Scientists failed to lure back into the sea the two humpback whales. The two whales, believed to be a mother and her calf, briefly headed seaward Friday before turning back into a shallow basin at the Sacramento port.

The scientists have tried to lure them by playing recorded sounds of other humpbacks feeding. After this plan failed, marine biologists are preparing another strategy: herding the animals by a large flotilla of 50 boats boat while banging pipes underwater. Until the new plan will be ready a marine mammal rescue crew would continue using different frequencies of sound at different intervals in different locations to entice the whales to move in the right direction.

According to Frances Gulland, a marine mammal expert, the mother whale might have swum upstream into the basin because she was looking for a secluded spot for her injured calf to heal.

"For all we know the female may not be interested in food at this time because she is focused on her calf," Gulland said.

Gulland also announced a good news. Despite their injuries, the two whales seem to be in a stable condition.

“Both mother and calf are still swimming and breathing and surfacing at similar rates as they were over the past few days,'' Gulland said.