Lost Whales Heading Home, Face New Perils
Whales at risk from large ships, wrong turns, disease
By Sam Gale Rosen,  Newser Staff
Posted May 28, 2007 12:45 PM CDT
One of two humpback whales surfaces in the Sacramento River near Rio Vista, Calif., Tuesday, May 22, 2007. Authorities spent the day trying to herd the pair, a mother and her calf, named Delta and...   (Associated Press)

(Newser) – The lost whales in the Sacramento River are on their way home, but may now be in danger from large ships. The mother humpback and her calf had lingered more than a week in the freshwater river, but now have made it to about 50miles from the ocean. The closer they get to the sea, however, the larger the vessels they will have to avoid.

The whales are also in danger from infection, due to skin damage from freshwater swimming. Vets have injected the pair with antibiotics to try to slow the damage. The whales also could take a wrong turn, so rescuers are trying to block off small tributaries the whales could swim into and get stuck.