13.7 meter female and her 6 meter calf are supposed to be from a group of humpbacks which migrated from Baja California, Mexico, to spend the summer at California coast. Both whales are injured by boats. Scientists want them to be back because there is much food in the ocean for them, and the salty water is good for their wounds.

Scientists are calling them back with recorded whale sounds which call for feeding, but it doesn't work, maybe because it's not a love sound of a male.

"Because she is with a tending calf we don't think she would be interested in any breeding-related calls at this point," said Joe Cordaro, a wildlife biologist at the National Marine Fishery Service.

Since scientist don't know clearly what to do, they are just experimenting, trying to make the whales swim back. The next try will be a noise of boats from the upper side of the river, which may frighten the whales to swim away from the 'boats'.

"We really do not want to stress the mother or calf in any way because they are compromised by the injuries," said Frances Gulland, director of veterinary science at the Sausalito-based Marine Mammal Center.

The facts that the whale is with her baby and that she is wounded make troubles for scientists, because they don't know how the whale will behave herself. Scientists take these facts into consideration and they have to act very carefully to make the whales swim back home.

By Ruzan Harutyunyan for HULIQ