Life History - Strandings

Life History Introduction l Strandings l Fishery Observer Program l Blubber Steroid Hormones l Frozen Tissue Archive

Report dead marine mammals

San Diego County:

Stranding Hotline #

(858) 546-7162

Report live stranded marine mammals:


Stranding #

(800) 541-7325

The SWFSC stranding team responds to all reports of dead whales and dolphins on San Diego county beaches and relies heavily on life guards and citizens for reports. SeaWorld responds to all live marine mammal calls.

What to do if you find a stranded marine mammal:

1) Notify the appropriate stranding network immediately.

2) Do not touch a dead animal. Some marine mammals can harbor diseases that can be transmitted to humans. For more information on zoonotic diseases, click here.

We coordinate San Diego County strandings for the Southwest Region as part of the National Stranding Network established by the 1972 Marine Mammal Protection Act (MMPA).

Currently, the National Stranding Network is part of the broader Marine Mammal Health and Stranding Response Program (MMHSRP) Although the passage of the MMPA established an official network, stranded cetaceans have been of interest to many people for a long time. In fact, our records for San Diego County date back to the early 1900s.

Data collected from stranded marine mammals provide us information about the species that live off our coast, and help us learn more about the species’ life history. In San Diego County, marine mammal strandings are typically of single animals rather than mass strandings. Group events are extremely rare. Most animals tend to be emaciated, indicating that they have been ill for some time before stranding. Necropsies sometimes reveal their ailment but not always. When responding to strandings we look for evidence of human interaction, particularly fisheries. In many cases, apparently healthy animals (i.e., not emaciated or showing other signs of ailment) will show evidence of having been entangled in fishing gear.

The most commonly stranded cetacean species on our beaches are short and long-beaked common dolphins, bottlenose dolphins, and gray whales. However, over the years we have recorded a dozen or so species stranded on our beaches, and they include the blue whale, Dall’s porpoise and the pygmy sperm whale. Currently we are using a data set that begins in 1904 to explore temporal stranding and health trends in San Diego County cetaceans.

Recent poster presentations about San Diego county strandings. Please click on each picture below to view larger image:

Click for larger image

click for larger image

2014 California Stranding Network Meeting

Additional information:

Danil, K., S. J. Chivers, M. D. Henshaw, J. L. Thieleking, R. Daniels, and J. St. Leger. 2010. Cetacean strandings in San Diego County, California, USA: 1851-2008. Journal of Cetacean Research and Management 11(2):163-184.

Geraci, J. R., and V. J. Lounsbury. 2005. Marine mammals ashore: A field guide for strandings, Second edition. National Aquarium in Baltimore, Baltimore, MD.

Last modified: 3/9/2016