Investigating the movements and behaviour of Patagonian toothfish (Dissostichus eleginoides Smitt, 1898) around the Falkland Islands using satellite linked archival tags

Judith Brown*, Paul Brickle, Beth E. Scott

*Corresponding author for this work

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Knowledge of the seasonal movements of Patagonian toothfish is an essential component for understanding their ecology and fisheries management. As only one demersal longline vessel participates in this fishery in Falkland's waters, over a vast slope area, the use of conventional tags to provide data on migration or stock assessment is not viable. In contrast, archival pop-up tags have enabled the examination of toothfish movements without having to recapture tagged individuals with reasonably high success rates. Patagonian toothfish (n = 30, >127 cm LT) were tagged with pop-up satellite tags between 19/09/2007 and 7/07/2010 in the South Atlantic close to the Falkland Islands. The data from 16 tags that successfully released and uploaded data (plus one recaptured fish) revealed strong site fidelity, with eleven toothfish moving less than 50 km from their release position over a 6 month period. Furthermore, depth data inferred three behavioural patterns showing seasonal bathymetric movements, foraging and spawning activities. Coinciding with the reported spawning months of July-August, spawning movements were recorded with fish moving repeatedly into shallower waters of 9001200 m. Foraging behaviours were also evident with differences in the scale of foraging movement related to fish size, possibly linked to a shift in diet with size. Fish were found to move deeper during December and these are potentially post-spawning movements allowing the fish to take advantage of different prey availability. (C) 2013 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)65-74
Number of pages10
JournalJournal of Experimental Marine Biology and Ecology
Volume443
Early online date19 Mar 2013
DOIs
Publication statusPublished - May 2013

Keywords

  • archival pop-up tags
  • Falkland Islands
  • feeding behaviour
  • Patagonian toothfish
  • spawning migration
  • Southwest Atlantic
  • gastric evacuation
  • marine animals
  • Southern-Ocean
  • fishery
  • diet
  • populations
  • patterns
  • Georgia
  • depth

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