Photo by Ron Eby
Sea otters live in shallow waters and often in areas with kelp beds where they feed on invertebrates, i.e., sea urchins, crabs, etc. . In the Aleutian archipelago down to California, it has been observed that the feeding habit of otters control herbivore populations in these areas, increasing the size and coverage of kelp and seagrass beds [1,2].
Seagrass recovery in the Elkhourn Slough, California, in spite of the degradation caused by excessive nutrients dumping, amazed University of California Santa Cruz researchers. A recent study from this group of researchers showed that interactions between sea otters and their prey is crucial in the recovery of its habitat. Sea otters feed on crabs, which feed on slugs and other invertebrates found on seagrass leaf blades. Predation by sea otters on crabs controls the latter’s effect on the population of slugs, which are important in maintaining the health of the seagrass population .
To know more about sea otters, visit SeaLifeBase.
 Estes, J.A.; Palmisano, J.F. (1974) Sea otters: their role in structuring nearshore communities. Science 185(4156):1058-1060.
 Stephens, T. (2013) Sea otters promote recovery of seagrass beds. http://news.ucsc.edu/2013/08/sea-otters-seagrass.html [Accessed 05/09/2013].