Local harbor seal population appears down, but should rebound
Harbor seals haul out of the water at the beach at Hopkins Marine Station in Pacific Grove on Wednesday. (David Royal – Monterey Herald)
Pacific Grove >> The stretch of coastline from Fisherman’s Wharf in Monterey along the rocky shores of Pacific Grove to Pebble Beach is home to a shrinking population of Pacific harbor seals, local experts said.
According to a population census taken on Nov. 25 by husband and wife Thom and Kim Akeman, volunteers with the National Oceanic and Atmospheric Association’s shoreline program Bay Net, the Pacific Grove Harbor seal population has declined by one-third. Numbers have plunged from about 700 individuals, based on preliminary counts taken by Monterey Bay Aquarium researcher Teri Nicholson in the 1990s, to fewer than 500 in the last couple of years, the Akemans reported. Uncharacteristically warm waters, which depleted the marine environment of oxygen and food, are to blame, they added.
But the bad news may not be as critical as it seems, said Dr. Andrew DeVogelaere, research director at the Monterey Bay National Marine Sanctuary.
“A lot of ocean species have evolved to have a few bad years,” he said. “The population will dip down, and then with more food, go up again.”
The normally cool water off the Central Coast is an oxygen-filled, nutrient-rich haven for all local marine life, from tiny anchovies to magnanimous humpback whales. But 2014’s mild winter made for uncharacteristically warm waters. Because of El Niño, the sea is still above its normal temperature today. The National Marine Fisheries Service, whose scientists have 35 years of oceanic climate data from California, have never seen years like the last few, DeVogelaere said.
The Monterey Bay’s lack of resources can be hard to take note of. Whale-watching companies are celebrating a heyday. Last year, naturalists and tourists watched cetaceans swarm like never before. But whales form large congregations because of the scarcity of food, DeVogelaere said, and they’re forced to converge in the few nutrient-rich locations where they can find a meal.
The changing conditions offshore undoubtedly affect harbor seals, he added.
The harbor seal may be a distant cousin to the adventurous California sea lion and elephant seal, but it’s an entirely different animal. Harbor seals are incredibly loyal to their rocky homes, straying a mere mile or two to swim and feed. If warming coastal waters kill off their food supply, they’ll likely starve.
Mother harbor seals are taking an additional hit. During the pupping season last spring, “lots of the moms didn’t have enough milk and had to abandon pups on the beach,” said Thom Akeman, who has been watching his flippered neighbors sleep and romp along the Pacific Grove shores for 13 years.
Two years ago, female seals weaned 90 healthy pups at Hopkins Marine Station, the largest harbor seal rookery in Pacific Grove. This year, the colony had only 30 pups, many of which were born to mothers too malnourished to rear them.
During Bay Net’s Pacific Grove harbor seal census on Nov. 25, Akeman saw only nine baby seals at Hopkins. He suspects these are the last remaining pups in the colony.
The Pacific Grove harbor seal population is expected to recover, but scientists are unsure how long it will take. Their comeback depends on ocean temperatures cooling, and staying cool for a prolonged time, allowing the food web to prosper once again. But no one can say when, or if, the temperatures will stay low enough for this to happen, said Akeman and DeVogelaere.
The unpredictable effects of global climate change make it a guessing game.
“We’re in an uncontrolled experiment. We’re changing the atmosphere of the world and the chemistry of the oceans. No one has done this experiment before, so we’re really rolling the dice,” DeVogelaere said.
Fortunately for Pacific harbor seals, the local population decline is an isolated oddity. Throughout California, Oregon and Washington, the population is steadily rising. California is home to about 31,000 harbor seals, and many colonies in the Monterey Bay are stable or thriving.
The next Pacific Grove harbor seal count, conducted by the Akemans, is scheduled for late March, when the pupping season begins. The couple, who just began tallying the seals this year, now plan to count them three times a year — in the early spring, summer and fall. They’ll report their findings to NOAA and fellow Bay Net docents through emails and the general public with Facebook.
Teaching others about the environment and the ways to respect wildlife, which Bay Net docents aim to do, is important, DeVogelaere said. And environmental issues and awareness should be given the prominence and attention they deserve, he added.
“I wish people would care about them more,” DeVogelaere said. “They might be affecting the world for their children and their children’s children … But I think in general, people want to do the right thing, if they know what the right thing is. Education is the way to go.”
Read the original post: http://www.montereyherald.com/