How oil spills harm birds, dolphins, sea lions and other wildlife
Ocean creatures that swim in deep water are less affected by spills. But oil disasters near the coasts often do the most harm to shorebirds and marine mammals that inhabit the ocean’s edge and on its surface.
Here’s a closer look at how certain species of marine life are affected by oil spills.
Coastal birds can be particularly vulnerable as oil coats the ocean surface, where they feed, and spills onto beaches, fouling their nesting areas.
In California, this most commonly affects brown pelicans, grebes, gulls, cormorants, plovers, and other birds.
When birds cover themselves with oil, it makes their feathers useless to keep them insulated and warm. Birds also instinctively preen themselves to remove anything on their feathers, exposing them to ingesting toxic amounts of oil, Anderson says.
“The visuals are heartbreaking,” says Anderson. “Even a person who doesn’t know anything about biology can see how birds are affected.”
Oiled birds that return to their nests can also contaminate their eggs and chicks with oil.
Dolphins are migratory and will often swim to safer waters if they smell or taste the oil, Anderson says.
Oil spills can also be fatal to blue whales, gray whales, humpback whales and other species. Exposure to toxic petroleum fumes was 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 is fouled with oil, Anderson explains.
This makes them more vulnerable to oil poisoning, which can seep into their mouths when they break the surface of the water to breathe.
The sea otter remains endangered after being targeted by hunters in the 1800s and early 1900s for its fur. The crowd-pleasing aquarium can be found in coastal Pacific waters, from Alaska to central California.
The oil can smooth the fur of otters, cause them to lose their insulation and die of hypothermia, in the same way oil harms birds.
These inch-sized creatures burrow in the sand where waves crash onto beaches, making them vulnerable when oil spills onto the shore.
“They are right to put themselves in danger,” says Anderson.
High concentrations of the oil kill adult crabs, while lower amounts can harm their babies and eggs. These invertebrates are a key part of our beach ecosystem because “everyone eats them,” says Anderson. “They are incredibly important for a range of species.”
As a result, an oil spill could potentially devastate an area’s lobsters – and its lobster fishing industry – five to seven years later, when those lobster larvae reach market size, according to the institute.
Some thicker oils sink to the bottom of the ocean, where they are ingested by rockfish, white croakers, and other species that feed in the depths of the ocean.
The oil won’t necessarily kill them, Anderson says, but toxins build up in their liver and other organs, making them unhealthy for humans to eat.