Marine Dumping


Marine Dumping has been defined as the deliberate disposal at sea of wastes or other matter from vessels, aircraft, platforms or other man-made structures, as well as the deliberate disposal of these vessels or platforms themselves. Marine dumping can destroy or degrade important habitats for aquatic species and cause coastal erosion and salutation, which affect the health and productivity of the marine environment.

Litter items such as 6-pack ring packaging and microfilament fishing lines can entrap pelicans and other seabirds, and ultimately strangle or starve the birds. Whales, dolphins, and other marine mammals are at risk through ingestion or entanglement of plastic refuse. Plastic bags are mistakenly ingested by sea turtles as jelly fish, a common food item. For example, the world’s largest living turtle, the leatherback, is found off our Atlantic and Pacific coasts. With a shell as long as 2.5 metres, it can weigh up to 900 kilograms. You wouldn’t think much could get in this giant’s way. However, common plastic debris is causing leatherbacks terrible trouble. They mistake plastic bags, balloons or containers for jellyfish — their favourite food. Once swallowed, the plastic clogs the turtles’ intestines, causing them to die. Leatherbacks are already endangered worldwide because humans hunt the adult turtles and their eggs for food. They certainly don’t need to deal with another deadly menace like plastic debris. When animals get tangled, the debris causes cuts and infection. Seabirds, turtles, dolphins, and seals get exhausted from trailing nets behind them. These creatures can slowly strangle, suffocate, or die from infection. Recent studies in Alaska show that, each year, as many as 30,000 northern fur seals get entangled in plastic debris and die. Marine debris can also damage boat engines by clogging intake valves and ports and becoming tangled around propellers. Although some claim the risk to human health is small, the long-term effects of nuclear dumping are not known, and some estimate up to 1,000 deaths in the next 10,000 years as a result of evaporated nuclear waste.

The ocean is the basin that catches almost all the water in the world. Eventually, water evaporates from the ocean, leaves the salt behind, and becomes rainfall over land. Water from melted snow ends up in rivers, which flows through estuaries and meets up with saltwater. Fertilizers, pesticides, and oil, mostly from farms, seep into the ground after a rain and then stream into rivers and ultimately into the ocean. Feedlots in the United States exceed the amount of human waste with more than 500 million tons of manure each year.

Not only does the waste flow into the ocean, but it also encourages algal blooms to clog up the waterways, causing meadows of seagrass, kelp beds and entire ecosystems to die. A zone without any life remaining is referred to as a dead zone and can be the size of entire states, like in coastal zones of Texas and Louisiana. All major bays and estuaries now have dead zones from pollution run-off. Often, pollutants like mercury, PCBs and pesticides are found in seafood meant for the dinner table and cause birth defects, cancer and neurological problems—especially in infants.

Swimming is becoming unsafe, as over 12,000 beaches in the United States have been quarantined due to contamination from pollutants. Developed areas like parking lots enable runoff to occur at a much higher volume than a naturally absorbent field. Even simply driving a car or making a house warm can leak 28 million gallons of oil into lakes, streams and rivers. The hunt for petroleum through offshore gas and oil drilling leaks extremely dangerous toxins into the ocean and luckily is one aspect of pollution that has been halted by environmental laws.

The ocean is a complex and interwoven ecosystem with each biotic and abiotic factor influencing every other component directly or indirectly. When one habitat vanishes, organisms that rely on that niche can no longer survive.

Animals like sea turtles, manatees, fish, shrimps and crabs rely on seagrass for survival. Unfortunately, seagrass is sensitive to dredging of channels, pollution and development and is being lost at an alarming rate. Since the ocean is an interlaced ecosystem, the loss of one species like sea lions can cause sea urchins (their prey) to soar in numbers. The loss of biodiversity in the oceans is more critical than simply losing a source of wonder for future generations. Loss of biodiversity has the power to affect human survival in the future in a profound way. For example, species like sea sponges have been found to hold chemicals capable of beating cancer and viruses, but they will be lost if pollution from runoff and ocean dumping is not curbed dramatically.

One survey estimates that recreational boaters dump an average of half a kilogram of garbage into the water every time they go out in their boats. For centuries, seafarers threw their litter into the drink without a worry. But that was before indestructible plastics came along. In those days, trash was made up of natural material that decomposed with no harm to wildlife. Today, litter is an enormous ecological problem, but one we can solve so easily. In the Maritimes, a group of commercial fishermen has organized a hugely successful plan to stop ocean pollution. In the Ship to Shore Trash Campaign, fishermen now bring their garbage ashore instead of tossing it overboard. Fishing boats along the Acadian shore of New Brunswick bring ashore about 9,500 kilograms of trash every week! The campaign could make the difference between life and death for leatherback turtles.

Different items take different lengths of time to degrade in water:

  • Cardboard - takes 2 weeks to degrade
  • Newspaper - takes 6 weeks to degrades
  • Photodegradable packaging - takes 6 weeks to degrade
  • Foam - takes 50 years to degrade
  • Styrofoam - takes 80 years to degrade
  • Aluminum - takes 200 years to degrade
  • Plastic packaging - takes 400 years to degrade
  • Glass - it takes so long to degrade that we don't know the exact time

The most toxic waste material dumped into the ocean includes dredged material, industrial waste, sewage sludge, and radioactive waste. Dredging contributes about 80% of all waste dumped into the ocean, adding up to several million tons of material dumped each year. Rivers, canals, and harbors are dredged to remove silt and sand buildup or to establish new waterways. About 20-22% of dredged material is dumped into the ocean. The remainder is dumped into other waters or landfills and some is used for development. About 10% of all dredged material is polluted with heavy metals such as cadmium, mercury, and chromium, hydrocarbons such as heavy oils, nutrients including phosphorous and nitrogen, and organochlorines from pesticides. Waterways and, therefore, silt and sand accumulate these toxins from land runoff, shipping practices, industrial and community waste, and other sources. When these materials find their way into the ocean, marine organisms suffer toxic effects and seafood is often contaminated. When "pure" dredged material is dumped into the ocean, fisheries suffer adverse affects such as unsuccessful spawning in herring and lobster populations where the sea floor is covered in silt. In the 1970s, 17 million tons of industrial waste was legally dumped into the ocean. In the 1980's, 8 million tons were dumped including acids, alkaline waste, scrap metals, waste from fish processing, flue desulphurization, sludge, and coal ash. If sludge from the treatment of sewage is not contaminated by oils, organic chemicals and metals, it can be recycled as fertilizer for crops. It is cheaper for treatment centers to dump this material into the ocean, particularly if it is chemically contaminated. The UN policy is that properly treated sludge from cities does not contain enough contaminants to be a significant cause of eutrophication (an increase in chemical nutrients—typically compounds containing nitrogen or phosphorus—in an ecosystem) or to pose any risk to humans if dumped into the ocean. The peak of sewage dumping was 18 million tons in 1980, a number that was reduced to 12 million tons in the 1990s. Radioactive waste is also dumped in the oceans and usually comes from the nuclear power process, medical use of radioisotopes, research use of radioisotopes and industrial uses. The difference between industrial waste and nuclear waste is that nuclear waste usually remains radioactive for decades.

What Has Been Done?

The Inter-Governmental Conference on the Convention on the Dumping of Wastes at Sea, which met in London in November 1972 at the invitation of the United Kingdom, adopted this instrument, generally known as the London Convention. The Convention has a global character, and contributes to the international control and prevention of marine pollution. It prohibits the dumping of certain hazardous materials, requires a prior special permit for the dumping of a number of other identified materials and a prior general permit for other wastes or matter. Wastes derived from the exploration and exploitation of sea-bed mineral resources are, however, excluded from the definition. The provision of the Convention shall also not apply when it is necessary to secure the safety of human life or of vessels in cases of force majeure. Among other requirements, Contracting Parties undertake to designate an authority to deal with permits, keep records, and monitor the condition of the sea. Other articles are designed to promote regional co-operation, particularly in the fields of monitoring and scientific research. Annexes list wastes which cannot be dumped and others for which a special dumping permit is required.

What Can Be Done?

Trash storage and disposal will not become a problem if boaters:

  • Designate an area where trash can be stored on board the boat.
  • Secure any loose items so they do not blow overboard or fly out of the boat when it is in operation.
  • Never throw anything (cans, plastic objects, miscellaneous items, leftover foods, etc.) overboard.
  • Use marina pump-out stations. Empty your boat’s marine sanitation devices and/or holding tanks at pump-out stations, not overboard. The U.S. Coast Guard requires sanitizing gear or an onboard holding tank within three miles of shore.

Other Measures to Help Prevent or Remedy the Problem:

  • Discourage others from littering.
  • Organize a shore-line cleanup.
  • Adopt a beach — once a week or month pick up all the litter you find there.
  • Inform your family, friends, and community about the dangers of plastic and other litter to wildlife.
  • Join a group in your area that’s actively combating dumping on shores and in marine habitats. If there isn’t such a group in your community, why not get one started?

The Safe Drinking Water Foundation has educational programs that can supplement the information found in this fact sheet. Operation Water Drop looks at the chemical contaminants that are found in water; it is designed for a science class. Operation Water Flow looks at how water is used, where it comes from and how much it costs; it has lessons that are designed for Social Studies, Math, Biology, Chemistry and Science classes. Operation Water Spirit presents a First Nations perspective of water and the surrounding issues; it is designed for Native Studies or Social Studies classes. Operation Water Health looks at common health issues surrounding drinking water in Canada and around the world and is designed for a Health, Science and Social Studies collaboration. Operation Water Pollution focuses on how water pollution occurs and how it is cleaned up and has been designed for a Science and Social Studies collaboration. To access more information on these and other educational activities, as well as additional fact sheets, visit the Safe Drinking Water Foundation website at


British Broadcasting Corporation. October 7, 2002. Is Dumping Destroying Our Beautiful Coastline?

The Guides Network. Water Pollution Guide.

MarineBio. Ocean Pollution.