Papers

Effects of Polystyrene Nanoplastics on Oxidative Stress, Blood Biochemistry, and Digestive Enzyme Activity in Goldfish (Carassius auratus)

Goldfish exposed to polystyrene nanoplastics in their diet for 21 days showed significant oxidative stress, disrupted blood chemistry, and reduced digestive enzyme activity, with effects worsening at higher doses. The smallest nanoplastics caused the most damage to the fishes' antioxidant defense systems and overall health. These findings add to the evidence that nanoplastics in aquatic environments can harm fish health in ways that may affect the safety of fish consumed by humans.

Role of 17β-estradiol injection on growth, physiology, and reproductive performance in male goldfish (Carassius auratus) with or without female interaction

Researchers injected male goldfish with the estrogen hormone 17β-estradiol to mimic exposure to endocrine-disrupting chemicals common in plastic pollution, finding significant damage to sperm quality, reproductive organs, and liver tissue. Social interaction with female fish partially offset some hormonal disruption, suggesting that environmental context influences how aquatic animals respond to plastic-associated estrogen-like contaminants.

Flow-dependent modulation of microplastic toxicity in grass carp: Insights from multi-level biological endpoints and machine learning

Researchers studied how water flow conditions affect microplastic toxicity in grass carp, finding that faster-moving water significantly worsened the harmful effects of polystyrene microplastics. Fish exposed to microplastics under high water velocity showed more severe gill damage, intestinal inflammation, immune system activation, and shifts in gut bacteria compared to still-water conditions. The study suggests that real-world flowing water environments may amplify the biological impact of microplastic pollution on freshwater fish.

Potential use of gammarus (Pontogammarus maeoticus) and shrimp (Palaemon elegans) as biomonitors of microplastics pollution in coastal environments

Researchers investigated whether two crustacean species, gammarus and shrimp, could serve as biological indicators of microplastic pollution in coastal environments. They found microplastics in both organisms as well as in surrounding water and sediment, with fibers being the dominant type. The study suggests these common coastal species could be useful biomonitors for tracking microplastic contamination levels in marine ecosystems.

Toxicity of polystyrene nanoplastic and copper oxide nanoparticle in Artemia salina: Single and combined effects on stress responses

Researchers tested polystyrene nanoplastics and copper oxide nanoparticles individually and in combination in brine shrimp (Artemia salina) and found synergistic toxicity — the combined exposure caused greater growth inhibition, oxidative stress, and cholinesterase disruption than either contaminant alone.

Hydrodynamic modulation of microplastic bioaccumulation in edible fish: Integrating biomarker networks, machine learning, and food safety perspectives

Scientists found that fish in faster-moving water absorb much more microplastic pollution than fish in still water, and these fish also showed more tissue damage and health problems. This matters because many of the fish we eat live in rivers and streams with flowing water, which means they could contain higher levels of harmful microplastics than previous studies suggested. The research shows we may be underestimating how much plastic pollution is getting into our seafood.

Microplastics abundance, distribution and composition in surface waters, sediments and fish species from Amir˗Kalayeh Wetland, Northern Iran

This study examined microplastic pollution in surface waters, sediments, and fish species from Amir-Kalayeh Wetland in Northern Iran. Researchers found microplastics across all sampled compartments, with varying abundance and composition, highlighting that wetland ecosystems are also susceptible to widespread microplastic contamination.

Microplastic Pollution in the Gastrointestinal Tract and Gills of Some Teleost and Sturgeon Fish from the Caspian Sea, Northern Iran

Researchers found microplastics in the gastrointestinal tracts and gills of three teleost fish species and one sturgeon from the Caspian Sea in northern Iran, with mean counts ranging from 1.0 to 2.8 microplastics per fish. This is the first report documenting microplastics in sturgeon from the Caspian Sea, highlighting contamination of commercially and ecologically important fish.

Microplastics in different tissues of some commercially important fish species from Anzali Wetland in the Southwest Caspian Sea, Northern Iran

Microplastics were detected in the gastrointestinal tract, muscle, and gonads of nine commercially important fish species from Anzali Wetland in the Caspian Sea, with fiber being the most common type and occurrence varying by species and tissue.

Abundances and characteristics of microplastics in core sediments of the Persian Gulf coast, Iran

Researchers sampled coastal sediments in Iran's Persian Gulf and found microplastics — including polystyrene, polyethylene, and PVC — at all six sites and at every depth down to 30 cm, averaging nearly 118 particles per kilogram of dry sediment. Fibers and fragments dominated, pointing to widespread plastic contamination from local waste mismanagement in this tidal ecosystem.

Spatial distribution of microplastics pollution in sediments and surface waters of the Aras River and reservoir: An international river in Northwestern Iran

Researchers investigated ingestion of microplastics by Antarctic krill, a keystone species in the Southern Ocean food web. Krill readily ingested polystyrene microspheres in laboratory experiments and excreted compacted pellets, suggesting a potential mechanism for transporting microplastics to the deep sea.

The Low Ontogenetic Diet Diversity and Flexibility of the Pike-Perch, Sander lucioperca (Linnaeus, 1758) (Osteichthyes, Percidae): A Case Study

Not directly relevant to microplastics — this study characterises the diet and feeding habits of pike-perch in rivers of the Tersko-Caspian region, a fisheries ecology paper.

Identification and distribution of microplastics in the sediments and surface waters of Anzali Wetland in the Southwest Caspian Sea, Northern Iran

Researchers documented the occurrence, abundance, and distribution of microplastics in sediments and surface waters of Anzali coastal wetland on the southwest Caspian Sea, finding concentrations between 140-2,820 items/kg dry weight in sediments and up to 4.41 items/m3 in surface water. Fibers were the most common shape and concentrations were higher in the dry season, with the wetland serving as a significant microplastic sink.

Assessing the relationship between the abundance of microplastics in sediments, surface waters, and fish in the Iran southern shores

Researchers found microplastic contamination across sediments, surface waters, and four fish species along Iran's Persian Gulf coast, with concentrations of 190 items/kg in sediments and 9.28 items/km in surface waters, though no correlation was observed between MP abundance across the different environmental compartments.

Investigating Micro-Plastic Pollution and its Consequences on Aquatic Communities

This review examined how microplastic pollution affects aquatic communities, discussing sources of microplastics, routes of exposure, and documented ecological consequences for wildlife and the human food supply that depends on healthy aquatic ecosystems.

Investigation of the Correlation between Microplastic Pollution and Potentially Toxic Elements in Caspian White Fish (Rutilus kutum)

Characteristics, accumulation and distribution of microplastics in different macroalgae species of the Caspian Sea: insights into removal of microplastics from coastal environments

Characteristics and Seasonal Distribution of Microplastics in the Surface Waters of Southwest Coast of the Caspian Sea (Guilan Province, Iran)

Researchers measured microplastic concentrations in surface waters along the southwest coast of the Caspian Sea in Iran across four seasons, finding an average of over 1,000 microplastic particles per cubic meter. Concentrations varied by season and location, with fibers being the most common type found.

Inland Water Fungi in the Anthropocene: Current and Future Perspectives

Pollution and health risk assessment of heavy metals in the soil around an open landfill site in a developing country

Researchers evaluated soil pollution and ecological and human health risks from heavy metals around a municipal solid waste landfill in Kazerun, Iran, collecting soil samples at multiple distances and depths from the site. They found elevated concentrations of multiple heavy metals in landfill-proximal soils compared to background levels, with risk indices indicating potential carcinogenic and non-carcinogenic hazards particularly for children through soil ingestion pathways.

Aliphatic hydrocarbons in fin spines of adult sturgeon (Acipenser stellatus) and their relationship with potentially toxic elements in the northern and southern regions of the Caspian Sea

Researchers measured petroleum-derived aliphatic hydrocarbons and toxic metals in fin spines of endangered starry sturgeon from the Caspian Sea, finding higher hydrocarbon concentrations in northern regions and correlations between hydrocarbon contamination and mercury and arsenic levels.

Microplastics in Sediments of Southwest Caspian Sea: Characteristics, Distribution and Seasonal Variability

This study monitored microplastic contamination in Caspian Sea sediments across four seasons, finding plastic particles present at all times and locations with an average of nearly 400 particles per kilogram of sediment. Seasonal variation in microplastic abundance was detected, likely linked to wind and current patterns that affect particle transport and deposition.

Natura 2000 A Panacea? Natura 2000 Site Oltul Mijlociucibin-Hârtibaciu (ROSCI0132) ‒ a Local Extinction of a Native Fish Species and a New Alien Fish Arrival Case Study

Researchers investigated biodiversity outcomes at the Oltul Mijlociu-Cibin-Hartibaciu Natura 2000 site in Romania, documenting the probable local extinction of the protected fish species Pelecus cultratus and the arrival of the alien species Babka gymnotrachelus as ecological indicators of inadequate conservation management. The findings challenge the assumption that Natura 2000 designation alone ensures effective biodiversity protection.

Evaluation of machine learning algorithms for groundwater quality modeling

Researchers developed a machine learning framework to predict groundwater quality across a large aquifer in northern Iran using data from 248 monitoring wells. The models could predict water quality parameters with reasonable accuracy, reducing the need for costly field sampling. The approach is relevant to microplastic research because groundwater quality monitoring is increasingly important given evidence that microplastics contaminate groundwater systems.