DAVID S. KIRBY

EDWARD R. ABRAHAM
MICHAEL J. UDDSTROM
HUDSON DEAN

Comments on Myers & Worm (Nature, 423:280-283, 15 May 2003)
(John Hampton, John R. Sibert, and Pierre Kleiber)

(Bruno Leroy - 2003 - Pdf 1,136kb)

Version Française

Up to now, conventional tagging has consisted of attaching numbered tags to the fish, releasing them into the wild and then waiting for them to caught again by fishermen. But as vital as the data collected in this way are, e.g. growth, migration, mortality, they do not give any indication of the fish’s behaviour between the time it is tagged and the moment it is recaptured, e.g. the times of day it ate, the depths it swam at, etc

(Bruno Leroy - 2003 - Pdf 1,136kb)

Up to now, conventional tagging has consisted of attaching numbered tags to the fish, releasing them into the wild and then waiting for them to caught again by fishermen. But as vital as the data collected in this way are, e.g. growth, migration, mortality, they do not give any indication of the fish’s behaviour between the time it is tagged and the moment it is recaptured, e.g. the times of day it ate, the depths it swam at, etc

(John Sibert, John Hampton)

We apply an advection-diffusion reaction model to data from three different tuna tagging experiments in the western and central Paci .c Ocean (WCPO)to reexamine the question of to what extent the population dynamics and spatial characteristics of tropical tunas require international cooperation for effective management.The median lifetime displacement of skipjack ranges from 420 to 470 nautical miles.The lifetime displacement of yellowfin is about 20%less.The median half-life,a measure of residence time,of skipjack and yellow .n in WCPO exclusive economic zones (EEZs)is 3 .6 months.Fishingdecreases the lifetime displacement and decreases the half-life.We conclude that international arrangements between neighboring EEZs are essential for effective conservation,but that Pacific Island countries can achieve bene .ts from domestic conservation and .shery development policies.