By Emily Watson, FracTracker Summer Intern
Sea otters, an endangered keystone species, are at risk due to offshore oil and gas drilling spills. Along the west coast of the U.S., this marine mammal’s habitat is commonly near offshore drilling sites, specifically in California and Alaska.
Sea Otters – a Keystone Species
Sea otter numbers used to range from several hundred thousand to more than a million. Today, there are estimated to be just over 106,000 in existence worldwide, with fewer than 3,000 living in California. Their habitats range from Canada, Russia, Japan, California and Washington, but the majority of all wild sea otters are found in Alaskan waters.
Sea otters play a significant role in their local environments, and a much greater ecosystem role than any other species in their habitat area. Sea otters are predators, critical to maintaining the balance of the near-shore kelp ecosystems, and are referred to as keystone species. Without this balancing act, coastal kelp forests in California would be devoured by other aquatic life. Sea otter predation helps to ensure that the kelp community continues to provide cover and food for many of the marine animals. Additionally, kelp plays a tremendous role in capturing carbon in the coastal ecosystems. In that sense, sea otters also inadvertently help to reduce levels of atmospheric carbon dioxide.
Oil Spills and their Health Implications
Recently, Alaska and California, home to a wide variety of marine life, have been popular areas for offshore oil and gas drilling, which may include the use of fracking to extract hydrocarbons. Oil spills are a great concern for the sea otter; unlike other marine animals that may be able to eventually rid themselves of the oil, contact with the oil causes the sea otters fur to mat, preventing insulation, which can lead to hypothermia. Additionally, the ingestion of toxic oil chemicals while cleansing their fur can cause liver and kidney failure, as well as severe damage to their lungs and eyes.
Because their numbers are low and their geographic location area is rather small compared to other sea otter populations, the California sea otter is especially vulnerable, and could be devastated by oil contamination.
Prince William Sound, Alaska
On March 24, 1989, the tanker vessel Exxon Valdez ran aground on Bligh Reef in Prince William Sound, Alaska, spilling an estimated 42 million liters of Prudhoe Bay crude oil. This incident affected marine life throughout western Prince William Sound, the Gulf of Alaska, and lower Cook Inlet. An estimated 3500–5500 otters from a total population of about 30,000 may have died as a direct result of the oil spill. Oiling and ingestion of oil-contaminated shellfish may have affected reproduction and caused a variety of long-term sublethal effects. Necropsies of sea otter carcasses indicated that most deaths of sea otters were attributed to the oil, and pathologic and histologic changes were associated with oil exposure in the lung, liver, and kidney. Studies of long-term effects indicate that the sea otter population in the Prince William Sound area suffered from chronic effects of oil exposure at least through 1991. While some populations may recover after a spill, it would seem that the threat of oil pollution impacts is intensified for populations in deteriorating habitats and to those that are in decline.
Santa Barbara Coast, California
On Tuesday, May 19, 2015, a pipeline was found to be leaking into the Santa Barbara Coast in California. This broken pipeline, owned by Plains All American, spilled approximately 105,000 gallons of crude oil into the ocean, according to various news reports, stretching out into a 4-mile radius along the central California coastline.
These waters are home to an array of shore birds, seals, sea lions, otters and whales. Numerous amounts of marine life have been found washed up on the shore, including crabs, octopuses, fish, birds, and dolphins. Elephant seals, sea lions, and other marine wildlife have been taken to Seaworld in San Diego for treatment and recovery.
The Santa Barbara accident occurred on the same stretch of coastline as spill in 1969 that – at the time – was the largest ever incident in U.S. waters and contributed to the rise of the American environmental movement. Several hundred-thousand gallons spilled from a blowout on an oil platform, and thousands of seabirds were killed and numerous ocean wildlife, including sea lions, elephant seals, and fish perished.
Overall, the ocean is home to a great diversity of marine wildlife, all of which are vulnerable to oil contamination. Offshore gas drilling is a significant threat to the survival of sea otters and other marine life, wherein spills and accidents could cause health problems, toxicity, and even death. Oil spills are exceptionally problematic for sea otters, due to the vulnerable state of this animal and its endangered species state. Keeping keystone species healthy is instrumental to maintaining a well flourished ecosystem, while protecting habitats for a large array of marine and wildlife. The potential impacts on CA sea otters and other marine life due to events such as the 2015 oil spill in California should not be taken lightly.