A brief characterisation of Patagonian toothfish tag survival and tag detection in CCAMLR Statistical Area 48.3

Mark-recapture data is a central element in the assessment of population size and growth and the stock assessment for Patagonian Toothfish (Dissostichus eleginoides) in CCAMLR subarea 48.3 relies on accurate tagging samples for its assessment. The bias in tagging survival and tag detection is assumed to be minimal in the model, but this assumption has not previously been tested; a pairwise comparison is used to examine the relative performance between vessels in subarea 48.3.

Tag retention in subarea 48.3 is generally good with less than 1% of double-tagged fish losing a tag. Individual vessel performance in tag detection was relatively good compared to all other vessels and tagging survival was also consistent.