Return of the Sea Otter

by Todd McLeish

  And it may not be the last keystone story that sea otters have to tell.

  * * *

  AFTER SINKING INTO the mud to our shins while climbing out of the Pursuit to scan the slough, we walked a short distance into the adjacent salt marsh, where Hughes had established experimental plots to assess the effect that otters have on marsh habitat. The abundant algae blooms have caused a spike in purple-lined shore crabs, a crab with a blackish carapace blending to pinkish claws that feeds on the algae. But the crabs burrow into the banks of the slough and create what Hughes calls “crab condominiums,” destabilizing the banks and causing increasing erosion. Hughes found that the resident otters are now feeding on the crabs and improving the condition of the salt marsh. “Where there are crabs, it looks like gophers have invaded your lawn—lots of holes from crab burrows eating away at the soil,” Hughes said.

  “Four years ago we didn’t believe the benefit otters provide to eelgrass, and now we’re finding it hard to believe the influence otters have on the salt marsh,” Tinker added.

  Tinker is right to be impressed by what is being discovered about the resiliency of sea otters and the influence the animals have on their environment. It makes it easy to feel optimistic about their future. They have survived a great deal already—the devastating fur trade, significant diseases in various parts of their range, food limitation and shark-bite mortality in California, killer whales in Alaska, competition with fishermen of all varieties—and yet they are still expanding their range and growing in abundance in many places. But that is not to say that additional threats aren’t lurking. The warming climate is one factor that is raising major red flags for many species and ecosystems around the globe, and yet its likely effects on sea otters are unknown. Sea otters prefer cold waters, so as the oceans warm the otters’ range may shift northward. But even that is uncertain. As the land warms, winds off the sea will likely intensify, driving an upwelling of cold waters from the deep into the sea otters’ coastal environment. That may keep the water cool enough so sea otters don’t have to move northward after all, at least not any time soon.

  The greater concern is a potential decline of otter prey due to ocean acidification. As carbon dioxide concentrations in the atmosphere increase and mix into the ocean, seawater becomes more acidic, making it more difficult for shelled organisms to produce the calcium carbonate they use to build their shells. And since most of what sea otters eat has some sort of shell—clams, crabs, urchins—a decline in those species could have serious implications for otters.

  Biologist Verena Gill may be the otter scientist most worried about climate-related threats to sea otters. She speculates that warming waters may force otter prey species to seek refuge in water too deep for sea otters to reach them on the bottom. She’s concerned that an increase in storm intensity and changes in ocean circulation may shift the populations of plankton that feed the clams that otters eat. And she worries that more intense storms may kill more pups or separate them from their mothers or bring novel diseases into their range.

  “We’re just starting to grapple with what it will mean,” she said. “Are otters adaptable enough to change their prey? Maybe. But could they sustain themselves on it? I don’t know.”

  Gill’s concern about the arrival of novel diseases as waters warm may already be realized. In the fall of 2015, more than three hundred sea otters mysteriously died and washed ashore in Kachemak Bay, Alaska, and most were determined to have died from an unknown bacterial infection. While fifty to one hundred sea otters in that area typically die each year from similar causes, the increase in 2015 had scientists speculating that something else was contributing to the otter deaths—perhaps another disease or a toxin from harmful algae blooms, either of which could have arrived in what many scientists were calling “a blob of warm water” that had spread throughout the region.

  While the possible threats to sea otters from climate change are still mostly unknown, the greater threat may be one we already know a great deal about—oil spills. The Exxon Valdez spill in Prince William Sound, in the heart of their range in Alaska, killed as many as three thousand otters in 1989, and it took twenty-five years for the population there to recover. A significant oil spill along the central California coast could wipe out the entire population of southern sea otters. The animals lucked out in 2015 when 105,000 gallons of oil spilled from an underground pipeline that ruptured in Santa Barbara County and ran into the ocean just a few miles from the southernmost point of the sea otter range. No otters were harmed, but if it had happened a little farther north, it could have been devastating.

  According to Laird Henkel, director of the Marine Wildlife Veterinary Care and Research Center of the California Office of Spill Prevention and Response, just a dime-size spot of oil on a sea otter is the equivalent of a hole in a diver’s wet suit, allowing cold water to rush in and disrupt the waterproofing abilities of the otter’s fur coat. The animal quickly becomes hypothermic, loses its buoyancy, and hauls out of the water to try to warm up. Then the otter begins grooming itself, causing the toxic oil to become ingested and leading to all sorts of nasty issues, from gastrointestinal lesions and organ failure to respiratory problems and burns on the skin. If the oil doesn’t kill the animal quickly, it certainly decreases its long-term survival.

  The one good thing that came from the Exxon Valdez spill, however, was a much-needed focus on oil-spill prevention, readiness, and research, including the establishment of the Oiled Wildlife Care Network in California and the construction of a dozen facilities around the state where oiled otters and other animals can be cleaned and rehabilitated. A research project even investigated the best way to clean an oiled sea otter—an hour of washing the animal with Dawn dishwashing detergent, an hour of rinsing, then drying with towels and a blow dryer, followed by soaking in a pool of warm, softened freshwater.

  The oiled otter rehab facility in Santa Cruz that Henkel manages was built to care for 125 otters, and floating net pens are available to house otters in harbors along the coast while they wait for their home territories to be cleaned. While he plans for the worst-case scenario of dozens of oiled otters arriving at his facility for days at a time, Henkel said that just one otter has required the facility’s services since it opened in 1997—an animal that found fame as Olive the Oiled Otter, and succeeded in raising three pups after being cleaned and released.

  “Any oil going into the water is bad for wildlife,” said Henkel. “The oil-spill risk is decreasing because there’s now more and more regulation. The transition to double-hulled cargo ships has helped. So has the establishment of marine sanctuaries, which pushed tanker traffic offshore. And now there is a greater focus on oil-spill prevention.” But he also said he wouldn’t be shocked if a major spill occurred on his watch.

  * * *

  AND YET DESPITE these looming threats, sea otters are still chugging along, like the proverbial little engine that could. Whether they will continue on that road is a question to which the leading sea otter biologists have very different answers.

  Jim Estes called the growing otter numbers in Southeast Alaska and British Columbia “a positive sign for the future.” But he said so with a tone of dread in his voice because he fears for the animal’s long-term survival, even where its populations seem healthiest today.

  “There are more and more people, and more people means more human impact [on the environment], and more human impact is going to probably be bad for otters in one way or the other, especially in coastal zones where people tend to aggregate in higher densities,” he said. “That’s my worry. I think that as long as we have a global human population that is continuing to utilize more resources, we ought to worry about everything. Are otters high on that list of things to worry about? I think they’re probably less high than a lot of species….But the fact that sea otters live in such a very narrow habitat type—the coastal zone—and this coastal zone is a place where people tend to aggregate I think forewarns
the potential for problems.”

  Estes’s protégé, Tim Tinker, sees things a little differently. He admits he’s more optimistic by nature than many other scientists, but his optimism stems from the sea otters’ healthy recovery from the fur trade in much of their range. He said that even though humans did just about everything possible to wipe out sea otter populations two centuries ago, the animals have made a major comeback, despite a few hiccups along the way.

  “Because of that big picture, I think they have a huge potential to recover,” he said. “And more importantly, I think that they’ve taught us more about how ecosystems work and about the importance of predators in ecosystems than probably any other species. And that message is getting propagated now.”

  For many years, Tinker said, people thought predators were something that should be controlled or removed, but that belief is fast disappearing, thanks largely to what has been learned about the role of sea otters in their ecosystem.

  “Although the nuances are different and they do different things in different areas, we haven’t seen anywhere where they recover and nothing happens,” he said. “Every time they recover, lots of big things happen, and in general it very often leads to increased biodiversity.”

  I hesitated before asking Tinker my last question. He had called himself “an unapologetic scientist” at a presentation he made at the annual meeting of the Friends of the Sea Otter, an indication that he can say only what the facts indicate. It’s difficult for him to speculate, and it’s even more difficult for him to make decisions that must factor in political considerations, economic realities, and public sentiments. So when I asked him what it would take to get sea otters to expand into Northern California and Oregon, to fill out their historic range, he started his answer with one simple fact. “We’d need to start another population.”

  And that’s when he hedged, pointing out that starting another population of sea otters is not a decision for scientists like him to make. It’s not even a question for wildlife managers or government regulators, he said. It’s a question for society, especially for the people who live and work in those coastal communities.

  “Do people in Humboldt County want to have sea otters in their marine ecosystem?” he asked. “They should be told very clearly that there would be impacts—if they have shellfisheries, there’s going to be negative effects on shellfisheries. But on the other hand, they should be told that there would be increases in kelp and things that depend on kelp. They should get the whole story and make an informed decision.

  “There is appropriate habitat all the way up the coast,” he added. “I think that is a social question, a broad social question that should be made in an informed way, and that’s the challenging part. There are those who want to sugarcoat it, and then there are those who want to make it sound as though it’s like you’re dropping a nuclear bomb, and neither of those extremes are true.”

  Regardless of whether the public has a chance to weigh in on that question, Tinker is confident that sea otters will continue to expand their range on their own.

  “More importantly,” he concluded, “I think they will continue to teach us about how ecosystems work a long way into the future. They’ve already taught us a ton, but they’ve only begun. There’s so much more to learn from them.”

  Acknowledgments

  MOST OF MY WRITING PROJECTS involve at least one field trip to join scientists at their research sites. Even when they take place in an office or laboratory, these adventures are always exciting. They’re partly why I enjoy writing so much—it gives me an opportunity to go on the road to meet researchers and observe the scientific process as it happens. But a project like this book, a three-year undertaking involving more than a dozen field trips, requires the cooperation of a long list of scientists and other helpers. All of these individuals were generous with their time and happily (I think) shared their knowledge, expertise, and insights in a way that allowed me to turn them into what I hope is engaging prose for my audience of nonscientists. Any inaccuracies in the text are entirely my doing.

  I am especially grateful to Tim Tinker, who somehow found time amid an immensely busy schedule of travel, research, writing, and teaching to spend many long hours with me in three different states over the course of two years. He patiently walked me through his complex research and provided me with some of my favorite wildlife adventures yet.

  Numerous others—scientists, fishermen, and more—invited me into their homes, offices, and research sites; agreed to be interviewed; or shared vital information that found its way into this book. I am truly appreciative of their assistance. In Alaska, those people include Verena Gill, Marc Webber, Kristin Worman, George Esslinger, Ginny Eckert, Zac Hoyt, Angela Doroff, Sunny Rice, Brett Long, Phil Doherty, Sonia Ibarra, Stephanie Jurries, Jim and Julie Alexander, Dave Beebe, Kathy Peavey, Dennis Nickerson, Mike Jackson, Peter Williams, Ben Weitzman, Matt Edwards, Brenda Konar, Craig Matkin, Doug Demaster, Dan Monson, Jim Bodkin, and Joel Garlich-Miller. In California, I am indebted to Lilian Carswell, Jim Curland, Laird Henkel, Melissa Miller, Andy Johnson, Karl Mayer, Angela Hains, Michelle Staedler, Sarah McKay Strobel, Zach Randell, Nicole Thometz, Lily Maxine Tarjan, Jim Estes, Tim Stephens, Brett Hughes, Sarah Espinosa, Gena Bentall, Brian Hatfield, Joe Tomoleoni, Mike Kenner, and Charles Kavanaugh.

  I also owe thanks to Roger Dunlop, Martin Haulena, Lindsay Akhurst, Taryn Roberts, Sion Cahoon, Jonathan Hulquist, and Linda Nichol in British Columbia; Jessie Hale, Kristin Laidre, Steven Jeffries, Deanna Lynch, and Shawn Larson in Washington; Ron Jameson and Quinn Read in Oregon; and Katya Ovsyanikova in Russia. Thanks are also due to Beth Ullucci and the staff of the Jesse Smith Memorial Library, as well as to Peter August, Erica Tefft, Rodd Perry, Kim Robertson, Teresa Gervelis, and Cindy Sabato.

  This is my fourth book about wildlife and natural history, and none of them would have gotten off the ground without the kindness and support of my literary agent, Charlotte Cecil Raymond, who has gracefully helped me navigate the publishing world and enthusiastically encouraged me throughout the research and writing process. Thanks also to my editor at Sasquatch Books, Gary Luke, and his fabulous staff.

  And finally, I must once again recognize my wife, Renay, who offers whatever support I need whenever I need it, pulls me through bouts of worry and writer’s block, never complains when I disappear on unplanned research trips, and leaves me alone when that appears to be the preferred strategy for success. I’m pleased—as she is—that she was able to join me for most of my sea otter adventures, earning her a prominent spot in several chapters of this book. All of my writing success is due to her encouragement, devotion, and understanding—not to mention her recent willingness to let me quit my job to write full time. I’m especially thankful to her for that.

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  Ames, J., J. Geibel, F. Wendell, and C. Pattison. “White Shark-Inflicted Wounds of Sea Otters in California, 1968–1992.” Great White Sharks (1996): 309–16.

  Ballachey, B. E., D. H. Monson, G. G. Esslinger, K. Kloecker, J. Bodkin, L. Bowen, and A. K. Miles. 2013 Update on Sea Otter Studies to Assess Recovery from the 1989 Exxon Valdez Oil Spill, Prince William Sound, Alaska. Open-File Report 2014-1030. US Geological Survey.

  Bockstoce, John R. Furs and Frontiers in the Far North: The Contest Among Native and Foreign Nations for the Bering Strait Fur Trade. New Haven: Yale University Press, 2009.

  Bolin, Rolf. “Reappearance of the Southern Sea Otter along the California Coast.” Journal of Mammalogy 19, no. 3 (1938): 301–303.

  Bowen, Lizabeth, A. K. Miles, C. A. Holden, J. A. Saarinen, J. L. Bodkin, M. J. Murray, M. T. Tinker. “Effects of Wildfire on Sea Otter (Enhydra lutris) Gene Transcript Profiles.” Marine Mammal Science 31 no. 1 (2015): 191–210.


  Burek, K. A., V. A. Gill, and D. S. Bradway. “The First Case of Locally Acquired Disseminated Histoplasmosis in Alaska and in a Free-Ranging Marine Mammal.” Journal of Wildlife Diseases 50 no. 2 (2014): 389–92.

  Burris, O. E., and D. E. McKnight. Game Transplants in Alaska: Wildlife Technical Bulletin No. 4. Juneau: Alaska Department of Fish and Game, 1973.

  California Legislature. Effect of the Sea Otter on the Abalone Resource: Hearing Transcript of the California State Senate Fact Finding Committee, Subcommittee on Sea Otters. San Luis Obispo. Nov. 19, 1963.

  Clarke, Louise R., and Arthur H. Clarke. “Zooarchaeological Analysis of Mollusc Remains from Yuquot, British Columbia,” edited by J. Dewhirst, in The Yuquot Project 2:37[1]57. Edited by W. J. Folan. Ottawa: Parks Canada, 1980.

  Counihan-Edgar, Katrina, V. A. Gill, A. M. Doroff, K. A. Burek, W. A. Miller, P. L. Shewmaker, S. Jang, et al. “Genotypic Characterization of Streptococcus infantarius subspecies coli Isolates from Sea Otters with Infective Endocarditis and/or Septicemia and from Environmental Mussel Samples.” Journal of Clinical Microbiology 50 no. 12 (2012): 4131–3.

  Cox, Kenneth W. California Abalones, Family Haliotidae: Fish Bulletin No. 118. Resources Agency of California Department of Fish and Game, 1962.

  DeGrange, Anthony R. Conservation Plan for the Sea Otter in Alaska. Anchorage: US Fish and Wildlife Service, 1994.