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The Impacts of Cruises on the Ocean: What Has COVID-19 Changed?

Angelique Howard


  • Discusses how the CDC’s “No Sail Order” during the Covid-19 pandemic effectively led to the cessation of waste discharge.
  • Addresses how cruise ships pose a significant threat to the marine environment.
  • Explores the large amounts of waste generated by cruise ships and the lack of regulation regarding waste disposal offshore.
The Impacts of Cruises on the Ocean: What Has COVID-19 Changed?
David Sacks via Getty Images

Those who have chosen a cruise for their next vacation are likely aware of the impacts the COVID-19 pandemic has had on their choice of vacation. Those same individuals, however, are probably unaware of the immense impacts their vacation choice has on the coastal environment and marine life—an unintended, but very real consequence. While other businesses were transitioning back to normal operations, the cruise industry was sidelined for over a year. COVID-19 has been one of the biggest detriments the industry has had to face, but one from which the marine environment has benefited.

On March 14, 2020, the Centers for Disease Control and Prevention (CDC) director issued a No Sail Order for all cruise ships. This meant that cruise ship operators were no longer permitted to commence or continue operations. This effectively led to the cessation of waste discharge. It was not until April 2, 2021, when the CDC released a guideline that outlined the framework for cruise operations to resume. It is no surprise that COVID-19 lockdowns decreased pollution worldwide, and the cessation of cruises was no exception.

Cruise ships pose a significant threat to the marine environment. Collision with marine mammals and sea turtles front a significant issue. Incidents from cruise ships near coral reefs have caused irreplaceable damage, harming millions of species. In 2017, a British cruise ship crashed into the coral reefs of Indonesia, destroying around 17,222 square feet of coral reefs. This damage caused more than $19 million in irreparable loss.

People are often aware of the impacts of the grounding of cruise lines but may not be aware of the huge amounts of waste produced and the impacts. While the cruise industry only makes up a portion of the global shipping industry, it is responsible for approximately a quarter of all waste produced by the sector. Before the COVID-19 pandemic, a comprehensive research review found recreational vacation cruising a major source of environmental pollution and degradation, with air, water, soil, fragile habitat, and wildlife affected.

According to the Bureau of Transportation, a sector of the U.S. Department of Transportation, a typical one-week voyage of a cruise ship generates 210,000 gallons of sewage (black water), 1 million gallons of graywater, countless different hazardous wastes that contain heavy metals ranging from mercury to silver, chemical pollution, and much more. Cruise ship sewage contains human waste, bacteria, viruses, and chemicals. Graywater is water that already has been used domestically, commercially, and industrially. It has the potential to cause adverse effects due to the concentration of nutrients and oxygen-demanding substances in the waste stream. Graywater is also known to introduce disease-causing microorganisms and excessive nutrients to waterways, which causes a reduction in the oxygen levels needed by marine species and triggers harmful algae blooms.

Although the Clean Water Act tightly regulates waste disposal of raw untreated sewage, there is no stopping a cruise ship from dumping untreated sewage 12 miles offshore. Treated sewage has only a three-mile offshore dumping limit, a close enough distance to still cause adverse effects to the coast. Even with the well-known amount of waste produced by cruise vessels, there is limited mandated monitoring on how much waste can be produced, nor any global effort to do so.

While there are no direct studies comparing the state of the marine environment before and after COVID-19 lockdowns, port cities are showing a preference for their cleaner waters and air. Large port cities have enjoyed over a year without cruise ships creating harm to their aquatic life with an absence of sewage water pollution. Residents of Key West, Florida, for example, have voted to ban large cruise ships from returning to the city when cruises resume. Large cruise ships with more than 1,300 people will not be permitted to dock in the city and priority docking will be available to the cruise lines with the best environmental and health records. These kinds of restrictions represent how cities, and potentially other major ports, take the direct, harmful effects of cruises seriously.

Although many economists have been concerned with the cruise industry’s ability to recover consumer confidence, it appeared not to be an issue. According to Royal Caribbean, over 150,000 people have volunteered for the test sails as required by the CDC’s Conditional Sailing Order. There is no current reconsideration by any country to restrict the pollution of water in the open ocean. So as cruise ships prepare to sail again under CDC’s Conditional Sailing Order, the waters will once again fill with waste and fragile marine life will be harmed.