All kinds of good stuff! Nutrient uptake and/or water storage capacity of wetlands (i.e, impact studies of development or restoration), population dynamics of food species in subtidal waters, effects of perturbation of food sources in commercially valuable species, cascade effects of ‘fishing down’ the food chain, impact of conservation or exploitation of apex predators on forage species (and vice versa)…
hopefully you get the idea. Don’t forget about using economic modeling to predict resource harvest and production pressures, too. Exploiting resources is about the money, and the money can be used to track and analyze exploitation, too.