Premium
Shark bycatch in the experimental tuna longline fishery in L akshadweep S ea, I ndia
Author(s) -
Kumar K. V. Aneesh,
Pravin P.,
Meenakumari B.,
Khanolkar P. S.,
Baiju M. V.
Publication year - 2015
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/jai.12682
Subject(s) - bycatch , tuna , fishery , carcharhinus , biology , thunnus , fishing , stingray , yellowfin tuna , fish <actinopterygii>
Summary Bycatch from the experimental longline operations in the Lakshadweep Sea were studied. The experiments were conducted on converted P ablo boats, originally used for pole and line fishing operations, to capture skipjack tuna in the L akshadweep I slands. The overall bycatch rate was very high, with a mean hooking rate of 8.05/1000 hooks compared to the targeted tuna catch (1.75/1000 hooks). Bycatch contributed 82.4% of the catch in comparison to the tuna (17.6%) T hunnus albacares, in the longline operations. Silky shark ( C archarhinus falciformes ) with 89.9% was the dominant shark species followed by C . amblyrhynchos , G aleocerdo cuvier, A lopias pelagicus, N egapriion acutedens and S phyrna lewinii with 4.7, 2.7, 1.4, 0.7 and 0.7%, respectively. Sharks contributed to 74.1% of the catch, followed by 15.7% sailfishes and 10.2% miscellaneous fishes. Higher bycatch rates were evident during evening hours compared to mornings, but the results were not significant statistically. Studies on the effects of depth on the overall fishing performance and species selectivity failed to establish any significant relationship at a depth range of 35–100 m. Soaking time had a significant effect on bycatch rates. The hooking rate of sharks declined with an increase in soaking time. Considering the high shark bycatch in the fishery, an accurate monitoring of the longline fish catches in the L akshadweep waters is an important step towards ensuring the sustainability of other populations, especially sharks.