8 Environmental Impacts of Shipping

Shipping is essential to international trade because it makes it easier for items to go across borders. However, because there are environmental impacts of shipping lines contributing to pollution and climate change, their effects on the environment have drawn attention.

There is a lot of worry about how shipping lines affect the environment. More than 10% of transportation-related CO2 emissions come from shipping, which also contributes significantly to air pollution. Decades of delay have increased its influence on the environment. However, the use of renewable fuels promises a cleaner future.

Transportation contributes 3% of the world’s annual CO2 emissions, or 1,000 Mt. If strict action is not taken, shipping emissions could climb by as much as 50% by the middle of the century, according to The International Maritime Organization. The International Maritime Organization (IMO) has not acted on several occasions.

Transportation also contributes to acid rain and poor air quality. As the top environmental group in Europe addressing shipping emissions, T&E collaborates with other Clean Shipping Coalition members to lower air pollution and the global warming effects of shipping.

If everything proceeds as normal and other economic sectors cut emissions to limit the rise in global temperature to less than two degrees, shipping may account for 10% of greenhouse gas emissions worldwide by 2050. Some of the worst fuels in the world are used by ships.

Environmental Impacts of Shipping

  • Air Pollution
  • Noise Pollution
  • Vessel Discharges
  • Wastewater
  • Solid Waste
  • Traffic Jams at Ports
  • Ballast Water
  • Wildlife Collisions

1. Air Pollution

As a result of burning fuel for energy, commercial ships release various air pollutants. Particulate matter, nitrogen oxides (NOx), sulfur oxides (SOx), and carbon dioxide (CO2) are among the pollutants originating from ships. This is because 80% of ships power these cargo vessels with bunker fuel, which is a low-grade heavy-fuel oil.

The release of carbon dioxide into the atmosphere alters the chemistry of the oceans, making them more acidic and endangering coral reefs and species that make shells. The water grows warm, thereby increasing the strength of storms, resulting in sea level rises and disruptions of ecosystems and ocean circulation.

Nitrogen oxide is a pollutant that causes smog, ground-level ozone, and respiratory problems in people. Over 60,000 premature deaths worldwide are attributed to particulate matter (PM) and sulfur oxide (SOx), which also cause respiratory issues for millions of individuals, particularly those who live near crowded ports.

The transportation sector is cutting back on air pollution while keeping in mind the emission data. There are rules to guide this, such as the “Greenhouse Gas Strategy (GHG)” of the International Maritime Organization (IMO).

How is the shipping sector attempting to meet the objectives that agencies and governments set forth? Using cutting-edge technology is one of the initial methods.

2. Noise Pollution

The amount of noise pollution brought on by shipping has grown over time. Because ship noise may travel great distances, it can negatively impact marine life, which depends on sound for navigation, communication, and nutrition.

According to research, shipping is the main source of the ongoing anthropogenic noise in the ocean, which harms marine life—particularly marine mammals—both immediately and over time.

On board ships, constant noise can be detrimental to one’s health. In 2012, the International Maritime Organization (IMO) enacted a regulation under the Safety of Life at Sea (SOLAS) convention that mandates that ships be built under the Code on noise levels on board ships to minimize noise pollution and safeguard crew members.

Utilizing cutting-edge technologies helps prevent negative effects on the environment by monitoring noise pollution in real-time, such as Sinay’s Aerial Acoustics Module and Underwater Acoustics.

With the use of these technologies, businesses can quickly and accurately decide how their operations impact the environment and protect both marine life and the local community.

3. Vessel Discharges

Even though there has been a general decline in the number of unintentional oil spills, they still happen occasionally. Large unintentional oil spills are responsible for between 10% and 15% of all oil that reaches the ocean globally each year, according to studies.

Water discharged from ships can potentially harm the ecosystem and marine life. Ships carrying cargo release bilge water, grey water, black water, etc.

The ship’s accommodations, which include the galley, shower, laundry, and sink, supply the grey water. Urine, feces, and greasy bilge water are all found in black water. These releases have the potential to harm marine habitats, lower water quality, and endanger public health.

4. Wastewater

Daily discharges into the ocean by the cruise line industry total 255,000 US gallons (970 m3) of greywater and 30,000 US gallons (110 m3) of blackwater.

Sewage, or blackwater, is the effluent from hospitals and toilets that may contain infections, viruses, intestinal parasites, germs, and toxic nutrients. The public’s health may be in danger from the bacterial and virus contamination of fisheries and shellfish beds that results from the discharge of untreated or insufficiently treated sewage.

Sewage contains nutrients like nitrogen and phosphorus that encourage excessive algal blooms, which deplete the oxygen in the water and can kill fish and destroy other aquatic life. An enormous cruise ship with 3,000 passengers and crew members produces between 55,000 and 110,000 gallons of blackwater waste every day.

Wastewater from onboard sinks, showers, galleys, laundry, and cleaning operations is referred to as greywater. Fecal coliforms, detergents, oil and grease, metals, organic compounds, petroleum hydrocarbons, nutrients, food waste, and dental and medical waste are just a few of the pollutants that it may contain.

Untreated graywater from cruise ships can contain contaminants at varying concentrations and levels of fecal coliform bacteria several times higher than those generally seen in untreated household wastewater, according to EPA and State of Alaska sampling results.

Greywater concentrations of nutrients and other things that require oxygen, in particular, have the potential to harm the ecosystem.

Ninety to ninety-five percent of the liquid waste produced by cruise ships comes from greywater. Greywater estimates vary from 110 to 320 liters per person per day, or 330,000 to 960,000 liters per day for a cruise liner with 3,000 passengers.

In September 2003, MARPOL annex IV went into effect, severely restricting the discharge of untreated waste. Modern cruise ships are most usually installed with a membrane bioreactor type treatment system for all blackwater and greywater, such as G&O, Zenon or Rochem bioreactors which create near drinkable quality effluent to be re-used in the machinery rooms as technical water.

5. Solid Waste

Solid waste generated on a ship comprises glass, paper, cardboard, aluminum and steel cans, and plastics. It may be dangerous or non-hazardous.

When solid waste finds its way into the ocean, it can turn into marine debris, which can endanger humans, coastal towns, marine life, and businesses that depend on marine waters. Usually, cruise ships combine source reduction, waste minimization, and recycling to manage solid waste.

Nonetheless, up to 75% of the solid waste is burned on board, with the ash usually being released into the ocean; however, some is also brought ashore for recycling or disposal.

Plastics and other solid debris that may be discharged or disposed of off cruise ships have the potential to entangle marine mammals, fish, sea turtles, and birds, resulting in harm or death. Every cruise ship passenger produces two pounds or more of non-hazardous solid garbage every day on average.

Large cruise ships that accommodate thousands of people can produce enormous amounts of trash every day. During a one-week cruise, a major ship produces approximately eight tons of solid garbage.

According to weight measurements, cruise ships are estimated to be responsible for 24% of the solid waste generated by ships worldwide. The majority of waste from cruise ships is prepared on board for overboard release by being ground up, pulped, or burned.

Cruise ships can impose a burden on port receiving facilities, which are rarely sufficient to handle the work of handling a big passenger vessel when rubbish must be off-loaded (for example, because glass and aluminum cannot be burned).

6. Traffic Jams at Ports

Many ports around the world, including the ports in London, Asia, the United States, and Los Angeles, suffer significant challenges due to port congestion. When a ship arrives at a port and is unable to berth, it is said to be in port congestion and must wait outside at anchorage until a berth opens up. A lot of container ships have a lengthy docking process that might take up to two weeks.  

It is expected of sippers to follow the guidelines for commercial vessel discharge. Additionally, the maritime industry needs to see more investments in digitalization. The growing amount of waiting time would be better managed if ports and shippers could track barges and have an accurate estimated time of arrival (ETA) for vessels.

7. Ballast Water

Ships’ releases of ballast water may be detrimental to the marine ecosystem. Cruise ships, large tankers, and bulk cargo carriers use a lot of ballast water, which is often absorbed in coastal waters in one area after ships discharge wastewater or unload cargo. It is then discharged at the next port of call, wherever more cargo is loaded.

Biological elements such as plants, animals, viruses, and bacteria are commonly found in ballast water discharge. These materials frequently contain exotic, invasive, bothersome, and non-native species that have the potential to seriously harm human health as well as inflict severe ecological and financial harm to aquatic environments.

8. Wildlife Collisions

Marine mammals are vulnerable to ship strikes, which can be fatal for species like manatees and whales. For instance, there is a 79% chance that a collision with a ship moving at barely 15 knots will be fatal to a whale.

The endangered North Atlantic right whale, of which there are only 400 or fewer left, is a prominent illustration of the effects of ship collisions. Right whales in the North Atlantic are most at risk from injuries caused by ship strikes.

Collisions were the cause of 35.5% of deaths that were reported between 1970 and 1999. Between 1999 and 2003, there was an average of one fatality and one serious injury occurrence linked to ship strikes each year. Between 2004 and 2006, the figure rose to 2.6.

Collision-related deaths are now considered an extinction threat. To prevent ship collisions with North Atlantic right whales, the National Marine Fisheries Service (NMFS) and the National Oceanic and Atmospheric Administration (NOAA) of the United States implemented vessel speed limits in 2008. These limitations ended in 2013.

But in 2017, there was an unparalleled mortality episode that claimed the lives of 17 North Atlantic right whales, mostly as a result of ship hits and entanglements in fishing gear.


Although there is global awareness of these shipping-related environmental problems, they constitute only a small part of the whole picture. However, it is anticipated that during the next 30 years, environmental issues brought on by the shipping sector will significantly decrease as a result of the IMO’s 2020 and 2050 policies, making shipping more affordable overall.


+ posts

A passion-driven environmentalist by heart. Lead content writer at EnvironmentGo.
I strive to educate the public about the environment and its problems.
It has always been about nature, we ought to protect not destroy.

Leave a Reply

Your email address will not be published. Required fields are marked *