Marine Mammal Care


Content Image


Arrival of Rescued Seals & Sea Lions
Examination of each seal or sea lion begins before removal from the transport carrier. A quick evaluation is made to assess the animal’s physical and mental status.  This information helps the medical team prepare to admit the animal safely. Rescue personnel also provide a history of the rescue and the condition of the animal as observed at the rescue site.

Next, medical team members perform a hands-on evaluation to determine the patient’s species, gender, age, length, weight, and physical and mental condition. Blood and fecal analysis round out the basic health parameters that help determine the initial course of treatment. 

Radiographs and other diagnostic tests may be performed at a later time or under anesthesia, once the animal is physiologically stable. Dehydration and malnutrition are common problems.

MMCC LA does not name its patients; instead, they are referred to by the unique number assigned during intake. This strategy is designed to minimize human attachment so that patients have a better chance of survival when they are healthy and released into the ocean. Staff assign an identification number or color code for each patient and put the number or color on a patient by:

Shaving a temporary mark in the animal’s fur (known as a Farrell number)

Tagging it with an orange, plastic number; or

Using a grease pencil marker to apply a color code.

Sometimes we use all three methods!

Medical Treatment of Seals & Sea Lions

A daily medical record is maintained for each patient, including nutrition intake and notable changes in behavior. This information is important when assessing how animals are housed within the facility and when they are ready to move to the next step in the rehabilitation process. 

Initially our interaction with the seal or sea lion may be labor intensive, including physical restraint for feedings and medications. But, as the animal regains normal health and strength, the animal care team is hands-off and the animal interacts with people less and less. At no point are members of the general public allowed to interact with recovering seals and sea lions.

Providing a clean and stress-reduced environment is paramount!


Our goal is for seals and sea lions to get healthy and be returned to the ocean as soon as possible. This takes place as soon as a patient recovers from its illness or injury, is at proper body weight, and can compete for food. Our attending veterinarian must clear each patient for release.

Criteria for release are established by National Marine Fisheries Service and include weight gain, resolution of medical conditions, ability to compete for food, blood parameters, and an overall assessment of the animal’s readiness to return to the ocean.

Criteria at the beach include an assessment of tide, weather and waves. While animals are expected to be able to navigate the ocean environment upon release, we take into consideration  that young animals may need a brief transition period when returning to the ocean.

Occasionally a seal or sea lion is unable to feed or protect itself due to blindness or other mobility issue. Thus, MMCC LA works with National Fisheries Service to find a permanent home for this type of dependent patient.

Post-Release Monitoring

Released seals and sea lions have been sighted as far away as San Diego to the south and Monterey, Marin and Humboldt counties to the north.  Prior to release, each patient receives a small orange roto tag in the front flipper possessing a unique number. These tags may remain with the animal for years; reports of tagged animals provide information about survival and location. However, reading the tag number requires close proximity to the animal. To obtain more detailed post release information, satellite tracking is used.

California Sea Lion “Marino” (Zalophus californianus) #13-091, was admitted as a pup, during the 2013 California Sea Lion Unusual Mortality Event (UME). She was released on August 16, 2013, with flipper tag #27873, as well as a satellite tag. While under sedation, the satellite tag was adhered to the fur.  The tag transmits details about the animal, her travels and post release survival.  It will fall off when she goes though her annual molt.  Battery life and position of the orbiting satellite determine the length of time and amount of data that can be collected.

Satellite tags are too cost prohibitive to be used on a large scale, but we are hoping to tag additional animals in the future. This effort was made possible through a collaborative effort between: the Marine Mammal Care Center LA in San Pedro, CA; the Riverhead Foundation for Marine Research and Preservation in Riverhead, NY; the Pacific Marine Mammal Center in Laguna Beach, CA; and, our generous donor, Patricia Cornwell.

Dr. Lauren Palmer, Marine Mammal Care Center LA, and Keith Matassa, Pacific Marine Mammal Center, secure the satellite tag while Marino is monitored under sedation.
Check out her travels since being released at White Point beach in San Pedro, CA. Initially, Marino headed north, then west out to the Channel Islands, spending a few weeks around Anacapa Island. After a few months of going between the Channel Islands and the Los Angeles/Ventura County line, she headed south to LA’s South Bay Area. As of the last transmission, Marino continues her journey southward into San Diego County. During this time, she has traveled over 1,200 miles along more than 48 miles of Southern California coastline.  Map generated by Robert A. DiGiovanni Jr., Riverhead Foundation for Marine Research and Preservation. http://www.riverheadfoundation.org/

Marine Mammal Care Center Los Angeles collaborates with scientists from around the country to conduct non-invasive research.  Post Release Monitoring is conducted using externally attached satellite tags.

Scientific Publications

Prager KC, Grieg DJ, Alt DP, Galloway RL. Hornsby RL, Palmer L, Soper J, Wu Q, Zuerner RL, Gulland FM, Lloyd-Smith JO. Asymptomatic and chronic carriage of Leptospira interrogans serovar Pomona in California sea lion (Zalophus californianus). Vet Microbiol 2013 May 31;164(1-2):177-83.doi:10.1016/j.vetmic.2013.01.032.Epup2013 Feb 4.

Wael KA, Smodlaka H, Leach-robinson L, Palmer L, Skin histology and its role in heat dissipation in three pinniped species. Acta Veterinaria Scandinavica 2012, 54:46. doi:10.1186/1751-0147-54-46

Smodlaka H, Khamas W, Tkalcic S,  Golub T, Palmer L, Histological Assessment of Selected Blood Vessels of the Phocid Seals (Northern Elephant and Harbour Seals). Anatomia Histologia Embryologia Journal of Veterinary Medicine. Jan 2010: 1-8. doi:10.111/j.1439-0264.2010.00994.x

Lloyd-Smith J O, Grieg DJ,  Ghneim G , Hietala S, Palmer L,  St. Leger  J, Grenfell B, Gulland FMD, Cyclical changes in seroprevalence of leptospirosis in California sea lions: endemic and epidemic disease in one host species? BMC Infectious Diseases 2007; 7: 125.