Biological Monitoring of Heavy-Metal Contamination in Coastal Waters Off Casey Station, Windmill Islands, East Antarctica
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Polar Biol ,2002) 25: 206±215 DOI 10.1007/s00300-001-0328-9 ORIGINAL PAPER S. Duquesne á M.J. Riddle Biological monitoring of heavy-metal contamination in coastal waters off Casey Station, Windmill Islands, East Antarctica Accepted: 17 September 2001 / Published online: 14November 2001 Ó Springer-Verlag 2001 Abstract Heavy-metal concentrations were determined formation gathered about processes of contaminant in tissues of dierent species of benthic invertebrates uptake and partitioning among dierent tissues and collected in the Casey region ,Australian Antarctic species could be used in later studies to investigate the Territory) where an old waste-disposal tip site is a source behaviour and the source of contaminants. of contamination. The species studied included the biv- alve Laternula elliptica, star®sh Notasterias armata, heart urchins Abatus nimrodi and A. ingens and gam- Introduction maridean amphipod Paramoera walkeri. The specimens were collected at both reference and contaminated lo- Antarctica is the most remote and least-inhabited con- cations where lead was the priority element and copper tinent; however, it is no longer free of environmental was the next most important in terms of increased contaminants. Processes such as ``global distillation'' concentrations. The strong association between a gra- cause the transfer of pollutants, particularly volatile dient of contamination and concentrations in all species hydrocarbons, from the industrialized regions of the tested indicates that they are re¯ecting well the envi- world to the polar regions ,Risebrough et al. 1976; Van ronmental changes, and that they appear as appropriate den Brink 1997). More locally, activities in the Antarc- biological indicators of heavy-metal contamination. tic, such as shipping activities and research stations, Aspects of the biology of species with dierent func- have created sites with contamination at levels compa- tional roles in the marine ecosystem are discussed in rable to industrial sites elsewhere ,Berkmann 1992; relation to their suitability for wider use in Antarctic Deprez et al. 1999). In response to these, all countries monitoring programmes. For example, in terms of operating in Antarctica have now agreed to a range of heavy-metal bioaccumulation, the bivalve appears as the measures to reduce or eliminate pollution ,Madrid most sensitive species to detect contamination; the protocol), and this requires the monitoring of levels of star®sh provides information on the transfer of metals contaminants. through the food web while the heart urchin and The present investigation deals with a contaminated gammarid give indications of the spatial and temporal site at a research station. In this case-study, there is patterns of the environmental contamination. The in- evidence showing that trace metals are the contaminants of most concern in the soil of an old onshore waste- disposal site ,Deprez et al. 1999). They are mobilized by meltwater during the summer thaw and ¯ow in to the S. Duquesne ,&) National Research Centre for Environmental Toxicology, adjacent bay, partly dissolved but mostly adsorbed to University of Queensland, Kessels Road, particles on land and in the marine environment ,Snape Coopers Plain, QLD 4108 Australia et al., in press). Analyses in leachate showed that lead, M.J. Riddle copper and, to a lesser extent, zinc are of concern Australian Antarctic Division, Channel Highway, ,Deprez et al. 1999). Analyses in marine sediment Kingston, TAS 7050, Australia showed that lead and copper concentrations are about Present address: S. Duquesne 17- and 3.5-fold more elevated than background values University of the West of England, whereas no signi®cant increase is detected for zinc. They Faculty of Applied Sciences, Frenchay Campus, also demonstrate the presence of a gradient of contami- Coldharbour Lane, Bristol, BS16 1QY, England e-mail: [email protected] nation among some of the sites currently investigated Tel.: +44-117-3442680 ,S. Duquesne and M. Liess, unpublished data). Strong Fax: +44-117-9763871 evidence supports the fact that the increase of metal 207 concentrations in the nearshore environment is due to also collected at other locations further away from the tip site, the vicinity to the old waste-disposal tip site rather than i.e.Newcombe Bay ,about 1.5±3 km from the tip), Shannon Bay to a natural background enrichment of the area, because ,about 1.5 km) and O'Brien Bay ,about 4km) ,Fig. 1). ,1) waters became enriched in contaminants compared to background levels when they ¯owed through the tip Collection and dissection of animals down towards the sea ,Snape et al., in press), ,2) only 2 out of 16 sites investigated along the shore had signi®- Bivalves, star®sh and heart urchins were collected by divers at all cantly high amounts of metals in suspended particulates; locations, at depths between about 5 and 20 m. Then individuals of both sites were adjacent to old waste-disposal tip sites sizes from similar ranges were selected. Animals were brought back alive to the laboratory and kept in aquaria in clean ®ltered seawater ,Wilkes and Old Casey) ,Liess and Duquesne 1997), and at 00.5°C for 2 days before dissection. Dierent tissues were ,3) the chemical pro®les of contaminants at sea and in dissected from the various species ,gills, kidney and muscle-siphon the soil of the tip site are similar. from the bivalve; pyloric caeca and stomach from the star®sh; di- Monitoring the levels of contaminants using biologi- gestive tract and skeleton from the heart urchin). After dissection, all tissues were stored in polyethylene bags and frozen at ±20°C. cal species will provide a measure of the fraction of The size and sex of each individual were recorded. The mean sizes chemicals that is bioavailable and thus potentially toxic. were 79.219.4 mm for bivalves, 40.54.6 mm for heart urchins Such monitoring is widely used ,Phillips 1980; Stebbing and 30.254.71 cm for star®sh. et al. 1992). Suitable benthic invertebrates for use Gammarids were collected at a reference site with hand nets and as biological indicators of trace-metal contamination in transplanted to two sites within Brown Bay ,Fig. 1, sites a and b). Adults ,1±1.5 cm) were placed in plastic enclosures ,15 l) with aquatic environments include bivalves ,Bryan et al. 1-mm-mesh netting at the top and bottom. These enclosures were 1985), echinoderms ,Warnau et al. 1995; Temara et al. held vertically at 1 m below the water surface and four of them 1998a) and crustaceans ,Rainbow and White 1989; were placed at each location. Each of them contained 50 individ- Moore et al. 1991; Zauke et al. 1995). The species selected uals. After 18 days of exposure, individuals from a single enclosure were kept in aquaria in clean ®ltered seawater at 00.5°C for in this study were the bivalve, Laternula elliptica, two 2 days. They were then pooled, rinsed with distilled water and heart urchins ,Abatus nimrodi and A. ingens), the aster- frozen at ±20°C. oid, Notasterias armata, and the crustacean, Paramoera walkeri, as they are common in nearshore waters of the investigated region. Furthermore, some of them are Analyses of heavy metals known to be distributed around the Antarctic continent. All samples were dried at 50°C under vacuum and about 0.5 g of The use of these species will provide information on the dry material was digested for 12 h at room temperature in 3 ml the biological availability of metals to species with a 70% nitric acid ,Aristar) in polyethylene-capped tubes. Samples variety of habitats and feeding modes and may indicate were then heated at 90°C in a water bath for 3 h and ®nally diluted how metals are distributed among dierent environ- to a total volume of 40 ml with distilled water. Blanks and standard mental compartments and accumulated in the environ- reference material ,NIST, oyster 1566a) were processed in the same way. Extra samples from each type of tissue were spiked with in- ment ,Rainbow 1985). ternal standards for calculation of metal concentrations. Prior to The objectives of this study were: ,1) to assess the digestion, a fraction of heart-urchin skeleton was ®rst cleansed of extent of contamination in a suite of representative non-calci®ed tissues using 1& ,w/v) proteinase N ,Serva) solution Antarctic nearshore invertebrates; this baseline study will according to the method of Dubois and Jangoux ,1985). Metal concentrations ,arsenic, cadmium, chromium, copper, be used for monitoring changes after clean-up operations, nickel, lead and zinc) were determined by ICP MS using a Perkin as part of remediation procedures of contaminated sites; Elmer Elan 5100 for all samples except the gammarids, which were and ,2) to determine whether the species tested are useful analysed on a Fissons PQ2+STE. Analyses of certi®ed reference as biological indicators of heavy-metal contamination, material ,SRM 1566a) were in the range of 87±112% of the certi®ed for further monitoring programmes in Antarctica. values, indicating that analyses were both accurate and precise. Statistical analyses Materials and methods Dierences in metal concentrations of specimens from dierent sites ,contaminated or control), tissues and species were tested Study area using analysis of variance ,ANOVA). The numbers of specimens collected at the dierent locations varied ,between 2 and 16, see The region around Casey Station, Wilkes Land, East Antarctica Table 1); hence the numbers of replicates used in the analysis were ,110°30¢E,66°17¢S), a small ice-free site in an area of peninsulas selected to make best use of the available samples. Some sites were and rocky islands, was selected for this study because there are excluded from the analysis because too few replicates were avail- several discrete sites nearby representing the full range of con- able.