Visiting the Canadian cousins of Monterey Bay’s sea otters
Since 1984, Monterey Bay Aquarium’s Sea Otter Program team has worked to understand and protect southern sea otters (Enhydra lutris nereis). The population has slowly recovered from near-extinction in the early 1900s to become an icon of California’s Central Coast. Northern sea otters (Enhydra lutris kenyoni) have a similar story on the Southwest Canadian Coast: After going locally extinct in the early 1900s, they’ve been reintroduced and are expanding their range.
Today, the Hakai Institute is studying how the presence of sea otters is changing kelp forest ecosystems in a marine protected area along the British Columbia coast. This summer, Aquarium Sea Otter Research Coordinator Michelle Staedler and Senior Research Biologist Jessica Fujii traveled to Calvert Island to help monitor northern sea otters. Michelle shares her insights from the expedition.
The pilot banked the small plane, flying up a narrow waterway at the upper end of Calvert Island. Jessica and I saw below us a floating dock, several boats and red-roofed buildings nestled among the trees. This would be our home base for the next two and a half weeks.
Our destination: Hakai Institute’s Calvert Island Field Station, a coastal research facility 400 miles a northwest of Seattle. The only way to the island is by boat or float plane, weather permitting—but the frequent fog and storms don’t always cooperate.
Jessica and I had come from Monterey to work with Erin Rechsteiner, a Hakai Institute researcher and PhD student who studies sea otter populations in this remote part of Canada. We were, in a sense, coming full circle. Several years back, Erin traveled to Central California to learn how the Aquarium—and our colleagues at the U.S. Geological Survey, the University of California at Santa Cruz and the California Department of Fish and Wildlife—collects data on the foraging habits of southern sea otters. Now, Jessica and I were paying a visit to Erin’s home turf, helping her study the foraging habits of northern sea otters in Canada .
After feasting on a lunch of fresh greens (grown in greenhouses on the island), we met with Erin. She was joined by Linda Nichol, a research biologist with Canada’s Department of Fisheries and Oceans and a leading expert on recovering sea otter populations in Canada.
As we chatted, we realized otter-spotting along the Monterey Peninsula, where Jessica and I do most of our field work, is strikingly different from data collection in British Columbia. In Monterey, we load our telescopes, backpacks and radio telemetry equipment into a vehicle and drive to several key locations along the shore. At each location we set up our gear, spot otters, identify them by their flipper tags, note what they’re eating and drive to the next stop.
A complicated process
In British Columbia, it was a little more complicated: We traveled between islands by boat, jumped off with our heavy gear and stayed in one spot for hours on end, until the boat picked us up again. Depending on sea conditions, the one-way travel time could be up to an hour.
On our first day out, we packed our waterproof backpacks with a telescope, tripod, iPad, clipboard, binoculars, extra clothes, rain gear and snacks—some 40 pounds in all. We also wore waterproof boots and heavy “float coats,” a must when working around cold seawater. We trekked down to a small boat, Tsitika, and headed out toward the observation sites.
Soon, we came upon a group of resting otters tucked behind some islands. There were about 100 of them! Erin told us these are all males. In California, most rafts of otters are much smaller, up to 10 animals on average. We often see resting otters with one territorial male, several independent females, and females with pups. Young and old males without territories will hang out in small bachelor groups in different locations, away from established territories.
We approached the rocky outcropping where I would spend the next six hours. Erin carefully positioned the boat along the slippery rocks. I strapped on my backpack and stood on the bow, waiting for the right moment to jump to the rocks. Once safely onshore, I did a radio check with the boat, and Erin headed off.
I climbed to a fairly flat spot on the rocks, set up my spotting scope and scanned the area to count all the otters in view. To the west was the open Pacific Ocean. Swell after swell crashed on nearby islands, spraying seawater 30 feet into the air. A seemingly endless line of forested islands and rocky islets stretched to the north and south.
Erin, Jessica and Linda each took up their stations at other lookout spots, the Tsitika tied up nearby. I could see Jessica across the way, looking through her scope on what she called “Shell Litter Rock,” a nod to the broken shells all around her.
After we settled in, the silence was amazing. In Monterey, the background noise when spotting otters includes the rumble of traffic, pedestrian chatter and crashing waves. In British Columbia, we heard the quiet rustle of wind, waves lapping the shoreline and occasional otter sounds: crunching on a crab, hammering a clam or splashing to avoid another otter’s attempted food-snatch.
Mostly, it was just quiet.
The otters stayed closest to Jessica, swimming to the middle of the channel and feeding on geoduck clams, green urchins and crabs. The clams were huge—as wide as four sea otter paws lined up side by side! I’ve never seen them this big in Monterey Bay.
Ever on the alert
At first the otters surrounding Jessica seemed oblivious to her presence. She stood stalwart and quiet, collecting foraging data. Then the wind changed direction ever so slightly, and one male otter “winded” her, catching a whiff of her unfamiliar scent. He periscoped in her direction—popping the upper third of his body out of the water to investigate—then slid underwater to forage elsewhere.
In California, female sea otters often sustain nose wounds during mating encounters with males. We rarely see a nose scar on a male southern sea otter. In British Columbia, the males were much larger than their California cousins—one individual weighed 83 pounds, compared with an average 65 pounds for a male around Monterey Bay—and several had very pink nose scars.
An explanation became clear as I watched these males fight over large prey items such as geoduck clams. I wasn’t sure why they needed to play tug-of-war when there was so much prey available. Were they trying to assert dominance, or was it simply easier for a male otter to steal from his neighbor rather than dive for a meal himself?
Erin’s work tracking otter movements and eating habits fits into Hakai’s broader research on how sea otters influence ecosystems like kelp forests, seagrass meadows, rocky intertidal areas and soft sediment habitats. It’s a story familiar to us in Central California, where sea otters were once abundant, then hunted to near-extinction, then protected and allowed to slowly recover. We’re only beginning to understand how critical the presence of this native species is to coastal ecosystems.
Now in the thousands
Around 1970, scientists reintroduced 89 sea otters to the west coast of Vancouver Island. The sea otters came from Alaska, where some of the animals needed to be removed because of nuclear weapons testing in the Aleutians. The sea otter population on British Columbia’s Central Coast wasn’t intentional—biologists think it is an offshoot of that Vancouver Island cohort. In the late 1990s, biologists pegged the northern sea otter population in British Columbia at about 1,000 animals. Today, Linda and her colleagues estimate the count around 7,000.
Jessica and I were fortunate to contribute to this important sea otter research, which is supported by the non-profit Tula Foundation through the Hakai Institute. Tula Foundation benefactors Eric Peterson and Christina Munck were inspired by David Packard, founder of the Monterey Bay Aquarium Research Institute, who encouraged researchers: “Take risks. Ask big questions.”
We hope to return next year to discover more about this unique place—its sea otters, killer whales, wolves, minks, ravens and sandhill cranes. Erin’s preliminary finding thus far is that northern sea otters change where they feed and what they eat in different seasons. In the winter, they enter sheltered bays to feed on clams, while in the summer they favor the urchins and mussels on the exposed rocky shores.
By researching northern sea otters on British Columbia’s Central Coast, we gain insights about their imperiled southern cousins on California’s Central Coast—and deepen our understanding of the many ways we are connected.
Featured photo: Northern sea otter mom and pup. Photo by Matthew Morgan Henderson