DECOMPOSITION - WHALE FALL
Once the killer whale does die, it will eventually sink to the ocean floor considering its weight, where it will be seen as an energy source to many organisms for decades to come. This process of decomposition is generally called ‘whale fall’ (also occurs with sharks, squid and other cetacean), and there are three stages to it:
1. The first step is called the mobile scavenger phase. Different types of fish and shark will discover the large carcass and feed off it, actively consuming the tissue, meat and remaining flesh of the whale. This process typically goes on for a few years, although it completely depends on the size of the carcass. Scientists have found that large whales carcasses undergoing whale fall can potentially support entire ecosystems because of their size.
2. The second step is called the opportunist stage. This is when all the meat and blubber of the whale has been eaten and all that is left is bone and leftover scraps. Snails, shrimp and worms will arrive to feed on the sediment as well as the bone itself. Zombie worms begin to spread their roots into the bones and feed on the lipid content. Once again, this process goes on for around 2 years.
3. The third and final step is called the sulfophilic stage. Hydrogen sulphide is anaerobically produced, and is used as an energy source by sulfophilic bacteria. Sulfophilic bacteria is key in this process as not only is it a large energy source for organisms such as clams, tube worms and mussels, it also breaks down lipids embedded in the bone. Lipids serve as 4-6% of a whale’s body weight, therefore is not expeditiously digested by limpets sea snails, clams and mussels, which is why this process stretches out for 50-100 years.
1. The first step is called the mobile scavenger phase. Different types of fish and shark will discover the large carcass and feed off it, actively consuming the tissue, meat and remaining flesh of the whale. This process typically goes on for a few years, although it completely depends on the size of the carcass. Scientists have found that large whales carcasses undergoing whale fall can potentially support entire ecosystems because of their size.
2. The second step is called the opportunist stage. This is when all the meat and blubber of the whale has been eaten and all that is left is bone and leftover scraps. Snails, shrimp and worms will arrive to feed on the sediment as well as the bone itself. Zombie worms begin to spread their roots into the bones and feed on the lipid content. Once again, this process goes on for around 2 years.
3. The third and final step is called the sulfophilic stage. Hydrogen sulphide is anaerobically produced, and is used as an energy source by sulfophilic bacteria. Sulfophilic bacteria is key in this process as not only is it a large energy source for organisms such as clams, tube worms and mussels, it also breaks down lipids embedded in the bone. Lipids serve as 4-6% of a whale’s body weight, therefore is not expeditiously digested by limpets sea snails, clams and mussels, which is why this process stretches out for 50-100 years.