Wednesday November 16, 2022
Forbes —
Microplastic pollution is widespread in the waters of California’s Monterey Bay, according to a recent study, and is found in the digestive tracts of northern anchovies, Engraulis mordax, which are small marine fish that feed on plankton, and that mistake these tiny plastic particles for breakfast. After ingestion by anchovies, these microplastics work their way up the food web and become more concentrated along the way. According to the study’s findings, microplastics were found in the digestive tracts of all common murres examined, and almost one-quarter of those particles showed estrogen-like activity. Common murres, Uria aalge, are a common black-and-white seabird that feeds almost exclusively on anchovies.
The study was conducted under the leadership of conservation biologist Sami Michishita, who was working on a Master’s Degree when this work was completed, and who now works as a California Sea Grant Fellow with the State Water Resources Control Board. The overall goal of the study was to provide information about the prevalence, composition, and estrogenic activity of microplastics in Monterey Bay because it is a highly productive and economically valuable ecosystem. For example, this is an important refueling and resting stop on the Pacific Flyway for tens of millions of migrating birds.
Microparticles were collected from the intestinal tracts of donated anchovies that had been locally fished, and from murres killed by oil spills. To identify the molecules in the microparticles, the researchers used a non-destructive method that is common in chemistry to provide a structural fingerprint to identify molecules.