Data from: No effect of realistic concentrations of polyester microplastic fibers on freshwater zooplankton communities

Zooplankton are a conduit of energy from autotrophic phytoplankton to
higher trophic levels, and they can be a primary point of entry of
microplastics into the aquatic food chain. Investigating how zooplankton
communities are affected by microplastic pollution is thus a key step
towards understanding ecosystem-level effects of these global and
ubiquitous contaminants. Although the number of studies investigating the
biological effects of microplastics has grown exponentially in the last
decade, the majority have used controlled laboratory experiments to
quantify the impacts of microplastics on individual species. Given that
all organisms live in multi-species communities in nature, here we use an
outdoor 1130L mesocosm experiment to investigate the effects of
microplastic exposure on natural assemblages of zooplankton. We endeavored
to simulate an environmentally relevant exposure scenario by manually
creating ~270,000 0.015mm x 1-1.5mm polyester fibers and inoculating
mesocosms with zero, low (10 particles/L) or high (50 particles/L)
concentrations. We recorded zooplankton abundance and community
composition three times throughout the 12-week study. We found no effect
of microplastics on zooplankton abundance, Shannon diversity, or Pielou’s
evenness. NMDS plots also revealed no effects of microplastics on
zooplankton community composition. Our study provides a necessary and
realistic baseline upon which future studies can build. Because numerous
other stressors faced by zooplankton (e.g. food limitation,
eutrophication, warming temperatures, pesticides) are likely to exacerbate
the effects of microplastics, we caution against concluding that polyester
microfibers will always have no effect on zooplankton communities.
Instead, we encourage future studies to investigate the triple threats of
habitat degradation, climate warming, and microplastic pollution on
zooplankton community health.