This limits the amount of greenhouse gas emitted from conventional food waste processing systems, helping reduce the company's environmental impact. Currently being evaluated on 15 ships with 12 more ships scheduled in coming months across seven of the corporation's nine cruise line brands – Carnival Cruise Line, Costa Cruises, Cunard, Holland America Line, P&O Cruises (UK), Princess Cruises and Seabourn – food waste bio-digesters are used for successful food waste management at some restaurants, hotels, government facilities, stadiums, theme parks and other locations. The bio-digester systems in Carnival Corporation's pilot test are among the first systems of this kind to be tested on a cruise ship. Throughout the day, as food scraps are added to the system, a mix of microorganisms, including microbes and enzymes, rapidly and naturally digest the organic waste.