Impacts of weathered microplastic ingestion on gastrointestinal microbial communities and health endpoints in fathead minnows (Pimephales promelas)

Microplastics are a ubiquitous presence in the world’s aquatic environments and their threat to aquatic biota is poorly understood, especially in freshwater ecosystems. In the environment, microbial biofilms can form on the surface of microplastics, and these plastics have the potential to adsorb harmful toxins. Because lab-based studies on microplastics are often conducted with clean polymers, in ecologically unrealistic conditions and concentrations, the impact of these weathered microplastics on aquatic organisms in ecologically realistic conditions is still unclear. To help address the need for ecologically relevant microplastic exposure data, we incubated 500 μm polyethylene microplastic beads in Muskegon Lake, Michigan, USA and used them to conduct a 28-day ingestion study with male and female fathead minnows (Pimephales promelas). We examined the effects of microplastic ingestion on the fish gut microbial community along with hepatic gene expression and health parameters. We foun..., Microplastic Incubation:
We used 500-micron, blue, polyethylene beads (Cospheric, Inc., Santa Barbara, CA) for the incubation and ingestion study. First, a subsample of the new, clean microplastic beads were collected and stored at -80°C for 16S ribosomal RNA (rRNA) sequencing (‘pristine-MP’ sample). Then, the particles were secured in 16-micron nylon mesh bags attached to a PVC frame in Muskegon Lake, Michigan, USA at the Annis Water Resources Institute. The frame was secured at mid-depth in approximately 5 meters of water along the break wall from 14 June 2021 and incubated for a total of 56 days before final retrieval on 9 August 2021. Approximately every week during the incubation, the bags were inspected and gently rinsed and on 18 July 2021, after 34 days of incubation, we rotated the bags and examined them closely for wear, reinforcing seams as necessary. At final retrieval, the microplastics were removed gently from the incubation bags and combined in a composite container. We h..., , # Data from: Impacts of weathered microplastic ingestion on gastrointestinal microbial communities and health endpoints in fathead minnows (Pimephales promelas)

[https://doi.org/10.5061/dryad.3j9kd51rn](https://doi.org/10.5061/dryad.3j9kd51rn)

This study broadly addressed three main areas: 1. health endpoints (growth, condition factor, and hematocrit), 2. gastrointestinal microbial community, and 3. hepatic gene expression. For each of these, respectively, this dataset includes the 1. health measurement data and R code, 2. the namefile, dada2 R code, and downstream ASV analysis R code, and 3. the RT-qPCR data and R code. The raw 16S sequence data for the microbial community analysis has been deposited on the NCBI Sequence Read Archive with the Accession Number PRJNA1088468. 

## Description of the data and file structure

* Health endpoints:
* fhm_health.csv
* NA explanations:
* fhm_01 was removed from test on day 1, no further data was collected on this fish
* fhm_3...