Meeting Abstract
Intertidal habitats are routinely exposed to varying levels of biotic and abiotic particles. As microscopic plastic (MP, plastic < 5mm) and sediment from runoff become more prevalent in our waters, it is important to determine if (and how) MP affects mussel physiology. We focused on mussels (Mytilus spp.), well-known filter feeder and bioindicator species that are known to ingest MP both in natural and laboratory settings. Silt and MPs are similar in size, lack nutritional value, and must be sorted from food, making the two abiotic particles an interesting and important comparison. Here we investigated mussel filtration rate response to current and extreme concentrations of MP exposure and how it compares to natural levels of algae and silt solutions. In all MP treatments mussels ingested and excreted MP as feces. Preliminary results suggest neither filtration rates in abiotic particle treatments deviate from algae-only treatments. In both abiotic particle treatments, mussels filter abiotic and biotic particles in equal proportions, however, in MP treatments pseudofeces containing MP are produced, indicating a selection against MP and not against silt. Comparisons among different bivalve species, increasing particulate concentrations, and potential implications will also be discussed.
