Environmental preferences of Alopias superciliosus and Alopias vulpinus in waters near Marshall Islands

This paper reports on a survey carried out in waters near Marshall Islands and on the analysis of catch rates of bigeye thresher shark, Alopias superciliosus, and thresher shark, Alopias vulpinus. The optimum swimming depth, water temperature, salinity and dissolved oxygen range of bigeye thresher s...

Full description

Saved in:
Bibliographic Details
Published in:New Zealand journal of marine and freshwater research 2011-03, Vol.45 (1), p.103-119
Main Authors: Cao, D-M, Song, L-M, Zhang, Yu, Lv, K-K, Hu, Z-X
Format: Article
Language:English
Subjects:
Alopias superciliosus
Alopias vulpinus
bigeye thresher shark
bycatch
environmental preferences
Freshwater
longline
Marine
Marshall Islands
thresher shark
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper reports on a survey carried out in waters near Marshall Islands and on the analysis of catch rates of bigeye thresher shark, Alopias superciliosus, and thresher shark, Alopias vulpinus. The optimum swimming depth, water temperature, salinity and dissolved oxygen range of bigeye thresher sharks were identified as 240-360 m, 10-16°C, 34.5-34.7 and 3.0-4.0 ml/l, respectively, while for thresher sharks they were 160-240 m, 18-20°C, 34.5-34.8 and 1.0-1.5 ml/l, respectively, during daytime. The bigeye thresher shark and thresher shark were widely distributed in areas where the dissolved oxygen was higher than 0.5 ml/l. Some mitigation measures were recommended to reduce the bycatch of bigeye thresher shark and thresher shark, including avoiding fishing in peak areas and periods of shark abundance, using fish as bait and using nylon monofilament leaders. Furthermore, the hook depth data could be input into the 'habitat model' to standardise the shark catch per unit effort (CPUE).
ISSN:0028-8330
1175-8805
DOI:10.1080/00288330.2010.540017