Monterey Bay has more microplastics than the Great Pacific Garbage Patch, say researchers

A study published in Nature of the Monterey Bay Aquarium and the Monterey Bay Aquarium Research Institute (MBARI) reveals that there is more pollution plastic in Monterey Bay only in the Great Pacific Garbage Patch.

The plastic pollution takes the form of microplastics, tiny pieces of plastic (less than 5 millimeters in diameter), which are spread throughout Monterey Bay at all the depths of the water plane, from the surface to the bottom of the sea, according to MBARI.

But at depths between about 650 and 2000 feet, there is a microplastic density equal to or greater than that of the Great Pacific Garbage Patch, a massive concentration of waste on the surface of the Pacific Ocean between California and Hawaii. . While giant floating waste contains up to 12 parts of microplastics per cubic meter of water, according to previous research, the microplastic density at the bottom of Monterey Bay contains up to 16 parts of microplastics per cubic meter of water. water.

The researchers, who took water samples at depths ranging from the bay surface up to 3,281 feet in the Monterey Bay National Marine Sanctuary, found that small marine animals, such as pelagic crabs and giant larvae resembling tadpoles, probably consume these microplastics. . This consumption is likely to introduce microplastics into the food web of the bay.

In this study, pelagic crabs and giant larvae, which filter out microplastic sized particles, were sampled so that researchers could determine their microplastic concentrations. They found microplastics in each animal sampled in the study.

"Our results corroborate a growing body of scientific evidence that deep sea water and animals, the largest habitat on Earth, is the largest deposit of small plastic debris," said researcher oceanographer Anela Choy. to MBARI and paper, said in a press release about the study.

The two most common types of microplastics in the bay study were polyethylene terephthalate and polyamide. Polyethylene terephthalate is used in single-use bottles and beverage packaging, while polyamide is used in textiles and the automotive industry.

In contrast, researchers found very few plastic particles that are typically found in fishing gear and found more plastic off the coast than near the shores of the bay. "This suggests that most of the particles do not come from local fishing gear," said Kyle Van Houtan, chief scientist at the Monterey Bay Aquarium, co-author of the study. "This also suggests that at least some of the microplastic has been transported into the region by ocean currents."

The fact that the researchers discovered that microplastics throughout the Monterey Bay water column indicated that source reduction, manufacture and use of less plastic products, was "the most more effective to solve this problem. "

"It may be virtually impossible to remove existing microplastics from the sea bed," he said. "But when we slow down the flow of plastic from the earth, we can help prevent the growing accumulation of plastic in our global ocean."

Drew Costley is a SFGATE editorial assistant. E-mail: [email protected] | Twitter: @drewcostley