Cruise companies and cruise ships negatively impact communities through air and water pollution, economic leakage and tax avoidance, as well as overtourism. Such negative impacts can arise where cruise companies are based, where they pass through, and where they dock.
Even though some cruise companies have responded to pollution issues when building new ships in recent years, most cruise liners still score badly when it comes to emissions, treatment of sewage and noise pollution. Most cruise ships sail with cheap heavy oil, which is particularly toxic and harmful to the environment. Furthermore, many cruise ships use outdated technology to treat sewage before discharging it into the sea, resulting in significant amounts of faecal bacteria, heavy metals, and nutrients entering the open water, with negative impacts on ecosystems. There have also been reports of cruise ships throwing waste overboard. Cruise ships mostly keep their engines running, including when docked. Related air pollution can have negative health impacts on residents living near the port.
Cruise ships commonly sail under the flags of a small group of countries that are considered tax havens by the OECD and have weak labour laws, enabling cruise owners to avoid taxes, provide poor working conditions and wages and follow potentially dangerous security practices. While cruise liners profit from systems and public services in the places they operate most, they generally do not pay taxes to these places. As passengers eat most of their meals on board, shop at cruise company-owned duty-free shops and participate in excursions organised by the cruise company, very little money they spend flows into the economies of the local communities they visit.
Opinions about the responsibility of cruises for overtourism are divided. Regardless, it is clear that cruise passengers temporarily overflow certain destinations when docking, which is particularly harmful for small destinations. In some places, protests against overtourism have targeted the cruise industry.