From 1992 to 1998, I was an animal care volunteer at the Marine Mammal Care Center at Fort MacArthur in San Pedro, California (near Los Angeles Harbor).
California sea lion (Zalophus californianus) pups; our most common patients.
We put Farrell shave markings in their fur to identify individual animals. National Marine Fisheries Service (NMFS) required us to tag the animals before release so if they were to re-strand, rescuers would know there would be a medical history on the animal available.
Harbor seal (Phoca vitulina) pups.
More of the same.
Northern Elephant Seal (Mirounga angustirostris) pups.
We could often see them watching us prepare their food.