Habitat use by Patagonian toothfish (Dissostichus eleginoides Smitt, 1898) on the Kerguelen Plateau around Heard Island and the McDonald Islands
The Patagonian toothfish (Dissostichus eleginoides) is one of the largest and most ubiquitous benthopelagic predatory fish found in the sub-Antarctic. This species supports the largest single species scalefish fishery in the southern ocean, and the largest fishery for toothfish occurs on the Kerguelen Plateau, with landings of >5 000 t.yr-1 from the French EEZ around Kerguelen Islands and 2 500 t.yr-1 from the Australian EEZ around Heard Island and the McDonald Islands in 2009. This study provides a synthesis drawn from a range of methods including otolith and tagging analyses, as well as population data collected from fisheries operations and research surveys from across the Kerguelen Plateau, to develop preliminary hypotheses about the Patagonian toothfish lifecycle and the importance of different habitats for different life stage of this species. It is evident that toothfish use a very broad range of habitats across the Kerguelen Plateau throughout their lifespan, from the epipelagic as planktonic larvae and post larvae, to benthopelagic habitats on deep slopes in excess of 2 000 m surrounding sub-Antarctic islands. Toothfish are also capable of making long distance horizontal movements exceeding 2 500 km, and this migration appears to be associated with maturation and movement to one of a few discrete spawning locations in the region. A description of the ecology of the early life history stages, up to 2-3 years old, and the dynamics of spawning stand out as the priority for future research into the biology of this species in this region.