Freshwater Fish
Freshwater fish are inland-water aquatic protein sources whose heavy-metal contamination profile differs materially from saltwater and marine fish. The defining difference is methylmercury biomagnification: freshwater systems with reducing sediments and microbial methylation activity (most notably in artisanal small-scale gold mining (ASGM) watersheds, mercury-impacted lakes, and historic industrial river basins) concentrate MeHg in piscivorous fish at levels that often exceed marine-fish equivalents. Sport-fishery advisories from US states, Canadian provinces, and the EFSA opinion on chronic methylmercury exposure target freshwater piscivores specifically.
This page is the structural anchor for freshwater-specific fish evidence. The broader fish page covers cross-cutting fish-as-food properties; saltwater-fish (when promoted) carries marine-specific evidence. Trophic level and fish age are the dominant within-species variance drivers, not species identity alone — a small, young pike from a low-Hg lake can carry less MeHg than a large, old walleye from the same lake.
Routing
Direct evidence for freshwater fish lands here; the broader fish category fans out via the routing layer to fish when sources address fish generally rather than freshwater specifically. Product-level routing flows through fish-containing-baby-foods.
Contamination Profile State
All ten contamination_profile sub-blocks are pending. tHg and MeHg are the central concerns for this commodity; Pb and Cd are secondary; iAs is generally low in freshwater fish but elevated in some mining-impacted watersheds. Synthesis values will populate as contributing source pages are integrated per Part 9.
Sources
Auto-generated from source-page frontmatter. The “Used on this page for” column is populated by the orchestrator’s POPULATE-SOURCE-LEGEND action; pending entries appear as *[awaiting synthesis]*.
| # | Citation | Year | Type | Used on this page for |
|---|---|---|---|---|
| 1 | Rusko et al. 2026. Risk-Benefit Assessment of Mercury, Lead, Cadmium, and Arsenic in Inland Fish from Latvian Lakes, Foods | 2026 | Peer-reviewed | tHg, MeHg, Pb, Cd, and tAs in 460 inland fish muscle samples (7 species, 5 Latvian lakes) by ICP-MS and CV-AAS; Pb, Cd, and tAs all below LOQ across all samples; MeHg dominant mercury form, with risk-benefit analysis identifying pregnant women and children as at-risk for high consumption of predatory species |
| 2 | Auzier et al. 2025. Systematic review and spatiotemporal assessment of mercury concentration in fish from the Tapajós River Basin: implications for environmental and human health, ACS Environmental Au | 2025 | Peer-reviewed | Systematic review of tHg in fish muscle from the Tapajós River Basin, Brazil (36 studies, 143 species, 14,113 individuals, 1992–2022); tHg range 0.01–3.82 mg/kg with piscivorous species highest; 89% of food species showed THQ ≥1 in at least one sub-basin under local average consumption, linked to artisanal gold mining hotspots |
| 3 | Dietz et al. 2025. Stable isotopes unveil ocean transport of legacy mercury into Arctic food webs, Nature Communications | 2025 | Peer-reviewed | [awaiting synthesis] |
| 4 | Katerin et al. 2025. Presence of Nematodes, Mercury Concentrations, and Liver Pathology in Carnivorous Freshwater Fish from La Mojana, Sucre, Colombia: Assessing Fish Health and Potential Human Health Risks, Archives of Environmental Contamination and Toxicology | 2025 | Peer-reviewed | [awaiting synthesis] |
| 5 | Jermilova et al. 2025. Assessing mercury exposure to water and fish of the Mackenzie watershed using a Bayesian network analysis, Integrated Environmental Assessment and Management | 2025 | Peer-reviewed | Bayesian network risk modelling of tHg and MeHg in 5 freshwater fish species (lake whitefish, northern pike, walleye, burbot, lake trout) from the Mackenzie Basin and Great Slave Lake, Canada (2005–2020 monitoring, n=1,044); northern pike mean 0.938 µg/g wet weight; dietary intake assessed against Health Canada, WHO, and USEPA pTWI thresholds for Indigenous communities |
| 6 | Lepak et al. 2025. Correction: Mercury Concentrations in Sport Fish from Colorado Reservoirs, PLOS ONE | 2025 | Peer-reviewed | Corrected tHg and MeHg concentrations in sport fish (walleye, northern pike, smallmouth bass) from Colorado reservoirs, US; formal correction notice superseding previously published values, relevant to US freshwater sport-fish consumption advisory context |
| 7 | Naz et al. 2025. Trace elements in fish species from the Punjnad headworks: bioaccumulation and human health risk assessment, PLoS ONE | 2025 | Peer-reviewed | Cd, Cu, Pb, and Ni in liver, gills, and muscle of 5 freshwater fish species from the Punjnad headworks, Punjab, Pakistan (AAS, n=27; 3 seasons); carnivorous Wallago attu highest in all metals; Cd and Pb THQ >1 for regular consumers of all 5 species |
| 8 | Paul et al. 2025. Arsenic bioaccumulation in fish of the lower meghna river: Seasonal dynamics, species sensitivity, and public health implications, PLoS One | 2025 | Peer-reviewed | tAs in muscle of 10 small indigenous freshwater fish species from the Lower Meghna River, Bangladesh (n=300 muscle samples, 10 stations, 3 seasons); 5 species exceeded the WHO threshold of 1 mg/kg in at least one season; pre-monsoon concentrations highest; benthic carnivores showed greatest bioaccumulation |
| 9 | Shumba et al. 2025. Assessment of total mercury (Hg) in soil, sediment, and tilapia fish (Oreochromis niloticus) and health risk assessment among residents of Kitwe mining area, Zambia, Environmental Science and Pollution Research | 2025 | Peer-reviewed | [awaiting synthesis] |
| 10 | Uthayarajan et al. 2025. Quality and sources of food and water consumed by people with chronic kidney disease of unknown etiology in Sri Lanka: a systematic review, Environmental Science and Pollution Research | 2025 | Peer-reviewed | [awaiting synthesis] |
| 11 | Venant et al. 2025. Community Awareness and Health Risk of Heavy Metals Through Consumption of Sardine (Rastrineobola argentea) From Lake Victoria, Tanzania, Food Science & Nutrition | 2025 | Peer-reviewed | Cd and Pb in 279 sardine (Rastrineobola argentea) samples from 3 Tanzanian Lake Victoria regions in fresh and dried forms (ICP); all samples below FAO/WHO limits; median Cd 12 ppb, Pb 81 ppb dry weight; all health risk metrics below thresholds of concern |
| 12 | Wu et al. 2025. Climate change amplifies neurotoxic methylmercury threat to Asian fish consumers, Proceedings of the National Academy of Sciences | 2025 | Peer-reviewed | [awaiting synthesis] |
| 13 | Barquero et al. 2024. A preliminary assessment of mercury, methylmercury and other potentially toxic elements in largemouth bass (Micropterus salmoides) from the Almadén mining district, Environmental Geochemistry and Health | 2024 | Peer-reviewed | [awaiting synthesis] |
| 14 | Escobar-Camacho et al. 2024. Mercury in aquatic ecosystems of two indigenous communities in the Piedmont Ecuadorian Amazon: evidence from fish, water, and sediments, Environmental Science and Pollution Research | 2024 | Peer-reviewed | [awaiting synthesis] |
| 15 | Gupta et al. 2024. Assessment of human health risks posed by toxic heavy metals in Tilapia fish (Oreochromis mossambicus) from the Cauvery River, India, Frontiers in Public Health | 2024 | Peer-reviewed | [awaiting synthesis] |
| 16 | Kovacik et al. 2024. Microelements, Fatty Acid Profile, and Selected Biomarkers in Grass Carp (Ctenopharyngodon idella) Muscle Tissue: Seasonal Variations and Health Risk Assessment, Research (journal not specified in text; published online 9 May 2024) | 2024 | Peer-reviewed | Al, tAs, Cd, Cr, tHg, Ni, and Pb in dorsal muscle of 36 grass carp from a Slovak agricultural-zone pond (ICP-OES + CV-AAS; summer vs autumn); Cd and Co below LOQ in all samples; Hg and Ni jointly drive 49% of total hazard quotient; TTHQ 0.27–0.76 across individuals |
| 17 | Laoye et al. 2024. Assessment of heavy metal contamination in fish, fruits, and vegetables in Southwest Nigeria: A systematic review, F1000Research | 2024 | Peer-reviewed | [awaiting synthesis] |
| 18 | Najem et al. 2024. Bioaccumulation of lead, arsenic, and mercury in vital organs of common carp (Cyprinus carpio L.): Assessment of pathological effects and possible hazards associated with human consumption, Open Veterinary Journal | 2024 | Peer-reviewed | [awaiting synthesis] |
| 19 | Páez-Osuna et al. 2024. Tilapia as a model fish for biomonitoring of metal pollution in dams associated with mining watersheds: contrasting diagnosis from different tissues and health risk assessment, Environmental Geochemistry and Health | 2024 | Peer-reviewed | [awaiting synthesis] |
| 20 | Paz-Suconota et al. 2024. Assessment of total mercury content in fish muscle tissue from the middle basin of the Pastaza River, Ecuador, PLOS ONE | 2024 | Peer-reviewed | [awaiting synthesis] |
| 21 | Hussein et al. 2023. Risk assessment of toxic residues among some freshwater and marine water fish species, Frontiers in Veterinary Science | 2023 | Peer-reviewed | [awaiting synthesis] |
| 22 | Lepak et al. 2023. Predicting sport fish mercury contamination in heavily managed reservoirs: Implications for human and ecological health, PLOS ONE | 2023 | Peer-reviewed | [awaiting synthesis] |
| 23 | Marriott et al. 2023. Considerations for environmental biogeochemistry and food security for aquaculture around Lake Victoria, Kenya, Environmental Geochemistry and Health | 2023 | Peer-reviewed | [awaiting synthesis] |
| 24 | Sirisangarunroj et al. 2023. Toxic Heavy Metals and Their Risk Assessment of Exposure in Selected Freshwater and Marine Fish in Thailand, Foods 2023, 12, 3967 | 2023 | Peer-reviewed | tAs, Cd, tHg, and Pb in 15 commonly consumed Thai fish species (7 freshwater, 8 marine) from Bangkok markets by ICP-MS-MS (AOAC 2015.01); Pb below LOQ in all species; high tAs risk identified for young children consuming certain freshwater and marine species |
| 25 | Stahl et al. 2023. Contaminants in fish from U.S. rivers: Probability-based national assessments, Science of the Total Environment | 2023 | Peer-reviewed | [awaiting synthesis] |