Marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Primary productivity, and its availability, is important for mammalian trophic structure and body size.
Examining Predator-prey body size Trophic level and body mass across marine and terrestrial mammals
Evolutionary predictors of mammalian home range size Body mass diet and the environment
Predator-prey and trophic relationships changed when mammals returned to the sea – large carnivorous mammals are no longer restricted to taking large prey.
Examining the Prey Mass of Terrestrial and Aquatic Carnivorous Mammals Minimum Maximum and