How sea otters are crucial for a healthy ocean and what we can do to protect them.
By Anne Kuckertz
In 1989, the Exxon Valdez tanker vessel crashed on a reef in Prince William Sound and released over 42 million liters of oil into the ocean, devastating the Alaskan coastal environment. The spill slaughtered approximately 250,000 sea birds, three hundred seals, two hundred and fifty bald eagles, and twenty two killer whales. Salmon fisheries collapsed and the economic loss was hundreds of millions. In the first few months following the spill, the bodies of a thousand sea otters killed by oil exposure washed ashore. And estimates of total mortality go up to 5,500 meaning that 40% of the otter population in Prince William Sound died. They faced hypothermia when the oil coated their fur, inhibiting their ability to stay warm. Liver disease from oil ingestion was also a deadly enemy and population numbers didn’t recover to pre spill levels until 2009, nearly two decades later.
But the death of so many otters in Prince William Sound didn’t just mean the loss and adorably fluffy creatures but of critical members of the coastal ecosystem and a valuable weapon in the fight against climate change. Sea otters have such a vital role in their habitats (which are located along the western United States coast, the Russian southeast coast, and in parts of Japan) because they are what as biologists refer to as a “keystone species.” This means that, like the center slab of an arch, they hold their habitat together. The loss of a keystone species can mean the end of any ecosystem in the worst case and a major shifting of its functioning in the best.
Sea otters received this designation thanks to their endless appetites. In order to maintain their body temperature, they must consume around 20-30% of their body weight, meaning, around 12 pounds, (the average human eats around 5.4 pounds) each day. And, a favorite snack among sea otters is the sea urchin, a spiky animal that comes in different shades of green, brown, red, and purple and feasts on kelp forests. Urchins function similarly to weeds, taking over the forest and crowding out the kelp.
These purple pests weren’t always quite such a menace to the sea floor. Before 2013 they were kept in check by their number one predator: sea stars. But that year another player came on the scene, an entity that scientists named “the blob.”
The blob is a patch of warm water 1,000 miles wide with temperatures ranging from 4 to 10 degrees Fahrenheit above normal. Because sea stars thrive in a colder environment, this blob made them more susceptible to disease. In 2013, sea star wasting disease resulted in massive die offs, leading to a huge loss in predators for the sea urchin. Without sea stars to keep the urchins from overrunning the California coast, the prickly animals took over the ocean floor and its kelp forests.
Since 2014, 95% of kelp in Northern California has died off due to what divers call the “purple carpet.” This aquatic deforestation is especially alarming because, just like regular land forests, kelp acts as a major carbon sink, ridding the atmosphere of 40 million tons of carbon dioxide each year (even with their depleted numbers). Through a process called carbon sequestration, kelp takes in carbon dioxide from the atmosphere and stores it. When the kelp dies, still holding onto that carbon dioxide, some will wash ashore where it will decay and release the greenhouse gas back into the atmosphere. But it’s the kelp that stays in the ocean that’s really helping to combat climate change. If the kelp sinks to the sea floor upon its death, then it drags the carbon dioxide down with it (where it can stay for hundreds of years.)
At least, it did, before the purple carpet.
In fact, the spiky villains became so prolific that local divers in California Northern have taken to plucking the urchins from the limbs of dying kelp by hand. But, in certain areas the divers have help. These small patches of lush kelp are like green beacons dotting the path towards a healthy planet.
As we all probably guessed, a study published earlier this year confirmed that these kelp forests were flourishing thanks to the presence of sea otters that took up residence in the area. Because of their voracious appetites, sea otters are keeping the urchin population in check, allowing kelp forests to thrive.
Given the enormously positive influence that sea otters have on both their habitat and the habitat of us humans, losing them to oil spills is especially devastating. Oil spills are particularly threatening for otters, more so than the other marine animals, because of how spills affect their fur. If you’ve ever seen a sea otter in the wild, then you know that they’re constantly grooming, attending to their sleek built-in coats that are seemingly slicked back with seawater. As a levelheaded observer you might have assumed that these small marine mammals are fretting with their fur to prevent tangling, the bane of many long-haired humans. But sea otters spend around five hours a day trying to make their fur as matted as possible, a cringeworthy fact to hairstylists everywhere.
Although sea otters would never be able to hack it in a salon, their knack for creating knots in their coats actually helps them stay warm. In fact, their matted wet fur keeps their skin completely dry, which may seem like an oxymoron but is just physics. You sea, when the otters are going about maintaining their tangled outer garment, what they are really doing is trapping air bubbles between their fur and skin, essentially creating a protective layer of air around their skin. Because air doesn’t conduct heat very well, it makes a perfect insulator, keeping the heat between the skin and the fur, creating a toasty bubble powered by the otter’s own body heat.
While otters do groom quite often, it’s not just the act of grooming that keeps their fur tightly tangled, but the structure of the hair itself. Each strand has miniscule, scale-like protrusions along its length that act like hooks allowing a hair to entangle itself with its keratin neighbors. Further adding to the complexity of the otter fur, their pelts contain two distinct types of hair: guard hairs and underhairs. Guard hairs are longer and provide a protective umbrella over the three or more underhairs sharing its follicle. Underhairs are shorter and more plentiful. Together these two hairs combine to provide the perfect home for air bubbles.
Because otter survival is very much dependent on keeping a certain body temperature, anything that gets in the way of them maintaining their matted manes poses a serious risk to their safety. One such force is oil spills. Sea otters are especially susceptible to oil spills. While other aquatic animals may be able to rid themselves of the oil covering their bodies given enough time, sea otters often die of hypothermia before they get the chance. Even if an otter does manage to survive an oil spill short term, the long-term effects can be devastating. In the Exxon Valdez oil spill devastation reigned as many otters fell prey to hypothermia and liver disease caused by the oil they ingested while trying to clean their fur.
Since otters are the only marine mammal without a fatty layer of blubber to keep them warm, oil spills are especially devastating for them. But unsurprisingly, human interference isn’t a new concept to sea otters. We first started dwindling their numbers hundreds of years ago. In the 18th and 19th centuries, sea otter pelts were a hot commodity in the fur trade, with a density of up to a million hairs per square inch (the most in the animal kingdom), their pelts made extremely warm and soft apparel. But the key to sea otter survival (their fur) was nearly the downfall of southern otters (aka California sea otters). In 1911, when sea otters were near extinction, the United States, Russia, Canada, and Japan signed the International Fur Seal Treaty, protecting otters from hunting. The flourishing population of what was once around 300,000 individuals was reduced to less than 2,000. They’re sprawling habitat range which stretched from Mexico, up along the western United States coast, across the Pacific to Russia, and down into Japan shrank to 13 small, scattered pockets of survivors.
The only otters left South of Alaska were a raft (a group of otter that holds hands to avoid floating away) of 32. Yes. 32. All California sea otters alive today descend from this lone gathering of furry creatures, basking in the sun, unaware that they were the last of their kind.
Since the 1920s, sea otters have recovered two thirds of their original habitat range and roughly a third of their numbers. Populations reached stable states in parts of Alaska and British Columbia. And, in Russia, are back up to what they once were, an encouraging fact for conservation efforts in other locations.
California sea otters, however, will continue to need TLC if their population is to ever return to what it was before the establishment of the fur trading industry. Although their current population of around 3,000 is certainly better than that raft of 32, it’s still far off from the estimated 16,000 that it used to be. This means that we must be diligent about preserving the otters we already have, which, to start, means avoiding any more oil spills.
Due to their small and relatively localized groups, a large oil spill in Central California could lead to the total extinction of the southern sea otter. This makes the recent spill near Long Beach, California, which released 25,000 gallons of oil, incredibly unnerving. Luckily for the sea otters, the spill wasn’t quite north enough to have an immediate negative affect (as far as we know). Local birds, fish, turtle, coral, and dolphins weren’t so lucky.
While this may seem like small potatoes in comparison to the devastating Exxon Valdez fiasco, it’s a blaring reminder that the west coast is still peppered with offshore oil drilling platforms and pipelines that are just waiting to explode like underwater oil volcanoes.
But President Biden announced a plan in January of this year to halt any new leases while a team analyzes the environmental impact of decommissioning the oil rigs and pipelines off the coast of Southern California. This was an encouraging step in the direction that Californians have been demanding for years: no offshore drilling.
Since Biden’s campaign team emphasized the end of offshore drilling and the fight against climate change so heavily, this came as no surprise. What was shocking were the resulting events in June. President Biden scrapped the order and followed it with an August announcement from the Bureau for Ocean Energy Management. The BOEM declared its intent to auction off leases on the Gulf of Mexico’s seabed. And a few months later, mere days after President Biden pledged in Glasgow to achieve a net zero emissions economy by 2050, the administration began selling off leases as a part of a total of 80 million acres to oil companies. Just a small portion of this sale could result in the emission of 516 million metric tons of greenhouse gases into the atmosphere.
And while the otters of California need not worry about direct contact with any potential oil released into the Gulf of Mexico, they should be apprehensive of what this means for the oil industry as a whole. Granting new leases to oil companies in this area secures a place for oil in the US economy for many years to come. This means more greenhouse gas emissions, higher temperatures, less inhabitable oceans, and very unhappy otters.
Another major enemy otters must fight because of global warming is disease. Parasites and protozoal diseases wreak havoc on the otter population. Coastal contaminants from human activities add more and more pathogens into the mix. And as was the case for the sea star wasting syndrome, the blob only aggravates the situation by providing a more favorable environment for infectious diseases as well as toxic algae.
Yep, toxic algae. In California, when the water is warm enough (thanks to rising temperatures) blooms of red algae crowd the ocean surface and release a neurotoxin called Domoic acid that causes heart disease in the otherwise healthy adult otter population.
Hope isn’t completely lost though. Biologists at the University of California, Santa Cruz believe that the Southern Sea otter population could be tripled by reestablishing groups in the San Francisco Bay. Historical evidence shows that the bay used to be home to the majority of California otters.
We can also look to places such as Russia and Alaska, where otter populations have recovered, as models. In Russia, it’s illegal to capture or hunt otters without obtaining a license that is only granted for scientific purposes. Russia also expanded the otter habitat range using translocation.
Translocation is a process where scientists move at risk animals and plants to new locations to encourage their survival. Experts might do this to increase genetic diversity (to avoid genetic diseases caused by inbreeding) or, as was the case in Russia and the proposed San Francisco Bay plan, to extend a species’ habitat range. And while otters that are moved to new places will still be vulnerable to harmful algae blooms, by increasing the population of otters in an area, we bolster the presence of a keystone species and improve the overall health of the aquatic ecosystem.
It’s also possible that some of Russia’s success is due to human emigration away from otter habitats. Although this probably isn’t a viable option for the California coast, it does show that limiting the human footprint on the coastal ecosystem will make a difference. This includes chemical run off from coastal industry and pet waste (parasites found in cat feces that makes its way to the ocean and kills sea otters is just one harmful example.) So be very intentional when you’re disposing of Fluffy’s excrement after her mid-morning walk.
It may seem dire, (and make no mistake, it is) but if Prince William Sound otters can recover from forty-two million liters of oil, then California can certainly reclaim its furry climate caretakers. In fact, the Alaskan population has recovered so well that some people in the fishing industry even view them as pests. Because the population there is thriving, Alaska has revived its sea otter fur trade (in a limited capacity) to keep Native Alaskan traditions alive. So, if you’re on the market for obscenely warm and soft (remember, a million hairs per square inch) apparel you can buy it in Alaska. But only from individual tradespeople (Alaska is being careful to avoid the industrialization that led to this mess in the first place) who are at least one quarter native Alaskan.
The Exxon Valdez spill may serve as a reminder of the chaos and terror that human consumption has wrought on the planet. But it’s also an example of how, with enough moxie and patience, we can work to reclaim the health of our home and all the creatures sharing it with us.
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