Microplastic Biomagnification in Invertebrates, Fish, and Cormorants in Lake Champlain
Microplastics are plastic particles that are microplastics, which are pellets commonly found in personal care products, and secondary microplastics, which are degraded plastics. Microplastics have made their way into waterbodies by passing through wastewater treatment plants, as marine debris, via mechanical- and photo-degradation of plastic, and release of pre-production raw materials. Microplastics are known to absorb other pollutants and are hydrophobic particles that can biomagnify up the food web. When ingested by fish, particulates embed within the digestive tract and leach into tissues, posing a potential concern for human consumption. The goal of this research was to determine whether microplastics biomagnify within invertebrates, fish, andPhalacrocorax auritus (Double-crested Cormorant) resident to Lake Champlain. We did so by quantifying and characterizing (e.g., fragment, fiber, film, foam, pellet) particulates. We performed wet peroxide oxidation digests on digestive tracts of (n = 438) lake organisms, specifically invertebrates (n = 258), 14 species of fish (n = 165), and Double-crested Cormorants (n = 15). Our research indicated that fibers were the most-abundant particulates in all organisms (n = 764), followed by fragments (n = 123), films (n = 40), pellets (n = 13), foam (n = 9). Microplastics were separated using stacked mesh sieves, with preliminary results showing a particulate size-distribution of: ≥1 mm, n = 86; less than 1 mm but ≥355 µm, n = 144; and less than 355 µm but ≥125 µm, n = 232. These findings illustrate biomagnification in Lake Champlain organisms, as invertebrates, fish, and Double-crested Cormorants contained on average 0.05, 3.6, and 22.93 microplastic particles. Results from this research serve to inform residents of the Lake Champlain watershed, anglers, non-profit lake organizations, as well as public health and government officials of the risks microplastics pose to aquatic biota and ultimately humans.