Estimation Of Short-Term Tagging Mortality Of Adult Atlantic Cod (Gadus Morhua) ...

• Main Authors: Brattey, John, Cadigan, Noel
• Format: Conference Object
• Language: unknown
• Published: ASC 2001 - O - Theme session 2024
• Subjects: Fisheries and aquaculture; Technologies and data; atlantic cod; Gadus morhua
• Online Access: https://dx.doi.org/10.17895/ices.pub.25635963.v1; https://ices-library.figshare.com/articles/conference_contribution/Estimation_Of_Short-Term_Tagging_Mortality_Of_Adult_Atlantic_Cod_Gadus_Morhua_/25635963/1

No abstracts are to be cited without prior reference to the author.We investigated short-term tagging mortality in Atlantic cod (Gadus morhua) tagged at the base of the first dorsal fin with t-bar anchor tags (Floy FD-68BC) by: (1) comparing the mortality of tagged and untagged cod held in submersible enclosures (cages) for several days; (2) tagging otter-trawl caught cod and holding them in tanks on board a research vessel and monitoring their mortality; (3) estimating tagging survival probabilities by comparing the number of recaptures among cod caught for tagging in the same area but with different gears. Overall mortality of tagged and untagged cod held in submersible enclosures was low, with 11.8 % of 719 tagged and 10.3 % of 146 untagged cod dead or in poor condition after retention periods of 5-10 days; only two fish lost a tag. Mortality of tagged cod among six enclosure experiments ranged from 0 to 25%; mortality was highest (21-25%) in summer and fall when water temperatures in the enclosures were ...