Sea otters were almost annihilated in the 18th and 19th centuries because of their remarkable fur, which is reputed to be among the softest in the animal world. Fortunately, the killing of otters ceased when the supply became too small to maintain the fur trade, and with the subsequent ban of otter hunting, they have rebounded to a significant degree. The largest current populations of otters exist in Alaska and off the California coast. Elkhorn Slough has a thriving colony and they apparently feel quite safe here. They also find a good supply or clams and marine worms, as shown by the first few images below.
The otter below is probably a female taking a rest from the attentions of the males in the water by hauling out with a bunch of harbor seals.
In a number of areas, the otters were grouped in large rafts, apparently socializing. Below, a solitary female with her pup. Mothers carry their pups with them everywhere and spend most of their time on their backs so the pup remains above water and can nurse easily. When she turns over, the mother grabs the pup by the scruff of the neck (with her teeth) to keep it from getting lost.
Below, looks like the pup has switched ends. Maybe it's time for a diaper change!
Below, Mom's face on the left, pup on the right getting a big hug.
Closeup of an otter in one of the rafts.
Below, romance occupies a lot of an otter's time!