Marine Debris

by Michele McKay

Most people never see it until it washes up on shore… but debris in the ocean damages more than just the beauty of our beaches. Bits of plastic, myriad containers, and derelict fishing gear are a serious threat to ocean and coastal ecosystems, killing marine mammals, fish and seabirds, even as they create a hazard to human health, safety, and navigation.

Marine debris is typically any human-made solid object, discarded or disposed, that enters the coastal or marine environment, originating from both land and ocean-based sources. Waste that is dumped at sea, lost or abandoned fishing equipment, coastal litter, and trash that washes to the sea from streams and storm drains all contribute to the problem. Pieces of plastic, nets, and line can be lethal when sea animals ingest or become entangled in them. Bits of floating debris are often mistaken for food, and cause internal injury, blockage, starvation, and death to marine life. Seabirds, such as the Laysan albatross, often feed plastic debris to their chicks, with deadly results.

Discarded fishing gear continues to trap and kill marine life for decades after being abandoned or lost. Whales, dolphins, Hawaiian monk seals and sea turtles become entangled in “ghost” nets and lines in Hawaiian waters every year. Derelict fishing nets accumulate and roll along the ocean bottom by wave and current action, breaking and destroying the coral reefs that are the heart of many Hawaiian marine ecosystems.

Marine debris degrades slowly. The Mote Marine Laboratory in Florida gives these decomposition times for common items floating in our waters:

  • Plastic bags – 10 to 20 years
  • Foam cups, coolers, and buoys – 50 to 80 years
  • Aluminum cans – 80 to 200 years
  • Disposable diapers – 450 years
  • Plastic beverage bottles – 450 years
  • Monofilament fishing line – 600 years

What you can do:

  • Remember that the sea and the land are connected.
  • Dispose of rubbish properly and pick up litter wherever you see it.
  • Participate in beach and litter cleanup projects.
  • Help educate friends and family about the harm marine debris can cause.
  • Learn more by visiting www.marinedebris.noaa.gov, the National Oceanic and Atmospheric Administration (NOAA) Marine Debris Program web site.
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