They'll also test whether the species they find are likely to survive in the cold waters of the sound. Tests to measure the effectiveness of exchanging ballast water while far at sea will be conducted, and a database reference of species found in the ballast tanks will be compiled. Empty oil tankers returning to Alaska routinely take on ballast water before leaving port. The ballast enhances ship stability during voyages across the Pacific Ocean. Federal law requires tankers coming from foreign ports to exchange ballast water while far at sea, in the belief that foreign species will be flushed into the deep ocean where they likely cannot survive.
Tankers coming from other U.S. ports are exempt from the exchange requirement.
The RCAC's Joel Kopp said ballast exchanges are not always effective at purging unwanted species. They could still be discharged into Port Valdez. Worldwide, the introduction of foreign species is a leading environmental issue. San Francisco Bay, for example, has more than 200 non-native species. Most of the species came to the bay in ships' ballast.