and what YOU can do about it
|Entangled Sea Turtle (Photo: The Ocean Conservancy)||Diver removing sunken trash (photo: Center for Marine Conservation)||Marine debris washed up on beach in Hawaii. (photo: Butch Tilley)|
|Marine garbage is the most visible and easily
recognized of all ocean pollution
and causes serious damage to marine wildlife. Every year millions of
marine animals die worldwide because of this type of pollution (Venizelos,
Lily 1998) . The small personal
pieces of garbage, casually discarded, are often the most damaging. While some
of this trash is left directly on the beach, much of it originates as street litter
from coastal and inland cities where it is washed down to
the sea through storm water drains and rivers. Some trash, particularly
plastics, can last in the ocean for years. There are many different items which
make up marine garbage, ranging from large commercial fishing nets which can
entangle and maim or kill animals, to small plastic bags
that can be mistaken for food and ingested by marine life.
|This party balloon, ribbon still attached, was found to be blocking the digestive tract of a male sperm whale at an autopsy.|
|Photo: Marine Mammal Stranding Center|
|Plastics are of most concern because they are not
generally biodegradable. However, over time, the sun's ultraviolet rays break
down plastic into smaller pieces where they can end up as
small as plankton. This breaking down process is very slow, allowing the garbage to
continue to float around year after year.
Some debris, like discarded commercial fishing nets, can continue to kill for decades as the trapped animals attract predators, which can then become entangled themselves. Some of the debris reaches the ocean bottom where it can suffocate immobile plants and animals, producing areas essentially devoid of life. The garbage being moved along by the global current conveyor system poses other more insidious problems than entanglement and digestive problems. It has recently been discovered that organisms harmful to delicate ecosystems are hitching rides across the globe on plastic trash, (Rachel Elbaum,2002). According to this report, tiny species like barnacles, worms and mollusks are using human garbage as a transport system, thus dealing a blow to biological diversity in fragile ecosystems such as Antarctica and the Galapagos Islands. Plastic is also a transport medium for toxic pollutants. A group of Japanese scientists from Tokyo University of Agriculture Technology released a study indicating that pre-production plastics (the way that plastics are shipped to end-use manufacturers) are accumulators of hydrophobic pollutants (molecules or molecular groups that mix poorly with water) like DDE and PCB. Based on this latest research, these pollutants can be up to one million times more concentrated on the surface of these pellets than they are in the ambient seawater. (Yukie et al, 2001)
Commercial material transport is also responsible for great volumes of trash being accidentally dumped into the ocean. During foul weather, tankers can lose many large containers that are filled with goods that are being shipped. In 1999, a freighter spill dumped 50,000 pairs of Nike shoes into the Pacific. In 1992, 29,000 bathtub toys packed in 20 giant containers fell off a ship into the Pacific. Dr. Curt Ebbesmeyer of the Beachcombers Organization [www.beachcombers.org] estimates approximately 10,000 containers fall overboard every year, mostly due to storms. Each 8-foot-by-40-foot container can carry up to 58,000 pounds of cargo. (Ebbesmeyer, Curtis C., 1998-2005)
Marine debris has direct negative consequences for humans. Sometimes marine garbage can cause health risks for people because it can carry toxic chemicals or infectious diseases. The near-shore and beached debris is also frequently a cause of cuts and scrapes as well as human entanglement.
There are also many examples of great losses to our economy. In 1988, the potential health hazards of medically related debris as well as high bacterial counts caused extensive beach closures along the northeastern coast of the United States. Estimates of the losses to the Long Island economy alone are as high as $1 to 2 billion for that one summer (U.S.EPA, 2004). What many people do not realize is that this widely publicized summer of 1988 was not a result of one near-shore illegal dumping. According to the United States EPA, it was determined to simply be a result of all of the accumulated debris from the streets being washed down into the storm sewers which then flowed through other sewer systems. All of it was then flushed into the sea following heavy rains. That summer also had persistent south-southwest winds that collected the floating debris and pushed it to the shore areas.
Marine debris, large and small, also acts as a navigational hazard to fishing and recreational boats. Larger debris, such as shipping containers, present a dangerous collision hazard. Smaller items frequently causes expensive and time consuming damage by entangling propellers and clogging cooling water intake valves.
What can you do about it?
Help to keep our oceans clean and safe for all.
|Photo source: NOAA photo library||Photo source: EPA.gov|