Update on California Sea Lion Pup Deaths

Rescued starving sea lion pup

Rescued starving sea lion pup


Charmaine Coimbra


 When we cruise the Central Coast ocean waters, the dance of the California sea lion is like a fantasy ballet. Like synchronized swimmers, they dolphin in and out of the swells.  The last time I was out, hundreds skipped through the water and followed our boat.   They communicated a certain kind of joy with their deep sea frolics.

 Last Sunday and Monday were spent out on the Piedras Blancas bluffs serving as a docent for Friends of the Elephant Seals.  The daily arrival of the largest of the male elephant seals thrills onlookers.  But outside of the elephant seal clusters are strewn bodies of dead California sea lion pups. These emaciated pups probably never frolicked through the sea.  It disturbs visitors. A plethora of questions follow. 

I’m not a marine life biologist, so I let them explain and update what is going on with the plague of ill and dying sea lions.  Here are the emails I received today:

From P. J. Webb at the Marine Mammal Center in Morro Bay:

The Marine Mammal Center volunteers are completely swamped with sick and dying California sea lions. Here in San Luis Obispo County we have been responding to 8 to 12 animal strandings EVERY DAY and picking up anywhere from 5 to 7 animals daily. These animals are stabilized, hydrated, medicated, fed, cleaned up after while we are continuing to respond to new strandings and trying to arrange transportation up to Sausalitoto the hospital. Monterey Bay Operations have been swamped as well and we have been holding patients for awhile as bottlenecks occur with the sheer number of animals. This has been going on since early June and started with starving yearling sea lions and now is starting to include larger animals (120 to 170 pounds) showing up with seizures and domoic acid poisoning. In addition to emaciation, worms and ulcers, the yearlings often have fish hook and fishing line entanglements.

Here is our current patient list:



Every sea lion that dies in our care has a necropsy done. With this mortality event, there are tons of CSL carcasses being necropsied up at the center. We do not have the resources to pick up sea lion carcasses on the beach for necropsy.The Marine Mammal Centeris not a government agency but a non-profit organization. The only marine mammal carcasses that are regularly picked up off the beach for necropsy are Southern Sea Otters (a threatened species necropsied by California State Department of Fish & Game otter biologists). [Joe Cordaro is with the federal government agency NOAA Fisheries. Let me know what his response is…]


Here is a website with links to the numerous current articles about this –




Robert  DeLong
California Current Ecosystem Research Program
National Marine Mammal Laboratory Seattle

Subject: California sea lion pup and yearling mortality

As most of you know there has been unprecedented mortality of yearling
sea lions along the central and southern California coast.

Based upon counts conducted last week we now know that pup production
is down on both San Nicolas and San Miguel islands and pup mortality
for the first month of life for pups born this year is the highest we
have ever recorded. There were 6,000 dead pups at San Miguel island
in a mortality study area where there are normally 1,000 to 1,500 dead
pups recovered. So things are going to be tough for a couple of CSL
cohorts going forward.

I suspect there will be a corresponding response in northern fur seals
pup mortality at SMI but no counts have been conducted to date.

I have been in touch with biologists at the NMFS Pacific Fisheries
Environmental Lab and received an evaluation of the coastal southern
California Current. Upwelling collapsed in early June as did
phytoplankton production and sea surface temperatures are strongly
positive over much of the west coast waters. This will likely persist
and will not bode well for prey production and availability for both
coastal marine mammals and sea birds.

Equatorial EN (El Nino) conditions have now developed with the first month of EN
positive indices. If this persists it will be approximately three
months before Kelvin wave generated water flow brings EN conditions to
California. So we may have an EN on top of this current anomaly which
would exert additional stress on top level coastal marine predators.


 “NOAA scientists today announced the arrival of El Niño, a climate phenomenon with a significant influence
on global weather, ocean conditions and marine fisheries. El Niño, the
periodic warming of central and eastern tropical Pacific waters,
occurs on average every two to five years and typically lasts about 12

And…”An El Niño event may significantly diminish ocean productivity
off the west coast by limiting weather patterns that cause upwelling,
or nutrient circulation in the ocean. These nutrients are the
foundation of a vibrant marine food web and could negatively impact
food sources for several types of birds, fish and marine mammals



Categories: California Sea Lion Deaths, Fisheries, Fishing Lines, Marine Mammal Rescue

Tags: , , , , , , , , , , , ,

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