The interaction rainfall vs. weight as determinant of total mercury concentration in fish from a tropical estuary

• Published in: Environmental pollution (1987) Vol. 167; pp. 1 - 6
• Main Authors: Barletta, M., Lucena, L.R.R., Costa, M.F., Barbosa-Cintra, S.C.T., Cysneiros, F.J.A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2012; Elsevier
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Body Weight; Climatology. Bioclimatology. Climate change; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Environmental Monitoring - methods; Exact sciences and technology; External geophysics; Fishes - physiology; Fundamental and applied biological sciences. Psychology; Global climatic change; Goiana Estuary; Marine and brackish environment; Mercury - analysis; Mercury - metabolism; Meteorology; Muscles - metabolism; Rain - chemistry; South America; Trichiurus lepturus; Tropical Climate; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; Water Pollution, Chemical - statistics & numerical data; Weibull regression model; South America; America; South America; Goiana Estuary; Global climatic change; Trichiurus lepturus; Weibull regression model; Brackish water environment; Interaction; Body weight; Estuaries; Environmental factor; Heavy metal; Dynamical climatology; Trace element; Climate change; Vertebrata; Rain; Regression model; Pisces; Water pollution; Biological accumulation; Mercury
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2012.03.033

Mercury loads in tropical estuaries are largely controlled by the rainfall regime that may cause biodilution due to increased amounts of organic matter (both live and non-living) in the system. Top predators, as Trichiurus lepturus, reflect the changing mercury bioavailability situations in their muscle tissues. In this work two variables [fish weight (g) and monthly total rainfall (mm)] are presented as being important predictors of total mercury concentration (T-Hg) in fish muscle. These important explanatory variables were identified by a Weibull Regression model, which best fit the dataset. A predictive model using readily available variables as rainfall is important, and can be applied for human and ecological health assessments and decisions. The main contribution will be to further protect vulnerable groups as pregnant women and children. Nature conservation directives could also improve by considering monitoring sample designs that include this hypothesis, helping to establish complete and detailed mercury contamination scenarios. ► Questions previous statistical approaches that used heterocedastic data after transformation. ► Corroborates other works that pointed seasonal variations of the mercury burden in fish muscle. ► Defines rainfall as a major driver of mercury in predatory fish at tropical latitudes. ► Progresses in environmental data analysis and steps forward from previous approaches to Hg in fish. ► Proposes a model to predict scenarios of Hg in fish as a function of biological and environmental variables. The Weibull Regression model was the most appropriate fit for T-Hg in fish and therefore more ecological insights emerged from previous data.