Is the ingestion of microplastics affecting the reproduction and mortality rate of daphnia? If so, does the microbead diameter matter? To test these questions, daphnia were split into 2 cohorts. The first cohort was exposed to microbeads for 24 hours, and the second was exposed for 10 days. Having two exposure periods allows microbead retention within the digestive tracts to be tracked. When daphnia are exposed to beads for an extended period of time, they’re likely to ingest more beads and clog their digestive tract. Each cohort were then separated into 3 groups of 20 daphnia. The first group were a control group and were not exposed to microbeads. The second group were exposed to 1mg of microbeads per 100mL of water, a moderate level of microbeads. The final group were exposed to a very high level of microbeads in their water, 10mg of beads per 100mL of water. This experiment is running multiple times over with various sizes of microbeads ranging from 1-100 micrometers (μm). The experiment is currently on-going, however the trial experiment showed evidence that daphnia within the highest exposure group had a much larger mortality rate. The experiment is also being run with different species of daphnia. This is to test and see if larger daphnia are less sensitive to microbead exposure. The different sizes of daphnia also shows how different sizes of microbeads affect different sizes of daphnia, whether or not bead size and density affect reproduction and mortality rates
