Development Potential of Underutilized Trawl Fish in the South Atlantic Bight
Total Page：16
File Type：pdf, Size：1020Kb
DEVELOPMENT POTENTIAL OF UNDERUTILIZED TRAWL FISH IN THE SOUTH ATLANTIC BIGHT R. A. Low, Jr. G. F. Ulrich F. Blum '. Marine Resources Research Institute South Carolina Wildlife and Marine Resources Department Charleston, South Carolina 29412 Technical Report Number July 1982 TABLE OF CONTENTS Page ABSTRACT ... .. ....................................... .................................... 1 PREFACE .... .. ........................... ......... ... ........................... l ACKNOWLEDGEMENTS. • . • • • . • . • • • • . • . • . • . • • • • . • • • • • • • • • • • • . • . • • • • • 1 INTRODUCTION. • • • • . • • • . • . • • • • • • . • • • • • • • • • • • • • • • . • • • • • • • • • • • . • • . • • . • . • • • • • • . • • . • 1 GROUNDFISH COMPOSTION BY DEPTH AND AREA. • • • • • • • • • • • • • • • • • • • • • • • • . • • • • . • • • • • • • • • • • • • • 2 DESCRIPTIONS OF MAJOR UNDERUTILIZED SPECIES ..•.••..••....•.• , • . • . • • • • • • • . • . • . • • • • • . • • • • 14 CONCLUSIONS. ............... .. ....... .. .. ... .......... .. .. ... .. ........ ......... 25 LITERATURE CITED • ....•• , • • • • • • • • . • • • . • • • • • • • • • • • • . • • • • . • • • • • • • • • • • • • • . • . • • • • • • • • • • • 29 FIGURE CAPTIONS FIG. 1. Minimum stock estimates of demersal teleosts over sand-mud bottom between C. Fear and C. Canaveral in 9-366 m (from Wenner et al. 1979a, b, c, d, 1980, unpublished~ data). FIG. 2. Seasonal composition of MARMAP d~mersal trawl catches (unpublished MARMAP data). FIG. 3 . Length distribution of southern porgy (from Wenner et al. 1979a, b, c, d, 1980). FIG. 4. Length distribution of orange f ilefish (from Wenner et al. 1979b' c, d). FIG . 5. Length distribution of planehead filefish (from Wenner et al. 1979a, b , c) . FIG. 6. Length distribution of inshore l i .zardfish (from Wenner et al. 1979a, b, 1980). FIG. 7. · Length distribution of spotted hake (from Wen ner et al. 1979a, b, d). FIG. 8. Length distribution of butterfish (from Wenner et al. 1979b, d) . FIG. 9. Length distribution of Spanish sardines (from Wenner et al. 1979a, c, 1980). FIG. 10. Length distribution of round herring (from Wenner et al. 1979b, d, 1980). LIST OF TABLES Page 1. Most abundant species by weight in 1974 - 1975 South Carolina shrimp trawl catches on a monthly basis. .... • • • . • . • • • . • • • . • • • • . • • • . • • • • • . • . • • • . • . • • . • . 6 2. MARMAP inshore catch rates (kg/hr) of fish in July-September 1980 and April- June 1981, using 40/60 4-seam shrimp trawls from a double-rigged 22-m shrimp boat...... .. 7 3. Dominant demersal teleosts by weight in MARMAP demersal trawl catches. ............... 9 4. Major findings of early trawl surveys in the South Atlantic Bight in depths of 55 m................. .. ... ........... ................................................ 13 5. MARMAP live-bottdm trawl results for three surveys...... ......... ..... ........ .. 15 LIST OF FIGURES Page 1. Minimum stock estimates of demersal teleosts over sand-mud bottom between C. Fear and C. canaveral in 9-366 m. ... .... ........... ... ............... ........ 3 2. Seasonal composition of MARMAP demersal trawl catches.................. ....... .. 4 3. Length distribution of southern porgy . ... • • ..••.• • •. , •• .. • • •.• • • .......•...• ; ..••.•• , 17 4 . Length distribution of orange file fish.. • . • . • • • • • . • . • . • . 19 5. Length distribution of planehead filefish . ..... ....... ......................... 20 6. Length distribution of inshore lizard fish.. ........ • • • • • . • . • • . • • • • • . 22 7. Length distribution of spotted hake... • . • • . • • . 23 8. Length distribution of butterfish. ..... • . • • . • . • . • . • . • . • . 24 9. Length distribution of Spanish sardines. • • . • • . • . • . • . • • . • . • . • . • . • . • • 26 10. Length distribution of round herring............................. ................... 27 1 Abstract ment Program (MARMAP) of the Marine Resourc es Research Institute for their assistance in Underutilized fish resources avail providing access to unpublished data. abl~ to demersal trawling in the South Atlantic Bight include (1) demersal fin fishes , (2) pelagic speci es, and (3) de Introduction mersal elasmobranchs. Brief descrip tions of species and size composition, The National Marine Fisheries Service, relative availability , geographic range, in the 1977 draft Fisheries Development in and depth distribut ion are provided for the United States, i ndicated that the poten each component. tial annual production of trawl groundfish in the southeast might r each 1. 5 million met The demersal f inf ish complex inshore ric tons (mt) . Such a resource could provide of the shelf break is dominated by a few alternative opportunities for vessels present species charact erized by small individual ly equipped for foodf ish trawling and shrimp size , limited availability, and wide dis ers seeking additional income during the off persal. These fishes include the south season. To i nvestigate the potential of this re ern porgy (St enotomus aculeatus), orange source, the Gulf and South Atlantic Fisheries De filefish (Aluterus schoepfi), planehead velopment Foundation contracted the Marine filefish (Stephanolepis hispidus) , sand Resources Center of the South Carolina Wild perch (Diplectrum formosum), and lizard life and Marine Resources Department. Objec fishes (Synodus spp. ) . Trawlable pelagic tives were to (1) describe underutilized de species, which include the r ound scad mersal fish resources of the South Atlantic (Decapterus punctatus) , Spanish sardine Bight; (2) evaluate their development poten (Sardinella aurita) , and butterfish tial r elative to (a) abundance, (b) availa (Peprilus tr~us) , appear to occur bility, (c) allowable level of exploitation , in small, widely dispersed Schools in and (d) suitability for harvesting; and (3) shore of the shelf break. The bulk of assess relationships with co- occur ring stocks the biomass taken in research surveys i n and with the habitats t hat affect their utili coa~tal ~aters consisted of elasmobranchs, zation. primarily large stingrays (Dasyatis spp. ) . The total amount of available fish de This report is a review of scientific pub creased with increasing depth. The extent lications, trade journals, cruise reports, and of resources deeper than 200 m is not well unpublished survey data of state and federal documented, although some survey results agencies. Consideration was l imited to (1) de suggest the presence of substantial quan mersal teleosts , (2) t rawlable pelagic species, tities of butterfish and round herring and (3) demersal elasmobr anchs. Composition (Etrumeus teres). and distri bution of groundfish in the South Atlantic Bight have been i nvestigated in sur veys dating back to at least 1950 (.Powell 1950; Preface Cummins et al. 1962; Struhsaker 1969; Wilk and Silverman 1976; Wenner et al . 1979a , b, c, d, This study was initiated with support 1980). These s urveys employed numerous types from the Gulf and South Atlantic Fisheries of otter trawls in depths to 400 m. Recent Development Foundation under contract foreign s urveys, targeted a t squid, have ex GASAFDFI No. 11-09-27613. Preliminary r e plored greater depths (Massey and Lacroix 1977; sults and our interpretation of them as Gutherz et al. 1978; National Marine Fisheries they relate to the development potential Service 1979) . The diversity of sampling gear of the resources are contained in a con permits an evaluation of the kinds of fish avail tract report fil ed in October, 1980. Some able to trawls when the data are pooled over additional information tas becQme and) able time. It is impossible, however, to evaluate since then. This report consists of an long-term trends i n relative species composition updated r eview of available factual infor and abundance because there are no synoptic ob mation r egar ding aspects of the life his servations using standardized gear and proce tory, distribution, and catchability of dures within any area or depth zone. All stock the resources that affect their develop estimates a r e based on data collected since ment potential. Transformation of such 1972; their status relative to historic popula informati on into an assessment of practi tion levels is not known. cal possibilities for commercial utiliza tion is an intuitive , s ubjective, and some Practical interest can be directed at (l) what speculative process beyond the scope a complex of species within a particular depth of this report. Our views in that regard range o·: (2) a par ticular species throughout are expressed i n t he contract repor t. its ran&e . In the f irst section below, the spe cies associations in each depth zone are de scribed by area and habitat, with availability Acknowledgements and stock size being considered for the ent ire complex. Depth strata were 9-18 m, 19-27 m, We are grateful to Dr. Roger Anderson 28-55 m, 56-110 m, 111-183 m, and 184-366 m. and the Gulf and South Atlantic Fisheries These correspond to six habitats having the Development Foundation for their initial following principal characteristics: support. We also thank the per sonnel of the Marine Resources Monitoring and Assess- 2 level. Their estimate is for the Gulf of Depth Surface Mexico and South Atlantic Bight combined and Habitat Range(m) Area (km2)a refers primarily to the incidental catch of fish by shrimpers. Coastal 0-18 18,083 (9-18 m) The trend in abundance of demersal tele osts (not including pelagics, elasmobranchs