PORTLAND — A team from the University of Southern Maine and the conservation organization Ocean Alliance left Saturday for the Gulf of Mexico to study whales’ exposure to toxins in the oil-tainted waters.

The Ocean Alliance’s laboratory-equipped sailboat Odyssey left Portland Harbor. John Wise, the expedition’s scientific director said today the 93-foot boat is expected to reach the gulf in several weeks.

A 10-member crew on board will start cell cultures, which will be transferred to USM for further study.

Researchers will use crossbows with special darts designed to avoid harming whales to obtain tissue biopsies from four species: humpbacks, sperm, Bryde’s and killer whales.