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In 1971, the US conducted its largest underground nuclear weapons test at a remote Alaskan island.
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Previously, scientists have successfully relocated hundreds of sea otters that may have died in the explosion.
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Their populations are thriving in Alaska, Canada and Washington but are causing some problems.
When a major earthquake shook Alaska’s Aleutian Islands in 2014, scientists with the US government rushed to assess the damage on Amchitka Island. They were looking for it leaking radiation from underground nuclear tests carried out decades earlier.
During the first half of the 20th century, the remote island was a wildlife preserve, until the US government converted it into a nuclear test site.
Three atomic weapons went off at Amchitka in the late 1960s and early 1970s, including the largest underground detonation ever set off by the US.
No one lived on the island, but at least 900 sea otters were killed by the biggest blast, in 1971. The Atomic Energy Commissionthe government agency in charge of nuclear research, predict at most 240 an otter would die.
If ecologists and others hadn’t pushed to relocate some otters before the detonation, it probably would have been much worse.
“There was pressure from the state of Alaska as well as environmental groups,” conservation biologist and author Joe Roman told Business Insider. “They ended up moving hundreds of otters.”
Roman wrote about otter relocation in his new book “Eat, Gum, Die: How Animals Make Our World.”
Why was the otter back?
By the time the AEC was looking at Amchitka in the 1960s, the island’s sea otter population was one of the few survivors of the near-extinction of marine mammals a century earlier.
Their luscious pelts were prized as “soft gold.” In the 1700s and 1800s, hunters killed an estimated one million sea otters to sell their fur.
The drop in population was alarming, from between 150,000 and 300,000 in the early 1700s to around 2,000 just 200 years later. Russia, Japan, Britain and the US signed a fur treaty in 1911 to help protect the animals. In recent years, the number of water dogs has risen to around 30,000.
By 1959, the energetic animals were featured in a nature film, “Amchitka Sea Otters.” Nobody wanted to see those magnificent otters destroyed by an underground explosion, John Vania, an otter specialist with the Alaska Department of Fish and Game, told the AEC.
The confluence of events made many Americans more environmentally conscious in the 1960s, from Ohio’s. Cuyahoga River always on fire with Rachel Carson’s investigation of the dangers of pesticides in his book “Silent Spring” to the greatest oil spill in US waters at the time, near Santa Barbara, California.
Protesters did not want a third nuclear test at Amchitka at all. In fact, the conservation group Greenpeace formed an organization that wanted to stop the testing.
A US Fish and Wildlife Service biologist, Karl Kenyon, had worked on relocating some otters to areas where they lived before hunting in the 18th century. The explosions at Amchitka were a good reason to move even more, ecologists and biologists thought.
If the AEC paid for it, Vania said, the scientists could relocate the water dogs.
Bring back the kelp forests
As well as funding the relocation, the AEC provided the scientists with a plane that could hold over 50 otters. Over the next few years, the scientists caught more than 700 otters in nets and carted them to southeast Alaska, Washington, Oregon, and British Columbia.
Over the next 50 years, the water dog population in many of these places, like Sitka, Alaska, would grow from a few dozen to hundreds or thousands. “All the sea otters — of which there are thousands — in Sitka now are the offspring of these air-breathing sea otters,” Roman said.
Eighty-nine otters went to British Columbia. Now there are over 7,000. Estimated 125,000 sea otters living in the Pacific Ocean as of 2015.
The presence of otters changed the landscapes they live in today. Their relocation allowed biologist Jim Estes to study islands with and without otters. As a result, he realized that there was a connection between the otter, the sea urchin, and kelp forests.
“In the absence of sea otters, you have a lot of sea pole,” said Roman. “When you have a lot of urchins, they create something called urchin barrens.”
The sea urchins eat the kelp holdfasts, which anchor the algae. Roman compares it to sawing down a forest. The kelp eventually disappears.
One of the otters’ favorite foods is the sea urchin. And they can eat a lot of them. “They have a very high metabolism,” said Roman. “They are eating machines.” When the number of sea urchins drops, the kelp returns.
In Gort Sitkeach, the sea otter reduced the number of sea urchins by 99%. Kelp forests exploded in return.
“The forests provide food and shelter for more than 800 species, including sea lions, harbor seals, lingcod, gobies, moray eels, octopus, crabs, sea anemones, and brittle stars,” Roman wrote.
Kelp forests are also great at sequestering carbon, a concern for a warming planet.
The otters can also affect land animals, writes Roman, directly, as food for wolves on Alaska’s Pleasant Island, or indirectly, with the kelp forests that attract birds that prey on fish.
Competing with the otter
The Romans called the resettlement of sea otters one of the “most successful cases” of its kind. However, he said, “you don’t shoot animals that way these days.”
For one thing, the US did not consult with indigenous peoples and First Nations before releasing the otters. The mammals brought back the kelp forests, but destroyed a reliable source of food for many people.
“Sea otters don’t just eat toys,” Roman said. “They also eat sea urchins and other valuable benthic invertebrates in the area.” That includes crabs and clams. “And of course that puts them in conflict with fishermen in that area,” he said.
Suddenly, the water dog seemed like they hadn’t been there for ages. “So nobody remembers sea otters being in that area,” Roman said. “They are used to harvesting these invertebrates, and they are quite abundant in the absence of a predator.”
The voracious appetite is one reason why some people call the water dog “rats of the sea.” For some Alaskans and Canadians, they are seen as a nuisance.
When otters arrived in new regions in Alaska, Washington, and Oregon in the 60s and 70s, it was still legal to hunt them. The Marine Mammal Protection Act of 1973 changed that, although Alaska Natives can still hunt otters, whales and seals.
“I talked to Mike Miller, who is originally from Sitka,” Roman said. “It promotes this idea of some balance” between the human population and the otter.
It’s an idea echoed by researchers as well. “We’re wondering if there’s a sweet spot where you can have it,” ecologist Kristy Kroeker said the BBC.
Although the number of sea otters is much greater than it was 100 years ago, the animals are still there in danger. They also face challenges due to the climate crisis. And not all resettled populations survived. They left Oregon after about ten years.
But the water dog’s success elsewhere – particularly their impact on kelp forests – has left Oregon wanting try to introduce again them again, this time with more attention and input from the coastal tribes.
Read the original article on Business Insider
