Most of people within the maritime industry are aware of the by-product which comes with the field itself as ships release a lot of pollutants into the sea.

So what goes in the ship in order to operate effectively and what comes out that damages ecology?

Starting from what makes the ship move; Fuel oil.
Oil spills are less frequent but very devastating when they happen as ships discharge oily water from fuel and lubrication oil; that gets dumped into the sea as many ports lack adequate waste disposal facility.

Following oil spills is the air pollution that is done with Carbon Dioxide, Nitrogen Oxide, Sulphur Dioxide coming from smokestacks. All emissions cause respiratory problems if inhaled.

For the ship to stay balanced, ballast water is required and this requirement is directly proportional to the size of the ship where the bigger it is the more ballast water is needed to keep it afloat.  This is done in ways that ballast provides moment to resist lateral forces of the sail and is easily emptied to reduce draft/weight of the boat.

The pollution from ballast water comes in the form of discharge of biological species of plants, animals, bacteria and viruses which are dumped into the ocean with the ballast water. Such discharge causes damage to marine ecology and even death to human population.



Examples of ballast water pollution is the release of vibrio cholerae in Peru that killed 10,000 people in 3 years.

Another form of ship emission is grey water and sewage which comes from toilets, showers, galleys, sinks and cleaning and contains pollutants such as metals, oils, detergents, organic compounds and petroleum hydrocarbons. Along with that, a form of bacteria fecal coliform is also among the emissions found in grey water which occurs due failure of sewage treatment facilities ; whose release contaminate water and cause a variety of health issues.


Finally, another emission from a ship is the phenomenon of hull leaching where a chemical reaction between ship hull paint and water takes place as the ship sails. This releases chemicals into the marine ecology.



Boat paints, designed to prevent materials from accumulating on the hull, (process known as “fouling”) contain copper as it is toxic to most biological organisms that stick to the ship’s hull. As ships sail across international waters the copper concentration is increased worldwide; polluting marine ecology and damaging life forms.

Concluding this brief summary of ship emissions it is visible that a conventional vessel produces a lot of pollution which is a by-product of important factors such as fuel to keep the ship moving and anti-fouling paint which protects the hull. However, there exist alternative methods to keep the ship moving and efficient; all possible with further investigation of your vessel and knowledge of other ways and materials which can replace more conventional ones.