Microplastic Bioaccumulation in invertebrates, fish, and cormorants in Lake Champlain

It is estimated in the United States that 8 trillion microbeads enter our waterways daily. Microplastics are typically discharged into local watersheds through wastewater treatment plant effluent and marine debris, with as much as 1600 synthetic fibers emanating from washing a single piece of clothing. In this project, we assessed microplastic load within Dreissena polymorpha (zebra mussels), Gammarus fasciatus (amphipods), fish, and Phalacrocorax auritus (double-crested cormorants) digestive tracts. Specimens were processed using KOH bath, followed by wet peroxide oxidation digests. Bioaccumulated microplastics were characterized based on type (e.g., fragment, pellet/bead, fiber, film, foam) and size. Results suggest that the majority of microplastics combined for all organisms investigated were fibers (67%), fragments (19%), films (10%), and pellets/beads (4%). No microplastics were observed in zebra mussels. Amphipods contained fibers (50%), fragments (25%), and films (25%). Species-specific trends were observed among fish, specifically Osmerus mordax (rainbow smelt), Cottus cognatus (slimy sculpin), and Micropterus salmoides (large-mouth bass) are primarily consuming fibers. Bluegill sunfish (Lepomis macrochirus) and rainbow smelt were the only species to consume pellets/beads (40%) and films (16%), respectively. Double-crested cormorants contained primarily fibers (78%), as well as films (19%), with minor contributions of pellets/beads and foam. Spatial distribution of microplastic load was greater in rainbow smelt at the most northern and southern sampling sites on Lake Champlain. In freshwater systems, microplastics absorb chemical pollutants and release plasticizers (e.g., carcinogens, neurotoxins, endocrine disruptors) into tissues, with the potential for fitness consequences in wildlife and humans.

Chad Hammer, Hope VanBrocklin, 05/01/2016

The poster

Microtrophic project: microplastic incorporation in marine food webs

Small pieces of plastic are accumulating in the oceans. Because they are smaller than 5 mm they are called microplastics. They are produced by many different processes of degradation and fragmentation, and can be found washed up on every beach of the world ocean. Recently their size is getting smaller and their abundance increasing. A recent evaluation finds five trillion particles weighing 268,940 tons floating at sea. However, these values are 10 orders of magnitude lower than the total plastic debris dumped into the sea since 1970. Thus, a significant portion of plastic waste has disappeared and one likely cause is ingestion by marine zooplankton and subsequent transfer up the marine food web. There, they pose a biohazard because microplastics absorb persistent organic pollutants (POP’s), including polychlorinated biphenyls (PCB’s) that, via marine fisheries, get transferred to people. Once in people’s bodies, these POPs can penetrate cells, chemically interact with important biomolecules, and disrupt the endocrine system. Because of this danger, it is imperative to estimate microplastic ingestion and egestion rates in zooplankton. Here at the University of Las Palmas on Gran Canaria in the MICROTROPHIC Project, we are determining microplastic abundance and temporal variability. In laboratory cultures of zooplankton, we are determining the ingestion and egestion rates of microplastics. In mesocosm experiments we are investigating microplastic transfer through the food chain and we are studying the relationship between the ingestion of microplastics contaminated with PCBs and the concentration of PCB’s in animal tissues.

Alicia Herrera, Maite Asensio, Ico Martínez, Ted Packard, May Gómez, Ecofisiología de Organismos Marinos (EOMAR), Univ. de Las Palmas de Gran Canaria, 2016

The poster

Tracing Microplastics in Marine Isopods

Background : ‘Microplastics’ have been recognized as a severe environmental problem since the 1970s. They are classified as particles < 5 mm (1) originating e.g. from fragmentation of larger plastic items, sewage-treatments and hygienic products. Due to their small size, micro-plastics can be ingested by a wide range of organisms (2). Today, plastic particles are found in the sediments of the remotest beaches from the poles to the equator (3).
Still, there is only marginal information about the potential adverse effects of microplastics on benthic species (4).

Julia Hämer, Lars Gutow and Reinhard Saborowski, AWI, 04/13

The poster