To amend the National Marine Sanctuaries Act to prescribe an additional requirement for the designation of marine sanctuaries off the coast of Alaska.

Amends the National Marine Sanctuaries Act to prohibit the Secretary of Commerce from designating as a national marine sanctuary an area of the marine environment off the coast of Alaska seaward of the high tide line unless an Act of Congress requires the Secretary to make the designation and prescribes the boundaries of the designated area.