Modelling the spatial distribution of Patagonian toothfish (Dissostichus eleginoides) by length and age around Heard Island and McDonald Islands on the Kerguelen Plateau

• Main Authors: Farmer, B, Nowara, GB, Barnes, TC, Burch, P, Woodcock, E, Ziegler, P, Welsford, DC
• Other Authors: Dell, J, Duhamel, G
• Format: Conference Object
• Language: English
• Published: Australian Antarctic Division 2019
• Subjects: modelling; age structure; Patagonian toothfish; Dissostichus eleginoides; Heard Island and McDonald Islands; Kerguelen Plateau; spatial distribution; ageing; Kerguelen; Heard Island; Heard; McDonald Islands; Patagonian Toothfish
• Online Access: https://eprints.utas.edu.au/32592/; https://eprints.utas.edu.au/32592/1/137701%20-%20Modelling%20the%20spatial%20distribution%20of%20Patagonian%20toothfish%20%28Dissostichus%20eleginoides%29%20by%20length%20and%20age.pdf; http://heardisland.antarctica.gov.au/research/kerguelen-plateau-symposium/the-kerguelen-plateau-marine-ecosystems-and-fisheries

Over 27 000 fish caught around Heard Island and McDonald Islands (HIMI) on theKerguelen Plateau have been aged from sectioned otoliths in the Australian ageingprogram since 1999, comprising more than 47 000 individual reads from seven differentreaders. Extensive length and age data for Patagonian toothfish (Dissostichus eleginoides)in particular can be used for large-scale spatial analyses across this region. In this paper wepresent spatial models of median toothfish length and age across the Australian exclusiveeconomic zone (EEZ) at HIMI. Both models revealed strong patterns in the spatialdistribution of toothfish, particularly in the concentration of smaller and younger fish onthe shallower parts of the plateau (<500 m), and the occurrence of fish with increasingsize and age in deeper water. These spatial analyses will aid in the further refinement ofhypotheses regarding the habitat use and movement of different life history stages oftoothfish in order to support appropriate management strategies for the species.