Whale falls are extraordinary ecological events that occur when large cetaceans, commonly known as whales, die and sink to the deep ocean floor. Whale falls are often so large and rich in nutrients compared to the rest of the environment that they create an ecosystem within the carcass. This ecosystem often consists of an abundance of diverse species including hagfish, sharks, and microorganisms. These whales provide not only food, but also a distinct shelter unlike the surrounding sea floor.
The decomposition of whale falls occurs in stages. The first stage is the mobile scavenger stage. During this stage, the soft flesh of the whale is devoured by organisms such as hagfish, sharks, and crustaceans. After the soft flesh has been removed, microbes take over the remaining bones. This attracts other organisms who intend to feed on the sudden increase of bacteria in the region. Whale falls have also allowed researchers to discover new species such as the Osedax worm. These are specialized feeders designed to bore through bone. This makes whale falls a prime environment for Osedax worms to thrive.
Whale falls are an example of an astonishing ecological event in which the death of one organism provides life to countless species for several years. Although the time it takes for a whale to fully degrade varies, researchers estimate that whale carcasses can remain a distinct habitat for up to a hundred years. Despite the recent influx of whale fall studies, natural whale falls are rarely found and there is still a great deal of research to be done on this incredible process.
This video describes the stages of whale fall decomposition as well as the role of the Osedax worm.
-by Megan Russell
Amon, Diva J., Adrian G. Glover, Helena Wiklund, Leigh Marsh, Katrin Linse, Alex D. Rogers, and Jonathan T. Copley. 2013. The discovery of a natural whale fall in the Antarctic deep sea. Deep-Sea Research Part II, Topical Studies In Oceanography 92: 87-96.