According to Chris Wilmers and James Estes, two UC Santa Cruz research professors, an otter supported kelp forest “can absorb as much as 12 times the amount of CO2 from the atmosphere than if it were subject to ravenous sea urchins.” Sea otters feed on sea urchins, which allow kelp forests to prosper and in turn diminishes the amount of carbon dioxide in the atmosphere. If there is not kelp to help reduce levels of carbon dioxide in the ocean, then marine environments are threatened due to the high acidity levels. Kelp forests absorb CO2 from the atmosphere and sea urchins destroy these greenhouse gas-absorbing plants. When sea otters are present, sea urchins hide and eat kelp scraps but when not around they devour the living kelp. Wilmers and Estes’ theory is outlined in the journal Frontiers of Ecology and the Environment and is of importance because it proves animals can strongly influence the carbon cycle. The professors have 40 years of data on otters and kelp forests from Vancouver Island to Alaska’s Aleutian Islands.
It was found that kelp diminished CO2 from the atmosphere through a photosynthesis process. CO2 concentration in the atmosphere has been at very high levels since the beginning of the industrial revolution and in turn causes global temperatures to continue rising. Wilmers states current climate change models do not include the use of animals, but animals can actually be influential in the carbon cycle and have a large impact. There can be a win-win situation, where marine environments are protected or even enhanced and CO2 can also be diminished. The increasing amount of CO2 in the atmosphere is a very concerning issue and there are no easy fixes. While sea otters wont be able to fix our global warming issue, natural aids similar to this will become more and more important to dull the climate change effects. There are recently established markets in Europe and the United States that create an economic incentive for reducing CO2. It is estimated that the CO2 removed from this kelp method could be worth between $205 and $408 million on the European Carbon Exchange.
Sources: “Sea Otters Helping Combat Ocean Acidification”, The Telegraph Online, September 12, 2012 http://www.telegraph.co.uk/earth/wildlife/9537353/Sea-otters-helping-combat-ocean-acidification.html
“Sea Otters Strike a Blow For The Environment”, Kate Andries, National Geographic News, September 10, 2012 http://news.ucsc.edu/2012/09/sea-otters-kelp.html
Student Researcher: Paige Henry and Sarah Crandall
Faculty Instructor: Kevin Howley Ph.D.
Evaluator: Vanessa Fox Ph.D, Associate Professor of Biology and Chair of Biology Department, DePauw University