Whale Falls: Not Just a Carcass

Dead whales that have sunk to the bottom of the ocean have been investigated in the past. But not until 1987 did researchers come to understand what an important role whale falls play in the oceans. In 1987, researchers discovered a dead and decaying whale on the typically “nutrient-poor” seafloor in Catalina Basin, off the shore of southern California. Unlike the usual barren, lifeless seafloor, the area surrounding the dead whale was surrounded by a diverse population of organisms (1). Hag fish, sharks, snails, bristle worms, and “zombie” worms surrounded the carcass, giving the researchers to believe that the dead whale was an important part in the survival of many organisms living in the deep seas harsh conditions.


Smith, an oceanographer from the University of Miami at Manoa, returned to the site of the whale fall to investigate the remains about a year later. Smith and his team discovered several previously unknown species. Other species found at the site were usually only found in areas rich in nutrients. This dive helped Smith and his team to see that whale falls, in fact, do release necessary nutrients into the surrounding waters instead of just being a waste product on the sea floor.

Whale falls are observed in three different stages (1):
1. Mobile scavenger stage- many hagfish and sleeper shark bite or take away large pieces of meat.
2. Enrichment opportunist stage- Lasts up to two years. High density of low diversity animals colonize the area.
3. Sulfophilic stage- Longest stage. Bacteria break down lipids in the bone. This stage generates energy for growth.

Whale fall community

They found new species of worm living in the dead carcasses of whales off the coasts of Sweden, Norway, and California. One of the new species found was called the Vigtorniella ardabilia, a chrysopetalid annelid. The massive bodies of whales, after falling to the sea floor, can provide nutrients to surrounding marine life for up to 8 years.
Unfortunately, the whale population has decreased in size. According to Smith and his team, whaling has caused more 40% of North Atlantic whale fall species to go extinct (6). Major whaling countries such as Japan, hunt for whales because of the large amounts of valued meat and oil.Each year, the hunting of whales is a heated topic. People hold various arguments. Some say that whaling is just wrong, some say that killing more whales will give a higher yield in fish, and some say that killing whales will bring back more fish to the sea (5). Many whales have died being beached. As they were washed up, their great weight crushes the internal organs after being washed up on land. After being washed up on land, the whales body temperature changes to a temperature they are not used to. The fluctuation of the temperatures through out the day is something the whale is not used to. An interesting point to wonder about is "The whales do not die because they are stranded; they are stranded because they are dying" (4). It is unfortunate that many of the whales get seriously injured by nets or pollution in the ocean and whale enthusiasts such as the men and women on the show "Whale Wars" are taking steps in preventing whaling.




Sources:

1. (Primary) http://www.scientificamerican.com/article.cfm?id=the-prolific-afterlife-of-whales
2. http://www.scientificamerican.com/blog/post.cfm?id=new-worm-species-found-in-unusual-h-2009-09-25
3.
http://www.uwrf.edu/biology/electives_dir/444_dir/VSmith/Page1.html
4.
http://www.time.com/time/magazine/article/0,9171,847940,00.html
5. "http://www.sciencemag.org/cgi/content/full/sci;323/5916/880?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=whale&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT"
6. http://www.sciencemag.org/cgi/content/full/sci;307/5713/1190c?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=whale&searchid=1&FIRSTINDEX=10&resourcetype=HWCIT