The Port of Seattle recognized several maritime businesses with Green Gateway Awards for their innovative approaches to environmental stewardship, including several cruise lines that dock at Terminal 91 (2001 W. Garfield St.).

The fifth-annual event highlighted the energy and effort that businesses along the working waterfront do on a daily basis to make Puget Sound a cleaner place.

The awardees include:

•Princess Cruises, which not only won the silver but was also recognized as the Most Innovative Partner. Its use of low-sulfur fuels beyond the required levels and zero discharge of ballast water in Puget Sound contributed to its high scores in the Air & Energy and Wastewater categories.

The innovations recognized include participation in an emission and control technology research project on three vessels, extensive efforts to minimize waste streams and a process to return expired chemicals and pyrotechnics to the supplying vendors.

•Celebrity Cruises, whose use of low-sulfur fuels beyond the required levels and energy efficient water consumption practices contributed to its scores in the Air & Energy and Wastewater categories.

Celebrity also earned points for additional Innovations described in its application, including innovative programs to engage crew and guests in Celebrity’s sustainability efforts.

•Holland America Line — which has an office at 300 Elliott Ave. W., Suite 100 — has zero discharge of ballast water in Puget Sound. Also, its progressive energy efficiency and waste management practices contributed to its high scores.

Holland America also earned points for additional for propulsion and handling systems that allow their vessels to routinely maneuver without tugboats.

•Royal Caribbean International, which uses low-sulfur fuels beyond the required levels and initiatives to reuse and reduce graywater contributed to its high scores in the Air & Energy and Wastewater categories.

Royal Caribbean also earned points for additional Innovations described in its application, including reuse of waste heat from the engines to heat shower water.