Still endangered after century of recovery, sea otters become scapegoats
ANCHORAGE, Alaska––Sea otters are now taking the rap from frustrated Alaskan shellfishers for one of the best-documented and longest foreseen effects of global warming: oceanic acidification, inhibiting the ability of species such as abalone, urchins, clams, crabs and sea cucumbers to build and maintain shells.
Blaming sea otters––and killing them––plays into the climate change denialism amplified by Alaska politicians eager to revive the oil extraction boom of 30 to 40 years ago by drilling on the North Slope, and coincides with the pro-hunting, fishing, and fur trapping rhetoric that helps to keep those politicians in office.
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“State lawmakers and other policymakers have drafted letters asking the Trump administration and a Republican-controlled Congress to loosen federal otter protections, and to grant local managers more power to cull” sea otters, reported Nathaniel Herz of the Anchorage Daily News on March 17, 2018.
“Dive fishermen, who swim or walk along the ocean floor in search of seafood, describe areas carpeted with shellfish 15 years ago that are now completely devoid of them,” Herz explained.
Politicians have more blubber
Lacking a blubber layer to help keep themselves warm, sea otters have a fast metabolism, eating about 25% of their body weight per day.
This means “probable sea otter predation,” as Herz’s sources described it, is easily but inaccurately scapegoated for the recent closure of approximately half of the former urchin hunting seabed off southeastern Alaska.
The 1972 Marine Mammal Protection Act allows only indigenous coastal Alaskans to hunt sea otters, and then only for personal use of meat and pelts. Indigenous Alaskans kill significant numbers––1,281 in 2012, and at least 1,380 in 2013––but might kill more if they were allowed to sell sea otter pelts.
Alaskan pols want to expand sea otter hunting
“U.S. Representative Don Young,” a former trapper, “introduced a bill in 2011 to allow the sale of raw pelts to non-natives,” Herz recalled. “Two years later, Sitka Republican state senator Bert Stedman proposed legislation to offer a $100 bounty for each sea otter harvested. The bill didn’t get a vote.”
But Alaska’s two Republican U.S. senators, Dan Sullivan and Lisa Murkowski, are both interested in reviewing elements of the Marine Mammal Protection Act,” Herz said, “and Sullivan plans to hold a subcommittee hearing on the issue.”
“There are more than 600 active commercial permits in the fisheries most affected by sea otters — urchins, geoduck clams, sea cucumbers and Dungeness crabs,” wrote Herz. “Their gross earnings in 2016 topped $15 million. But lawmakers acknowledge that sea otters help boost Southeast Alaska’s growing tourism industry. And scientists say that while sea otters do deplete shellfish stocks, they can also help boost the presence of some species like kelp — which produces habitat for fish and can even trap climate-warming carbon from the atmosphere.”
“Greatest threat to the future of dive fisheries”
Herz followed up on a January 21, 2018 report by Anchorage Daily News colleague Laine Welch that “Sea otters and their [alleged] devastating impacts on southeast Alaska shellfish were among the many emotionally charged topics at the state Board of Fisheries marathon meeting running from January 11 to January 23 in Sitka. Crabbers and fishermen who dive for lucrative sea cucumbers, geoduck clams and urchins again pleaded for changes to regulations to help protect their livelihoods.
“In testimony to the board,” Welch recounted, “Kyle Hebert, dive fisheries research supervisor for the Alaska Department of Fish & Game, called sea otters ‘the greatest threat to the future of the dive fisheries.’”
The would-be sea otter hunters cited a 2011 claim by the McDowell Group, a research and consulting firm that tends to favor natural resource extraction industries, that sea otter predation has cost the southeast Alaskan economy more than $28 million since 1995. This has been, the McDowell Group argued, chiefly through losses experienced by the Dungeness crab and shellfish dive fisheries.
Shellfishers & sea otters “cannot coexist”
“The report concluded that those fisheries and large populations of sea otters cannot coexist in the same waters,” summarized Welch.
According to the McDowell Group, Welch finished, “Once commercially viable numbers of geoducks, urchins, sea cucumbers and crab are gone, they are not likely to return while sea otters remain.”
While that assessment might be debated, the opposite statement would clearly be true: the sea otter population would be lost if the species they rely upon for food disappear, and could not recover if the food species fail to recover first.
Meanwhile, the Alaskan crabbing and shellfishing industries grew to the unsustainable scale of recent decades in part because the sea otter population was reduced to the verge of extinction by fur hunters in the 18th and 19th century, and then crashed again after the Exxon Valdez oil spill of March 23, 1989.
Protected by law since 1911
Sea otters before the mid-18th century were plentiful in coastal waters from northern Japan to the tip of Baja California, Mexico.
After 150 years of aggressive fur hunting, however, remnant sea otter populations are known to have survived, isolated from each other and unknown to hunters, at 13 locations in some of the most rugged and remote areas off the Russian, Alaskan, and California coasts.
The 2,000-or-so remaining sea otters were protected by U.S. law in 1911, but––hunted out of their former San Francisco Bay stronghold by 1840––the California sea otter subspecies was believed to have been already extinct.
A small colony was discovered, however, near Big Sur on March 19, 1938 by retired soldier, rancher, and author Howard Granville Sharpe.
Since then, the California sea otter population rose gradually to 3,272 as of 2016, but fell 25% to 2,688 in 2017.
Sea otter habitat expansion has meanwhile been bitterly resented by abalone, sea urchin, and lobster collectors.
The California Sea Urchin Commission, California Abalone Association, California Lobster & Trap Fishermen’s Association, and Commercial Fishermen of Santa Barbara fought in court from 1987 to March 2017, when U.S. District Judge Dolly Gee of Los Angeles threw out their case, to keep sea otters out of the waters south of Point Conception in Santa Barbara County, contending that this was not historically sea otter habitat.
Feds nuked sea otter habitat
The northern sea otter subspecies, by far the most abundant, persisted mainly in the Aleutians, disappearing from British Columbia by 1929 and from southeast tongue of Alaska before 1950.
In 1965, ahead of four underground nuclear bomb tests that were conducted at Amchita Island in the Aleutians between then and 1971, the Alaska Department of Fish Game relocated 367 sea otters from Amchita Island to the southeastern tongue of the state, along with 45 sea otters from Prince William Sound.
By 1973 the total Alaskan sea otter count had increased to as many as 125,000, including about 10,000 along the southeastern coast. But the March 23, 1989 Exxon Valdez oil spill killed thousands of sea otters outright in Prince William Sound, and hit their food sources hard as well. Though the southeastern sea otter population reached 26,000 in 2014, the total number of sea otters in Alaska has declined to circa 73,000.
60% as many sea otters now as when shellfishing peaked
That fact alone should suggest that sea otters have little or nothing to do with declining shellfish takes, since there are overall barely 60% as many sea otters now as when shellfish captures peaked in Alaskan waters. The southeastern Alaskan sea otter population could not continue growing, as it did until 2014, amid a food shortage.
But shellfish poaching is taking an evident toll. On March 16, 2018, for instance, three men from Naukati Bay on Prince of Wales Island were charged with stealing nearly four tons of sea cucumbers from a Whale Pass scientific preserve that has been closed to fishing for nearly 40 years.
“Troopers identified the men as 43-year-old Jonathan McGraw Jr., 52-year-old Keith Wagner and 27-year-old Curtis Looper,” wrote Anchorage Daily News reporter Zaz Hollander. “McGraw took seven trips to the closed area in Whale Pass for a haul totaling more than 7,500 pounds of sea cucumbers valued at $35,288, Alaska state troopers say.
Load 800 tons & what do you get?
“The giant red sea cucumber — Parastichopus californicus — is common from Mexico to the Gulf of Alaska to Chignik on the Alaska Peninsula,” Hollander elaborated. “A little over 1.6 million pounds a year on average [800 tons] are taken by about 230 divers during a fall and winter season, state officials say.”
In other words, the three suspects managed to poach about half of one percent of the legal sea cucumber catch, just a bit more than the average take of legal divers.
By far the greatest threat to shellfish comes from global warming, and not just in Alaskan waters, but the Alaskan coastal waters are among those where the effects of acidification are most obvious.
“Shellfish most directly affected”
Warned five scientists in an extensive “Ocean acidification risk assessment for Alaska’s fishery sector,” published by the peer-reviewed journal Progress in Oceanography in August 2015, “The highly productive fisheries of Alaska are located in seas projected to experience strong global change, including rapid transitions in temperature and ocean acidification-driven changes in pH and other chemical parameters.
“Of Alaska’s many marine resource species, shellfishes appear to be the most directly influenced by oceanic acidification,” the scientists wrote.
For example, “Declines in larval survival would likely affect overall population productivity through reduced recruitment, ultimately reducing the number of crabs available for commercial harvest.”
Prey species for fish might also crash
As well as directly decreasing the abundance of commercially collected shelled species, the scientists cautioned, prey species for fish such as salmon might crash, the scientists cautioned.
The scientists concluded that, “The impacts that oceanic acidification could have on Alaskan resource species through its effects on lower trophic level, pelagic calcifying and non-calcifying organisms, could be more significant than the direct effects on some of those resource species.”
The Department of Ecology for the state of Washington has warned repeatedly since 2012 that the same effects of global warming seen in Alaska are already wreaking havoc on the species category called “calcifiers,” including shellfish and crabs.
“Oceanic acidification appearing decades early”
According to the most recent update of the Washington Department of Ecology web page “Oceanic Acidification in Washington State,” posted in December 2017, “Ocean acidification is appearing in Washington decades sooner than anticipated. Research shows calcifiers are particularly affected by ocean acidification.
“Calcifiers are marine organisms that depend on the mineral calcium carbonate to make shells, skeletons, and other hard body parts.
“Ocean acidification makes an essential component of calcium carbonate – the carbonate ion – more scarce. As a result, calcifiers have to use more energy to pull carbonate ions out of the water to build their shells.
Shellfish dissolve alive
“Calcium carbonate also dissolves more easily as acidity increases,” the Washington Department of Ecology web site explains. “These changes can result in slower growth and/or higher mortality among calcifiers, especially in shellfish larvae and juvenile shellfish,” whose shells may dissolve from their bodies as they grow, making them more vulnerable to predation.
“More than 30% of Puget Sound’s marine species are calcifiers: oysters, clams, scallops, mussels, abalone, crabs, geoducks, barnacles, sea urchins, sand dollars, sea stars and sea cucumbers,” according to the Washington Department of Ecology assessment.
“Even some seaweeds produce calcium carbonate structures,” the web site continues. “Many calcifiers provide habitat, shelter, and/or food for various plants and animals. For example pteropods, the delicate free-swimming snails, are eaten by seabirds, whales and Alaska pink salmon.
How long has this been going on?
“Some species of copepods––small crustaceans eaten by juvenile herring and salmon––are also affected. Impacts on species like the pteropods and copepods are a significant concern because of their ability to affect the entire marine food web.”
This has been predicted, in theory, for decades. How long has it actually been observed?
“Massive die-offs of oyster larvae at Pacific Northwest hatcheries between 2005 and 2009 due to low pH seawater entering the hatcheries highlighted the potential impacts of ocean acidification,” says the Washington Department of Ecology.
In short, oceanic acidification was already visibly depleting shellfish populations when Alaska dive fishers began blaming sea otters.