Composição, abundância numérica e sazonalidade da pesca de tubarões e raias desembarcados na enseada do Mucuripe, Fortaleza - CE

Abstract

The fisheries for sharks and rays (elasmobranchs) off Ceará State is primarily conducted by artisanal fishermen that usually use small boats. Since elasmobranchs are susceptible to overfishing, it is important to monitor their captures along the State's coast. Therefore, in order to understand the dynamic of elasmobranch fisheries conducted by the fishing fleet that land at the Mucuripe Embayment, Fortaleza, Ceará, a monitoring program was conducted. Between November 2008 and October 2009, shark and ray landings were recorded weekly. Landed specimens were identified to the lowest taxonomic level possible. Each specimen was then sexed and measured for total length (sharks) and disc width (rays). A total of 935 elasmobranchs of 21 species from 9 families were recorded. Shark specimens totaled 51.4% of the records. The southern stingray Dasyatis americana was the most abundant ray, followed by the longnose stingray Dasyatis guttata. As for sharks, the sharpnose species Rhizoprionodon lalandei and Rhizoprionodon porosus were jointly the most abundant taxon, followed by the nurse shark Ginglymostoma cirratum. Overall catch sizes varied seasonally. This possibly reflected a variation of the fleet's fishing effort according to spiny lobster (Genus Panulirus) fishing season. A seasonal pattern of abundance was observed for some species, as the blacktip shark Carcharhinus lirnbatus and the stingrays D. americana and D. guttata.