Moura & de Lacerda 2022 — Mercury in Jaguaribe River Estuary: tissue concentrations in shrimp and fish
Moura and de Lacerda measured total mercury (tHg) in water, sediments, aquatic plants, shrimp, and fish from the Jaguaribe River Estuary in Ceará state, northeastern Brazil, a region receiving both natural geogenic and anthropogenic Hg inputs. Sediment tHg was 9.94 ng/g dry weight in the dry season and 6.14 ng/g DW in the rainy season, with total annual Hg load to the estuary estimated at approximately 243 kg/year. Tissue concentrations in commercially fished species were reported; shrimp (Littopenaeus vannamei) and two fish species (Eugerres brasilianus, a grunt, and Cathorops spixii, a sea catfish) were sampled. The paper provides a food-chain perspective on Hg bioavailability in a subtropical estuarine system that supplies seafood to local and regional markets.
Key numbers
- Sediment tHg: 9.94 ng/g DW (dry season), 6.14 ng/g DW (rainy season); basis: dry weight
- Total annual Hg load to estuary: approximately 243 kg/year
- Tissue concentrations reported for Littopenaeus vannamei (white-leg shrimp), Eugerres brasilianus, and Cathorops spixii (exact tissue values tabulated in source; see raw file for table data)
- All tHg; no speciation into MeHg fraction reported
- Dissolved Hg in surface water also reported (exact values in source tables)
Methods (brief)
Field sampling across dry and rainy seasons in the Jaguaribe River Estuary (Ceará, NE Brazil). Sediment cores, surface water, aquatic macrophytes, shrimp, and fish muscle tissue collected. Digestion and cold-vapor atomic fluorescence spectrometry (CV-AFS) for tHg; no MeHg speciation performed. Seasonal variation assessed. Study aims at environmental monitoring and food-chain bioaccumulation rather than product-safety compliance.
Implications
Certification: Reports tHg (not MeHg); the HMT&C analyte vocabulary distinguishes tHg from MeHg. This paper informs the tHg column for seafood/shrimp matrices in a Brazilian estuarine context. MeHg fraction must not be inferred from tHg without speciation data.
Courses: Illustrates how estuarine sediment Hg loads translate into tissue burdens in commercially important shellfish and fish species; demonstrates seasonal variation in sediment Hg availability.
App: Contributes to tHg baseline for shrimp and estuarine fish from subtropical Brazilian aquaculture/fishing regions. Values should be attributed to the specific estuarine source system, not generalized to all Brazilian or global shrimp.