Concentration of heavy metals in two fish species (Cynoscion regalis and Pomatomus saltatrix) from an oil drilling area in Western Coast of Ghana and public health risk assessment

This study assessed heavy metals (Lead (Pb), Nickel (Ni), Iron (Fe), Chromium (Cr), and Cadmium (Cd)) concentration in water (from borehole, hand-dug well and the sea) and fish (Cynoscion regalis and Pomatomus saltatrix species) and possible health risk exposure by the consumption of these fishes. A total of 18 samples of water and samples of two species of fish (C. regalis and P. saltatrix) were collected from Jomoro, Ellembelle and Ahanta West District and analyzed for the concentration of Pb, Ni, Fe, Cr, and Cd using Atomic Absorption Spectrometer (AAS). Results revealed appreciable concentrations of Pb, Ni, and Fe in the fish muscle and Ni, Cr, and Fe in water. Cadmium and Cr were not detected in the fish samples. Heavy metals in fish increased in the order Pb < Ni < Fe. The Estimated Daily Intake of fish value for adult ranged 1.88 x 10-3 to 2.03 x 10-1 (mg/kg bw/day), however, those for children were 4.40 x 10-3 to 4.74 x 10-1(mg/kg bw/day). For health risk assessment, the Total Targeted Hazard Quotient for adults was < 1; however, those for children were >1 for C. regalis but less than 1 (< 1) for P. saltatrix meaning children who consume C. regalis are exposed to health risk in their life time. The results confirmed that contaminated environments could result in bioaccumulation of metal pollutants in fish's muscle, which poses a health risk to humans when consumed. Awareness and education of the general public on the threshold of heavy metals in fish and water are crucial to safeguard against health risks.

What’s for Dinner? Assessing the Value of an Edible Invasive Species and Outreach Actions to Promote Its Consumption

Promoting the consumption of edible aquatic invasive species has gained popularity to minimize its impacts while easing pressure on native resources. Weakfish Cynoscion regalis (Bloch & Schneider, 1801) is one of the most recent invasive fish species in the Iberian Peninsula (Europe) which once sustained an important fishery in the native range (Northwest Atlantic Ocean). Portugal ranks third in the list of the world’s top fish consumers, so promoting a weakfish fishery could at least help minimize the impacts upon native species, since weakfish have innate traits that are likely appreciated by Portuguese fish consumers. However, introducing a new species to consumers is challenging owing to consumers’ habits and unfamiliarity with the species. So, we aimed to (i) evaluate the acceptance of weakfish by a panel of Portuguese fish consumers and (ii) create outreach actions – partnerships with local Chefs and press releases – to explain to a broader public what invasive species are and promote the consumption of edible aquatic invasive species. The survey that we conducted to Portuguese fish consumers showed that weakfish has great chances of being well accepted by the public – 90% of consumers would buy weakfish because they appreciated its appearance, flavour, and texture, besides being a wild fish. The outreach actions reached a few million people because 46 online articles were published, and three news pieces broadcasted on national television. Overall, our strategy greatly increased the public’s awareness about invasive species, which can be replicated elsewhere in the world.