May 9, 2012
Pacific Ocean ‘Garbage Patch’ Increasing At Alarming Rate
Brett Smith for RedOrbit.com
Plastic trash has been accumulating in the Pacific Ocean at an alarming rate and its effects are reverberating throughout the ecosystem, according to a new study by researchers at Scripps Institution of Oceanography at UC San Diego.
The study, published in the May 9 online issue of the journal Biology Letters, found that plastic trash in the "Great Pacific Garbage Patch" has increased by 100 times over in the past 40 years. Experts disagree over the scale of the debris zone, but some say it is twice the size of Hawaii, while other say it covers a swath of ocean the size of Texas.
"Plastic only became widespread in late '40s and early '50s, but now everyone uses it and over a 40-year range we've seen a dramatic increase in ocean plastic," said Scripps graduate student Miriam Goldstein, lead author of the study. "Historically we have not been very good at stopping plastic from getting into the ocean so hopefully in the future we can do better."
The effect of this plastic can be seen on the population of Halobates sericeus. Also known as ℠sea-skaters´, these insects are related to the ℠water-skaters´ or ℠water bugs´ typically seen gliding across ponds in the U.S. The sea skaters reproduce by laying their eggs on floating debris. The natural sources for these eggs, like feathers or driftwood, are being replaced by the tiny bits of plastic garbage floating on the ocean´s surface.
Ironically, the widespread availability of artificial egg-laying surfaces is driving up the population of these insects, according to researchers. In turn, this population boom will be felt all the way up the food chain, starting with the sea skaters natural predators, such as sea birds and crabs.
The garbage patch appears benefit other invertebrates as well. Barnacles, crabs, fish that like to live under some kind of cover could be well-suited to take advantage of the garbage patch. The explosions of these populations would also have unforeseen effects of the ocean´s food chains.
"The study raises an important issue, which is the addition of hard surfaces to the open ocean," Goldstein said.
"In the North Pacific, for example, there's no floating seaweed like there is in the Sargasso Sea in the North Atlantic. And we know that the animals, the plants and the microbes that live on hard surfaces are different to the ones that live floating around in the water,” Goldstein told BBC News
"So, what plastic has done is add hundreds of millions of hard surfaces to the Pacific Ocean. That's quite a profound change."
The Garbage Patch is directly affecting other organisms besides just the sea skaters. Another Scripps report found that 9 percent of fish collected in the debris zone had ingested some form of plastic trash. The report, published in Marine Ecology Progress Series, estimated the fish at intermediate ocean depths could be ingesting plastic at a rate of roughly 12,000 to 24,000 tons per year. These fish are often eaten by larger predators, which then send the plastic trash further up the food chain.