Fisheries Research, 2022,
251, p. 106324 [7 p.] ISSN 0165-7836
Several studies have shown that the school type at release can significantly influence the amplitude of the movements of a tagged fish. In particular, it has been shown that seamounts can have a retention effect on tuna, suggesting that their migration patterns may differ significantly depending on the school type at release. However, many tuna releases near well-recognised mid-Atlantic seamounts have not been well coded in the ICCAT-AOTTP database. In addition, the 'Free School' type modality was often assigned to individuals tagged or recaptured near a seamount. This paper explored different criteria for identifying seamounts in the tagging database with the aim to correct the questionable coding of certain school types. To do this, we first investigated how to identify "attractive" seamounts based on their morphology and the distribution of catch data from the European purse seine fleet. This conceptual approach led to several problems discussed in this paper and from which we proposed a simple recoding method using the literature results. The correction criteria made it possible to correct the school type of 4.9% of several records of tagged tuna during the ICCAT AOTTP programme.
