Age, growth and maturity of the Australian sharpnose shark Rhizoprionodon taylori from the Gulf of Papua

Baje, Leontine, Smart, Jonathan J., Chin, Andrew, White, William T., and Simpfendorfer, Colin A. (2018) Age, growth and maturity of the Australian sharpnose shark Rhizoprionodon taylori from the Gulf of Papua. PLoS ONE, 13 (10).

[img]
Preview
PDF (Published Version) - Published Version
Available under License Creative Commons Attribution.

Download (1MB) | Preview
View at Publisher Website: https://doi.org/10.1371/journal.pone.020...
 
3


Abstract

Coastal sharks with small body sizes may be among the most productive species of chondrichthyans. The Australian sharpnose shark (Rhizoprionodon taylori) is one of the most productive members of this group based on work in northern and eastern Australia. However, life history information throughout the remainder of its range is lacking. To address this knowledge gap, the age, growth and maturity of R. taylori caught in the Gulf of Papua prawn trawl fishery in Papua New Guinea, were studied. One hundred and eighty six individuals, comprising 131 females (31–66 cm TL) and 55 males (31–53 cm TL) were aged using vertebral analysis and growth was modelled using a multi-model approach. The lack of small individuals close to the size at birth made fitting of growth curves more difficult, two methods (fixed length at birth and additional zero aged individuals) accounting for this were trialled. The von Bertalanffy growth model provided the best fit to the data when used with a fixed length-at-birth (L0 = 26 cm TL). Males (L∞ = 46 cm TL, k = 3.69 yr-1, L50 = 41.7 cm TL and A50 = 0.5 years) grew at a faster rate and matured at smaller sizes and younger ages than females (L∞ = 58 cm TL, k = 1.98 yr-1, L5o = 47.0 cm TL and A50 = 0.93 years). However, none of the methods to account for the lack of small individuals fully accounted for this phenomenon, and hence the results remain uncertain. Despite this, the results reaffirm the rapid growth of this species and suggest that the Gulf of Papua population may grow at a faster rate than Australian populations. Rhizoprionodon taylori is possibly well placed to withstand current fishing pressure despite being a common bycatch species in the Gulf of Papua prawn trawl fishery. However, further research needs to be undertaken to estimate other key life history parameters to fully assess the population status of this exploited shark species and its vulnerability to fishing in the Gulf of Papua.

Item ID: 57009
Item Type: Article (Research - C1)
ISSN: 1932-6203
Keywords: shark, fisheries, Papua New Guinea, Pacific, marine biology, fish, management
Copyright Information: Copyright © 2018 Baje et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funders: National Fisheries Authority of Papua New Guinea, Australian Centre for Internation al Agricultural Research (ACIAR), CSIRO Oceans and Atmosphere, ACIAR John Alwright Fellowship, Schlumberger Foundation
Projects and Grants: ACIAR project FIS/2012/102
Date Deposited: 04 Feb 2019 23:22
FoR Codes: 07 AGRICULTURAL AND VETERINARY SCIENCES > 0704 Fisheries Sciences > 070403 Fisheries Management @ 50%
06 BIOLOGICAL SCIENCES > 0608 Zoology > 060809 Vertebrate Biology @ 30%
05 ENVIRONMENTAL SCIENCES > 0502 Environmental Science and Management > 050202 Conservation and Biodiversity @ 20%
SEO Codes: 83 ANIMAL PRODUCTION AND ANIMAL PRIMARY PRODUCTS > 8302 Fisheries - Wild Caught > 830204 Wild Caught Fin Fish (excl. Tuna) @ 50%
96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960808 Marine Flora, Fauna and Biodiversity @ 50%
Downloads: Total: 3
Last 12 Months: 3
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page