Trails of Trash on Ocean Floor
6/6/13
Look out across Monterey Bay, and one hardly thinks of a junkyard. But below the surface, decades of garbage have been piling up, a new study by the Monterey Bay Aquarium Research Institute shows.
Go 1,000 meters down, and it's still there. Go a mile down, it's still there. Go two miles down and beyond -- down to the limits of scientific exploration -- and it's still there. Old boots, tires, fishing gear and especially plastic, litter the ocean floor.
"Once it gets in the ocean, it's not going to get cleaned up," said Susan von Thun, a senior research technician at MBARI. "Especially with plastic or metal, it doesn't really break down. It'll be there for possibly thousands of years."
The study is based on 22 years of deep-sea video accumulated and cataloged by marine researchers. They decided to search their database and came up with more than 1,150 hits for human-produced garbage in the Monterey Bay region alone, much of it within the boundaries of a national marine sanctuary.
While there have been some eye-popping finds -- a shipping container full of 10,000 steel-belted tires lies at the bottom of the bay -- about a third of the findings were plastic, with about half of those being plastic bags.
PLASTIC POLLUTION
That goes to the heart of an ongoing debate about single-use plastic bags, with the plastics industry recently helping defeat a proposed statewide bag ban, as well as a second bill, by Assemblymember Mark Stone, D-Scotts Valley, aimed at getting plastics producers to help cut back on pollution.
When the bag ban was defeated by three votes, the industry group American Progressive Bag Alliance hailed its victory, saying the proposal was based on "unfounded stats, junk science and myths."
Dave Asselin, executive director of the American Progressive Bag Alliance, reiterated the group's position in a statement Wednesday.
"We have not had a chance to review this particular study, but we do know that the rationale behind efforts to ban or tax plastic bags is largely based off of junk science and exaggerations," Asselin said.
The study is far more exhaustive that any prior examination of debris on the ocean floor, with MBARI's submarines routinely plumbing depths rarely seen by human eyes. Whether it makes a difference in the political debate about plastic bags remains to be seen. Wednesday, Stone held a previously scheduled legislative hearing that dealt with plastics and the marine environment.
Laura Kasa, executive director of Santa Cruz-based Save Our Shores, a group that holds beach cleanups throughout the region, said the study is another sign that plastic bags need to be banned.
"This is why it's so important that we prevent trash that people leave on the beach from getting into the ocean," Kasa said. "If one person doesn't think that it makes a difference, if they leave their piece of trash on the beach, they're wrong. It'll end up in the bottom of the ocean."
Von Thun said researchers combed through video for instances where marine life interacted with plastic and found several. They include plastic bags wrapped around deep coral -- which eventually will kill the coral -- and debris serving as habitat for anemonies and other marine life, giving them a home in areas they would not normally settle.
The study also found plastics and metals were more likely to be found in deeper waters, and researchers speculated that because Monterey Bay is a national sanctuary and subject to heightened environmental protections, it is likely that oceans elsewhere have a more significant problem.
"I was surprised that we saw so much trash in deeper water. We don't usually think of our daily activities as affecting life two miles deep in the ocean," said Kyra Schlining, the study's lead author. "I'm sure that there's a lot more debris in the canyon that we're not seeing."
