Tag-shedding rates for tropical tuna species in the Atlantic Ocean estimated from double-tagging data

An objective of the Atlantic Ocean Tropical tuna Tagging Programme (AOTTP) was to estimate Type-I (immediate) and Type-II (long-term) tag-shedding rates for tropical tunas from double-tagging experiments. Historical information on studies conducted in different parts world incorporated as prior distributions using a Bayesian approach new parameters. were respectively estimated at 0.007 0.084/yr bigeye tuna, 0.021 0.051/yr skipjack 0.088/yr yellowfin tuna. Using realizations derived MCMC posterior distributions, shedding rate reach 50% tags after seven half years sea eight The loss conventional is lower skipjack. Our results suggested that continuous size-dependant (i.e., showing three-fold increase between individuals less than 45 cm fork length (FL) release fishes larger 65 FL). This study reinforces need account along with other sources uncertainty, such reporting rate, order accurately exploitation mortality tagging data.