The Kerguelen Plateau is a large, isolated submarine plateau in the southern Indian Ocean. The plateau is home to a significant and high-value Patagonian toothfish fishery, as well as being home to significant populations of seals, seabirds and whales. In 2016, the Australian longline fishery on the Kerguelen Plateau experienced lower than average catch rates. At the same time, the Kerguelen Plateau experienced a surface heatwave. A preliminary investigation concluded that the declining catch rates were unlikely to be caused by a decline in fish stock biomass, but instead could have been related to a change in fish catchability driven by environmental factors. Here we examine the influence of environmental variability on Toothfish catch rates over the last 20 years on the plateau. We combine the outputs from satellite products and oceanographic models with detailed catch data using spatio-temporal models. We discuss how much of the variability in catch rates can be attributed to environmental factors, which factors are relatively important and map a time series of spatial changes in catch across the plateau. We also discuss the implications of these models for predicting environmental impacts on future catch and for management within the fishery.