According to the marine biologists on Tuesday the whales showed
the first real signs of stress, rolling quickly from side to side in what
observers described as a thrashing movement.
"We are concerned that she is getting increasingly stressed," said Frances Gulland, a veterinarian with the Marine Mammal Centre, who was aboard a boat tracking the whales, dubbed Delta and Dawn. Also Gulland warned that there have been changes for the worse in the whales' propeller wounds and skin condition.
On Sunday, marine biologists manages to make the whales to swim from from the Sacramento Port back to ocean, after previously they resisted scientists' attempts to lure them using recordings of whale feeding calls.
On Monday, the reports were positive as the whales had swum some 40 kilometres to Rio Vista, where they stopped just before a bridge. In the next day, scientists
On Tuesday, crews aboard 26 boats began banging on steel pipes to prompt them to resume their swim to the ocean, but the whales just swam in circles. Initially scientists thought they were just resting, but by midday the whales turned around and slowly started making their way upriver again, away from the safety of the ocean."They're at this point lost. We don't think they have any clue," said Rod McInnis of the National Marine Fisheries Service.