Age, growth and maturity of oceanic whitetip shark (Carcharhinus longimanus) from Papua New Guinea
Journal Publication ResearchOnline@JCUAbstract
Oceanic whitetip sharks (Carcharhinus longimanus) in the Western Central Pacific have been overfished and require improved assessment and management to enable planning of recovery actions. Samples from 103 individuals (70 males and 33 females; 76.0-240- and 128-235-cm total length (TL) respectively) were used to estimate age, growth and maturity parameters from sharks retained by longline fisheries in Papua New Guinea. Back-calculation was used because of the low number of juveniles and a multimodel framework with Akaike's information criterion corrected for small sample size (AIC(c)) estimated growth parameters. The von Bertalanffy growth model provided the best fitting growth model for both sexes. Parameter estimates for males were: asymptotic length (L-infinity) = 315.6 cm TL; growth coefficient (k) = 0.059 year(-1); and length at birth (L-0) = 75.1 cm TL. For females, the parameter estimates were: L-infinity = 316.7 cm TL; k = 0.057 year(-1); and L-0 = 74.7 cm TL. Maximum age was estimated to be 18 years for males and 17 years for females, with a calculated longevity of 24.6 and 24.9 years respectively. Males matured at 10.0 years and 193 cm TL, whereas females matured at 15.8 years and 224 cm TL. C. longimanus is a slow-growing, late-maturity species, with regional variation in life history parameters, highlighting increased vulnerability to fishing pressure in this region.
Journal
Marine and Freshwater Research
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Volume
68
ISBN/ISSN
1448-6059
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Issue
6
Pages Count
12
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Publisher
CSIRO
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EISSN
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DOI
10.1071/MF16165