In warming ocean, record number of seals and sea lions sicken and starve – ‘Their liver, their pancreas, their intestines are basically shut down, and they are eating themselves from the inside.’Posted by Jim at Wednesday, January 06, 2016
By Jed Kim
30 December 2015
(KPCC) – Malnourished and dying California sea lion pups are likely to be seen again in high numbers on California beaches this winter and spring. Scientists with the National Oceanic and Atmospheric Administration have been monitoring sea lion rookeries on the Channel Islands and have found the lowest weights in pups in 41 years of recorded history.
“We’re preparing for higher than normal numbers, because the information that’s coming from the islands, from the scientists, are saying that the pups are the smallest that they’ve really ever been,” said Justin Viezbicke, stranding coordinator for the National Marine Fisheries Service in California.
Since January 2013, starving California sea lion pups have been washing up on beaches at alarmingly high numbers. The cause is believed to be a wide swath of abnormally warm water that has depressed the number of sardines in typical hunting areas. Sardines are important food sources for nursing mothers.
Viezbicke said strandings on the mainland could be high, because many pups are continuing to survive in the rookeries. When they leave, they’re not able to forage successfully and end up washing ashore on mainland beaches. Those strandings could begin occurring in late December and early January.
“If that’s similar to what we were having last year, where the pups are good enough to get off the island but not overall healthy enough to last within the system that they’ve got because of their situation, then we’re anticipating seeing higher than normal strandings again this year,” Viezbicke said.
The “blob” of warm water that has extended for thousands of miles into the Pacific Ocean from the West Coast has cooled in recent months. That would normally be a good sign for returning sardines. However, Nate Mantua, a research scientist with NOAA Fisheries, said the strong El Niño is likely to warm up the water near the coast again.
“It’s expected to have stronger and stronger influences on ocean currents and weather patterns off the West coast that are likely to keep it really warm for the next few months,” Mantua said. “That means that the marine food webs are still going to be disrupted near shore and really around those rookeries.” […]
Despite the multiple consecutive seasons of strain on young California sea lions and the subsequent low survivorship, scientists said the overall population remains healthy at around 300,000 individuals.
“At this time, the health of that population remains really good and really strong and much better than it was just a few decades ago,” Mantua said.
Viezbicke said scientists will continue monitoring the population in coming years.
“If it keeps happening, there will be concerns, but with a robust population of 300,000 animals, the reality is that it’s not a population concern at this point, but it’s something that we’re definitely keeping an eye on,” Viezbicke said. [more]
By Azure Gilman
6 January 2016
(Al Jazeera) – They are brought in with all sorts of problems: lockjaw, poisoning, cancer, and even bullet wounds from fishermen. But most among the record number of seals and sea lions washing up on California's shores and being brought to a regional rescue center are starving.
Unprecedented warm waters off the Pacific coast over the past two years have led fish that marine mammals feed on to move to colder waters — making it difficult for seals and sea lions to nourish themselves, let alone feed their pups. With the current El Niño weather event expected to continue bringing warm water over the rest of the winter, this slow-motion catastrophe is likely to continue.
The Marine Mammal Center in Sausalito, just outside San Francisco, rescues 600 to 800 seals and sea lions a year on average from the 600 miles of California coastline it covers, from north of San Francisco to just above Santa Barbara County in the south.
But in 2015, the center was brought a record 1,799 animals — including California sea lions, Guadalupe fur seals and northern fur seals. The 106 northern fur seals it rescued more than tripled its previous record.
And the Marine Mammal Center sees only a fraction of strandings statewide. The California Marine Mammal Stranding Network, a network of independent groups overseen by the National Oceanic and Atmospheric Administration (NOAA), keeps track of stranding events for both live and dead animals, including seals and sea lions, across California. In 2015, they counted more than 4,200 California sea lions, 90 Guadalupe fur seals, and 70 northern fur seals.
The center's staff began to realize something was different early in the year. Their network of volunteers and workers began bringing in distressed sea lion pups last January rather than, as usual, in summer. And the pups brought in for rescue were unlike anything the veterinarians had ever seen.
“They were basically just skin and bones,” said Dr. Shawn Johnson, director of veterinary science at the center. “Their liver, their pancreas, their intestines were basically shut down. And they were eating themselves from the inside to stay alive by the time we saw them.” […]
Though 2015 was a record year, the warming of parts of the Pacific Ocean and the resulting deleterious effects on seals and sea lions began before the onset of the current El Niño effect.
An area of warm ocean water many scientists call “the blob” began forming off the U.S. West Coast in 2013. A second area of warm water — unofficially referred to in come circles as “El Blobo” — has formed off Mexico, said Toby Garfield, director of the environmental research division at NOAA.
“In these two patches of warm water we were getting surface temperatures that were up to three to four degrees centigrade warmer than normal,” Garfield said. “A lot of the forage fish that the sea lions and fur seals were going after migrated outside of their regular areas.”
The warm water also likely contributed to the largest toxic algae bloom ever recorded. Pseudo-nitzschia, a type of algae that produces domoic acid, was both more plentiful and produced domoic acid with a higher toxicity, according to Garfield. When this algae makes its way up the food chain, domoic acid can cause seizures and other brain problems, mostly in sea lions. Sea lions with domoic acid poisoning have only about a 30 percent survival rate at the Marine Mammal Center. [more]