LE3 .A278 2020

2020

Avery, Trevor

Acadia University

Bachelor of Science

Honours

Biology

Biology

Although fish provide great health benefits for consumers, they are also repositories for contaminants. Current Nova Scotian consumption guidelines for fish are limited to six freshwater species and are based on mercury content only, disregarding coastal fishes and other potentially harmful elements. In this study, total mercury, arsenic, and selenium were analyzed in the tissues of five species of marine fishes: Striped bass Morone saxatilis, American eel Anguilla rostrata, Alewife Alosa pseudogarengus, American shad Alosa sapidissima, and Atlantic tomcod Microgadus tomcod. Samples of muscle, liver, and gonad tissue were cryogenically ground and freeze-dried prior to elemental analysis by TDA-AAS and ICP-MS. Nearly all species and tissues had concentrations exceeding Health Canada’s maximum level of 0.5 mg∙kg-1 for mercury and 3.5 mg ∙ kg-1 for arsenic in fish. All sample selenium concentrations were consistently below the EPA’s toxic threshold of 11.3 mg ∙ kg-1 for freshwater fishes. Atlantic tomcod were particularly high in arsenic and selenium compared to other species. Significant relationships between total mercury concentrations in fish tissues, total length, and across trophic levels indicated mercury bioaccumulation and biomagnification was occurring. Total arsenic concentrations as a function of length increased in Alewife and decreased in Striped bass. Tissue contaminant distribution varied according to element and fish species; however, small sample sizes prevented some analyses. Concentrations of mercury and arsenic were higher than reported in previous studies. This study highlights the need for restricted fish consumption, a regional database, and a continued monitoring program to assess fish health, and for creating consumption guidelines and advisories where they are currently lacking.

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https://scholar.acadiau.ca/islandora/object/theses:3489