Assessment of trace element content throughout the white shrimp (Litopenaeus vannamei) farming cycle

Abstract

Environmental context Intensive aquaculture is the main source of fisheries products. Thus, investigating the food safety of these products and the environmental impacts of the farms on mangroves is necessary. A shrimp productive cycle was evaluated with a focus on trace element accumulation in shrimps and effluent. The results revealed secure levels of elements in the final product; however, the effluent produced in farms is an important source of contamination to mangrove environment. Rationale Aquaculture systems have increased in the last years due to the high demand for seafood consumption, this could impact the environment and subject fisheries to accumulation of toxic elements. To understand some parameters of food safety and environmental impact, the present study evaluated the concentration of trace elements (Al, As, Cd, Co, Cr, Cu, Mn, Mo, Pb, Se, V and Zn) throughout the production cycle of shrimp. Methodology About 50 shrimps per cycle were collected in a shrimp farm in Brazil and their trace element contents were determined by inductively coupled plasma–tandem mass spectrometry (ICP-MS/MS) and microwave-induced plasma–optical emission spectroscopy (MIP-OES). Results At their final lifecycle stage, shrimp samples present a content (mg g−1) of elements following the trend: Cu (102 ± 12) > Al (20.06 ± 4.24) > Zn (14.82 ± 2.46) > Mn (6.24 ± 0.94) > As (2.65 ± 0.42) > Se (0.932 ± 0.140) > Co (0.380 ± 0.05) > Mo (0.254 ± 0.03) > V (0.204 ± 0.02). Discussion The content of Cd and Pb are in allowance with Brazil and USA legislation for crustaceans, however, the content of As is 3–4-fold higher than that allowed by guidelines in all stages of the growth of the shrimp. The final effluent of the shrimp’s pond into the mangroves shows a high mass fraction of Zn and Mn that could be a source of contamination. Some correlations between some elements in the shrimp samples were found, such as As–Se, Se–Co and Se–V. This study was a scoping experiment to study the content of trace elements throughout the farming cycle of shrimps, encouraging the researcher to undergo a wide survey to evaluate the environmental impact of aquaculture shrimp farming.