1
"Marine debris is a worldwide problem. Every year about 7 billion tonnes of rubbish makes it way into the sea. Marine debris is a big problem in Auckland's harbours too where over two million litres of rubbish has been collected by the Waitemata Clean up Trust since it began it's clean up operations in 2002.
Worldwide nearly 80 percent of all marine debris is plastic from bottles and other packaging. Most will not break down easily. In some parts of the ocean plastic outweighs plankton 6:1.
An estimated 46,000 pieces of plastic litter alone are floating on every square mile of ocean, 70 percent of which will eventually sink. It will stay in the environment for hundreds of years, if not forever.
Eighty percent of marine debris comes from land via our stormwater system, rivers and streams and is then transported out to sea. Marine debris causes harm to underwater ecosystems and wildlife in many ways.
By carrying out a coastal cleanup on foot, diving, by boat or kayak you can stop litter travelling out to sea as well as making the beach a nicer place for everyone to safely enjoy. "
2
3
4
5
"Marine debris is defined as "any manufactured or processed solid waste material that enters the marine environment from any source." Debris is everywhere—found around every major body of water on the planet, and below water as well. Marine debris is a global pollution problem that impacts human health and safety, endangers wildlife and aquatic habitats, and costs local and national economies millions in wasted resources and lost revenues.
Many people assume that if trash exists in the ocean, it must be that the fishing and shipping industries are to blame. But in fact, only 20% of the items found in the ocean can be linked to ocean-based sources, like commercial fishing vessels, cargo ships (discharge of containers and garbage), or pleasure cruise ships.
The remainder (80%) is due to land-based sources, like litter (from pedestrians, motorists, beach visitors), industrial discharges (in the form of plastic pellets and powders), and garbage management (ill-fitting trash can lids, etc).
HOW MARINE DEBRIS HARMS WILDLIFE
Entanglement
Common items like fishing line, strapping bands and six-pack rings can hamper the mobility of marine animals and cause injury. Once entangled, animals have trouble eating, breathing or swimming, all of which can have fatal results. Plastics do not biodegrade and may continue to trap and kill animals year after year. Marine debris entanglements have been documented for more than 200 species of animals. (Read summaries of some recent whale entanglements in the Monterey Bay National Marine Sanctuary.)
Ingestion
Birds, fish and mammals can mistake plastic for food. Debris may cause choking and injuries, and with plastic filling their stomachs, animals may have a false feeling of being full and may die of starvation. Sea turtles mistake plastic bags for jellyfish, one of their favorite foods. Ingestion of debris has been documented in 56% of cetacean species. Even gray whales have been found dead with plastic bags and sheeting in their stomachs. A recent study of harbor seals in the Netherlands found that more than 12% had plastic in their digestive system. 95% of Northern Fulmars studied in the North Sea between 2007 and 2011 were found to contain plastic, on an average 0.38 grams. This could equal as much as 8.4% of the bird's body weight.
The Laysan albatross is a sea bird that nests in the Northwest Hawaiian Islands. The adult birds collect plastic debris (along with food) from the ocean to feed to their chicks. In a study of dead chicks during 1994 and 1995, 97.6% of carcasses were found to contain plastic.
Disruption of Habitat
Floating marine debris can provide a new and increased method of transport for species across vast ocean distances, which may cause trouble for biodiversity if the introduced species prove to be invasive. A 2002 study of 30 remote islands throughout the world showed that marine debris more than doubled the "rafting" opportunities for species. In 2005 and 2006, surveys of marine debris in the Seychelles Islands showed that on some beaches more than 60% of debris items carried non-native species.
Marine debris is not just an issue for the surface of the ocean. Debris is also found on the deep ocean floor. An extensive survey extending down to 4,000 meters off the coast of Monterey found that debris was more common in the deeper parts of Monterey Canyon, below 2,000 feet. Found items included large numbers of plastic bags, as well as metal cans, fishing equipment, glass bottles, shoes, and tires.
HOW MARINE DEBRIS HARMS PEOPLE
Marine debris can present a danger to human health. Nails, glass, and syringes on the beach can cause physical harm to beach-goers. Additionally, trash in our waterways increases the amount of pathogens and chemicals, impacting water quality.
A study of predatory fishes in the North Pacific Subtropical Gyre found that 19% of the individuals contained marine debris, most of it plastic. This included species commonly eaten by people. Plastic debris serves to concentrate and transport chemical pollutants into the marine food web, and potentially to human diets. Chemicals of concern include those used in the manufacture of the plastics, as well as pollutants present in the ocean water absorbed and concentrated in the plastic (and thus made available for animal consumption). A study of fish that consumed plastic that had absorbed chemical pollutants from the marine environment were found to bioaccumulate the chemicals, resulting in greater physical harm than to fish that consumed plastic that had not been exposed to a marine environment.
Marine debris is a hazard to economic health. Fishing line and nets can entangle propellers, causing damage to boats. Unsightly trash on beaches detracts from tourism. The Asia-Pacific Economic Cooperation released a report valuing different marine debris abatement measures and found that the loss of tourism from littered beaches in the APEC region was $622 million/year. The damage to the fishing industry totaled $364 million/year, the damage to the shipping industry was $279 million/year, and the total cost of marine debris in the APEC Region totaled $1.265 billion/year."
No comments:
Post a Comment