By Naomi Klouda
Sea otters along the Homer Spit are catching tourists’ attention like the famed Homer Spit eagle flocks in their heyday.
Otter numbers are high and they are rafting closer to the Homer Spit, offering closer inspections than what is normally encountered there.
High tide brings the fun-to-watch marine mammals ever closer to Spit Road, where cars pull over to observe their antics and snap photos. This isn’t always a safe situation for the flow of traffic, as Homer Police Chief Mark Robl cautions.
“It goes with the season. I would just really urge folks to be careful and pull completely off the roadway. Be cognizant of pedestrians, bicyclists and other traffic,” Robl said. “I witnessed a woman who stopped in the middle of roadway to take photos. Not a good idea. She created an unsafe situation.”
Verena Gill, a wildlife biologist with the Marine Management Division of the U.S. Fish and Wildlife Service, has studied the Kachemak Bay population of otters for several years and said the population is “stable and in good numbers.”
The population estimate in the last year studied, 2008, was 3,600 otters, up from the 1990s when the bay’s otter population topped out at 1,000 or fewer. The numbers may have changed again, and a new population count is set for August, Gill said.
Angela Doroff, a research coordinator with the Kachemak Bay Research Reserve who has worked with otter population studies for 25 years, said one development appears to be new this season.
“It’s surprising to see more animals around the Spit in the summertime. Usually we see high numbers there in wintertime and less in summer,” Doroff said.
Otters take refuge in the less windswept coves of the Homer Spit during winter storms. Now they are spending some days closer than is their usual habit of being spread out in many other areas of the bay.
Otters move around in the bay periodically for reasons relating to food abundance and currents, Doroff explained.
“We’re seeing a distribution shift now. It likely relates to several factors, including food sources, weather patterns and ocean currents, which affect where they rest. In the summertime, fresh water from rain, snowmelt and melting glacier ice influences how the surface water circulates in the bay. A typical summer pattern is that gyres set up at the mouth of the bay and the head of the bay. Sea otters usually rest there because the water is not moving so fast,” she said. “They use water and space differently. When it’s less stormy, they are out in more open water.”
This makes otters seem either to be absent altogether or visible in big numbers in the bay.
“In reality, they’ve been there all the time, but now it is in highly visible space,” she said.
The bay’s otter population is at its highest peak in the past five decades.
In a study, “Aerial Surveys of Sea Otters, (Enhydra Lutris) in Kachemak Bay, Alaska 2008,” by Gill, Doroff and Douglas M. Burns, the known history of otter populations dates back just prior to statehood. It documents that, prior to the 1960s, Kachemak Bay had not yet been repopulated with sea otters. In the late 1960s, there were sporadic reports of single otters, usually older males, moving into the bay.
Sea otters had repopulated the outer Kenai Peninsula in the 1960s, and biologist Karl Schneider believed it was these animals that were expanding into Kachemak Bay. By 1975, an increase in sightings in offshore areas west of the Homer Spit was recorded, and reports from residents began to increase. Still, only 11 otters were found in a helicopter survey in October of that year. From February to June 1976, Schneider flew monthly surveys in a Grumman Goose in various areas of Kachemak Bay looking for sea otters and found as many as 49. Most of the sightings were in the Seldovia area. Based on his observations, Schneider estimated there were 400 sea otters in the bay, but that it was a nonbreeding population made up of males seeking new territory.
It was 20 years before another survey was conducted. From February to March 1994, U.S. Fish and Wildlife crews counted 355 otters by aircraft and 151 by boat. From this they estimated the population of sea otters in Kachemak Bay to be about 1,104. They also observed mothers and pups, which brought new native generations to the bay.
In 2002, the first complete abundance survey for sea otters in Kachemak Bay was completed and estimated at 912 animals. Two other surveys made in 2007-08 showed a three-fold increase to 3,724.
Despite a virus that continues to impact, particularly, otherwise-healthy male juveniles, the otter population remains strong in the area. Necropsies are performed on 60 otters each year found dead in the bay, for reasons ranging from old age to accident to virus.
An increase in any one population also carries ramifications for other populations. A common anecdote links loss of crab and clams available for humans to the abundance of hungry otters.
But drawing that conclusion would be pure conjecture, said Charles Trowbridge, area groundfish management biologist for Homer with the Alaska Department of Fish and Game.
Crab and shellfish declined along the coasts from Yakutat to western Kodiak in the same period of time as they declined in Kachemak Bay, he said. Otter populations, meanwhile, aren’t identified as high in that entire sweep.
“A lot of things eat crab — cod, pollack, halibut,” he noted, recalling a time he caught a 70-pound halibut and found several legal-size tanner crabs in its belly.
A larger pervasive issue is thought to be the Pacific Decadal Oscillation, a pattern of Pacific climate variability that shifts phases about every 20 to 30 years. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20 degrees north latitude. During a “warm,” or “positive” phase, the west Pacific becomes cool and part of the eastern ocean warms. During a “cool” or “negative” phase, the opposite pattern occurs.
“We saw a switch in the late 1970s that turned ‘positive,’” Trowbridge said. “That caused a regime change from shellfish to fish dominating the region.”
Other factors also impact in a highly “complex system,” he said.
What otters eat, and where they gather to rest, is of significance for helping scientists learn about ocean dynamics or alterations. This summer, Doroff and her team will study otters using forage observations studies of otters. The Kachemak Bay Research Reserve received a grant through the Exxon Valdez Oil Spill Trustee Council to continue long-term water-monitoring work. In the study, they will look at conductivity, temperature signatures in water and surface circulation patterns.
“Otters are helping give us feedback on how their use of space is influenced by larger ocean patterns,” Doroff said.