title: Mercury accumulation in Yellowfin tuna (Thunnus albacares) with regards to muscle type, muscle position and fish size.
abstract: The concentrations and relationships between individual mercury species and total mercury were investigated in different muscle parts and sizes of Yellowfin tuna (Thunnus albacares). Fourteen Yellowfin tuna caught in the South Atlantic off the coast of South Africa had an average total Hg (tHg) concentration of 0.77 mg/kg wet weight. No differences were detected (p > 0.05) in tHg, MethylHg (MeHg) or inorganic Hg (iHg) accumulation among the four white muscle portions across the carcass, but both tHg and iHg were found in higher concentrations (p < 0.001) in dark muscle than white muscle. Positive linear correlations with fish weight were found for both tHg (r = 0.79, p < 0.001) and MeHg (r = 0.75, p < 0.001) concentrations. A prediction model was formulated to calculate toxic MeHg concentrations from measured tHg concentrations and fish weight (cMeHg = 0.073 + 1.365 · tHg-0.008 · w). As sampling sites and subsampling methods could affect toxicity measurements, we provide recommendations for sampling guidelines.
authors.affiliation: Department of Food Science, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa; Department of Animal Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
authors.forename: Adina C
authors.initials: AC
authors.lastname: Bosch
authors.affiliation: Department of Animal Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
authors.forename: Bernadette
authors.initials: B
authors.lastname: O'Neill
authors.affiliation: Department of Food Science, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
authors.forename: Gunnar O
authors.initials: GO
authors.lastname: Sigge
authors.affiliation: Department of Animal Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa; Department of Agriculture, Forestry and Fisheries, Private Bag X2, Rogge Bay 8012, South Africa.
authors.forename: Sven E
authors.initials: SE
authors.lastname: Kerwath
authors.affiliation: Department of Animal Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa. Electronic address: lch@sun.ac.za.
authors.forename: Louwrens C
authors.initials: LC
authors.lastname: Hoffman
mesh_terms: D000818:Animals; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D008767:Methylmercury Compounds / Q000032:analysis; D009132:Muscles / Q000378:metabolism; D014413:Tuna / Q000378:metabolism*
chemical_list: D008767:Methylmercury Compounds; D008628:Mercury
keywords: Cross-carcass variation; Fish muscle; HPLC–ICP-MS; Mercury speciation; Size effects; Yellowfin tuna