Researchers from Oregon State University and the University of Victoria have noticed a new feeding habit in snow crabs off the coast of British Colombia (The Canadian Press, 2019). Snow crabs were discovered feeding on methane seeps, which consist of bacteria that feed on methane (Floyd, 2019). This is rare because snow crabs were thought to only eat phytoplankton, but with the amount of phytoplankton being reduced due to climate change, this change in food sources is a sign of the crabs adapting to climate change (The Canadian Press, 2019). Snow crabs are a commercially harvested species and they are the first of this kind to be seen eating at a methane seep (Floyd, 2019). However, there is no concern for humans as methane seeps are not a health concern because they do not form a toxic environment (Floyd, 2019).
Snow crabs live on the seafloor and the fact that they are able to find other food sources is a good sign for other marine species because less food will fall to the seafloor as global temperatures continue to rise (Floyd, 2019). If snow crabs are able to switch their food source to methane seeps, then it is likely that other marine species will be able to adapt to a new food source as well. As long as methane gas continues to seep out of the Earth, methane seeps will be present and will be a viable food source. This snow crab adaptation is an example of an organism adapting to an external stressor. In this example, global warming is depleting a food source. In order to keep their energy levels and fitness high, the snow crabs have to find a new food source that will keep their population alive and their is evidence that they have begun to do this. If phytoplankton levels continue to decline, this could be just the beginning of marine species feeding on marine seeps.
Floyd M (2019) Researchers discover a flipping crab feeding on methane seeps. https://phys.org/news/2019-02-flipping-crab-methane-seeps.html (last accessed 15 April 2019).
The Canadian Press (2019) Methane-munching crabs may be adapting to climate change: report. https://www.cbc.ca/news/canada/british-columbia/methane-munching-crabs-adapting-climate-change-1.5034886 (last accessed 15 April 2019).