SAN FRANCISCO — A humpback whale that has become an unusual presence in San Francisco Bay may be ill.

The San Francisco Chronicle reported Friday that the humpback has remained in the waters near Alameda for more than two weeks.

Biologists say the whale, which has been nicknamed "Allie," appears to be an adult female in poor health.

Officials at the Marine Mammal Center near San Francisco say the whale appears underweight with poor skin condition including a "moderate amount of whale lice."

Biologists believe the animal entered the bay searching for shelter from the harsh open ocean.

Officials say humpbacks feed near the Golden Gate Bridge where the waters can be rich with anchovies, but rarely travel deep into the bay.

Mammal center officials ask the public not to approach the whale.