NOAA Technical Memorandum NMFS - SEFC - 127 REPORT OF THE SOUTHEAST FISHERIES CENTER STOCK ASSESSMENT WORKSHOP August 3-6, 1982 Joseph E. Powers November 1983 U. S. Department of Commerce National Oceanic and Atmospheric Administration National Marine Fisheries Service Southeast Fisheries Center Miami Laboratory 75 Virginia Beach Drive Miami, Florida 33149 NOAA Technical Memorandum NMFS - SEFC - 127 REPORT OF THE SOUTHEAST FISHERIES CENTER STOCK ASSESSMENT WORKSHOP August 3-6, 1982 Joseph E. Powers November 1983 U.S. Department of Commerce Malcolm Baldrige, Secretary National Oceanic and Atmospheric Administration John V. Byrne, Administrator National Marine Fisheries Service William G. Gordon, Assistant Administrator of Fisheries Technical Memorandums are used for documentation and timely com- munication of preliminary results, interim reports, or similar special purpose information. Although the memorandums are not subject to complet~ formal review, editorial control, or detailed editing, they do reflect sound technical work. TABLE OF CONTENTS INTRODUCTION •........•....••...•••......•......•.....••.•...... i SPECIES GROUP REPORTS Billfish, Swordfish and Sharks (BSS) B 1 ue Mar 1 in 1 Whit e Ma r 1 in ••••••..••••.•••••••••••••••.•••••••••••.•• 7 Sai 1fi sh/Spearfi sh 9 Swordfish 10 Sharks 15 Groundfish and Coastal Pelagics (GCP) King Mackerel 37 G r 0 und f ish 48 Marine Mammals and Turtles (MMT) Sea Turtles 83 Mar i n e Mamm a 1 s •••••••••••••••••••••••••••••••••••••••• 9 5 Menhaden and Coastal Herrings (MCH) Atlantic Menhaden 107 Gulf of Mexico Menhaden ....•........•...•........•... 114 Coastal Herrings 119 Reef Fish and Reef Resources (RFR) South Atlantic Reef Fish •....•..•.••••.•....•......•. 139 Puerto Rico and U.S. Virgin Islands Reef Resources ••. 146 Gulf of Mexico Reef Fish •...........••••..•.•......•. 151 Gulf of Mexico Stone Crabs ......................•.... 154 Gulf of Mexico and South Atlantic Spiny Lobster 157 Shrimp (SHR) ............................................ 175 GENERAL RESEARCH RECOMMENDATIONS •.•.•..•..••...•.•.•.......• 209 LIT ERAT UR E CI TED ..•..•.........•....••........•..•...•.•..•. 2 11 APPENDICES Appendix 1: List of Participants .........•...•......••.. 222 Appendix 2: List of Workshop Documents •••....•••...••••. 225 INTRODUCTION The first Southeast Fisheries Center (SEFC) Stock Asses~ment Workshop was convened at the SEFC i s Miami Laboratory on August 3-6, 1982~ The purpose of the Workshop was four-fold. The first objective was to develop written documentation on the present status of fishery stocks under the research purview of the SEFC. The report so developed represents existing knowledge and resul til1g management ...advice for. use by regional Fishery Managemerit Councils and other institutions and agencies. The second purpose of the. meeti ngwas to provide a timely forum for critical review of the stock assessment research being done by the SEFC and other research groups in the Southeast. The documents presented to the Workshop are the most current updates of analyses, given available data and available models. The third objective of this Workshop was to direct discussion of current stock assessments with the view toward improving their applicability and timeliness via further data collection and research efforts. The final objective was to promote scientific interchange between stock assessment researchers working on the fishery resources of the Southeast. The Workshop provided the first opportunity in the Southeast for formal and inf~rmal discussions of ongoing research. Thi s was par ticula,rly.effective in trans... ferring knowledge about analytical techniques, population models and statistical procedures from researcher to researcher and institution to institution. The emphasi s of the Stock Assessment Workshop was the bio- logical status of the stocks and the effects of fishing effort and mortali ty on the production, recrui tment and yield of the stocks. No attempt was made to incorporate economic analyses on the status of the fisher ies and fishing industr ies. Analyses of fishery operations were only included as they relate to the quantification of fishing effort and the measurement of ensuing fishing mortality. Economic assessment awaits further data collection, analyses and future workshops. It should be noted that the SEFC' s stock assessments per- taining to bluefin tuna were not reviewed during the Workshop and thus are not included in this year's Workshop Report. Bluefin tuna analyses were reviewed by a separate group of experts which culminated in the presentation of the SEFC's analysis to the Standing Committee for Research and Statistics of the International Commission for the Conservation bf Atlantic Tunas. The Workshop was attended by more than fifty people repre ... senting individual laboratories within the Southeast Fisheries Center, the Northeast and Southwest Fisheries Centers, state -i- agencies of the southeast United States and Territories( the three Fishery Management Councils within the region South Atlantic, Gulf of Mexico and Caribbean) and various academic institutions. More than thirty stock assessment reports and documents were submi tted to the Workshop by participants. These were reviewed during the Workshop by working groups covering: (1) Billfish, Swordfish and Sharks; (2) Groundfish and Coastal Pelagics; (3) Marine Mammals and Sea Turtles; (4) Menhaden and Coastal Herrings; (5) Reef Fish and Reef Resources; and (6) Shrimp. These groups represent an extremely diverse set of resources exhibiting a wide variety of biological, ecological and fishery characteristics. They demonstrate the complexity of stock assessment research and resource management in the southeast. The Workshop provided a succinct update and review of the status of these resources. -ii- SAW/82/BSS _________BILLFISH ~ SWORDFISH 1.... AND SHARKS. (BSS).__ BLUE MARLIN I. DESCRIPTION OF FISHERIES The following history of the fisheries applies to white marlin, sailfish, and spearfish as well as to blue marlin. 1.1. History of the Fisheries 1.1.1. Commercial Longline Fishery The commercial fishery for billfishes (excluding swordfish) in the Atlantic Ocean is conducted by the nations that maintain longline fleets. The _,fishing effort of these fleets is prin- cipally directed at tuna. However, billfishes occur in the same areas and depths as tunas and consequently, the incidental by- catch of billfishes is significant. The principal nations currently longlining in the Atlantic are Japan, Taiwan, Korea, Cuba, Venezuela, and to a lesser extent, Brazil, U.S.S.R., and Panama (SAW/82/BSS/2). Prior to 1956, the only fisheries for billfishes in the Atlantic were the sport fishery and small subsistence fisheries throughout the Caribbean and off South America (Ueyanagi 1974). In 1956 the Japanese began longlining for yellowfin tuna in the waters north of Brazil. Within two years their opera tiol). expanded, in equatorial waters, to the African coast. A rapid expansion followed both to the north and south in pursui t of albacore, and by 1965 the fishery covered the area between latitude 45'S and 45·N. Japanese fishing effort declined after 1965 but an increase in the activity of the Cuban, Korean, Taiwanese, and Venezuelan longline fleets in the late 1960's more than made up the decrease in Japanese effort (Kikawa and Honma 1976). During the 1970's, the Japanese fleet increasingly targeted bluefin and bigeye tunas. Longline catches of billfishes, as illustrated by the blue marlin and white marlin catches in the North Atlantic (Figs. BSS-l and BSS- 2, respectively), have declined appreciably since the mid-1960's. Blue marlin catches have decreased 90% from the peak level in 1963 to the 1979 level. Simila rly, white marlin catches have declined 76% over the period 1965-79. Similar declines have probably occurred in sailfish and spearfish catches but the practice of reporting sailfish and spearfish in a single catch category - a practice employed by all longlining nations makes the interpreta tion of trends more difficuIt. -1- SAW/82/BSS Furthermore, the rela tive proport ion of the catch taken by the individual longline nations has also changed markedly (Tables BSS-l and BSS-2). Over the period 1963-65, the average annual Japanese catch of blue marlin (4174 MT) comprised 95% of the total longline catch of blue marlin and their white marlin catch (1608 MT) represented 90% of the total. By 1977-79 the Japanese percentages had decreased to 14% for blue marlin and to 20% for white marlin. Although the fishing effort. of the Atlantic longline fleet is principally tuna-directed, billfishes have been a valuable bycatch, commanding prices comparable with tunas on the world markets. Prices for the marlins at Japanese fish markets are typically lower than prices for bluefin and bigeye tunas but albacore, skipjack, and yellowfin do not command as high a price as the marlins (NMFS 1981). 1.1.2. Recreational Fishery Sport fishing for billfishes is conducted in nearly all the warm ocean areas, primarily in the tropical and subtropical seas (de Sylva 1974). In the Atlantic, sport fisheries are concen- trated from Massachusetts to North Carolina and about Bermuda, southeastern Florida, the northern Gulf of Mexico, the Bahamas, the larger islands of the Caribbean, Mexico (mainly Cozumel), Venezuela, from the Ivory Coast to Senegal in West Africa, and off Portugal and Spain. Landings from all these fisheries, other than the U.S. sport fishery (which includes Puerto Rico and the Virgin Islands), are not