Abiotic pollutant concentrations in fish: A comparative review of wild-caught and aquaculture sources

Abstract

Background: The levels of contaminants and nutrients in fish from aquaculture and wild-caught sources are a timely and relevant issue for food safety. Contaminants such as heavy metals and metaloids, PCBs, DDT, and PAHs pose toxic risks due to bioaccumulation, while nutrient levels like Se, Zn, and Fe vary depending on diet and habitat. Objective: This review synthesizes studies evaluating the levels of abiotic contaminants and nutrients in aquaculture and wild-caught fish, in order to compare them. Scope and approach: In this scoping review, all the published literature on the comparison of heavy metals and metaloids, other contaminants and nutrients in aquaculture fish and wild fish was analysed. The search was conducted in different databases, and 31 studies were selected that met the eligibility criteria. Key findings and conclusions: The review provides an overview of the comparison between aquaculture and wild fish in terms of heavy metals and metaloids, other contaminants, and nutrients, due to the difference in their environmental conditions, feed and origin. Higher concentrations of some heavy metals and metaloids were observed in wild fish than in aquaculture as well as in other contaminants. The mean Hg and As concentration in wild fish was 0.06 and 3.26 μg/g, respectively; while in aquaculture fish was 0.038 and 1.23 μg/g. The DDT mean concentration in wild fish of 196.48 ng/g, while in aquaculture fish was 44.64 ng/g. The difference in these concentrations does not only depend on the production system, other factors such as age, physiological state or the degree of environmental pollution can have a considerable effect.