-area methods may underestimate fish abundance and are more variable than ROV surveys in many cases.

The Coastal Division is conducting a molecular genetics project that compares the population structure of Scorpaenid fishes with long planktonic dispersal phases (e.g. longspine and shortspine thornyheads, Dover sole) with the population structure of live bearing Scorpaenids that have larger, precocious young, and shorter larval stages (e.g. rosethorn rockfish). The hypothesis is that most dispersal in deep water Scorpaenid groundfishes occurs in the pelagic larval and juvenile stages and that the rockfish species will show more regional genetic differentiation and less dispersal than thornyheads. Mitochondrial DNA sequences from samples from Alaska, Oregon and five sites in California have been and are being sequenced. Preliminary results support the hypothesis is valid because rockfish species show substantial regional variation in mitochondrial DNA while thornyheads and Dover sole do not.

Investigations of the physiological ecology of the groundfish complex are proceeding based on extensive shipboard studies in Monterey Bay and laboratory experiments. Studies have focused on flatfishes and the rockfish-thornyhead group. Many of these fishes have adult spawning biomass maxima in the Oxygen Minimum Zone (600-1000 m). The specific adaptations and bioenergetic constraints imposed by this food- and oxygen-poor habit is being addressed through a series of field and laboratory studies. These studies help define limits on productivity of deep water fisheries and help predict the effects of exploitation on groundfish adapted to life in the deep water community.

A new research program will be initiated in 1997 aimed at measuring the reproductive output of groundfish and other species in relatively small habitats. The proposed approach, based on site intensive ichthyoplankton sampling, may provide information about the type of habitat and size or areas required for marine refugia. DNA based methods for identifying cryptic rockfish larvae (described above) will be an important part of this work.

Coastal Division economists regularly develop and analyze information regarding the commercial and recreational groundfish fisheries off the Pacific Coast, emphasizing the California region. Regular data collection activities include periodic updating of cost and earnings data for groundfish trawlers, fuel prices, and economic indices of trawl fishery productivity.

Research on economic effects of individual transferable quota, other limited entry approaches and measuring economic capacity in the groundfish and other fisheries continues to be a priority. Division economists are currently working on an FAO/NMFS sponsored workshop on measuring fishery capacity that will be held in La Jolla in 1997.

An economic description of the California rockfish fishery, emphasizing recent trends such as the near shore fishery for live rockfish is being developed by Coastal Division economists working collaboratively with state and federal biologists.

A workshop dealing with fixed costs in benefit-costs analyses was conducted during 1995 and a report was published in 1996. Results of the workshop were applied to analysis of hake allocation options during 1996.

In 1997, an bioeconomic analysis of harvest policies for hake was begun by economists and biologists at the University of Oregon, Alaska Fisheries Science Center and Coastal Division. The work may lead to ways of setting quotas in the US fishery that better balance goals for consistent and high catch levels while protecting biological productivity.