Coming clean on cruise ships

As a vacation choice, cruises have grown increasingly popular over the past two decades, making the industry one of the world’s fastest growing tourism sectors. In 2008, more than 9 million passengers took cruises on the seventeen largest cruise lines. But in 2019 over 30 million passengers globally embarked on a cruise.

Cruise ships offer passengers the chance to visit new and exciting destinations and view pristine coastal habitats and marine and animal life with little effort. When not in port or on deck watching the passing scenery, passengers can while away the hours engaged in any number of activities, including swimming and mini-golf or they can refuel with food after an afternoon of fun. 

An average ship has multiple dining rooms serving a plethora of cuisines, sometimes lavishly adorned with fruit carved into flowers and accompanied by elaborate deserts and ice sculptures. Food is available on a cruise ship 24 hours a day, seven days a week. It’s been estimated that a large cruise ship goes through 12,000 pounds of beef, 7,500 pounds of seafood, 10,000 pounds of fresh fruit, 48,000 eggs, and 500 gallons of ice cream per week.

Cruise ship food supply: What goes in must come out

The down and dirty truth is that after consumption, this cruise ship food waste — and human waste — has to go somewhere. 

What do cruise ships do with food waste?

Cruise ships are like floating mini metropolises. With thousands of hungry mouths to feed, the cruise has to have plenty of food on board. But each day, passengers leave behind food that they couldn’t consume. And after the trip is done, cruise ships can have up to 30% of food waste left behind. 

Where does this cruise ship food waste go? You guessed it — the food waste is often pulverized and pureed to be turned into “fish food” — aka it’s dumped into the ocean. 

Do cruise ships dump waste into the ocean?

At home, what you flush down the toilet is sent to a municipal treatment plant before it can be discharged into a water body. But have you ever wondered what do cruise ships do with poop and other human waste? What most people don’t know is that what you flush down the toilet in your cruise ship stateroom can be dumped untreated into many parts of our oceans to float with the fish. The dumping of sewage into coastal and ocean waters has significant implications.

The contaminants in human waste and wastewater – known as blackwater or sewage – pose a risk to public health not only through the food supply, as fisheries and shellfish beds can be contaminated, but also through direct contamination of water ingested by surfers, beachgoers, and water-sport enthusiasts. In addition, blackwater contains nitrogen and phosphorus that promote excessive algal growth, which in turn consumes oxygen in the water and can lead to fish kills and the destruction of other aquatic life, including coral. Algal blooms have been implicated in the deaths of more than 150 manatees off the coast of Florida.

In spite of the potential harm, a cruise ship (which often carries as many passengers as there are people in a small town) can legally dump human waste directly into the water as long as it is at least four miles from shore. Within four miles of shore, cruise ships are allowed to discharge sewage treated by a Marine Sanitation Device (MSD). However, the EPA’s MSD regulations governing sewage discharges from ships have not been revised since the early 1980s. 

More importantly, EPA does not require testing or monitoring of sewage discharges, so even if an MSD malfunctions or a ship discharges raw sewage without using an MSD within four miles of shore, there is no way of knowing whether a violation has occurred. In response to a stronger cruise ship law in Alaska, many cruise ships traveling to Alaska began using Advanced Waste Water Treatment Systems. While these treatment systems are more effective than MSDs they do not eliminate metals which can bioaccumulate in the food supply or ammonia which leads to algal blooms. They also produce larger quantities of sewage sludge – a concentrated waste left over after the sewage treatment process. Sludge, like sewage, can be dumped just four miles from shore. 

And cruise ship pollution from human waste can have toxic consequences. In 2006, more than 25,000 days of closings and advisories at ocean, bay and Great Lakes beaches occurred, most due to the presence of bacteria associated with fecal contamination. 

Two popular cruise ship destinations, Jamaica and Florida, are prime examples of how dumping cruise ship waste into our oceans causes extreme harm to marine biodiversity. In 2002, only five percent of the coral reefs around Jamaica supported living coral compared with 60 percent 10 years earlier. In 2002, about 90 percent of Florida’s coral reefs were believed to be dead or dying. And a more recent study from 2021 shows the significant impact that cruise ships have had on the Key West region in Florida. When cruises stopped due to COVID the researchers documented significant improvements in water clarity. Although cruise ships are not the only cause of this devastation, they are one source of harm that can and should be controlled. It is imperative that we protect our ocean resources and the public health from cruise pollution.

In addition to sewage, cruise ships also produce and discharge a number of other polluting substances.

Graywater: “Graywater” is the name given to wastewater from sinks, baths, showers, laundry and galleys. Graywater is typically the largest source of liquid waste generated by cruise ships. While it might seem like this wastewater would be less polluting than blackwater, EPA’s 2008 Cruise Ship Discharge Assessment Report (released as a result of a Friends of the Earth lawsuit) revealed that graywater can contain levels of fecal coliform bacteria higher than those found in untreated domestic wastewater. As a result, graywater poses many of the same public health and environmental risks as sewage. 

Oily Bilge Water: The bilge is the lowest part of the hull of a ship and typically houses engines and machinery. Oil often leaks from engines and machinery into the bilge during operation and the performance of routine maintenance activities. These bilge spaces are periodically flushed with water and pumped dry. Before the bilge can be cleared and the water discharged, federal regulations require that accumulated oil be extracted. The extracted oil can then be reused, incinerated, and/or off-loaded in port. Unfortunately, cruise ships have not always been very compliant with the regulations governing oil discharges. Carnival Corp. and its subsidiaries have been on criminal probation since 2017 as part of a $40 million fine and plea agreement for illegally dumping oily waste into the ocean and obstruction of justice for hiding it from regulators. During its probation, Carnival companies have been violating the terms of the criminal plea agreement by dumping wastewater, oil and plastic into the ocean and polluting our air in excess of federal and state regulations. Even small concentrations of oil can kill or chronically disable fish. In humans, oil and byproducts from the biological breakdown of petroleum products can pose health threats if ingested.

Hazardous Waste: Cruise ships offer many of the same amenities that can be found on dry land – including dry cleaning and photo processing. Unfortunately these services produce the same hazardous waste byproducts as their land-based counterparts. Although cruise ships do not generate large quantities of hazardous waste, the waste they do generate can cause harm to sensitive marine life and needs to be carefully managed so that it doesn’t find its way into bilge water, graywater, or the solid waste stream. Additionally, hazardous waste tracking measures do not apply when cruise ships offload waste at international ports, opening up a large loophole through which hazardous waste can be lost.

Friends of the Earth works to clean up cruise ship pollution

Friends of the Earth is fighting on both the local and national level to put the brakes on cruise ship pollution. In 2000, concerned with increasing levels of pollution from the ever growing cruise industry and a series of incidents in which cruise lines admitted to routinely dumping oil waste and hazardous chemicals into U.S. harbors and coastal areas, Friends of the Earth, with the support of 58 other organizations, petitioned EPA to regulate cruise ship pollution. EPA failed to act on the petition, so Friends of the Earth sued and forced EPA, through a settlement agreement, to release its Cruise Ship Discharge Assessment Report in December 2008. In the Cruise Ship Discharge Assessment report, EPA found that, “[s]ewage contamination in swimming areas and shellfish beds poses potential risks to human health and the environment by increasing the rate of waterborne illnesses.” EPA also found that, in samples taken from cruise ships in Alaska, the average discharge exceeded EPA’s fecal coliform limit by 10,200 times. 

In California, we helped pass five bills which collectively ban cruise ships from discharging sewage, graywater, oily bilge water, sewage sludge, and hazardous waste into state waters and prohibit cruise ships from burning garbage, paper, sludge and any other materials in on-board incinerators while operating in state waters. In addition, we successfully petitioned the National Oceanic and Atmospheric Administration (NOAA) for a ban on these same cruise ship discharges within the sensitive and ecologically important National Marine Sanctuary System — the ocean equivalent to the national park system. California has four of these sanctuaries along its coast, including the Monterey Bay and Gulf of Farallones National Marine Sanctuaries. We also championed the creation of a No-Discharge Zone for large ship sewage dumping for all of California’s waters out to 3 miles which went into effect in 2012.

Friends of the Earth has also expanded its cruise ship work into the Pacific Northwest. We have successfully protected the Olympic Coast National Marine Sanctuary in Washington State from cruise ship discharges and compelled the Port of Seattle to send hazardous dredged material to a landfill rather than dumping it back into Puget Sound. We are also working with the Port of Seattle and other state agencies to protect the delicate marine ecosystem of Puget Sound from the rapidly expanding threat of cruise ship and ocean-going vessel pollution and have successfully strengthened an agreement with the cruise industry to limit cruise ship discharges in the Sound. In addition, we championed the creation of a No-Discharge Zone in Puget Sound in 2018 which prevents any ship—large or small, cruise ship or cargo vessel—from dumping its sewage into the waters of the Sound.

Cleaning up the poop deck: What you can do to help

Our coastal communities, marine wildlife, and planet need your help to stop the cruise ship pollution problem. You can urge your local representatives to do something about the problem of cruise ship pollution in our country. Currently, Alaska, California, and Maine are the only states with laws that address cruise ship pollution. More states could benefit from local action to stop the destruction of human health and the environment. 

If you are scheduled to take a cruise and are unable to cancel, you can ask to meet with the environmental officer on board the ship to learn more about what they do with their waste. Let them know that you care about what cruise ship pollution is doing to our oceans and public health. You can also call up the major cruise lines and tell them that you want them to stop dumping their waste indiscriminately and to support legislation to fix the problem.

To explore each cruise line and their cruise ships in further detail, check out the Friends of the Earth Cruise Ship Report Card. It provides insight into the polluting ways of each ship in the fleets.