https://phys.org/news/2018-08-feds-options-ailing-endangered-orca.html

Another female orca from the group of just 75 animals, known as J35, has attracted global attention over the past week as she has tried to keep her dead calf's body afloat while swimming miles.

Individual whales are identified by unique markings or variations in their fin shapes, and each whale is given a number and name.