Habitat use and diel vertical migration of bigeye thresher shark: Overlap with pelagic longline fishing gear. | - CCMAR -

Journal Article

TítuloHabitat use and diel vertical migration of bigeye thresher shark: Overlap with pelagic longline fishing gear.
Publication TypeJournal Article
AuthorsCoelho, R, Fernandez-Carvalho, J, Santos, MN
Year of Publication2015
JournalMar Environ Res
Volume112
QuestãoPt B
Date Published2015 Dec
Pagination91-9
ISSN1879-0291
Palavras-chaveAnimal Migration, Animals, Atlantic Ocean, Circadian Rhythm, Conservation of Natural Resources, Ecosystem, Fisheries, Sharks
Abstract

Pelagic longliners targeting swordfish and tunas in oceanic waters regularly capture sharks as bycatch, including currently protected species as the bigeye thresher, Alopias superciliosus. Fifteen bigeye threshers were tagged with pop-up satellite archival tags (PSATs) in 2012-2014 in the tropical northeast Atlantic, with successful transmissions received from 12 tags for a total of 907 tracking days. Marked diel vertical movements were recorded on all specimens, with most of the daytime spent in deeper colder water (mean depth = 353 m, SD = 73; mean temperature = 10.7 °C, SD = 1.8) and nighttime spent in warmer water closer to the surface (mean depth = 72 m, SD = 54; mean temperature = 21.9 °C, SD = 3.7). The operating depth of the pelagic longline gear was measured with Minilog Temperature and Depth Recorders (TDRs), and the overlap with habitat utilization was calculated. Overlap is taking place mainly during the night and is higher for juveniles. The results presented herein can be used as inputs for Ecological Risk Assessments for bigeye threshers captured in oceanic tuna fisheries, and serve as a basis for efficient management and conservation of this vulnerable shark species.

DOI10.1016/j.marenvres.2015.10.009
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/26559889?dopt=Abstract

Alternate JournalMar. Environ. Res.
PubMed ID26559889
CCMAR Authors