Distribution and abundance of skates ( Bathyraja spp.) on the Kerguelen Plateau through the lens of the toothfish fisheries

•Analysis of biology and fishery impacts on skates forming incidental by-catch in toothfish and icefish fisheries on the wider Kerguelen Plateau.•Skate abundances on the shallower plateau area around Heard Island are not declining.•In the deeper waters B. irrasa have shown a slight decline in abundance over the duration of the fishery at Heard Island.•Fishery independent biomass estimates of skate species indicate either increasing or stable populations of skates.•Larger populations of skates occur in the Kerguelen Islands area than at Heard Island.