Oct 22, 2015 - rasptail skate (Raja velezi), brown smoothhound .... May 2009) and 2 during the dry season (March 2010 tÃnez et al., 2010; Clarke .... branch bycatch along the Pacific coast of Costa Rica, Central America, during 2010â2012.
1
NOAA
Fishery Bulletin
National Marine Fisheries Service
Abstract—Demersal sharks and rays are common yet vulnerable components of the bycatch in tropical bottom-trawl fisheries. Little is known about the elasmobranch assemblages associated with most of these fisheries, particularly within the eastern tropical Pacific. This study characterized the elasmobranch assemblage associated with the shrimp trawl fishery along the Pacific coast of Costa Rica. Between August 2008 and August 2012, 346 trawl hauls were conducted at depths of 18–350 m. These hauls resulted in a sample of 4564 elasmobranchs from 25 species and 13 families. The Panamic stingray (Urotrygon aspidura), rasptail skate (Raja velezi), brown smoothhound (Mustelus henlei), and witch guitarfish (Zapteryx xyster) accounted for more than 66% of the elasmobranch abundance within the bycatch. Depth was the main factor influencing the elasmobranch assemblage; species richness was significantly higher at depths 100 m 2.3 8 2.0 8 1.7 7 1.3 5 – – 7.0 27 Total 12.1 27 7.3 28 218.0 113 167.3 111 165.6 66 570.0 345
common (1–5% of total abundance) and 11 were rare (
