- Marine debris is defined as any persistent solid material that is manufactured or processed and directly or indirectly, intentionally or unintentionally, disposed of or abandoned into the marine environment.
- Marine debris can be almost anything made by man from discarded fishing lines and fishing nets, floating plastic bottles, soda cans and pieces of wrecked boats.
- Marine debris injures and kills marine life, interferes with navigation safety, impacts the environment and poses a threat to human health and safety.
- Six million tonnes of debris enters the world's oceans very year.
- More than 260 animal species worldwide have become entangled in or consumed fishing line, nets, ropes and other discarded equipment.
- One million seabirds are killed by marine debris every year.
- Over 100,000 turtles and marine mammals, such as dolphins, seals and whales, die each year from ingesting or becoming entangled in plastic debris.
- Plastics are the most common man made objects sighted at sea, with 18,000 pieces of plastic litter floating on every square kilometre of the world's oceans, outnumbering sea life 6 to 1.
- 44% of marine mammals and 86% of turtle species have plastic in their guts.
- Every day ships throughout the world discard 5.5 million pieces of rubbish into our oceans. Annually, three times as much rubbish is dumped into the world's oceans as the weight of fish caught.
- Fishing nets, plastic bags, and tires can sink to the ocean floor and break and smother coral reefs.
- A majority of the trash and debris that covers our beaches comes from storm drains and sewers, as well as from recreational activities such as picnicking and beachgoing.
- Since marine debris is swept along by water currents, it often accumulates most noticeably along coastlines.
- Environmental Impacts
Direct impacts occur when marine life is harmed by marine debris through ingestion or entanglement or marine debris physically alters an ecosystem (e.g., a fishing net is dragged along the ocean floor by strong ocean currents and suffocates a coral reef).
Seabirds, sea turtles, fish, and marine mammals often ingest marine debris mistaken as food. For example, whales and sea turtles often misidentify plastic bags for squid, and birds often mistake plastic pellets for fish eggs. Starvation or malnutrition occurs when the marine debris collects in the animal's stomach causing the animal to feel full or prevents vital nutrients from being absorbed. Ingestion also causes internal injuries and infections, as some marine debris contain toxic substances that can cause death or reproductive failure in fish, shellfish, or any marine life.
Marine life often become entangled in marine debris, causing serious injury or death. Entanglement can lead to drowning, suffocation, starvation and increased vulnerability to predators, or other injury. Marine debris can constrict movement which results in exhaustion or development of an infection from deep wounds caused by restrictive material.
- Ecosystem Alteration
Coral reefs can be damaged by abandoned fishing gear that breaks or suffocates coral. Plants and other living organisms can be smothered by plastic bags and fishing nets. Ocean floor ecosystems can be degraded by the movement of an abandoned vessel or other marine debris.
- Invasive Species
Marine debris can contribute to the transfer of invasive species as floating marine debris can carry invasive species from one location to another, causing serious harm to fragile eco-systems.
TYPES OF MARINE DEBRIS
- PLASTIC: Plastic items are the most common type of marine debris. Plastic is non-biodegradable and studies have found that it takes a plastic water bottle nearly 450 years to dissolve at sea. Plastic grocery bags, industrial pellets, and product packaging flow into our waterways every day.
- FISHING GEAR: Debris such as nets, lures, buoys, and lines are extremely dangerous to wildlife. Broken fishing gear and discarded nets (sometimes referred to as "ghost nets") can entangle and drown marine life.
- FOOD PACKAGING: Plastic wrappers, disposable cups, and plastic utensils are frequently tossed over the side of a boat, left behind after a picnic at the beach, or simply washed out to sea from storm drains.
- GLASS: Broken bits of bottles can be dangerous to humans and marine life alike.
- METAL: Metals, such as soda cans, aerosol cans, bottle caps, fishing hooks are sometimes mistaken for food by sea creatures. It takes an aluminum can 200-500 years to dissolve at sea.
- MEDICAL WASTE: Medical waste dumped into the ocean is an especially dangerous form of marine debris.
- CIGARETTE FILTERS: Cigarette filters absorb cancer-causing chemicals from tobacco, and research has found that these chemicals can be deadly to small marine creatures.
This bird's stomach contents shows the devastating effect that marine debris has on wildlife
Photo: Chris Jordan