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In 1971, the United States launched its largest underground nuclear weapons test on a remote island of Alaska.
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Previously, scientists had managed to relocate hundreds of otters that may have died in the explosion.
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Their populations are increasing in Alaska, Canada and Washington, but they are causing some problems.
When a massive earthquake shook Alaska’s Aleutian Islands in 2014, scientists along with the U.S. government rushed to assess the damage on Amchitka Island. they were looking for radiation leak From underground nuclear tests conducted decades ago.
In the first half of the 20th century, the remote island was a wildlife sanctuary until the US government turned it into a nuclear testing site.
Three atomic weapons exploded in Amchitka in the late 1960s and early 1970s; these included the largest underground explosion the United States had ever initiated.
No humans lived on the island, but the largest eruption in 1971 killed at least 900 otters. Atomic Energy CommissionThe government agency responsible for nuclear research had predicted at most 240 The otter dies.
The situation would likely have been much worse if ecologists and others had not pressed for the relocation of some sea otters before the eruption.
“There was pressure from environmental groups as well as the state of Alaska,” conservation biologist and author Joe Roman told Business Insider. “They moved hundreds of otters.”
Roman wrote about the otter relocation in his new book “Eat, Poop, Die: How Animals Make Our World.“
Why did the otters regroup?
When the AEC studied Amchitka in the 1960s, the island’s sea otter population was one of the few marine mammal populations threatened with extinction a century earlier.
Their sweet hides were prized as “soft gold.” In the 1700s and 1800s, hunters killed approximately one million sea otters to sell their fur.
The decline in population was alarming; It fell from 150,000 to 300,000 in the early 1700s, to about 2,000 just 200 years later. Russia, Japan, Britain and the United States signed a fur treaty in 1911 to help protect the animals. Over the next few decades, sea otter numbers rose to around 30,000.
“By 1959, charismatic animals were starring in a nature movie.”Amchitka Sea OttersJohn Vania, an otter expert with the Alaska Department of Fish and Game, told the AEC that no one wants to see these adorable otters wiped out by an underground explosion.
A confluence of events that made many Americans more environmentally conscious, starting in Ohio in the 1960s Cuyahoga River is constantly on fire Rachel Carson’s discovery dangers of pesticides In his book “Silent Spring” the biggest oil leak at the time in US waters, near Santa Barbara, California.
The protesters certainly did not want a third nuclear test in Amchitka. In fact, the conservation group Greenpeace formed an organization that tried to stop the testing.
U.S. Fish and Wildlife Service biologist Karl Kenyon had studied the relocation of some sea otters to areas where they lived before hunting in the 18th century. Ecologists and biologists thought the eruptions in Amchitka were a good reason to move even further.
Vania said scientists could relocate the otters if the AEC paid for it.
The return of the kelp forests
In addition to funding the relocation, the AEC also provided the scientists with an aircraft capable of transporting more than 50 otters. Over the next few years, scientists captured more than 700 sea otters in nets and transported them to southeast Alaska, Washington, Oregon and British Columbia.
Over the next 50 years, sea otter populations in many of these places, such as Sitka, Alaska, will grow from a few dozen to hundreds or thousands. “Thousands of sea otters in Sitka are now descendants of airborne sea otters,” Roman said.
Eighty-nine otters made their way to British Columbia. Now there are more than 7,000. Approximately 125,000 sea otters As of 2015, it lives in the Pacific Ocean.
The presence of otters soon changed the landscape they inhabit today. Their relocation allowed biologist Jim Estes to study islands with and without otters. As a result, he realized there was a connection between otters, sea urchins and kelp forests.
“In the absence of sea otters, there would be a lot of sea urchins,” Roman said. “When you have too many chestnuts, they create what’s called a chestnut barren.”
Sea urchins eat algae debris that anchors the algae. The novel compares this to the cutting down of a forest. The moss eventually disappears.
One of the otters’ favorite foods is sea urchins. And they can eat most of it. “They have very high metabolisms,” Roman said. “They’re eating the machines.” When sea urchin numbers decrease, the kelp returns.
In Sitka Sound, sea otters reduced the sea urchin population by 99%. In response, kelp forests exploded.
“Forests provide food and shelter for more than 800 species, including sea lions, harbor seals, lingos, rockfish, moray eels, octopuses, crabs, sea anemones, and brittle stars,” Roman wrote.
Moss forests are also great at capturing carbon, a concern of a warming planet.
Roman wrote that otters can also affect land animals; either directly as food for wolves on Alaska’s Pleasant Island, or indirectly through kelp forests that attract birds that prey on fish.
Competing with otters
Roman described the sea otter relocation as one of the “most successful cases” of its kind. But he said, “You don’t release animals like that these days.”
First, the United States did not consult with indigenous and First Nations people before releasing the otters. Mammals brought back kelp forests, but they destroyed a reliable food source for many people.
“Sea otters don’t just eat urchins,” Roman said. “They also eat geoducks and other valuable benthic invertebrates in the area.” This includes crabs and oysters. “And of course that brings them into conflict with the fishermen in that area,” he said.
Suddenly otters appeared where they had not been for generations. “So no one remembers there being sea otters in that area,” Roman said. “They are used to collecting these invertebrates, and in the absence of predators they are quite abundant.”
One of the reasons some people call them otters is because of their voracious appetites.sea mice.” For some Alaskans and Canadians, they are considered a nuisance.
In the 60s and 70s, when otters reached new areas of Alaska, Washington and Oregon, it was still legal to hunt them. The Marine Mammal Protection Act of 1973 changed this, but Alaska Natives can still hunt otters, whales, and seals.
“I talked to Mike Miller, a native Sitkan,” Roman said. It “promotes the idea of some balance” between the human population and the otters.
This is an idea that researchers have also expressed. “We wonder if there’s a beautiful place where you can have it all,” ecologist Kristy Kroeker said. he told the BBC.
Although sea otter numbers are much higher than 100 years ago, the animals are still which endangered. They also face challenges due to the climate crisis. And not all relocated populations survived. They disappeared in Oregon about a decade later.
But the success of sea otters elsewhere — particularly their impact on kelp forests — led Oregon to want it. try reintroducing this time more carefully and with the participation of coastal tribes.
Read the original article on Business Insider