The Coast Guard said the boat sank in 600 feet of water, but the crew was able to abandon ship in a skiff.
Two people escaped serious injury Saturday afternoon after their floatplane crashed during takeoff in the Misty Fjords National Monument.
The Coast Guard credits LaDuke with making all the right moves after the Saami got into trouble.
Four birds have died in the area and crews have set up additional containment booms around a nearby hatchery and the Valdez Duck Flats.
If certain officials decide an Alaska-bound ship threatens public health, they could take extraordinary measures to contain or manage an outbreak.
Rescuers on scene said the elements were against them: 40 mph winds, well-below-freezing temperatures, and high seas as they searched for the boat and crew.