ABOVE: The carcass of a gray whale stranded in San Pedro area this spring. Photo courtesy of Alisa Schulman-Janiger and the Gray Whale Census and Behavior Project. OPPOSITE: Jen Levine at the marine mammal hospital at the Channel Islands Marine and Wildlife Institution. Schulman-Janiger. “There doesn’t appear to be a connection. They’re just not getting enough food.” Gray whales migrate to the icy waters off Alaska in the summer to feed. Some scientists fear that as global heating in the far north reduces the extent of sea ice in the Arctic, this may reduce the amount of amphipods in Arctic seas. A study by Sue Moore and Jacqui Grebmeier comparing sightings of gray whales in the Bering Sea between Alaska and Russia, with measurements of declining abundance of amphipods in feeding grounds, “has potential” to explain the emaciation of a high percentage of the gray whale population, said Dave Weller, a NOAA scientist in La Jolla. At the same time, he pointed out that the gray whale population has crashed and recovered before, and that as a species the gray whale is known for its ability to search widely for food, even venturing into San Francisco Bay and Los Angeles Harbor this year. “If this mortality event were to continue year after year for a decade, that would be alarming,” Weller said. “Right now it’s concerning, and we want to gather as much information as we can.” “There has been a long-term increase in the abundance of some of our marine mammals, such as gray whales,” said Mantua, an expert in shifting fish populations in the ocean. “Because this abundance is relatively high compared to past decades, that could also make the gray whales vulnerable to running out of food when there’s a scarcity.”
SEA LIONS PUPS AT RISK IN 2019
This year an Unusual Mortality Event was declared for the gray whale population. Six years ago, the “marine heat wave” that came to Southern California waters resulted in NOAA declaring an Unusual Mortality Event for sea lions from 2013-17 and a stranding of 4,000 sea lion pups in California in 2015. That was the worst stretch in recent memory for sea lions in Southern California, according to Sam Dover, the chief veterinarian and executive director at the Channel Islands Marine and Wildlife Institution (CIMWI).
SAFE PRACTICES AROUND SEA LIONS 1) If you see a sea lion in distress on the beach, DO NOT TOUCH, disturb, feed, harass, pour water on, let dogs bark at, try to drag back into the water, or take selfies with the animal. 2) Observe the behavior of the sea lion at a distance. 3) Drop a pin at the animal’s location on a GPS mapping service. 4) Call the CIMWI hotline for marine mammals in distress at 805567-1505 and send the location. CIMWI will come and pick up the animal for hospitalization. Similarly, if you see a whale stranded on the beach or in distress, call the CICRU hotline at 805-896-0858.
But 2019 has been the second-worst year for sea lions, according to Dover and Jen Levine, the animal care manager at CIMWI. With a cadre of dozens of volunteers, mostly students, they oversee a small outdoor hospital for sea lions and sick pups north of Santa Barbara. CIMWI volunteers rescued 60 sea lion pups in May and 30 in June, stretching the staff to the limits, Levine said. About half the rescues take place in Ventura County. The same poison, domoic acid, that resulted in the shutdown of the crab industry in 2015-16, can build up in forage fish populations along our coasts, and can lead to domoic acid poisoning in sea lions. The poison attacks the hippocampus area in the brain, Dover said, and in high enough doses can lead to seizures or death. Even at lower doses it can result in strange and unpredictable behaviors. “A couple of weeks ago a girl up in Pismo Beach was attacked by a sea lion,” Dover said. “She wasn’t doing anything to provoke it, just playing in the surf while a friend was taking pictures when this sea lion came out of nowhere and bit her in the leg. That’s why
we advise the public to stay away from these animals.” Dover stressed that given care and feeding with uncontaminated foods, sea lions usually recover. “It’s a cyclic phenomenon, produced by a naturally-occurring algae, and sometimes that algae produces toxins, and sometimes it does not,” he said. “We often see domoic acid poisoning in small amounts, but this year it’s been massive. Santa Barbara and Ventura County were the areas hit first.” At CIMWI’s animal hospital, over 60 dark brown juvenile sea lions flop on flippers in pens, tended by volunteers in yellow slickers and big rubber boots, using “herding boards” to drive the curious young sea lions from pen to pen for cleaning and feeding. The animal managers take care not to give the young sea lions names, or to encourage any sort of human-animal bonding, so the sea lions can be returned to the wild unscathed by exposure to humans. Both veterinarian Dover and animal care manager Haring stress that overall the wild populations of sea lions in the Channel Islands have recovered from the 2014 mortality event, noting that thousands upon thousands of wild creatures live in rookeries in remote stretches of the Channel Islands. “The population [of sea lions] has basically come into balance with its environment,” said Sharon Melin, a research biologist who has been tracking sea lion populations in the Channel Islands for NOAA. She noted that the population in the Channel Islands has grown steadily from a low of about 90,000 in the l970’s — when the population was depressed by factors such as hunting and DDT — to over 300,000 in 2012. The increase in ocean temperatures did reduce the sea lion population, she said, but not enough to put the species as a whole at risk. “The marine environment is always changing, and their population is at a point where it responds very quickly to changes in the environment,” she said. F For more information, visit Channel Islands Marine and Wildlife Institution at cimwi.org.
August 1, 2019 —
Ventura County Reporter | August 1, 2019