On 13 November, 2002, the structurally deficient Prestige tanker split up and sank off northern Spain,
causing thousands of gallons of crude oil to wash up on European beaches with devastating consequences on countless fish, birds, and mammals.
Dreadful enough on its own, but a more insidious threat quietly sails our waters in plain sight – cruise ships.
Built like floating vacation resorts, these vessels release tons of solid waste and pollutants into the ocean every day with an ever more increasing threat to marine creatures.
In this article, we are going to look at cruise ship pollution effects on marine life.
Do Cruise Ships Pollute the Environment
There are several ways in which cruise ships affect marine life. Common problems with cruise ships include:
1. Ballast Water Pollution
Cruise ships use plenty of ballast water to stabilize the vessel while sailing.
During long cruises, it is common for ships to collect Ballast water from one region and discharge it in another whenever needed.
Cruise ships can release up to 1,000 metric tons of ballast water, making this one of the major causes of cruise pollution.
The problem with ballast water is that it contains tar balls that can cause problems in navigation.
The water is also packed with harmful organisms like the killer algae, comb jellyfish, and zebra mussel,
which can compromise native species once they colonize their new environment.
A good example is the ecological damage done by the huge population of jellyfish in the Black Sea.
2. Air Pollution
The World Health Organization ranks poor air quality as one of the major health hazards in the world today, with 4.2 million people dying due to air pollution.
Cruise ships have their fair share of blame when it comes to releasing unwanted air, just like vehicles are known for emitting noxious air and waste fumes.
In fact, research has shown that the air pollution on the aft areas of cruise ships almost rivals that of major cities like Beijing.
The two main air pollutants from cruise ships are Sulphur oxides (SOx) and Nitrogen oxides (NOx). Both SOx and NOx are combustion byproducts emitted in the form of smoke.
These gases have a significant impact on the ozone layer, which contributes to global warming and the greenhouse effect.
To give you an idea, one large cruise ship can emit over 5 tons of NOx emissions and about as much SOx as 3.6 million cars!
3. Noise Pollution
Noise pollution from cruise ships can come from anything, including the ship’s noise, the seismic air gun noise from gas and oil exploration, and the low frequency sonar sounds often used in submarine detection.
Noise pollution has a significant effect on marine life as noise travels a lot more in water than on land.
The quandary is that marine life is awfully sensitive to noise pollution.
They rely on underwater sounds for basic life functions such as looking for food or even a mate, so outside interference can really hinder their ability to survive.
For example, the population of cetacean (dolphins and whales) has dropped considerably in areas that are prone to noise pollution from ships.
Some animals (e.g. whales) can die merely hours after being exposed to extreme noise.
Common causes of death include damage to internal organs, migration to newer places, changed diving pattern, hemorrhages, and general panic response to the alien sounds.
Underwater noise pollution can also cause death by disrupting normal communication between marine animals, as the animals cannot call for help when in trouble or even look for food.
4. Grey Water Pollution
Cruise ships dump more wastewater offshore than any other vessels, especially grey water from galleys, showers, laundries, and sinks onboard.
Thus, even the most basic activity on a cruise ship like doing your laundry or cleaning utensils contributes to cruise ship pollution.
A single large cruise ship can release up to 1 million gallons of grey water in just a week’s voyage.
This water is typically packed with harmful chemicals and even minerals and metals in some cases, all of which have a negative impact on marine life.
Grey water pollution always comes back to haunt us in the long run, as substances in grey water have toxic and
carcinogenic properties that can damage your DNA and affect childbirth when they find their way into your food.
For example, shellfish consumers in Europe are exposed to about 11,000 micro-plastics every year.
Micro plastics often come with other stubborn contaminants like pesticides, PAHs, PCBs, and metals.
Similarly, a single albacore tuna can contain up to 40% more mercury than the average thermometer, while one Pacific oyster has more cadmium concentration than a pack of cigarettes.
5. Sewage/Black Water Pollution
Sewage (aka black water) is concentrated with pollutants such as pathogens, toxins, metals, and certain nutrients.
As such, black water discharged from your cruise ship can severely affect water quality and subsequently jeopardize aquatic ecosystems.
Unbeknown to most cruisers, it is actually illegal to dump raw sewage into navigable U.S. waters according to federal law.
This includes coastal waters within three miles of shore as well as inland waters such as rivers, reservoirs, lakes, etc.
In fact, you cannot discharge any type of sewage (treated or untreated) in a No Discharge Zone (NDZ). An NDZ is usually created if a body of water:
- Has drinking-water intake zones
- Needs special environmental protection
- Has certain environmental importance (for example sensitive areas like coral reefs or shellfish beds)
In addition, all boats in American waters with permanent toilets are legally obligated to have an onboard Marine Sanitation Device (MSD) that either treats sewage or stores it until it can be transferred ashore.
Regardless of these measures, cruise ships can deposit as much as 210,000 gallons of human waste into the ocean in a single week’s voyage.
This sewage is rich in algae and bacteria that adversely affect oceanic life forms and the whole marine ecosystem at large.
6. Chemical Pollution
Cruise ships release toxic chemicals from dry cleaning products, batteries, and other substances.
These chemicals end up polluting the waters the ships are traveling on, which can be a threat to marine creatures and life forms.
7. Oil Pollution
Oil pollution is a major threat to marine life, and cruise ships burn heavier fuel oil than any other vessels (about 150 tons daily).
Heavy fuel is one of the dirtiest fossil fuels in the market with dangerous concentrations of heavy metals, sulfur, and other toxic substances.
Oil pollution can also result from accidents and collisions. Alternatively, it can leak from improper repair work or faulty engine system and find its way into the ocean.
Oil in water bodies destroys the ability of fur-bearing mammals like sea otters to insulate themselves, as well as that of a bird’s feathers to repel water.
As a result, these creatures are exposed to the harsh elements and eventually succumb to hypothermia.
Oil can also poison and kill juvenile sea turtles when they mistake it for food.
Many birds and animals often ingest oil accidentally when trying to clean themselves.
Whales and dolphins, on the other hand, have been known to inhale oil that in turn affects their immune function, lungs, and reproduction.
Why Ship Accidents Cause Marine Pollution
Given the size of a typical cruise ship and its potential for causing marine pollution, it is not hard to imagine the impact on the environment in the event of an accident.
Shipping accidents can be caused by several factors, including route conditions, shipping factors, natural conditions, technical failures, and of course, human errors.
- Natural conditions – natural phenomena like darkness, sea storms, reduced visibility (rain, heavy snow, fog, etc.), heavy winds, tidal flow, current, etc.
- Technical failures – flaws within the ship like engine failure, constructive damage, corrosion, and any other type of damage resulting from poor maintenance.
- Road conditions – navigation error like mooring close to cruise dangers such as centimes, reefs, and rocks; narrow channel directions with random changes in movement leading to limited maneuverability; and using inaccurate maritime charts.
- Shipping factors – e.g. large dimensions that in turn affect maneuverability
- Human errors – e.g. technical inadequacy, and lack of knowledge and experience.
An example of how cruise ship accidents affect marine life is the destruction of coral reefs on several water bodies across the world.
For instance, when British cruise ship MS Caledonian crashed in Indonesia back in 2017, it destroyed more than 17,000 square feet of coral reefs and caused over $19 million in irreparable damage.
Large cruise ships are also responsible for injuring and killing large numbers of marine species, particularly humpback whales, killer whales, and fin whales.
Due to their large sizes, cruise ships are usually not able to spot and successfully avoid these sea creatures when sailing, so it is extremely easy to hit them without even knowing it.
FAQs on Cruise Ships’ Pollution
1. Are river cruises bad for the environment?
River cruises are currently one of the greenest ways to travel the world, especially when you compare them to planes, cars, and larger water vessels.
However, since they sail on relatively smaller water bodies, the impact of river cruise vessels on the environment can be significantly worse.
2. How bad is cruising for the environment?
Cruising has a pretty bad reputation when it comes to the environment. From pumping ballast water into the ocean, introducing invasive species,
polluting the air, and dumping rubbish and sewage into the water, the effect of cruise ships on the environment has been likened to that of a million cars.
Cruise ship pollution effects on marine life are many and varied. The good news is that major cruise lines and countries across the world have already laid down proper resolutions in a bid to protect oceanic surroundings.
Slowly and steadily, people are beginning to understand the importance of preserving the marine eco-system.
Hopefully we will soon be able to achieve a healthy balance between creating a good cruising experience and caring for marine life forms.