The first ecosystem managers in the Americas

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The maritime fur trade, which began in the 1700s and centered on the North Pacific Ocean, killed an estimated one million sea otters and left the species on the brink of extinction with a global population as low as 1000. On the west coast of Canada, the animal did not survive. The last sea otter was seen in the area in 1929, off Vancouver Island, British Columbia. But beginning in the 1960s, restoration efforts brought sea otters back to British Columbia. Of 89 sea otters initially displaced from Alaska, a population of 8,000 people now spread across the province. Yet, after generations of absence, the upsurge in sea otters is stirring resentment among some locals.

The problem is that a sea otter consumes 25 to 30 percent of its own body weight each day. The voracious appetites of otters can have dramatic ecological effects. It also doesn’t help that sea otters eat many of the same seafood that humans in the region have long favored, such as crabs and clams, triggering conflicts with shellfish fishing and get some to argue that the reintroduction effort has worked too well.

Now a new study suggests that conservation efforts may indeed have exceeded target – and the reason is particularly interesting.

When considering restoring natural ecosystems, the goal for many would probably be to see a species regain its carrying capacity, that is, the maximum population that a given habitat can support, without human impact. So for the sea otter, it would amount to reversing the effects of colonization, the fur trade, hunting, land use planning and other pressures at a time when abundant sea otters inhabited. maybe the coast, feeding on abalone and other seafood. But to take that as a goal is to overlook the way native peoples have largely managed the sea otter population for thousands of years.

Led by Erin Slade, a graduate student at Simon Fraser University in B.C., new research examining the size of mussels found along the coast calls into question the hypothesis that late-1800s sea otter populations the Holocene would never have reached, or even approached, their carrying capacity.

Slade, who is supervised by Simon Fraser University ecologist Anne Salomon and anthropologist Iain McKechnie * at the University of Victoria in British Columbia, measured the size of mussels at six locations on the contemporary coast of the British Columbia and discovered that in places where the growing sea otter population has not yet arrived, the mussels are larger. At some sites on the central coast of British Columbia without sea otters, for example, mussels are 16 percent larger than in areas with sea otters, while at sites on the south coast they are up to 47 percent larger. Seeing that mussel size can be used as an indicator of the relative abundance of sea otters, the team looked back in time.

Mussel shells are relatively common in archaeological records. Although they are often found broken and fragmented, the strong, hard umbo where the valves meet often remains intact. By measuring the thickness of mussel umbos found at six sites dating from 2,700 to about 6,000 years ago, the team found mussels as large as those from modern sites without otters. The finding suggests that otters may have been deliberately kept away from areas of human settlement, with hunters targeting them to preserve their own access to the shellfish, while allowing them to thrive in kelp forests.

But recognizing the role that indigenous peoples have played in managing healthy ecosystems, including through hunting, is an area where environmentalists with a Western settler perspective have work to do.

As a species of special concern, the sea otter is managed by Fisheries and Oceans Canada (DFO). The scientific panel advising DFO recently calculated that a reasonable annual biological catch, or take, for sea otters on the B.C. coast would be around 500.

The realization that historical populations of sea otters were likely much smaller than previously assumed stems from analyzes of mussel shells. Photo courtesy of Slade et al.

What’s interesting about this number is that it was calculated using a formula that forces those entering the numbers to choose a recovery factor, a value that can range from zero (no recovery) to a (fully recovered). Some environmentalists take this recovered state to mean the restoration of a pre-human population. This use of the formula and the goals it generates are aimed at an Edenic population of pre-human sea otters that probably never existed, as sea otters are believed to have arrived in the Americas around the same time. than humans – after the glacial ice opened near the Bering Land Bridge.

Based on DFO’s 500 count, Indigenous groups may request to hunt a small number of sea otters for food and ceremonial purposes, but this is not enough to keep animals away from the seafood these communities depend on. for their livelihood.

“The number is applied generally across the coast, so it’s really different from the very specific spatial management that happened in the past,” says Salomon. “This is not a hunting debate. It’s about recognizing humans as part of a place.

“There is a parallel between the coexistence of otters and humans on the one hand, and [the] coexistence of indigenous managers and conservation managers, on the other hand, ”explains McKechnie. “There has to be some reconciliation of coexistence in management perspectives, as indigenous communities are fighting for their livelihoods on this point. “

Recognizing this essential role of Indigenous peoples in the history of the sea otter, the Coastal Voices Project brings together Indigenous leaders and knowledge holders, scientists and artists from British Columbia and Alaska to discuss and plan the return of sea otters, with its multiple ecological and social effects. They have collected their views online as a resource for policy makers and the public.

“We should have a say in how we run things. We live here, [sea otters are] are part of our lives and we know them, ”says Walter Meganack Jr., president of Alutiiq of the Port Graham Corporation in Alaska, who participated in the Coastal Voices project. “Who better to run something than people where it means something to them, [rather] than the government where it is just numbers. With the government, it’s always just numbers. It’s sad, but that’s what it is.


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