Working with the Santa Barbara -based CIMWI (Channel Islands Marine and Wildlife Institute) and Whalefish, I have been assisting regularly with the stranding program of sea lion pups along the Californian coast. As part of a joint statewide rescue and research team the findings to date indicate that a likely contributor to the large number of stranded, malnourished pups has been a change in the availability of sea lion prey, especially sardines, a high value food source for nursing mothers. This year alone there have been over 2600 unusual mortality events for the whole coast and stranding network. CIMWI on its own have rescued over 320+ animals this year, predominantly California sea lions.
In this case, a collective investigation overseen by NOAA has determined that warmer ocean temperatures had forced fish to move further offshore, thereby forcing the sea lion mothers to swim further out and effectively abandon thier young. This resulted in thousands of pups being left emaciated, dehydrated and confused.
The pups that were rescued and rehabilitated had a high rate of survival. After stranding network member rehabilitation centers provided malnourished, stranded pups with nutrition and hydration, over 50% survived to be released. For the animals outfitted with a satellite tag, tracking data show most survived following release.
The examination of the root couses for the California sea lion UME is ongoing.