Marine Pollution Bulletin, Vol. 30, No. 6, pp. 414-418, 1995 Pergamon Copyright ~ 1995 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0025-326X(95)00058-5 0025-326X/95 $9.50+0.00 Temporal and Spatial Variation in Concentrations of Trace Metals in Coastal Sediments from the Ninety Mile Beach, Victoria, Australia DAVID HAYNES, DAVID TOOHEY, DEBRA CLARKE and DONOVAN MARNEY* Gippsland Water, P.O. Box 348, Traralgon, Victoria 3844, Australia *Present address:TasmanianAlkaloidsPty.Ltd,BirraleeRd, Westbury, Tasmania 7303, Australia. Metal concentrations in sediments usually exceed those of the overlying water column by three to five orders of magnitude (Bryan & Langston, 1992). As a con- sequence, metals originating from human activities and contaminating coastal environments can often be identified more readily by analysis of sediments than by the quantification of metal concentrations present in solution (F6rstner & Wittmann, 1981). Sediments also integrate the temporal variability that characterizes metals originating from human sources (F6rstner, 1989). Fine-grained, oxidized particles are believed to constitute the most important sources of available metals contained in sediments (Bryan & Langston, Marine PollutionBulletin 1992) and direct analysis of metal concentrations in the <63 Ixm sediment fraction is an economical and effective method for the surveillance of changes in metal concentrations in the environment in relation to human activities (Luoma, 1990). This work reports the results of an investigation into the temporal and spatial variability of metal concentrations in sediments collected along the Ninety Mile Beach, Victoria, Australia. This investigation was carried out prior to the commencement of the discharge of a secondary-treated wastewater containing pulp and paper, domestic and industrial effluents at Delray Beach, in June 1992 (Fig. 1). Comparison of these results with data collected during subsequent surveys using the same sampling and analytical techniques will assist in determining the extent of any change in sediment pollutant levels that may occur as a result of commencement of the effluent discharge. Sediment samples for metal analysis were collected from the seabed at Delray, Woodside and Seaspray beaches in acid-soaked plastic containers by divers in April 1989, June 1991 and May 1992 (Fig. 1). Two 5 kg replicate samples were collected from four randomly located stations within a 0.4 km 2 area at each site. Samples were collected between 1.5 and 3.5 km off- shore in a water depth of approximately 16 m. The sediments were collected from the top 5 cm of the seabed surface and were frozen within 12 h. Prior to analysis, the frozen sediments were thawed and sub- sampled. Subsamples were freeze-dried for the subsequent analysis of metals in the entire sediment fraction (Hg, Cu, Cr, Cd, Pb, Fe, Ni and Mn), and the remainder of each sample was wet-sieved through a 63 nk Snce M'J" '~:~I-%U Ya,"ram" /)'% S w 146 E 147 E 148 E Fig. 1 Sediment sampling locations, Ninety Mile Beach, Victoria. W, Woodside Beach; S, Seaspray Beach; D, Delray Beach. 414