Like many nonprofits, CWC’s greatest hope is for our services to be a last resort. We care deeply for our patients and treasure our experiences with them, but they arrive in our care due to accidents and illnesses.
Every pinniped (seal and sea lion) is released from CWC outfitted with an orange flipper tag. These tags are not satellite trackers, and thus require direct observation and reporting to be effective.
The CWC Marine Mammal team has seen the impact of plastic pollution in our oceans firsthand. It is not uncommon to receive a call about fishing line entanglement.
At 9am on March 16th, 2024, we received a report that a deceased whale had come ashore at Little Dume. Upon arrival, it was determined that this 30-foot-long sub-adult male, weighing approximately 25,000 pounds (the same as seven cars), was still alive, yet in grave condition and floating at the surf line.
Read this pictorial story about the rescue and release of a malnourished California Sea Lion pup found on a busy beach
By: Heather Henderson, Marine Mammal Program Manager
Marine mammal strandings have a somewhat predictable pattern – spring and summer are extremely busy! A sharp bell curve of activity to be precise. Winter and fall months are generally slower seasons, as we respond to the rhythms of nature and the birthing calendar of our native species. There are fewer rescue calls received during the fall months in SoCal, and we close for rehabilitation during the winter. We are often asked, “what do you do when there are no patients on-site?” The reply – reflect, improve, and prepare for the next busy stranding season.
Once the enclosures are empty, annual maintenance becomes top priority. The marine mammal staff and volunteers stay busy rebuilding, repairing, deep cleaning, training, and doing quality control on data entry. The most intense aspect of repairing revolves around performing safety checks in every nook of the enclosures, carriers, and rescue gear so that we may be prepared for the busy months.
Exam Room Painting
Kevin Fixes the Wall
Rick Prepping Floor
Joanna Paints
2023 did not follow the usual normal pattern of ramping down during June and July. On the contrary, due to the Domoic Acid Crisis experienced by California sea lions during the summer months, patients were kept in-house through mid-September. It was wonderful to have the opportunity to assist dozens of additional patients, but it abbreviated the time available to complete off season projects and repairs.
Projects include laying new flooring, freshening up and protecting the areas with a coat of paint, and replacing all the valves throughout the marine mammal enclosures and pool filtration system. In addition to performing necessary repairs, project season is a time for our crews to meet new volunteers and forge new friendships.
The volunteer family at California Wildlife Center is comprised of an amazing and diversely talented group of people. It is easy to see why they choose to be involved when beautiful seals and sea lions are around, but the true expression of their commitment shines during the fall, when this devoted team is focused on improving our facility in order to be ready to offer the best care possible to stranded marine mammals in Malibu.
By Marine Mammal Program Manager, Heather Henderson
California Sea Lion on Beach
You may have seen California sea lions in the news recently. Starting in June, we have been experiencing an increase in sick sea lion calls all along the Southern California coast. What has caused this?
Upwelling ocean currents along the Southern California coastline bring nutrient-rich water to the surface. The upwelling mixes deep, cool water with warmer sea surface water, resulting in an explosion of growth when sunlight is present, supporting a wide diversity of ocean life. Along with healthy growth, toxic algal blooms can also flourish. Fed by fertilizer runoff, these poisonous blooms can experience dynamic growth.
Pseudo-nitzschia is a single celled plant that has a non-toxic and toxic variety. Concentrations build up in filter feeding fish and shellfish that are consumed by California sea lions. When in the toxic form, Pseudo-nitzschia is referred to as Domoic Acid and acts as a neurotoxin. The result on the body when ingested can vary from abnormal behavior to full-body seizures, and even death. As a sentinel species, sea lions are telling us (and lab analysis has confirmed) that Domoic Acid is at unusually high levels in the Pacific. In early June, we saw the beginning of this historic mass poisoning event.
The Domoic Acid bloom synced with the pregnancies of the California sea lions, as the majority give birth in June. To prepare for nursing their newborns, pregnant females consumed dozens of pounds of fish daily, bulking up and staying in top shape. However, this June, instead of traveling out to the Channel Islands, hundreds of adult females and their pups were knocked off course. After consuming large quantities of the neurotoxin, they ended up stranded on the mainland beaches, experiencing disorientation, seizures, and even dying as a result of consuming large quantities of contaminated fish.
During the five most severe weeks of this event, CWC’s marine mammal team fielded over 800 reports of stranded California sea lions, performing 125 responses in Malibu. By comparison, a normal year will yield on average 15 responses during the same five-week timeframe.
What are the main challenges that accompany the response to a large toxic algal bloom? It arrives with little to no warning and intensifies within just a few days. Rescue programs quickly reach maximum capacity and are unable to admit every stranded animal as a patient, so triage and beach monitoring are implemented.
Can sea lions survive this massive assault on their bodies? The fortunate answer is yes! Although a mentally and physically difficult time, there were numerous successes to celebrate throughout this event. All patients currently in care are no longer displaying seizure activity and are self-feeding. 75% of the California sea lions rescued during this event survived and have been released or are on track to be released.
Harbor seals are found in nearly every ocean across the globe. There are even two local sites in Malibu that support year-round populations, and yet our Marine Mammal Rescue Team receives only one or two reports per year about a harbor seal in distress. How can this be? Pacific harbor seals (Phoca vitulina) are very shy and go to great lengths to keep their distance from humans.
Yellow Tagged Sea Lion Hiding in the Rocks on Westward Beach
By Heather Henderson, Marine Program Manager
Each winter CWC prepares for the imminent arrival of young sea lion pups in need of help. In nature, California Sea Lions are born in June, with over half of the births occurring on June 15th. This is because sea lions have synchronized reproduction, where individual animals breed, birth, and wean on the same schedule. Ideally sea lion pups should stay with their mothers until April and wean when they are ten months old. While with their mothers, young pups practice fishing and learn important life survival skills.
Unfortunately, not all sea lion pups are able to stay with their mothers until April. Overfishing has led to a decline in available food for sea lions, which often causes mothers to venture farther and farther away looking for fish. This abandonment can force young pups to venture off looking for food, and sometimes they end up on the beaches of Malibu in need of help.
Our first patient of the season was fortunate to be discovered hiding in the rocks on Westward beach. The young female was reported to our Marine Mammal Response Team by a group of caring Malibu residents who were taking advantage of a long awaited warm and clear day. This winter, unseasonably cold days and heavy rains have left local beaches very quiet. Minimal human activity is a positive for healthy wildlife, however it is a drawback for distressed wildlife that may go unnoticed.
The little pup arrived in a malnourished state (weighed only 10.1kgs, which is about 50% of the healthy weight for her age), but with a feisty attitude. This was an encouraging sign that she may respond well to care and be able to return to the wild after her stay in rehabilitation. An interesting detail: this pup came in already outfitted with identifying yellow flipper tags. Most pups do not have identifying markers at rescue since they are too young to have gone through rehabilitation and release. These yellow flipper tags, and all colors other than orange, are population study tags. From the tags, we now know that she was born on San Miguel Island. At release the yellow tag on her right flipper will be replaced with an orange rehab tag. In California, rehabilitated seals and sea lions are tagged on the right flipper if a female and on the left flipper if a male.
After just a few weeks, yellow tag pup was eating whole fish and beginning to gain weight and strength. She is continuing to improve and is playing with the other pups in our care. California sea lions are a gregarious species and seek out companions. While in care, it is essential that sea lion pups are housed with other pups or older sea lions to promote competition while foraging and deter bonding with humans.
We anticipate that the yellow tag pup may meet a dozen more sea lion pups in the coming weeks. In 2017, which was the most recent severe wet winter in Los Angeles, we stayed busy with the stranding season from January through June. Will this rainy winter prove to be busy for our Marine Mammal Team? Cooler sea surface temperatures that accompany La Nina weather patterns can lead to schools of prey closer to the surface, which is beneficial for newly weaned animals. Yet rough seas and cool rainy conditions quickly exhaust young and weak pups. If you observe a marine mammal that is skinny, injured, small or seems out of place, please do not approach, or touch them – Report to our rescue team. #310 458 WILD. Together we can give them a second chance to thrive!
By Dr. Guthrum Purdin, DVM, Wildlife Veterinarian
In mid-August, California Wildlife Center rescued a sea lion (Zalophus californianus) that had been spotted frothing at the mouth and stuporous. After capture and during transport, full seizures developed. Just a few days later, another sea lion was rescued – this one was weaving their neck and head in a serpentine motion, alternating with what’s called “stargazing” where the head points upward and back, blindly directed toward the sky. Sadly, this was the beginning of a trend, one that would reach up and down the Pacific coast.
Sea lion suffering from DA poisoning, “stargazing”
The culprit was a “harmful algal bloom” (HAB) where a type of diatom, an algal plankton called Pseudo-nitzschia australis, reproduces in massive numbers and produces a toxin called domoic acid (DA). The diatoms are eaten by shellfish and other tiny grazers who are themselves eaten by larger predators. At each step in the food chain, the toxin is concentrated in the animal’s tissues. During one of these HABs, sardines & anchovies, tasty meals for hungry sea lions, may become heavily contaminated with DA, a neurotoxin that can be fatal to marine mammals. Fish eating marine birds, like pelicans and loons, can be likewise affected. Among other properties, DA mimics a certain neurotransmitter called glutamate, activating cells in the nervous system that then can’t be switched off. It also causes calcium to flood into certain cells in the brain, especially the hippocampus and amygdala. Humans exposed to DA may develop Amnesiac Shellfish Poisoning. In animals, the brain, the kidneys, and the heart can be damaged. There is no antidote to this toxin and treatment is supportive: primarily controlling the seizures and providing fluids. Providing good healthy, DA-free food is another key component to treatment.
Problems may persist even after treatment if permanent brain damage occurs. People can have deficits in short-term memory and mood swings. Recovered sea lions have sometimes been found confused, wandering miles away from the ocean.
Way back in 1961, open ocean birds called Sooty Shearwaters appeared at Capitola near Santa Cruz, crashing into people and windows. No one knew what was causing this bizarre behavior and the upsetting event inspired Alfred Hitchcock’s classic horror film “The Birds”. HABs were rare then, but researchers now believe this was an early appearance of DA. Blooms of Pseudo-nitzschia and other toxic plankton are increasing in frequency as ocean temperatures rise. Nutrient runoff from agriculture can further compound the problem.
There are several monitoring stations up and down the coast that keep tabs on concentrations of Pseudo-nitzschia in seawater with the intent of detecting an incipient HAB before it becomes a problem for humans who consume fish and shellfish. Likewise, sea surface temperature is regularly evaluated. In 1987 hundreds of people became ill and three died after consuming DA-contaminated shellfish at Prince Edward Island in Canada. Such large outbreaks have become rare thanks to environmental monitoring. Unfortunately for marine mammals and birds, the vast ocean that is their home and larder can also be a trap when their only food sources become contaminated with toxins like DA.
For now, this year’s harmful algal bloom has passed, and rescue calls have tapered off dramatically. If you see a stranded sea lion on the beach, especially if you suspect something like DA, do not approach the animal. These are wild animals and may behave in unexpected ways. This is especially true with DA, which can cause permanent neurological damage. DA animals can be hyperexcitable and, if they feel threatened, can be very aggressive. So stay back, at least 50ft or more, and notify your local animal control agencies, lifeguards, or a marine mammal rescue organization. Report any unusual behaviors and response teams can evaluate whether the animal is in distress or merely taking a nap after a long day at sea.