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Bigeye Tuna behavior and physiology. Their relevance to stock assessments and fishery biology.

Brill, RW; Bigelow, KA; Musyl, MK; Fritsches, KA and Warrant, Eric LU (2005) In Collective Volume of Scientific Papers 57(2). p.142-161
Abstract
Bigeye tuna (Thunnus obesus) have distinctive depth distributions and vertical movement

patterns. They remain in the uniformed temperature surface layer at night and can descend to

greater than 500 m depth at dawn. They thus mirror the vertical migrations of the small

nektonic organisms of the deep sound scattering layer and extensively exploit these as a food

resource. At their maximum depths, bigeye tuna frequently experience prolonged exposure to

ambient temperatures (.5 EC) that are up to 20EC colder than surface layer temperature, and

oxygen concentrations less than 1.5 ml O2 l-1. In contrast, skipjack tuna (Katsuwonus pelamis)

and yellowfin tuna (T. albacares) generally... (More)
Bigeye tuna (Thunnus obesus) have distinctive depth distributions and vertical movement

patterns. They remain in the uniformed temperature surface layer at night and can descend to

greater than 500 m depth at dawn. They thus mirror the vertical migrations of the small

nektonic organisms of the deep sound scattering layer and extensively exploit these as a food

resource. At their maximum depths, bigeye tuna frequently experience prolonged exposure to

ambient temperatures (.5 EC) that are up to 20EC colder than surface layer temperature, and

oxygen concentrations less than 1.5 ml O2 l-1. In contrast, skipjack tuna (Katsuwonus pelamis)

and yellowfin tuna (T. albacares) generally limit their forays to depths where water

temperatures are no more than 8EC below surface layer temperatures, and ambient oxygen

levels are above 3.5 ml O2 l-1. Understanding the vertical movements and depth distribution of

bigeye tuna, as well as the physiological abilities/tolerances and oceanographic conditions

controlling them, has been shown key for improving longline catch-per-unit effort analysis and

long-term populations assessments in the Pacific. Similar work is needed in the Atlantic. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Collective Volume of Scientific Papers
volume
57
issue
2
pages
142 - 161
publisher
International Commission for the Conservation of Atlantic Tunas (ICCAT)
language
English
LU publication?
yes
id
e3d3f54b-2f43-421a-8bdd-acd7738a61a4 (old id 762190)
alternative location
http://www.soest.hawaii.edu/PFRP/reprints/iccat_bigeye.pdf
date added to LUP
2007-12-18 15:20:37
date last changed
2016-04-16 07:15:14
@misc{e3d3f54b-2f43-421a-8bdd-acd7738a61a4,
  abstract     = {Bigeye tuna (Thunnus obesus) have distinctive depth distributions and vertical movement<br/><br>
patterns. They remain in the uniformed temperature surface layer at night and can descend to<br/><br>
greater than 500 m depth at dawn. They thus mirror the vertical migrations of the small<br/><br>
nektonic organisms of the deep sound scattering layer and extensively exploit these as a food<br/><br>
resource. At their maximum depths, bigeye tuna frequently experience prolonged exposure to<br/><br>
ambient temperatures (.5 EC) that are up to 20EC colder than surface layer temperature, and<br/><br>
oxygen concentrations less than 1.5 ml O2 l-1. In contrast, skipjack tuna (Katsuwonus pelamis)<br/><br>
and yellowfin tuna (T. albacares) generally limit their forays to depths where water<br/><br>
temperatures are no more than 8EC below surface layer temperatures, and ambient oxygen<br/><br>
levels are above 3.5 ml O2 l-1. Understanding the vertical movements and depth distribution of<br/><br>
bigeye tuna, as well as the physiological abilities/tolerances and oceanographic conditions<br/><br>
controlling them, has been shown key for improving longline catch-per-unit effort analysis and<br/><br>
long-term populations assessments in the Pacific. Similar work is needed in the Atlantic.},
  author       = {Brill, RW and Bigelow, KA and Musyl, MK and Fritsches, KA and Warrant, Eric},
  language     = {eng},
  number       = {2},
  pages        = {142--161},
  publisher    = {ARRAY(0xac1a738)},
  series       = {Collective Volume of Scientific Papers},
  title        = {Bigeye Tuna behavior and physiology. Their relevance to stock assessments and fishery biology.},
  volume       = {57},
  year         = {2005},
}