0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Detection Methods Environmental Sources Food & Water Gut & Microbiome Marine & Wildlife Policy & Risk Remediation Sign in to save

Quantifying and classifying microplastics and microparticles across aquatic heterotrophs from headwater streams in central Pennsylvania

Journal of Freshwater Ecology 2025 Score: 38 ? 0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
Isaac Carachilo, C Starr, Rachel Foster, Monica M. Arienzo, Christopher J. Grant

Summary

Researchers found microparticle contamination across multiple trophic levels in remote forested headwater streams in central Pennsylvania, with secondary consumers showing the highest contamination rates and µFTIR confirming true microplastics at two of five sampling sites.

Body Systems
Study Type Environmental

Microplastics (<5 millimeters) are a prominent contaminant globally, negatively affecting terrestrial, freshwater, and saltwater systems. Virtually no research has investigated microplastic contamination in remote, forested headwater streams in Pennsylvania. At five streams in central Pennsylvania, we assessed microparticle/microplastic contamination across three trophic levels: tertiary consumers (Salvelinus fontinalis), secondary consumers (Rhinichthys atratulus), and primary consumers (Trichoptera, Plecoptera, Ephemeroptera, Odonata, and Megaloptera). From 100-meter unblocked reaches, fish (n = 46 total, n = 21 tertiary consumers, n = 25 secondary consumers) and benthic macroinvertebrates (n = 106 total, Trichoptera: n = 40, Plecoptera: n = 39, Ephemeroptera: n = 22, Odonata: n = 4, Megaloptera: n = 1) were collected using standard wadeable stream sampling procedures. Fish gastrointestinal (GI) tracts and macroinvertebrates were digested in 10% potassium hydroxide (KOH) solutions, and microparticles were identified after vacuum filtration and visualization with a dissecting microscope at 45× magnification. Microparticles were categorized as microplastics at two of our five sites using μFTIR spectroscopy on Salvelinus fontinalis, Rhinichthys atratulus, and Plecoptera. Our efforts resulted in the identification of 159 microparticles and 5 microplastics among all heterotrophs across all sites. Microparticle contamination was highest among secondary consumers with no heterotroph or site effect on microparticle count (p > 0.05). The distribution of microparticle morphology and color combinations varied significantly across the heterotroph groups, and there were negative correlations between brook trout morphological characteristics and microparticle count (e.g. total length: r = –0.62, p = 0.03; weight: r = –0.62, p = 0.03; gastrointestinal tract weight: r = –0.66, p = 0.02). Negative relationships between size characteristics among all fish and microparticle count were expressed by δ15N analysis (r = –0.37, p = 0.03). We believe that the disparity in microparticle contamination by fish size and between trophic levels is driven by divergences in feeding strategies, ontogenetic shifts in feeding behavior, and contrasts in life histories. Overall, our data highlight the presence of microplastic/microparticle contamination in remote, forested headwater streams in Pennsylvania without any known upstream point-source pollution.

Sign in to start a discussion.

More Papers Like This

Article Tier 2

Automated μFTIR Imaging Demonstrates Variability in Microplastic Ingestion by Aquatic Insects in a Remote Taiwanese Mountain Stream

Researchers used focal plane array micro-FTIR spectroscopy to characterize microplastic ingestion in aquatic insects from a high-altitude stream (~2,000 m) in a Taiwanese national park. Microplastic ingestion was detected in nearly all insect taxa examined, with polyethylene (65%) dominating and most particles smaller than 500 µm, demonstrating that MP contamination reaches even remote, low-pollution environments.

Article Tier 2

Widespread Microplastic Pollution in Central Appalachian Streams: Implications for Freshwater Ecosystem Sustainability

Researchers evaluated microplastic pollution in freshwater streams across central Appalachia by examining the gut contents of 55 northern hogsucker fish from seven streams. They found an average of nearly 40 microplastic particles per fish, with the highest contamination in watersheds affected by mining, agriculture, and urban development. The study fills an important gap in understanding microplastic contamination in Appalachian freshwater systems and its potential consequences for ecosystem health.

Article Tier 2

Automated μFTIR Imaging Demonstrates Taxon-Specific and Selective Uptake of Microplastic by Freshwater Invertebrates

Researchers used automated micro-FTIR imaging to quantify microplastic ingestion by multiple freshwater invertebrate taxa from field-collected sediments, finding taxon-specific differences in ingestion rates and selectivity for particle type and size, suggesting that feeding behavior mediates microplastic exposure.

Article Tier 2

Ingestion of microplastics and textile cellulose particles by some meiofaunal taxa of an urban stream

Researchers evaluated ingestion of microplastics and textile cellulose particles by five meiofaunal taxa and multiple functional feeding guilds in an urban first-order stream in Florence, Italy, using fluorescence microscopy and µFTIR, finding evidence of particle uptake across scrapers, deposit-feeders, predators, and various locomotion groups.

Article Tier 2

The effect of urban point source contamination on microplastic levels in water and organisms in a cold‐water stream

Microplastic concentrations in water, macroinvertebrates, and trout in a Wisconsin stream increased significantly downstream of stormwater outfalls and a wastewater plant. The study demonstrates that point sources of pollution drive measurable increases in microplastic contamination in freshwater food webs.

Share this paper