Scientists find microplastics in Monterey Bay water, anchovies, and seabirds

A research of microplastic air pollution in Monterey Bay has discovered widespread incidence of microplastics in the seawater and in the digestive tracts of anchovies and frequent murres, diving seabirds that feed on anchovies.

The research, accepted for publication in Environmental Air pollution, included testing microplastic particles recovered from the murres for estrogenic exercise, which signifies the potential for hormone disrupting results. The researchers discovered that every one the murres examined had microparticles in their digestive tracts, and virtually 1 / 4 (23%) had particles that exhibited estrogenic exercise.

“These tiny plastic particles are leaching substances that have the potential for hormonal disruption that can have cascading effects on reproductive and immune functions,” mentioned senior writer Myra Finkelstein, adjunct professor of environmental toxicology at UC Santa Cruz.

The research, led by UCSC graduate pupil Sami Michishita, sought to quantify the prevalence and composition of microparticles in Monterey Bay. The researchers discovered that 58% of anchovies and 100% of murres had microparticles (particles smaller than 5 millimeters) in their digestive tracts. Many of the particles (78%) have been fibers, and greater than half of the particles (57%) have been recognized as plastic utilizing an optical method known as Raman spectroscopy.

The Raman spectroscopy was achieved in collaboration with Jenessa Gjeltema at UC Davis College of Veterinary Drugs, and testing for estrogenic exercise was achieved in collaboration with the San Diego Zoo Wildlife Alliance.

“When you’re looking at tiny fibers under the microscope, you can’t always tell if it’s cotton or polyester, so we took that next step to determine what it was, and then took the further step of testing them for estrogenic activity,” Finkelstein mentioned.

Seawater samples obtained from two consumption methods—one in Santa Cruz and one in Moss Touchdown—contained about 2 microparticles per 1,000 liters. Anchovies would almost certainly accumulate the particles in their digestive methods as a result of they feed by filtering tiny plankton from the seawater. As a major factor of the murres’ diets, the anchovies are most likely a serious supply of the microplastics in the murres’ digestive methods.

Finkelstein has been finding out the impression of plastic air pollution on seabirds for years. Many seabirds eat comparatively massive items of plastic (“macroplastics”), mistaking it for meals.

“One of the main problems with macroplastics is that they’re taking the place of food. With microplastics, a major concern is the toxic compounds that may be leaching out of it,” Finkelstein mentioned.

Lots of the chemical substances related to plastics are referred to as endocrine disrupting compounds as a result of they will mimic hormones akin to estrogen by binding to the hormone receptors in the physique and disrupting physiological capabilities. On this research, the researchers didn’t attempt to decide how the murres or anchovies may be affected by the microplastics. That is a tougher query to check and one which Finkelstein’s lab is at the moment working to reply in collaboration with San Diego Zoo Wildlife Alliance.

“The next step is to see how this may be affecting the birds,” she mentioned. “With microplastics, it seems we are finding them anywhere we look. But we need to do more work to find out what the biological impact is.”

Christopher Tubbs, affiliate director of reproductive sciences at San Diego Zoo Wildlife Alliance, mentioned, “We know plastic debris, both large and small, in our oceans and waterways is an issue. This partnership between UCSC and San Diego Zoo Wildlife Alliance gives us the chance to dig into the reproductive consequences for seabirds when they consume microplastics. We believe this is the first time this type of estrogen-based assessment is being conducted for this type of widespread marine pollution.”