Whales and some other large marine animals feed on and follow large aggregations of zooplankton for sustenance. Based on simple trophic structure, this would mean whales and other large zooplankton feeders can be found at higher abundance around areas of high primary production, potentially making them important exporters of carbon to depth through food falls. Biological pump models indicate that a large amount of carbon uptake by the deep sea is not supplied by particulate organic carbon (POC) alone, and must come from another source. Lateral advection of carbon, especially in coastal areas contributes to this deficit in the model, but food falls are also another source of organic carbon for the deep ocean. Various percentages of the food fall contribution to the total carbon flux to the deep ocean have been hypothesized, ranging from 0.3% to 4%.