Reducing Elasmobranch Bycatch in the Atlantic Seabob (Xiphopenaeus kroyeri) Trawl Fishery of Guyana

The Atlantic seabob (Xiphopenaeus kroyeri) trawl fishery is very important to Guyana, with 88 licensed industrial vessels harvesting about 15,000 mt annually, representing Guyana’s most valuable seafood export. All vessels are already using both teleost by—catch reduction devices (BRDs) and turtle excluder devices (TEDs) to satisfy international market standards. However, the key stakeholder, the Guyana Association of Private Trawler Owners and Seafood Processors, is now seeking to access sustainable seafood markets through pursuing Marine Stewardship Council (MSC) certification. To this end, this study documents elasmobranch by—catch in the current fishery and examines the effectiveness of a modified TED (with a reduced bar spacing and the addition of a brace bar) in reducing elasmobranch by—catch. From July—August 2014, 131 tows were made, 80 of which represented simultaneous hauls with control and modified TEDs. One shark and 8 ray species were recorded. A statistically significant 40% decline in the elasmobranch catch rate was observed when using modified TEDs compared with control TEDs (mean by—catch rate dropped from 2.3 to 1.4 individuals per twin—trawl/h). Furthermore, modified TEDs significantly reduced the mean size of rays caught by 6.3%. This also resulted in a virtual elimination of 3 IUCN—designated \u27Near Threatened\u27 ray species in the by—catch, although having little effect on the capture of small—sized elasmobranch species, including the \u27Critically Endangered\u27 Caribbean Electric Ray (Narcine bancroftii). We conclude that the modified TED was successful in reducing the by—catch of vulnerable elasmobranch species and should advance progress towards attaining by—catch standards required for MSC certification

Short-term Estimate of Finfish Bycatch Discards in the Inshore Artisanal Shrimp Fishery of Guyana

The artisanal shrimp fishery in Guyana is important for livelihood and food security, involving around 300 vessels owned and crewed exclusively by Guyanese nationals. This fishery uses Chinese seines and operates in major river estuaries. It targets penaeid shrimp, but also retains some finfish and is known to discard a significant but undocumented quantity of smaller finfish bycatch. The lack of knowledge regarding the bycatch is a concern for fishery management and biodiversity conservation. In this study, we quantify for the first time the finfish bycatch discards through onboard observations (July—August 2016) of a single typical vessel operating in the Demerara estuary. Wet weights of the total catch, retained catch, and finfish discards were recorded separately for each of 76 seine hauls, and subsequently presented as catch rates per trip, catch rates per seine haul (kg/haul), and catch rates standardized per hour of seine net soak—time (kg/hr). A sub—sample of finfish discards was taken from every haul to determine taxonomic composition and species—specific length frequencies. Examination of 2,012 discarded finfish distributed among 32 species revealed high taxonomic diversity, none of which were considered vulnerable by the IUCN Red List. Most finfish discards were small (modal size class 5—7 cm fork length) and included juveniles of 15 species of importance to other fisheries in Guyana. On average, a standardized total catch rate of 14.8 kg was taken per hour of seine net soak—time, yielding 3.9 kg retained catch (shrimp and a few selected finfish), 10.3 kg of finfish bycatch discards, and 0.6 kg of miscellaneous invertebrate discards. This demonstrates significant wastage (finfish discards represent about 69% of the total catch weight) and potential for negative impact on biodiversity and other commercial fisheries. The information provided here addresses an important knowledge gap in the artisanal fisheries of Guyana

The Biology of Wahoo (Acanthocybium solandri) in the Western Central Atlantic

This contribution summarizes aspects of the biology of the wahoo, Acanthocybium solandri (Scombridae), that are pertinent to assessment and management of this species in the western central Atlantic (WCA). In this region wahoo is a target species for both commercial and recreational fisheries, and annual landings appear to have increased steadily over the last 30 years to in excess of 2000 mt. Wahoo is believed to be migratory, but little is known of the migration patterns. Significant seasonal variation in catches within the region indicates that it is seasonally abundant in most locations. Periods of peak abundance occur from the fall through spring in the southeastern and northern Caribbean islands, and are restricted to the warmer months (late spring through early fall) in the more northerly locations (northern Gulf of Mexico, North Carolina, and Bermuda). Wahoo exhibits early sexual maturity (within the first year) and a spawning season that extends from at least May to October. Females are multiple batch spawners and are highly fecund. Limited age and growth studies indicate that it is a relatively fast-growing species, has high mortality, and probably lives for 5-6 years. Wahoo is primarily piscivorous, although some invertebrates including squids are eaten. A relatively small number of parasite species have been associated with it. There is no evidence of more than a single shared stock of wahoo in the WCA, and recent genetic studies, using RAPD markers, suggest that stock boundaries may extend beyond this region. The status of the wahoo resource in the WCA remains unclear. Reliable wahoo catch and fishing effort data from the entire WCA, improved knowledge of migration patterns, reproductive characteristics and critical habitat (e.g., preferred spawning areas), validation of age, growth and mortality estimates, and a more comprehensive analysis of stock structure for the entire Atlantic are needed for informed wahoo stock assessment and management