Sacramento, Calif. – After 10 days cruising the Sacramento River and its delta, two wayward humpback whales are showing the first signs of ill health from prolonged exposure to fresh water, experts said Tuesday.
At midafternoon Tuesday, the mother and calf put on a display of tail flipping – which biologists described as a potential sign of stress – as they continued to swim in a broad loop at the north edge of the Sacramento-San Joaquin River Delta near Rio Vista.
Biologists also noticed that the whales’ wounds, believed to have come from a ship’s propeller, were not healing as well as expected.
Dr. Frances Gulland, of the Marine Mammal Center in Sausalito, said the whales’ skin, normally smooth and shiny, had begun to turn pitted and irregular. Fresh water can have a negative effect on the healing ability of skin cells in saltwater animals.
High winds and choppy water prevented attempts to plant a satellite tracking device on the mother whale.
Officials planned to hit the water early today with a flotilla of Coast Guard and state boats and attempt to press the whales toward the saltier waters of San Francisco Bay.
