Whale falls are recent yet important discovery in deep- sea biology. The deep sea is usually a nutrient poor environment. The nutrients are found in the form of dead or dissolved organic matter. The dead organic matter that makes up the sediments comes in the form of marine snow. This usually comes in the form of dead organic matter. Sometimes whole fish can fall intact or partially intact to the seabed and become a feast for benthic organisms. However whale falls have the ability to sustain organisms several years or even several decades depending on the species and size of the individual (Goffredi et al 2003).
Whale falls were first observed by Bruce Bennett, who was mapping the Santa Catalina Basin using side scan sonar when he observed an anomaly at first he thought it must be a shipwreck. The team used an underwater submersible and found the bones of an 18m whale. Since 1987 numerous whale carcasses have been found some by accident others using sampling techniques and sonar. Some whales that have died due to stranding are often sunk for research purposes. This is seen in Japan (Fujiwara et al, 2006) and in Sweden (Glover et al, 2010). The first studied whale carcass was conducted by Craig Smith in 1987 (Smith et al 1989). The team used the submersible ALVIN, the same submersible that found Hydrothermal Vents in 1977 and was the first manned submersible to visit the wreck of the infamous Titanic in 1986.
The ecology of whale falls differs depending on their depths. Deep-sea whale carcasses have a variety of mobile predators including invertebrates and vertebrates. Some of which can reach large sizes like the sleeper shark (Somniosus pacificus). Many of the organisms found on whale carcasses are relative of hydrothermal vent communities, for examples vestimentiferans (Feldman et al, 1998). Some scientists speculate that some vent organisms use whale falls as stepping-stones to other vent sites (Smith et al 2003). This can explain why many vent organisms are similar genetically. Despite vent site beings hundreds of kilometres apart.
However shelf sea whale falls have tend to have smaller vertebrates and are dominated by crustaceans, they also do not exhibit many vent organisms and their succession rates are more variable than their deep sea counterparts (Fujiwara et al, 2006) (Glover et al, 2010).
Whale falls undergo 4 main stages of decomposition, each stage has a different biodiversity with each species occupying a niche, and each stage goes through different stages of breakdown of the whale carcass.
Stage 1: Mobile Scavenger
Stage 2: An enrichment opportunist stage
Stage 3: A Sulphopilic stage
Stage 4: Reef Stage
(Smith et al, 2002)
Whale falls are usually found in areas like breeding and feeding grounds, where the whales spend a lot of their time, as a result older individuals may die from age, juveniles may be predated and their remains can sink to the seabed. Whale falls are also found along migratory routes where the environmental stresses are at their highest, weaker individuals may die. By working out the number of whale deaths per year, which may be in the hundreds of thousands, the average whale fall could be within 9 km of each other on average. Each carcass in a different stage of decomposition. (Rice et al, 1984)