The unsettling environmental cost of cruises - Vacation season is coming and many people are looking for an epic summer adventure. Cruise ships are becoming more popular as people are drawn in by the on-board attractions, relaxation while cruising paradisaical waters, and the opportunity to explore various destinations. However, cruise ships are a major source of pollution and have devastating effects on the environment. 

Learn more about the environmental costs of cruise ships and ways in which the industry can improve its carbon footprint, in the following gallery.

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Cruise ships - Cruise ships are increasing in popularity as more people are drawn to sea travel as a way of experiencing and visiting more destinations.

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Cruise ships - Global cruise statistics show that the industry will carry around 27.2 million passengers in 2018. However, while most people are drawn by the luxury, adventure, and relaxation that cruise lines boast, many are unaware of the dark side of cruise ships.

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Climate change - Scientists have all come to an agreement that climate change is occurring at rapid and disturbing rates. When most people think of climate change, they imagine pollution from factories and cars, or the burning of fossil fuels.

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Hidden damage - Most people don't think of cruise ships as being a major cause of both air and ocean pollution. 

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Hidden damage - According to Global Citizen, reports find that cruise ships put out as much pollution daily as one million cars.

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Pollution - The pollution is due to the heavy fuel oil used in cruise ships. 

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Pollution - The engines burn 150 tons of fuel every day, as shown on Global Citizen. The large diesel engines churn out exhaust that saturates the air.

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Pollution - The exhaust contains sulfur dioxide and nitrogen oxides, two components of acid rain, which raises the acidity of the water and harms ocean life. 

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Pollution - Not only do cruise ships pollute the air, they also contaminate the ocean water by releasing sewage directly into the sea.

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Sewage - According to the U.S. Environmental Protection Agency, a cruise carrying 3,000 passengers and crew members for a week is capable of producing around 794,850 L of sewage stream, 3.785 million L of gray water, 95,000 L of oily bilge water, 568 L of hazardous wastes, and eight tons of solid waste.

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Sewage - The same website states that cruise ships make up about 77% of the global marine pollution.

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Sewage - A study by Friends of the Earth, a non-profit organization for environmental consciousness, estimated that cruise lines dump around one billion gallons of sewage into the oceans every year.

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Pathogens - Pathogens and bacteria present in human fecal matter, including E. coli, hepatitis, and salmonella, can contaminate the seafood we eat and the water we swim in. 

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Eutrophication - Another problem associated with sewage disposal is eutrophication. Sewage contains high levels of phosphorus and nitrogen. When these nutrients are added to the water, they cause algae growth, which in turn depletes the water of oxygen and suffocates the animals living in it.

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Waste - Unfortunately, waste removal is still highly unregulated and cruise ships are allowed to dump waste once they are several kilometers away from shore without properly disposing of it. Ocean currents carry the waste throughout the ocean and eventually returns it to shore.

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Sanitation standards - According to The Guardian, even if a cruise ship treats their sewage before dumping it, the sanitary practices are outdated and may not actually make water any safer.

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Sanitation standards - The US Environmental Protection Agency reported in 2009, "Traditional Type II [marine sanitation devices] routinely fail to treat sewage to meet the current EPA standards and are inadequate to protect US waters."

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Ballast water - The dumping of ballast water is another way cruise ships damage the environment. Ballast water is held in large tanks in the bottom of the ship and is meant to improve stability while at sea.

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Ballast water - Ships refill their tanks at one port and then empty them into the water when they arrive at the next port. This practice can introduce invasive species from one region to another by transporting plants, animals, viruses, and bacteria that are not normally found in the area where the water is dumped.

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Bilge water - Bilge water is the highly contaminated water that collects at the bottom of the ship and often contains oil. While ships are required to treat this water and offload it when docked, this isn't always the case.

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Bilge water - In 2016, Princess Cruise Lines paid a $40 million US fine for illegally dumping oily water into the ocean, according to The Guardian. This illegal practice was found among other cruise lines as well.

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Environmentally friendly - While the damage cruise ships cause to the environment is shocking and disheartening, there are ways that cruise lines can improve their carbon footprint and reduce their environmental impact.

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Shore power - One way cruise ships can reduce environmental damage is with shore power. Instead of using their fuel to make electricity, ships can draw energy from land-based power plants when docked.

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Shore power - Unfortunately, the infrastructure for these power plants is still widely lacking. Cruise ships must invest in the infrastructure and partner with ports to pay for the power.

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Solar panels - Cruise ships are installing solar panels in order to reduce power consumption and overall carbon dioxide emissions.

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Alternative fuels - Biodegradable fuels can be used in cruise ships to reduce the negative effects of oil leaks while out at sea. 

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Dual-fuel engines - Specific engines, known as dual-fuel engines, enable cruise ships to adhere to strict emission standards. These engines reduce carbon dioxide emissions and produce cleaner exhaust. 

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Reducing wastes - According to Renewable Energy World, a cruise ship can produce up to seven tons of waste a day if there are no attempts made to reduce this. By reusing dishes, using recycled items, and waiting to dock before eliminating waste (instead of dumping it during the trip), cruise ships can significantly reduce the waste they produce.

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Purification systems - Improvements in water purification systems treat bilge, ballast, and other waste water that can harm the environment when discharged. Many cruise lines have committed to using advanced purification systems and dumping the water properly when docked, instead of out at sea.

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Going green - Fortunately, cruise lines are becoming more aware of the impact they cause on the environment and are switching over to more environmentally friendly methods. If you're looking to go on a cruise vacation this summer, do your research and make sure you choose a company that has committed to going green.

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