Spatial and Temporal Variations in Trace Metal Concentrations in the Cockle, Austrovenus Stutchburyi from Otago, New Zealand

Abstract

This is the first comprehensive study of sources of variation in metal concentrations within the whole tissues of a shallow burrowing, filter-feeding intertidal clam, Austrovenus stutchburyi. Samples were collected from 12 sites in April, August, November and February in 1993-1994 in the vicinity of Otago Harbour and Peninsula, New Zealand. Total tissue trace metal concentrations (microg g(-1) dry weight) were measured in individual animals for the essential metals : Mn, Cu, Zn, Ni and the non-essential Cr using trace-metal clean acid-digestion and ICP-OAES techniques. Average metal concentrations were 3-60 microg g(-1) for Cu, 40-118 microg g(-1) for Zn, 2-12 microg g(-1) for Mn, 5-35 microg g(-1) for Ni and 1-44 microg g(-1) for Cr. These levels decreased with body weight and differed amongst sites except for Cr in February (mid-summer). Highest concentrations occurred at sites close to a city (Dunedin) and within the central harbour region although the Cu, Zn, Ni and Cr concentrations did not correlate with the environmental gradient or season. At one coastal site, samples of both the blue mussel Mytilus galloprovincialis and cockles gave similar trends in trace metal levels. These results suggest that the cockle could be a useful trace metal biomonitor within NZ estuaries.

Investigation of heavy metals in sediments and Manila clams Ruditapes philippinarum from Jiaozhou Bay, China

“…It has been reported that the soft tissue dry weight of the mollusk Arctica islandica reached maximum values during the summer months (Swaileh 1996). Peake et al (2006) reported that the Cu tissue concentration of Austrovenus stutchburyi appeared to increase with declining the condition index. In our investigation, the condition index (soft tissue dry weight/shell Wet tissue-based data were converted to dry tissue-based data by assuming water content of 83% (Usero et al 1997) dry weight × 100) of R. philippinarum was 10.84-12.12% in August compared to 4.60-6.10% in December.…”

The Applicability of Plasma‐Based Techniques to Biological Monitoring

“…M. galloprovincialis can be used as a sensitive indicator for the availability of trace elements in the coastal waters off Korea [301]. A study of sources of variation in element concentrations within the whole tissues of the shallow burrowing, filter-feeding intertidal clam Austrovenus stutchbury was performed [302]. Bioaccumulation of 12 heavy metals in the shells of Mytilus edulis was investigated [303].…”