Arsenic in the water, sediment and fish in the Neretva River Delta, Croatia

Summary The Neretva River Delta in Croatia is under constant threat of pollution from various sources along the river watercourse, such as the aluminium industry and bauxite mining, intensive agriculture and untreated sewage from towns. The area is also an important fishing ground and food source for the local residents, whereby the suitability of fish for human consumption is always in question. In this paper the presence of arsenic from six sources was analysed: in water, sediment and fish organs (kidneys, liver, muscles and gonads) of 11 fish species: Lepomis gibbosus, Carassius auratus gibelio, Cyprinus carpio, Anguilla anguilla, Ameiurus nebulosus, Mugil cephalus, Leuciscus svallize, Oncorhynchus mykiss, Salmo trutta, Tinca tinca and Scardinius plotiza. The research showed that arsenic concentrations varied significantly from one source to another in the water, sediment and organs of different fish species. Average concentrations in water and sediment were 18.1 μg L−1 and 32.7 μg kg−1, respectively. Average arsenic levels in the fish organs were 115.9, 105.8, 76.1 and 61.9 μg kg−1 in muscles, kidneys, gonads and livers, respectively. These values are below legally permitted concentrations, although individuals with higher than average concentrations were recorded.