

Lakes and rivers still have otters and beavers, etc. Not huge biomass but still relevant. Oceans have all sorts of mammals, most of the largest ocean creatures. Only 30% of land is inhabited by humans and our agriculture but land and freshwater is only 29% of earth and 71% of earth is oceans. 30% of 29% is like 8.5%. Once you start factoring in how little of the earth we actually inhabit or our agriculture, it is pretty surprising how heavily we dominate the mammal kingdom.
I’m not smart enough to spot the error in your comment, so I guess you’re an AI.