How do oil spills kill sea otters

However, while they are present, light oils present two significant hazards. First, some can ignite or explode. Second, many light oils, such as gasoline and diesel, are also considered to be toxic. They can kill animals or plants that they touch, and they also are dangerous to humans who breathe their fumes or get them on their skin. In contrast, very "heavy" oils like bunker oils, which are used to fuel ships look black and may be sticky for a time until they weather sufficiently, but even then they can persist in the environment for months or even years if not removed.

While these oils can be very persistent, they are generally significantly less acutely toxic than lighter oils. Instead, the short-term threat from heavy oils comes from their ability to smother organisms whereas over the long-term, some chronic health effects like tumors may result in some organisms. Also, if heavy oils get onto the feathers of birds, the birds may die of hypothermia they lose the ability to keep themselves warm. We observe this same effect if sea otters become oiled.

Ocean creatures that swim in deep waters are less affected by spills. But oil disasters near coastlines often do the most harm to shorebirds and marine mammals who live at the ocean's edge and on its surface. And if you want to help wildlife rescue efforts in the wake of the spill, you can donate here.

Coastal birds can be especially vulnerable because the oil covers the surface of the ocean, where they feed, and washes onto beaches, fouling their nesting areas. In California this most often affects brown pelicans, grebes, gulls, cormorants, plovers and other birds. When birds become covered in oil, it renders their feathers useless for keeping them insulated and warm. Birds also instinctually preen themselves to remove anything on their feathers, which exposes them to ingesting toxic amounts of oil, Anderson says.

Dolphins are migratory and will often swim to safer waters if they smell or taste oil, Anderson says. But the playful mammals have been sickened and killed by spills, which can spew toxic fumes from the petroleum chemicals floating on the ocean's surface. Two dolphins were found dead after a May oil spill near Santa Barbara, Calif. Oil spills also can be deadly for blue whales, gray whales, humpbacks and other species. Exposure to toxic oil fumes has been recognized to kill whales and dolphins even years later, according to the Center for Biological Diversity.

Unlike dolphins, sea lions are territorial and less likely to flee their coastal region, even if it gets fouled with oil, Anderson says. Do you think Canada needs more in-depth, fact-based reporting?

So do we. The Tyee is an independent, paywall-free, reader-funded publication. Over 5, Tyee readers chip in to fund our newsroom on a monthly basis, and that supports our rockstar team of dedicated journalists. New risks from Canadian oil tanker spills confront the 1, sea otters living around the Olympic Peninsula, said an internal report of March by the Washington State Ecology Department.

The otters live from Point Grenville to Neah Bay on the rocky and perilous west coast of the state, about half of them around Destruction Island. Their cousins who share the Salish Sea north of the B.

A spill near the kilometre long Juan de Fuca Strait could spread south throughout the state's otter habitat: "It is conceivable that a large oil spill could result in a devastating impact on the Washington sea otter population, possibly resulting in its extinction," warned the report, found by The Tyee under the state's freedom of information law. Oil spills endanger otters because they have a very high metabolism, lack insulating blubber, and rely on their dense fur for warmth.

When their fur becomes oiled, they lose their thermal protection and ability to forage for food, all of which can quickly lead to hypothermia and death. Despite exhaustive labours by rescuers, only oil injured otters were captured and treated, of which 34 percent died.

The Valdez spill of up to , cubic meters of crude oil also killed about , seabirds, harbour seals, bald eagles, 22 killer whales, and an unknown number of salmon.

Last March on the 25th anniversary of the spill, scientists from the U. National Oceanic and Atmospheric Administration reported that some species seem to have recovered, with the sea otter the latest one to return to pre-spill numbers. The Washington State Ecology Department study considered three possible solutions -- try to prevent spills, improve spill response, and find new methods to rescue oil injured otters. The Valdez spill indicated the first option is by far the best way of helping the otters, but "unfortunately, the total volume of oil transported is expected to rise.

The completely exposed nature of the Washington coast will likely present a challenge even greater than the one presented by the Exxon Valdez oil spill with regard to collecting oil injured sea otters.

Around Destruction Island, there are four "protective strategies" that might help the otters: placing booms to stop the oil spread, dropping chemical oil dispersants, restricting vessel traffic around the island, and skimming the oil off the water.

Because the waters on the Washington coast are often so rough, they noted, the booming and skimming strategies are "impractical," and so applying dispersants before the oil's arrival is the best response. These groups likely do not retain enough surplus capacity to perform their primary functions and support ongoing wildlife rehabilitation operations. Clint Wright, Vancouver Aquarium's general manager, told The Tyee that its Marine Mammal Rescue Centre has pledged to rescue and rehabilitate the American oiled otters as it did during the Valdez spill.

But it can only do so if enough staff are free, as the summer months are the centre's busiest, and before accepting the otters they would need permits issued by the U.

In their efforts to clean themselves from oil and put their feathers in their original state, the birds may inhale or ingest oil. This poisoning is often as deadly as hypothermia, although the effects may not manifest themselves as quickly. Oil may also affect the reproductive success of the birds as oil from feathers of a bird that is laying on eggs may pass through the pores in the eggshells and either kill the embryos or lead to malformations. Seals, sea lions, walruses, polar bears, sea otters, river otters, beavers, whales, dolphins and porpoises, and manatees, are groups of marine mammals that may be affected by oil spills.

Their sensitivity seems to be highly variable and appear to be most directly connected to how important their fur and blubber layer of fat under the skin are for keeping them warm. Thus, marine mammals living in cold climates seals, sea lions, polar bears and otters are likely to be more vulnerable than those living in temperate or tropical waters.

Effects of oil on marine mammals depend upon species may, in addition to hypothermia, include: toxic effects and secondary organ dysfunction due to ingestion of oil; congested lungs; damaged airways; interstitial emphysema due to inhalation of oil droplets and vapour; gastrointestinal ulceration and hemorrhaging due to ingestion of oil during grooming and feeding; eye and skin lesions from continuous exposure to oil; decreased body mass due to restricted diet; and stress due to oil exposure and behavioural changes.

Seals true seals, sea lions, fur seals and walruses. Seals are very vulnerable to oil pollution because they spend much of their time on or near the surface of the water. They need to surface to breathe, and regularly haul out onto beaches.

During the course of an oil pollution incident, they are at risk both when surfacing and when hauling out. Fur seals are more vulnerable due to the likelihood of oil adhering to their fur which will result in the fur losing its insulating ability as they lack any blubber for additional insulation. Heavy oil coating on fur seals may result in reduced swimming ability and lack of mobility when the seals are on land.

Seals could also be damaged through the ingestion of oiled food or the inhalation of oil droplets and vapours. Oil, especially light oils and hydrocarbon vapours, will attack exposed sensitive tissues. These include mucous membranes that surround the eyes and line the oral cavity, respiratory surfaces, anal and urogenital orifices. This can cause corneal abrasions, conjunctivities and ulcers.

Consumption of oil-contaminated prey could lead to the accumulation of hydrocarbons in tissues and organs. Sea otters. Sea otters spend a lot of their time on the sea surface and are totally depending on their fur for isolation and for the ability to float. As a consequence, sea otters are regarded as being very sensitive to oil spills as oil may result in the fur losing its capacity to insulate the animals.

However, inhaling hydrocarbons or ingesting oil when they groom themselves can damage their lungs, cause ulcers, and result in liver and kidney damage. Habitat loss and diminishing food resources constitute indirect effects on the otters.

The Exxon Valdez incident is believed to have led to the death of 15, otters, mainly as a result of ingestion of oil.