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Ocean pollution and marine debris

• Nov. 07, 2022

Marine pollution is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide.

Marine litter is any persistent, manufactured or processed solid material discarded into the sea or rivers or on beaches; brought indirectly to the sea with rivers, sewage, storm water or winds; or discarded or lost at sea. Marine litter poses environmental, economic, health, aesthetic and cultural threats, including degradation of marine and coastal habitats and ecosystems that incur socioeconomic losses in marine-based sectors.

According to the United Nations, at least 800 species worldwide are affected by marine debris, and as much as 80 percent of that litter is plastic. It is estimated that up to 13 million metric tons of plastic ends up in the ocean each year—the equivalent of a rubbish or garbage truck load’s worth every minute. Fish, seabirds, sea turtles, and marine mammals can become entangled in or ingest plastic debris, causing suffocation, starvation, and drowning. Humans are not immune to this threat: While plastics are estimated to take up to hundreds of years to fully decompose, some of them break down much quicker into tiny particles, which in turn end up in the seafood we eat.

Each year, billions of pounds of trash and other pollutants enter the ocean. Where does this pollution come from? Where does it go? Some of the debris ends up on our beaches, washed in with the waves and tides. Some debris sinks, some is eaten by marine animals that mistake it for food, and some accumulates in ocean gyres.

Where does pollution come from?

Oceans, which account for 70 percent of the surface of our planet, play a pivotal role in the health of our planet and those who inhabit it. Unfortunately, our oceans are polluted. According to the National Oceanic and Atmospheric Administration, billions of pounds of trash and other pollutants enter our oceans every year.

The majority of pollutants that make their way into the ocean come from human activities along the coastlines and far inland. One of the biggest sources of pollution is nonpoint source pollution, which occurs as a result of runoff. Nonpoint source pollution can come from many sources, like septic tanks, vehicles, farms, livestock ranches, and timber harvest areas.

80% of the world’s ocean plastics enter the ocean via rivers and coastlines. The other 20% come from marine sources such as fishing nets, ropes, and fleets. To tackle plastic pollution we need to know where these plastics are coming from.

Marine debris

Marine debris is a persistent pollution problem that reaches throughout the entire ocean and Great Lakes. Our ocean and waterways are polluted with a wide variety of marine debris, ranging from tiny microplastics, smaller than 5 mm, to derelict fishing gear and abandoned vessels. Worldwide, hundreds of marine species have been negatively impacted by marine debris, which can harm or kill an animal when it is ingested or they become entangled, and can threaten the habitats they depend on. Marine debris can also interfere with navigation safety and potentially pose a threat to human health.

All marine debris comes from people with a majority of it originating on land and entering the ocean and Great Lakes through littering, poor waste management practices, storm water discharge, and extreme natural events such as tsunamis and hurricanes. Some debris, such as derelict fishing gear, can also come from ocean-based sources. This lost or abandoned gear is a major problem because it can continue to capture and kill wildlife, damage sensitive habitats, and even compete with and damage active fishing gear.

The impact of marine pollution on seafood

Heavy metals and other contaminants can accumulate in seafood, making it harmful for humans to consume. Microplastics can be ingested by fish and other species that filter their food out of the water.

In addition to contaminating seafood, plastic particles in the ocean can injure and kill marine life, in turn disrupting the ecosystems and food chains and leading to potential extinctions along the way.

Environment Education

Before we dive into environmental education, let’s review some of the most pressing ocean issues.

By 2050, scientists expect more plastic than fish in the oceans (by weight). As a result, many marine animals are forced to feed on plastic, but because plastic is indigestible, it gets trapped inside their digestive system, taking up stomach space meant for food.

Roughly over one million seabirds, 100,000 sea mammals, and about 300,000 dolphins or porpoises are affected by plastic pollution each year, according to Coastal CA.

Plastic affects the health of marine organisms directly and indirectly by affecting coral reefs, an organism and an ecosystem. Coral reefs are vital for the health of the marine biome, holding more than 25% of marine life. Yet, they are threatened by human activities.

Whether humans live near the coasts or far inland, they are a part of the problem — and the solution — to ocean pollution. Through this collection of resources and information, students can be informed of the types of pollution harming our ocean, and learn about actions they can take to prevent further pollution no matter where they live.