The article explores how body size, trophic level, and predator-prey relationships differ between marine and terrestrial mammals. Marine carnivores tend to be higher on the food chain than terrestrial carnivores, with larger predator-prey ratios. Despite expectations, body mass does not always correlate with trophic level in mammals. The researchers suggest that differences in primary productivity and energy flow play a key role in shaping the feeding ecology and community structure of marine and terrestrial mammal populations.