Abstract
Trawl samples were collected from shrimping vessels throughout the Matagorda Bay System during the 1997 and 1998 Spring and Fall inshore commercial food shrimp seasons. These samples were used to estimate the level of incidental harvest associated with the inshore shrimp fishery, characterize the composition of this bycatch, and identify temporal relationships of constituent species. Monthly mean bycatch biomass levels ranged from 3.32 (December 1998) to 8.71 kg (August 1998) and were highest during summer months. Percent contribution of bycatch biomass to total monthly biomass exceeded 50% during May - September 1997 and July - October 1998. Bycatch:shrimp biomass ratios across seasons ranged from 1.03:1 to 1.68:1. Seasonal abundance ratios for bycatch:shrimp were <1:1 and increased between Spring and Fall of both years. Finfish:shrimp biomass and abundance ratios were as much as 9 times larger than those for invertebrates:shrimp. A total of 108 species (82 finfish, 26 invertebrate) comprised bycatch characterization samples taken, 23 of which have commercial or recreational value. Twenty-two species were dominant (contributing []5% of a monthly total), with the top five species (in terms of biomass and abundance) - blue crab (Callinectes sapidus), Gulf menhaden (Brevoortia patronus), sand seatrout (Cynoscion arenarius), spot (Leiostomus xanthurus), and Atlantic croaker (Micropogonias undulatus) - being important components in other commercial fisheries or recreationally valuable. Assemblages of dominant bycatch constituents (biomass and abundance) varied monthly. Changes in species composition probably resulted from factors such as species specific life history patterns, trawling location, and shrimping techniques. Dominant bycatch species identified in the current study have been documented as bycatch throughout other inshore areas. The majority of individuals taken as bycatch were juveniles, with commercially- and recreationally-important constituents typically smaller than their legally harvestable size limits.
Sparks, Debbie Laura (2000). Assessment of bycatch associated with the inshore shrimp fishery in Matagorda Bay, Texas. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -S684.