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Email the author (Login required) Evaluation of the artisanal longline fishery and its effect on the longnose stingray (Dasyatis guttata) in Zapara Island, Gulf of Venezuela
Submited: 2016-04-12 07:03:30 | Published: 2017-05-18 16:23:41
DOI: https://doi.org/10.3856/vol45-issue2-fulltext-6
Abstract
The longnose stingray (Dasyatis guttata) is a target species in the artisanal fisheries of the southern Gulf of Venezuela. Despite its economic importance, nowadays, studies about its status are lacking. During six continuous months (18 working days in total), we followed the artisanal fishery activities from Zapara Island, and evaluated morphometric characteristics, sex ratio, and the capture per unit effort (CPUE/ind/1000 hooks) of D. guttata. Biological sampling included: disc widths (AD), body mass total (PT), and sex. Using statistical analysis we assessed: a) the length-weight relationships by sex, b) monthly body condition, using the Fulton Index (K), and c) the CPUE. We evaluated 210 individuals of D. guttata. The mean values of our results were: AD = 64.14 ± 13.18cm (range 32-95 cm); PT = 8.36 ± 4.87 kg (range 0.80- 24.50 kg). The sexual proportion was (2.26♀: 1♂) (X2= 31.716, P < 0.05); hence we presume a spatial segregation occurred between females and males in the studied area. Length-weight relationship was statistically significant (P < 0.0001), and also varied according to the sex ♀: PT(kg) = [(0.00027)×(AD(cm)2.46)]; ♂: PT(kg) = [(0.00035)×(AD(cm)2.34)]. The K value showed differences between sexes during November and December. We obtained a CPUE of 4.88 individuals/1000 hooks. We compared our findings with previous research carried out in the southern Caribbean. Further research about this species in the area is recommended.
