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. Sign in to save

Microplastic abundance and composition along an anthropogenic pressure gradient in an Andean river (Colombia)

Hydrobiologia 2026 Score: 40 ? 0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
A. Prado-Guasca, F. A. Villa-Navarro, E. O. López-Delgado, V. A. Arana-Rengifo, Giovany Guevara-Cardona

Summary

Researchers surveyed microplastic abundance across an altitudinal gradient in a Colombian Andean river, finding highest concentrations in downstream urban and agricultural zones, with fibers and polypropylene dominating across water, sediment, and fish samples—the first report of microplastics in freshwater fish from the Tolima region.

Abstract This study evaluated the presence, distribution, and composition of microplastics in the Combeima River sub-basin (Tropical Andes, Colombia), under the hypothesis that their abundance increases with greater anthropogenic pressure. Sampling was conducted along an altitudinal gradient to characterize microplastics in riverbanks, water, sediment, and freshwater fish, and to assess the influence of hydrological regimes and flow variations on their accumulation across environmental compartments. Microplastics were extracted using alkaline digestion and density separation, visually classified under a stereomicroscope, and chemically identified through Fourier transform infrared spectroscopy. The highest concentrations were found in downstream areas associated with urban and agricultural land use. Fibers, particularly polymeric blends and polypropylene, were the most abundant type, especially in fish samples. A wide variety of polymers were identified, including polyethylene terephthalate, high-density polyethylene, and others related to synthetic textiles and industrial materials. Water and fish showed higher microplastic abundance compared to soil and sediment, where larger particles tended to accumulate. This study is the first report of microplastics in freshwater fish from the Tolima region and provides essential information on spatial variation in composition and the influence of land use and hydrological dynamics on distribution, valuable for future monitoring and management strategies in tropical Andean ecosystems.

Sign in to start a discussion.

More Papers Like This

Article Tier 2

Microplastics and other anthropogenic particles contamination and their potential trophic transfer in a tropical Andean reservoir, Colombia

Researchers assessed microplastic contamination across water, sediment, and aquatic organisms in a tropical Andean reservoir in Colombia, finding plastic particles present in all environmental compartments and at every level of the food chain studied. The most common particles were fibers and fragments made of polyethylene, polypropylene, and polyester. The study provides evidence that microplastics are being transferred up through the food web in this freshwater ecosystem, from tiny crustaceans to fish.

Article Tier 2

Occurrence of microplastics in Fish from Mendoza River: First Insights into Plastic Pollution in the Central Andes, Argentina

Researchers found microplastics in the gastrointestinal tracts of all three fish species examined from Argentina's Mendoza River in the Central Andes, with fibers comprising 85% of particles, marking the first evidence of microplastic pollution in this high-altitude freshwater system.

Article Tier 2

Microplastics and other anthropogenic particles contamination and its potential trophic transfer in a tropical Andean reservoir, Colombia

Researchers sampled water, sediment, and multiple trophic levels of biota in a tropical Andean reservoir in Colombia, finding microplastics and other anthropogenic particles at every level and documenting evidence of trophic transfer from zooplankton through macroinvertebrates to fish.

Article Tier 2

Microplastics in tropical Andean rivers: A perspective from a highly populated Ecuadorian basin without wastewater treatment

Researchers measured microplastic concentrations in a highly populated Ecuadorian river basin that lacks wastewater treatment, finding contamination throughout the system and demonstrating that rivers in low-income tropical countries with poor infrastructure are major conduits for microplastics.

Article Tier 2

Microplastics in river sediments in two streams in an Andean region of Peru

Researchers measured microplastic concentrations in surface sediments from two Andean streams in Peru, finding levels ranging from 0-2,216 items/kg in Ishoj stream and 0-6,383 items/kg in Uyru Rume stream, with highest concentrations near solid waste dumping sites. Fragments smaller than 1 mm dominated, polypropylene was the most common polymer by Raman analysis, and all particles were secondary microplastics.

Share this paper