Marine debris

Marine debris, also known as marine litter, is stuff people make that ends up in the seas or the ocean. This can happen on purpose or by mistake. Many pieces of this debris float and collect in special areas of the ocean called gyres or wash up on coastlines. We call this beach litter.

One big problem with marine debris is plastic. Unlike natural materials, plastic does not go away easily. A lot of the plastic in the ocean comes from old fishing nets that were lost or thrown away. This plastic can hurt many ocean animals, like fish, seabirds, marine reptiles, and marine mammals, as well as boats and coastal areas.

Many things add to this problem, like dumping waste into the water, spills from ships, litter that goes into storm drains and waterways, and waste from landfills blown by the wind. All of this creates big patches of garbage in the ocean and adds harmful substances to the food chain.

To try to stop and fix this problem, many countries and groups have made rules and started programs to clean up the ocean.

Types

Researchers sort debris into two groups: from land or from the ocean. In 1991, experts from the United Nations guessed that most pollution came from land. Newer studies show that a lot of plastic on Korean shores comes from the ocean.

Many human-made things can end up as marine debris. Common items found on beaches include plastic bags, balloons, buoys, rope, medical waste, glass and plastic bottles, cigarette stubs, cigarette lighters, beverage cans, polystyrene, lost fishing lines and nets, and waste from cruise ships and oil rigs. Six-pack rings are a well-known example of this problem.

Most marine debris is plastic. Plastics stay in the ocean for a long time because they don’t break down easily. They break apart slowly when exposed to sunlight.

Persistent industrial marine debris

Some materials from industrial work, like fishing and boating, don’t break down easily. These materials can stay in the environment and build up over time. They can be as big as a fishing boat or as small as a piece of Styrofoam float. Small pieces of plastic or foam can look like food to animals such as birds, whales, and fish. If animals eat these pieces, they may feel full but not get proper nutrition, which can harm them.

Ghost nets

Macroplastic

Main article: Marine plastic pollution

Microplastics

Deep-sea debris

Marine debris can also be found deep under the ocean. Most studies focus on plastic near the coast or on the surface. Research using special underwater cameras has shown that human-made debris, especially plastic, is present in deep ocean areas. Light materials like glass and metal can float and spread across the ocean floor. Plastics that normally sink can become heavier when covered in tiny sea plants. Ocean currents help move debris around.

In 2017, a database of deep-sea debris became public. It included photos and samples from deep-sea dives. Of the human-made items found, the most common were plastic and metal. Plastic debris has even been found at the bottom of the Mariana Trench, and plastic bags have been found wrapped around deep-sea vents.

Garbage patches (gyres)