One Stock or Two:
the Movements and Biology of Atlantic Bluefin Tuna with Electronic Tags
- Charles & Elizabeth Prothro Professor in Marine Sciences,
The deployment of electronic
data storage tags that are surgically implanted or satellite-linked provides
marine researchers with new ways to examine the movements, environmental
preferences, and physiology of pelagic vertebrates. We report the
results obtained from tagging of Atlantic bluefin tuna with implantable
archival and pop-up satellite archival tags. The electronic tagging
data provide insights into the seasonal movements and environmental preferences
of this species. Bluefin tuna dive to depths of >1000 meters and
maintain warm body temperature. Western-tagged bluefin tuna make trans-Atlantic
migrations and they frequent spawning grounds in the Gulf of Mexico and
eastern Mediterranean. These data are critical for the future management
and conservation of bluefin tuna in the Atlantic.
Barbara A. Block received her
Ph.D. from Duke University. Her research is focused on how large pelagic
fishes utilize the open ocean environment. Investigations center upon
under-standing the evolution of endothermic strategies in tunas, billfishes
and sharks. Block and her colleagues investigate the cellular mechanisms
underlying heat generation and force production in skeletal muscle, the
evolution of endothermy, and the physiological ecology of tunas and billfishes.
The research in the lab is interdisciplinary, combining physiology, ecology
and genetics with oceanography and engineering.
Professor Block and colleagues at the Monterey Bay Aquarium have
also established the Tuna Research and Conservation Center, a unique
facility that permits physiological research on tunas. They are employing
new techniques in wildlife telemetry and molecular genetics to directly
examine the short- and long-term move-ment patterns, stock structure
and behavior of tunas and billfishes. The fish are highly exploited in
international fisheries, and effective management of existing biodiversity
requires an under-standing of their biology and population structure.
The Block lab actively engages in research at sea to understand the movements
and physiological ecology of tunas and billfishes and to gain insight into
the selective advantage
of endothermy in fishes.
Block and her colleagues are conducting research with a new type
of remote telemetry device, called pop-up satellite archival tags. The
tags are essentially computers that record navigational information,
body temperature, depth and ambient temperature data. The information
gained with these tags will improve our understanding of the biology of
these species and increase our knowledge of stock structure. The successful
implementation of the novel satellite archival tag technology has provided
marine researchers with new tools for studying inaccessible marine vertebrates.
Block, Barbara et al.
, 2001. Science 293, p. 1310-1314.
Block, Barabara et al.
, 2001. Electronic Tagging and Tracking in Marine Fisheries,
Block, Barabara et al.
, 1998. Proc. of Nat. Acad. of Sci. 95, p.
Powell, Chris, 2001. Wildlife in North Carolina - Tuna Online.
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