MOSS LANDING, Calif. - Wildlife rescuers say they're seeing epidemic numbers of a mysterious occurence of oily sea birds, similar to cases that killed dozens of birds in the Monterey Bay in 2007.

Some 150 birds are being transported from Portland, Oregon, to Fairfield, California, suffering from cases of algae slime on their feathers.

The slime affects the structure of their feathers, leaving the birds unprotected from the cold and un-able to fly.  Dozens of birds died from the problem in 2007.

Moss Landing's WildRescue is helping in the effort to clean affected birds from the Pacific Northwest.

One of the problems wildlife rescuers say they're facing is the cost, which they say is expected to grow as more and more birds are found.