Just a few hours from Palo Alto is Monterey Bay, a haven for many marine mammals—including the famously cute and furry sea otters. Monterey is not just a home to sea otters, though. It is also one of the leading conservatories in restoring the sea otter population along the Californian coast. In fact, sea otters appear as endangered species on the International Union for the Protection of Nature’s red list of threatened species.

Sea otters have long been hunted for their rich fur coats—it is estimated that since 1741, hunting has completely eliminated the otter population in many parts of the world. About half a million otters have been killed since then, and by 1911, only 1000 to 2000 otters remained in 13 habitat colonies.

Otters are now legally protected, and while hunting no longer threatens their survival now, oil spills do. Oil breaks the air pockets in otters’ furs that keep them warm—as a result, many otters exposed to oil die of hypothermia. In addition, otters can also ingest the oil while grooming themselves. This can lead to lesions in their livers and kidneys and to the erosion of the stomach lining. According to an American University case study, up to 5000 otters were killed in the 1989 Exxon Valdez oil spill in Alaska.

Overfishing also affects sea otters and is a major contributor to their endangered species status and marine habitats’ destruction. Overfishing in the northern Pacific causes sea lions and other marine mammals to die from lack of food. Killer whales are also forced to move down the coastline for more food, and they thus end up in our Monterey Bay. Because of an absence of sea lions (the killer whales’ main food source), the whales resort to eating sea otters, which aren’t as fatty. As a result, they end up eating many more otters to appease their hunger. This predation sets off another domino effect. The otters’ main source of food is sea urchins, so as the otter population falls, the urchin population increases exponentially. The urchins then overfeed on kelp, which destroys the kelp forests. The destruction in turn causes a plethora of sea animals to lose their habitats.