FILE - A pair of sea otters are seen at the Monterey Bay Aquarium in Monterey, Calif., March 26, 2018. Federal regulations stipulate that the pool of water for sea otters in captivity, “shall be at least three times the average adult length of the sea otter contained therein (measured in a horizontal line from the tip of its nose to the tip of its tail) and the pool shall be not less than .91 meters (3.0 feet) deep." (AP Photo/Eric Risberg, File)