https://phys.org/news/2018-11-oceans-fur-deaths-hookworm-infection.html

"Increasing ocean temperatures are associated with changes in the patterns of wind and ocean currents, which cause a decrease in the cycling of nutrients and, by extension, the abundance of life including fishes," says first author Mauricio Seguel, Postdoctoral Associate in the Odum School of Ecology at the University of Georgia, Athens, US.

"Reductions in marine life have also been linked with the decline of marine mammal populations, as they rely on fish as their main food supply. Fur seals and sea lions may be included here, because although their pups live on land, they depend on their mother's' milk for survival, which can only be produced if the mothers eat enough fish."