Contribution to the biological pump The amount of carbon tied up in a typical single whale carcass (about two tonnes of carbon for a typical 40-tonne carcass) is roughly equivalent to the amount of carbon exported to a hectare of abyssal ocean floor in 100–200 years. This amount of organic material reaching the seafloor at one time creates a pulse equivalent to about 2000 years of background carbon flux in the 50 square meters of sediment immediately beneath the whale fall. This helps to sustain the community structure that develops around a whale fall, but it also has potential implications for the biological pump, or the flux of organic material from the surface ocean to depth. 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%. There is growing evidence that the contribution of food falls to the deep ocean carbon flux is larger than originally proposed, especially on the local scale in areas of high primary productivity. Unfortunately, contributions of food falls to the biological pump are hard to measure and rely on a few serendipitous studies on discovered falls as well as planted carcasses with much of the deep sea carbon flux studies relying on sediment traps. Discovery The earliest indication that whale carcasses could host specialized animal communities occurred in 1854 when a new mussel species was extracted from a piece of floating whale blubber. By the 1960s, deep sea trawlers unintentionally recovered other new mollusc species including limpets (named Osteopelta) attached to whale bones. The first recorded abyssal whale fall was discovered by US Navy bathyscaphe pilots LT Ken Hanson, Master Chief George Ellis and LT Tom Vetter