One Stock or Two:
Studying the Movements and Biology of Atlantic Bluefin Tuna with Electronic Tags

Barbara Block - Charles & Elizabeth Prothro Professor in Marine Sciences, Stanford University

Seminar Abstract:

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. 

Speaker Bio:

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,   p. 65-88.

Block, Barabara et al. ,  1998.  Proc. of Nat. Acad. of Sci.  95,  p. 9384-9389.

Powell, Chris, 2001.   Wildlife in North Carolina - Tuna Online.

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