@article{fdi:010063907,
  title = {{T}ag shedding by tropical tunas in the {I}ndian {O}cean and other factors affecting the shedding rate},
  author = {{G}aertner, {D}aniel and {H}allier, {J}ean-{P}ierre},
  editor = {},
  language = {{ENG}},
  abstract = {{A} key objective of the {R}egional {T}una {T}agging {P}roject {I}ndian {O}cean was to estimate tag-shedding rates, {T}ype-{I} (immediate tag shedding) and {T}ype-{II} (long-term tag shedding). {T}o assess this, a series of double-tagging experiments (26,899 double tags released with 4555 recoveries) were conducted as part of the broader tagging program. {A}fter omitting data from tags placed by less experienced taggers, the results of our analyses did not show any evidence that individual differences between taggers (i.e., a tagger effect) impacted estimates of tag-shedding rates. {H}owever, it was shown that the probability of retaining the second tag (inserted in the left side of the fish) was larger than retaining the first tag (inserted in the right side, i.e., the side typically tagged in single-tagging experiments). {W}e used a {B}ayesian model averaging approach to account for model uncertainty in the estimates of the parameters a and {L} used to calculate the probability of tag retention {Q}(t)= alpha e-(({L} t)) for the right tag. {T}he parameter estimates were alpha = 0.993 and {L} (per year) = 0.030 (skipjack); alpha = 0.972 and {L} (per year) = 0.040 (yellowfin); and alpha = 0.990 and {L} (per year) = 0.021 (bigeye). {T}hese results agree with estimates obtained by other large-scale tropical tuna tagging projects. {W}e showed that tag loss has a moderate impact on the underestimation of the exploitation rate (bias = 2-6% depending on the tuna species). {H}owever, non-reporting leads to a bias of around 7% when using the high reporting rate estimate of purse seiners. {F}inally, tag shedding (specifically {T}ype-{II} shedding) modified the individual weights of the samples of recaptures. {C}onsequently, the total instantaneous mortality estimates ({Z}; calculated from mean times-at-large) were reduced by a range of 1-3%.},
  keywords = {{T}agging data ; {S}hedding rate ; {B}eta-binomial model ; {B}ayesian model ; averaging ; {T}ropical tunas ; {I}ndian {O}cean ; {OCEAN} {INDIEN}},
  booktitle = {{IO} {T}una tagging},
  journal = {{F}isheries {R}esearch},
  volume = {163},
  numero = {{SI}},
  pages = {98--105},
  ISSN = {0165-7836},
  year = {2015},
  DOI = {10.1016/j.fishres.2014.02.025},
  URL = {https://www.documentation.ird.fr/hor/fdi:010063907},
}