Cruise ships are powered with heavy crude
oil. According to the environment
association NABU, a cruise ship emits
the same quantity of pollutants during one
cruise as 5 million cars on the same route.
That definitely does not make them
“eco-friendly”. The US Federal
Environmental Protection Agency estimates
that in a single day, passengers on a
typical cruise ship will cause

·         “21,000 gallons of sewage
·         one ton of garbage
·         170,000 gallons of wastewater from sinks, showers and laundry
·         More than 25 pounds of batteries, fluorescent lights, medical wastes and expired chemicals
·         Up to 6,400 gallons of oily bilge water from engines
·         Four plastic bottles per passenger – about 8,500 bottles per day”

The EPA further states that ships incinerate the majority of their garbage, thus contributing to the pollution of the air, especially in coastal regions and on the ocean.
The bad news is that the cruising industry is huge, generating billions of dollars every year. In 1970, ships were only accommodating 600-700 people while nowadays, 5000 people find room on the luxury cruise liners which are growing rapidly due to the strong demand.   

Sewage and waste waters
Incinerator ash and sewage sludge is pumped into the ocean which pollutes the oceans with nutrients, metals, ammonia, pharmaceutical waste, chemical cleaners and detergent. They do not need to be concerned when doing this though, as they are not obliged to have a permit to be able to dump these waters into the sea three miles from the shore. Furthermore, they do not need to report the quantities of waste they release into the ocean which makes it hard for governments and the public to know the degree of pollution actually caused by cruise liners. Untreated gray water which contains the wastewater from galleys, dishwashers, bathrooms and laundries may equally be released into the ocean. 

Sewage under Marpol
On November 2nd, 1973, the MARPOL agreement was adopted which is the International Convention for the Prevention of Pollution from Ships. It regulates the different types of pollution in connection with the operation of ships. With regards to the dumping of sewage water, it is outlawed to dump sewage water into the ocean EXCEPT if it was mechanically processed and disinfected and the ship is situated 3 sea miles from the nearest land OR if it was not treated, ships are allowed to dump it into the ocean at least 12 sea miles away from the nearest land. 
Although cruise ships are required to have onboard waste treatment systems and are required to record their discharges, they do not need to monitor the quality of the released waters. Hence, these waters dumped into the ocean can contain dangerous toxins. These sewage and waste waters which contain high quantities of fecal coliform, harmful nutrients, bacteria and pathogens threaten the marine life in the oceans. Oxygen is reduced which increases the growth of algae. These blooms can destroy coral reefs and cause the development of plagues. San Francisco Bay was invaded by Chinese mitten crabs and Asian clams due to waste water that was dumped into the port by ships. In the Black Sea there was an invasion of jellyfish. This shows that dumping waste waters and sewage sludge into the ocean disrupts ecosystems and diminishes or spurs the growth of animal populations.   

This might be hard to believe but under Annex V of the International Convention for the Prevention of Pollution from Ships, cruise ships are not permitted to dump plastics anywhere at sea. However, they are able to dispose of packaging that swims at least 25 sea miles from the nearest land and food scrapes and other kind of garbage like paper, glass, metal, bottles, stone ware and ashes at least 12 sea miles from shore. The regulation is even less strict if the garbage was ground. In this case ships are allowed to dump their garbage 3 sea miles from shore. 

Air pollution
An average cruise ship with 3,000 passengers on-board emits about the same quantity of pollutants as 12,000 cars every day. The diesel engines on ships emit dangerous pollutants and represent a special risk for people suffering from asthma. These emissions are unregulated.  
Tourists are booking their tours to see primeval oceans, beautiful coral reefs and marine life. Ocean liners do not realize, that they are actually destroying these attractions through their sewage and waste water practices.
The association states that on July 21st 2011, another cruise ship was launched that neither possessed a particulate filter nor a desulphurization unit, which is disastrous from an environmental perspective. Currently, the sulphur content on cruise ships amounts to 2.5% while cars and trucks may only contain 0.0001% which is practically sulphur-free. The emissions of the cruise ships harm the climate and the health of the people living in port cities and along the coasts. NABU has asked cruise liners to become more responsible for instance by using marine diesel with a sulphur content of 0.5%.
There will be stricter rules in 2020, when the level of permitted emissions will be reduced significantly and the times of crude oil will be over. The EU Parlament, however, is planning to reduce the limit values of sulfur in marine fuels used on cruises in the Mediterranean Sea and in the Black Sea much earlier than that. 

The reaction of cruise ships
Cruise companies are protesting against the planned restrictions even though they are the ones that should be concerned about the environmental damage their swimming hotels are causing and the image this might give them. The regulations of the International Marine Organization are not sufficient and cruise liners should make efforts to reduce the air pollutants that are emitted through the chimneys of the ocean liners. Port cities should also put more pressure on these marine companies and motivate them to use eco-friendly practices on-board.

How about hitting the high sea on an eco-friendly cruise ship? Below, you will find an overview of 7 eco-friendly cruises and their eco-contribution:

Holland America 

  • black water treatment system aboard
  • reduced its waste by working with their supply chain network
  • environmental officers on-board and is eco-educating its staff. 
  • A water-reduction system has been implemented through the installation of low-flow showerheads and faucets
  • Bilge water is treated by two systems before discharge
  • Each ship is ISO14001 certified which means that the ship has established an environmental management program
  • Use of non-toxic cleaning products such as detergents that use soy, banana and orange extracts
  • Reduction of fuel use due to new ship routes
  • Silicone paint on the hull of the ship to reduce drag
  • Use of efficient engines. 
  • Making an effort to reduce SOx emissions and particulate matter by using plug-in power at shore
  • Windows equipped with a dark film which leads to cooling and reduces the use of air conditioning and thus leads to energy savings

Solstice, Celebrity Cruises

  • Uses solar panels to power the elevators on-board
  • Saving 50% on energy demands due to the use of 7,000 LED light
  • Water treatment system: returns black and waste water in almost pristine conditions back into the ocean
  • Windows designed to keep rooms cool which reduces electricity needs: A lot of natural light cuts down on the use of electricity
  • Aluminium and tin recycled and glass crushed before offloaded at shore
  • Batteries and light-bulbs collected
  • The big loss: the materials not mentioned afore are incinerated on-board. Engine oil is cleaned and left in the port cities

 Disney Cruise Lines

  • Water purification system put into place: water from air condition system used by laundry facilities
  • Heat is used to power evaporators that turn 1,200 tons of ocean water into drinking water
  • Staff and guests are eco-educated by an environmental officer aboard who also controls environmental practices on-board
  • Implementing energy-efficient devices such as automatic air conditioning and efficient lighting
  • Weight on the ship reduced: result was energy savings of 5%
  • Hull of the ship coated with non-toxic substances in order for the ship to glide instead of dra
  • Recycling system managed to save 405 tons of material from the waste stream
  • Partnership with Keep America Beautiful helps with recycling process
  • Disney donates furnishings and materials from the ship to needy communities
  • Guests are able to donate a dollar for wildlife programs around the world

 Royal Caribbean Cruise Lines

  • Received ISO14001 and ISO9001 certification
  • Environmental officers aboard
  • Eco-education of staff and guests are eco-educated
  • Managed to reduce waste and dispose of all waste waters which means nothing is dumped into the ocean
  • Uses less packaging, gotten rid of plastic water bottles and instead using reusable options
  • Has converted its waste water treatment system into a modern purification system
  • Installed a new hull shape and achieved energy savings of 8%
  • Purchased 15 million tons of biodiesel in 2007 and agreed to buy 18 million tons for the next four years
  • Using energy-efficient light bulbs and reducing the use of air conditioning
  • On the Explorer of the Seas, two laboratories are on board that do research on water pollution and climate change

 Lindblad Expeditions

  • Cruise in cooperation with National Geographic where guests can get into close contact with nature without destroying it
  • Ship only carries 148 passengers who travel to places such as the Galapagos Islands, Egypt and Antarctica
  • On expeditions, cruise serves local food and fish that was sustainably raised: in 2001, the cruise stopped serving shrimp because a sustainable source could no longer be found 
  • The cruise liner’s partnership with important environmental organizations has helped it develop climate action strategies end provide guests onboard with eco-training

Norwegian Cruise Lines

  • Newest ships on the market
  • Black and gray water is treated until it reaches a better quality of municipial drinking water before it is released either 12 or 4 miles offshore
  • The big loss: the cruise incinerates everything that cannot be recycled or thrown overboard 
  • First to implement an eco-ballast system which ensures that water being released into the oceans does not contain toxins or invasive species
  • Gives its used cooking oil for free to farmers in port cities which is a great way of disposing of garbage on board
  • Annual audits are carried out to ensure that the respective environmental practices are carried out.


  • Awarded the Green Star notation environmental award in 2005
  • Has to adhere to strict environmental regulations
  • Working with WWF to establish and implement environmental management programs with regards to energy savings, recycling practices and eco-training
  • Provides local communities in Kenya with low energy stoves
  • Implemented a modern recycling system
  • Intensively invested in eco-training for the cruise staff
  • In 2010, the cruise announced to prepare a “Green Passport” which would list all the materials used to construct three of its ships which would facilitate the recycling at the end of the ships lifecycle
  • If you are interested in finding out more about Costa’s environmental programs, you will find detailed information in the company’s sustainability reports

We can see that even though cruise ships are considered to be the biggest polluters of the sea, some companies have made a step towards ridding themselves of the dirty image. If you are one of those tourists that loves cruises, try opting for one of the eco-friendly cruises mentioned above. You can travel without having a bad conscience and you can pronounce yourself an ecotourist.


  1. Norwegian Cruise Lines is the biggest and the nice eco-friendly ship. The water of this ship which is released in oceans is doesn't toxins for the oceans.

  2. Norwegian Cruise Lines are definitely a role model in the world of cruise ships and it remains to be seen whether other cruisers will follow in their footsteps!