Occurrence of heavy metals in the sediments of Uranouchi Inlet, Kochi prefecture, Japan

Abstract

The present status of contamination by heavy metals, and the impact of cage culture on sediments at the Uranouchi Inlet, Kochi Prefecture, Japan, were investigated from two stations influenced by intensive aquaculture and a control station, during May-July 2006. The moisture content of the sediments at the aquaculture stations was over 65%, and the organic matter was always over 100 mg/g dry wt. In contrast, the highest moisture content and organic matter at the control station was 45.5% and 62.9 mg/g dry wt, respectively. Concentrations of zinc (Zn) (178 ± 4.8 mg/kg dry wt) and copper (Cu) (125 ± 1.2 mg/kg dry wt) were highest at the aquaculture stations. Lead (Pb) was highest (50.7 ± 0.77 mg/kg dry wt) at the aquaculture station though it was as high as 33.2 ± 0.77 mg/kg dry wt at the control station. One-way ANOVA showed that the differences in concentrations of Zn and Cu in sediments from the aquaculture and control stations were highly significant (P = 0.01), whereas Pb showed no such trend. Occurrence of a large fraction of labile Zn (56.1%) and Cu (40.3%) in these sediments warrants attention. Although factors other than metals may explain the distribution observed, the information presented here may be useful in predicting long-term effects of heavy metal contamination from aquaculture in the marine environment.

Rainbow Trout (<i>Oncorhynchus mykiss</i>) Cage Culture: Preliminary Observations of Surface Sediment’s Chemical Parameters and Phosphorus Release in Gokcekaya Reservoir, Turkey

“…These findings did not exceed the hazardous levels for aquatic organisms according to [24]. The pollution index of the sediment called the Schaanning Pollution Index and developed by Schaanning MT (1994), can be determined by using Zn and Cu concentration ranges in relation to pH levels [25]. Gokcekaya Reservoir's pH (8.85 and 9.12) was >7.7, and the sediment Zn and Cu concentrations were also <5.…”

Environmental Effects of A Marine Fish Farm of Sea Bass and Sea Bream in The Eastern Mediterranean Sea on Water Column and Sediment

“…Other studies reported that elevated concentrations of elements such as Cu, Zn, Fe, and Cd in superficial layers of marine sediments are caused by fish farming and decreased as a result of increasing distance from fish cages. Many other studies indicate that this state was mainly attributed to fish food inputs (Chou et al, 2002;Sutherland et al, 2007;Uotila, 1991;Belias et al, 2003;Kempf et al, 2002;Brooks & Mahnken 2003;Smith et al, 2005;Dean et al, 2007;Jaysankar et al, 2009;Rooney & Podemski, 2010;Russell et al, 2011).…”

“…However, high values of Cd, Mn, Pb, Zn and Fe can be related to other important anthropogenic input such as atmospheric emission, fly ash, domestic and industrial effluent discharge and, extensive use of antifouling paints by shipping activities (Sarkar et al, 2004). Many others authors demonstrated that the differences found between control stations and fish farms stations may be attributed to differences in natural background levels as well as, in the case of impacted stations, to differences of element input through fish farm wastes (fish feed and faces) (Brooks & Mahnken, 2003;Dean et al, 2007;Jaysankar et al, 2009). The surface sediment composition under and in the vicinity of the cages is continuously changing depending on the composition of the solids contained in aquaculture effluents (Mendiguchia et al, 2006).…”

Genome-resolved year-round dynamics reveal a broad range of giant virus microdiversity

“…Uranouchi Inlet, Japan is a semi-enclosed eutrophic inlet with high biodiversity, from unicellular organisms to large animals (Fig. S1) 58,59 . A previous study 16 identified year-round recovery of the Imitervirales community based on amplicon sequence variants of a single marker gene, DNApolB, in Uranouchi Inlet.…”