DOI: 10.5061/dryad.vdncjsz2n
title: Data from: No effect of realistic concentrations of polyester microplastic fibers on freshwater zooplankton communities

description: 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.
description: We conducted an outdoor mesocosm experiment with 15 tanks. 5
 tanks received no microplastics, 5 tanks received 10 particles/L, and 5
 tanks received 50 particles/L. We sampled zooplankton communities three
 times for 12 weeks. We measured total zooplankton, Shannon diversity, and
 Pielou's evenness.
description: # No effect of realistic concentrations of polyester microplastic fibers
 on freshwater zooplankton communities
 The data are a CSV file of
 the zooplankton collected at each sampling period, in each of the 15
 outdoor mesocosms. ## Description of the data and file structure There are
 12 columns of data and 451 rows. Variable descriptions: sample_idz: code
 assigned to the zooplankton sample sample_date: year-month-day the sample
 was collected Month: calendar month the sample was collected Month.2:
 description of the sample month relative to when microplastics were added
 Month.3: numerical categorization of the month where 0 is
 pre-microplastics addition, 1 = 1 month post microplastics addition, and 3
 = 3 months post microplastics addition Tank: arbitrary number assigned to
 each tank (15 tanks total) zoop_group: taxonomic grouping broad_group:
 zooplankton taxonomic groups more broadly defined count.per.10L: the
 number of each type of zooplankton that was found in one 10L sample of the
 mesocosm. zoop.per.L: number of each type of zooplankton in 1L (this is
 count.per.10L/10) Treatment: the treatment assigned to each tank. Low MP =
 low microplastics treatment; High MP = high microplastics treatment, No MP
 = no microplastics added sampler_id gives the initials of the person who
 identified the zooplankton