Marine debris

Marine debris, also known as marine litter, is human-created solid material that ends up in the seas or the ocean. This can happen on purpose or by accident. Many pieces of this debris float and collect in special areas of the ocean called gyres or wash up on coastlines, where it is called 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. But if we do not take big steps to change, there may be more plastic than fish in the ocean by the year 2050.

Types

Researchers sort debris into two groups: from land or from the ocean. In 1991, a group of experts from the United Nations guessed that up to 80% of pollution came from land, and the rest from big accidents or ships. Newer studies show that more than half of the 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—about 80%—is plastic. Plastics stay in the ocean for a long time because they don’t break down easily like other materials. They break apart slowly when exposed to sunlight, but this only happens when they are dry, since water stops this process. A 2014 study estimated there were about 5.25 trillion pieces of plastic in the oceans, weighing around 269,000 tons, spread equally between the Northern and Southern Hemispheres.

Persistent industrial marine debris

Some materials from industrial work, like fishing, boating, and farming in the water, 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. A study in 2003 looked at these materials along the shores of Charlotte County, New Brunswick. 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 or 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, but there is less information about debris deeper down. Research using special underwater cameras and submarines has shown that human-made debris, especially plastic, is present in deep ocean areas, particularly near busy places like the Mediterranean. Light materials like glass, metal, and some plastics can float and spread across the ocean floor, getting caught in corals or other sea life. Plastics that normally sink can become heavier when covered in tiny sea plants and other organic matter. Ocean currents and storms help move debris around, and underwater landscapes can trap microplastics in certain spots.

In 2017, a database of deep-sea debris from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) became public. It included photos and samples from 5,010 deep-sea dives. Of the 3,425 human-made items found, the most common were macro-plastic (33%), mostly single-use items, and metal (26%). Plastic debris has even been found at the bottom of the Mariana Trench, almost 11,000 meters deep, and plastic bags have been found wrapped around deep-sea vents and communities.

Garbage patches (gyres)