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Temporal and spatial variation in concentrations of trace metals in coastal sediments from the Ninety Mile Beach, Victoria, Australia
Marine PollutionBulletin 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 consequence, 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,
1992) and direct analysis of metal concentrations in the < 6 3 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 offshore 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 subsampled. 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
Fig. 1 Sediment sampling locations, Ninety Mile Beach, Victoria. W, Woodside Beach; S, Seaspray Beach; D, Delray Beach.
414
148 E
Volume 3 0 / N u m b e r 6/June 1995
~tm nylon mesh. The fraction passing through the mesh was split into two portions and freeze-dried in polythene Whirl-pacs. One dried portion was analysed for Hg, and the other for Cu, Cr, Cd, Pb, Fe, Ni and Mn. A nitric/perchloric acid digestion (Anon., 1984) was carried out on the fine sediment fraction ( < 63 Ixm) in order to obtain an estimate of the background concentrations of acid-digestible (total) metals within this fraction of the sediment. Acid-digestible or total metal concentrations are defined here as those metals that are in the exchangeable, adsorbed or lithogenic phases, and not part of the silicate matrix of the sediment (Anon., 1993). This digest was also carried out on the entire sediment sample for comparison purposes. Concentrated nitric acid (5 ml) was added to 1 g of each of the dried sediment samples and allowed to stand overnight. Digestion mixtures were heated to 95°C, cooled and then refluxed at 95°C with perchloric acid. The resulting solution was filtered through an acid-washed Whatman No. 541 filter paper into 10 ml of concentrated hydrochloric acid, diluted with deionized water, and analysed with a Varian SpectrAA-400 atomic absorption spectrophotometer. Each analysis was carried out in duplicate and the mean of the two results is reported here. The concentrations of acid-digestible (total) Hg present in the fine (< 63 ~tm) and the entire sediment fractions were determined using the digestion procedure of Elrick and Horowitz (1987). Approximately 1 g of dried sediment was weighed and added to a mixture of concentrated nitric and hydrochloric acids, and heated to 150°C for 30 min. Potassium dichromate (5 ml of 5%) was added to each solution, before dilution with deionized water and analysis for mercury with a Varian SpectrAA-400 atomic absorption spectrophotometer. Each analysis was carried out in duplicate and the mean of the two results is reported here. Blanks and a certified reference material (National Bureau of Standards Standard Reference Material 1646, Estuarine Sediment) were analysed concurrently with the sediment samples to ensure consistency of recoveries over the 3 years of sample collection (Table 1). A two-way (Model 1) hierarchical analysis of variance (ANOVA) was used to compare metal concentrations in the < 6 3 ~tm fraction over time, and
between sampling locations. Data were inspected for gross deviations from normality and transformed (log~) where necessary, before analysis. Where concentrations were less than the detection limit, values were assigned at half the detection limit (this was necessary only for some Hg analyses, for samples collected in 1992). A Tukey HSD multiple comparison procedure with an experimentwise type 1 error probability of 0.05 was used to locate any significant differences in metal concentrations. Pearson correlation coefficients and Bonferroni adjusted probabilities associated with each coefficient were calculated for metal concentrations in the < 63 ~tm fraction. All computations were carried out using the SYSTAT V5.03 statistical package (Wilkinson, 1990). Significant spatial and/or temporal differences existed in the concentrations of all metals assessed in the < 63 ~m sediment fraction (Table 2). Of the eight metals analysed, only Pb and Hg exhibited a significant interaction term for the main effects. Sediment samples from Woodside Beach contained consistently higher average concentrations of all metals excluding Fe, Pb and Hg over the 4-year survey period, although this difference was not statistically significant in all cases (Table 3). Fe occurred at highest concentrations in sediments from the Seaspray stations, although the average concentrations was not significantly higher than at the Woodside stations (Table 3). There was no consistent pattern in differences in mean metal concentrations over time (Table 3), although group comparisons suggested that there may have been an increase in average Fe, Ni and Mn concentrations with time. No significant difference in mean Pb concentrations in sediments was detected between sites in 1989 and 1992, but in 1991 the concentration was significantly higher in Seaspray Beach sediment samples than in those collected from Delray Beach (Table 4). No significant difference in mean Hg concentrations in sediments was detected between sediments collected from the three sites in 1989 and 1991, but in 1992 the Hg concentration was significantly higher in Woodside Beach sediments than in samples collected at the other two sites (Table 4). Statistically significant correlations (following a Bonferroni adjustment) were found between Cr and Pb
TABLE 1 Mean recoveries of sediment standards using nitric/perchloric and nitric/hydrochloric acid digestions.* < 63 ~tm Sediment fraction
Total sediment fraction
Metal
NBS reference material 1646
1989
1991
1992
1989
1991
1992
Cadmium Chromium Copper Iron Lead Manganese Mercury Nickel
(i.36 _+(/.(t7 76 _+3 18_+3 3.35 _+0.10 28.2 __+1.8 375 -+ 20 0.063 _+0.012 32_+ 3
0.46 33 15 2.33 13.8 171 0.077 18
0.36 53 15 2.60 20.0 203 0.068 22
(/.34 38 15 3.(13 17.4 276 0.064 23
(t.32 35 13 2.4(I 15.0 220 (I,(t5(t 18
0.36 33 18 3.12 29.9 238 0.088 21
(I.36 36 20 3.02 28.4 24 I 0.087 24
*Values reflect the degree of consistency of metal recoveries over the period of sample collection. All results are shown as {tg g-~ dry wt, except iron (wt %),
415
Marine Pollution Bulletin TABLE 2 Total cumulative concentrations of metals from the < 63 i,m sediment size fraction following extraction by nitric/hydrochloric and nitric/ perchloric acids and summary of results of two-way ANOVA on metal concentrations.* Year
Site
Station
Copper
Chromium
Cadmium
Lead
Iron
Nickel
Manganese
Mercury (A)
1989
Woodside
W1 W1 W2 W2 W3 W3 W4 W4
28.5 35.0 19.0 16.8 14.2 6.6 10.7 8.6
20.0 19.5 19.4 18.4 22.4 24.6 24.1 26.5
0.30 0.40 0.10 0.34 0.20 0.05 0.35 0.25
4.6 5.8 5.8 4.0 6.1 10.7 4.2 5.4
8900 69011 10 120 8700 9800 8800 11 000 9300
9.0 12.0 8.0 8.2 9.8 5.9 9.0 11.0
103 128 124 l 18 1S 128 139 119
0.36 IS 0.16 0.16 (/.39 0.14 0.12 0.22
Delray
D1 D1 D2 D2 D3 D3 D4 D4
NS NS 19.0 14.3 12.0 22.7 11.8 16.4
NS NS 27,1 18.9 21.4 19.1 14.6 19.7
NS NS 0.20 0.25 0.40 0.24 0.15 0.15
NS NS 7,1 5,5 4,1 8.6 3.1 4.1
NS NS 10 5011 10 i 00 8600 8200 13 200 9800
NS NS IS IS 7.8 10.2 6.0 6.9
NS NS 69 67 66 74 66 88
NS NS 0.22 0.16 0. l 5 0.25 0.11 0.13
Seaspray
S1 $1 $2 $2 $3 $3 $4 $4
14.3 11.0 9.6 8.0 6.3 6.5 11.8 11.3
21.0 16.6 15.4 14.2 15.4 20.3 24.3 28.2
0.35 0.25 0.60 0.30 0.40 0.10 0.30 0.25
3.6 1.6 0.1 2.5 2.1 6.8 6.0 10.0
10 800 11 100 l 0 200 9100 10 300 11 100 13 200 14 300
8.0 6.0 6.0 5.4 6.4 10.4 10.3 15.0
107 115 124 76 66 76 IS 216
0.16 0.15 0.13 0.32 0.16 /).21 0.13 0.15
Woodside
W1 W1 W2 W2 W3 W3 W4 W4
11.1 10.5 NS 21.2 10.0 26.4 10.0 5.2
75.6 58.4 NS 67.1 62.6 55.4 39.5 49.8
0.23 0.51 NS 0.10 0.48 0.24 0.07 0.07
44.3 13.5 NS 11.6 14.6 13.1 8.1 10.6
16 000 16 100 NS 16 401) 16 000 15 800 11 200 13 800
21t.5 16.1 NS 18.2 16.8 13.8 7.9 10.6
635 172 NS 377 192 3211 323 557
0.05 0.05 NS 0.86 0.66 IS 0.26 0.05
Delray
D1 D1 D2 D2 D3 D3 D4 D4
10.0 4.3 4.7 7.0 5.0 5.9 7.0 10.0
40.6 41.1 30.0 46.9 44.0 49.0 48.5 50.0
0.11 0.08 0.12 0.12 0.33 0.21 0.11 0.11
12.0 12.0 5.1 7.6 3.5 6.4 7.6 6.5
12 600 10 400 7500 12 000 13 100 13 600 10 500 10 600
8.9 5.9 5.6 8.5 10.0 10.8 5.9 6.9
1311 144 77 136 102 103 120 130
0.17 0.84 0.59 1.10 0.10 0.87 1.2/) 1t.93
Seaspray
$1 S1 $2 $2 $3 $3 $4 $4
8.2 10.7 6.3 6.3 8,0 7,6 8,1 10,2
58.8 47.1 51.5 46.l 46.0 46.9 43.7 47.1
0.11 0.12 0.18 0.15 0.10 0.12 (/.07 0.1 l
11.7 9.3 17.8 18.9 18.2 18.0 15.4 17.7
13 17 15 14 14 14 13 17
900 5011 900 800 400 800 2110 200
9.9 14.4 11.9 11.8 9.9 11.5 10.4 14.0
208 117 1117 152 256 193 258 236
0.88 1t.95 0.15 0.05 IS 0.05 0.05 0.05
Woodside
W1 W1 W2 W2 W3 W3 W4 W4
15,8 23.9 7.8 4.8 12.4 4.8 25.5 6.3
44.4 44.5 56.6 61.5 35.4 21.6 41.2 33.3
0.45 0.77 0.33 0.21 2.04 1.01 0.70 0.51/
10.8 7.9 13.8 5.8 7.4 6.6 13.2 10.1
18 19 17 10 19 17 20 20
500 300 700 300 900 500 600 000
13.6 15.5 11.5 6.3 12,7 1(1.4 20,6 19,0
252 344 478 183 331 243 665 447
0.36 0.28 0.26 0.06 0.13 0.16 t).23 0.25
Delray
D1 D1 D2 D2 D3 D3 D4 D4
7.1 19.5 4.6 9.4 13.1 6.1 9.3 7.1
46.9 35.8 31.8 35.3 35.8 47.5 47.2 48.5
0.33 0.39 0.22 0.14 0.24 0.13 0.17 0.34
18.4 21.8 8.6 10.9 15.0 12.6 12.5 12.2
17 16 15 20 17 17 16 16
000 000 000 000 700 000 400 700
10,6 10,2 10.0 13.3 10.7 10.7 9.6 9.8
134 155 115 126 81 155 177 140
0.06 < 0.05 < 0.05 < 11.05 < 1t.1t5 < 0.05 < 0.05 0.11
Seaspray
S1 SI $2 $2 $3 $3 $4 $4
6.8 1.1 4.2 6.9 7.8 7.2 9.1 7.5
36.7 41.1 30.6 45.4 38.1 40.2 30.6 30.9
1.54 IS IS 0.28 0.44 0.26 0.16 0.34
12.5 12.5 7.1 12.0 9.2 11.6 10.4 14.5
19 19 20 l9 20 20 20 21
900 600 000 300 100 200 4110 200
13.0 12.0 12.2 13.8 12.8 15.0 14.6 15.4
204 235 437 660 205 201 189 205
< 0.05 11.07 < 0.05 0.15 < 0.05 < 0.05 < 0.05 < 0.05
1991
1992
Source of variation Year Site Year × site
Station (year, site)
F value 5.54* 5.45* 1.34 1.50
88.18"** 0.90 2.18 1.08
14.51"** 2.94 2.64 1.73
16.11"** 0.38 3.36" 1.80
56.07*** 7.56*** 2.62 1.25
7.56** 6.11"* 1.69 2.36*
21.34"** 21.66"** 1/.37 0.17
12.63"** 4.21 * 4.01 * 2.48**
*All concentrations are shown as ~tg g-I dry wt. NS = Not sampled, IS = insufficient sample for analysis. (A) Nitric/hydrochloric extraction only. *0.01 < p < 0.05; **0.001 < p < 0.01; ***p < 0.001.
416
Volume 3 0 / N u m b e r 6/June 1995
TABLE 3 Summary of Tukey multiple comparison testing, <63 pm sediment fraction.*
TABLE 4 Summary of Tukey multiple comparison testing, mercury' and lead, < 63 ~tm fraction.*
Metal
Metal
Year
Lead
1989
Seaspray
Site multiple comparison
Time multiple comparison
Site multiple comparison
Copper
Seaspray Delray Woodside
1992 1991
Chromium
Seaspray Delray Woodside
1989 1992 1991
1991
Delray
Cadmium
I)elray Seaspray Woodside
1991
1992
Woodside
Iron
Delray Woodside Seaspray
1989 1991
1989
Delray
Nickel
Delray Seaspray Woodside
1989 1991 1992
1991
Seaspray
Manganese
Delray Seaspray Woodside
1989 1991
1992
Delray
1989
1989 1992 1992
1992
*Sites and years joined by a horizontal line showed no significant difference in metal concentration.
(r----0.601, 0.01 < p < 0 . 0 5 ) and Ni and Fe ( r - 0 . 7 6 6 , 0.001 < p < 0.01) at Woodside Beach; between Cr and Pb (r=0.868, p<0.001), Cr and Fe (r--0.817, 0.001 < p <0.01) and Ni and Fe (r=0.883, p < 0 . 0 0 1 ) at Seaspray Beach; and between Cr and Mn ( r - 0 . 8 4 5 , 0 . 0 0 1 < p < 0 . 0 1 ) at Delray Beach in the < 6 3 ~tm fraction of the sediment. Inter-metal correlations differed with locality, which may be indicative of differences in the origins of the metals, particularly in the vicinity of Seaspray Beach, which is adjacent to a freshwater creek discharge. Correlations along the eastern seaboard of Australia are more complex (deForest et al., 1978), with sediments having a higher degree of inter-element correlation than that found in the present study. Metal concentrations in sediments along the New South Wales coast are, however, probably influenced by inputs from industrial complexes in the Wollongong-Port Kembla area (deForest et al., 1978). Most results of the nitric/perchloric and nitric/ hydrochloric acid extractions for the entire sediment fraction were below detection limits, with the exception of Cr, Fe and Mn (Table 5). Nearshore sediments from the Ninety Mile Beach west of Lakes Entrance have generally low acid-extractable (total) concentrations of metals compared with other nearshore sites sampled around the Australian coastline (Table 6). Approximately 3 0 0 x 106 1 per annum of untreated domestic sewage originating from the Yarram township (population 2100) is discharged over the beach 5 km to the west of the sampling stations at Woodside Beach. The effluent contains relatively high concentrations of metals, including Cd, Cu, Pb and Zn, and is highly toxic to the amphipod test species Allochestes c o m p r e s s a (McKenzie & Goudey, 1991). There is a net easterly current movement along the Ninety Mile Beach (Wright et al., 1982) and the results of the < 63 {tm sediment fraction analyses suggest that it is likely that the Yarram outfall has resulted in minor metal contamination of the sediments in the vicinity of Woodside Beach.
Mercury
Delray
Woodside
Woodside
Seaspray
Seaspray
Seaspray
Woodside
Woodside Seaspray
Delray
Delray
Woodside
*Sites joined by a horizontal line showed no significant difference in metal concentration.
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Marine Pollution Bulletin The staff of Marine Science & Ecology Pty. Ltd collected sediment samples from the Ninety Mile Beach. Steve Shinners (Gippsland Water) is thanked for providing useful discussions, Gus Fabris and Geoff Nicholson (Marine Science Laboratories, Queenscliff) provided advice on metals analysis during the course of this study and reviewed a draft manuscript. Gerry Quinn (Monash University) is thanked for advice on statistical analysis of the data.
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Anon. (1984). Digestion Procedures for the Determination of Heavy Metals in Sediments by Atomic Absorption Spectrophotometry and ICP Emission Spectroscopy. Unpublished Report of the Rural Water Commission of Victoria. Rural Water Commission, Armadale, Victoria, Australia. Anon. (1993). Guidelines for the Sampling and Analysis of Contaminated Sediments. Draft report prepared for the Australian and New Zealand Environment and Conservation Council. Environment Protection Authority, Victoria, Australia. Black, C., Bolger, M. & Schaap, H. (1983). Background Levels of Trace Elements at the McGauran's Beach Outfall Site and Interaction of Ash Effluent with Seawater. State Electricity Commission of Victoria Report No. SO/83/66, Victoria, Australia. Bryan, G. W. & Langston, W. J. (1992). Bioavailability, accumulation and effects of heavy metals in sediments with special reference to United Kingdom estuaries: a review. Environ. Pollut. 76, 89-131. deforest, A., Murphy, S. P. & Pettis, R. W. (1978). Heavy metals in sediments from the central New South Wales coastal region. Aust..l. Mar, Freshwat. Res. 29,777-785. Elrick, K. A. & Horowitz, A. J. (19871. Analysis of Rocks and Sediments for Mercury by Wet Digestion and Flameless Cold Vapour Atomic Absorption (Varian Notes, No. AA-72). Varian Analytical Instruments, Palo Alto, CA, USA. F6rstner, U. (1989). Contaminated Sediments: Lectures on Environmental Aspects of Particle-Associated Chemicals in Aquatic Systems (Lecture Notes in Earth Sciences, Vol. 21). Springer, Berlin, Germany. F6rstner, U. & Wittmann, G. T. W. (1981). Metal Pollution in the Aquatic Environment (2nd edn). Springer, Berlin, Germany. Glover, J. W., Bacher, G. J. & T. S. Pearce (1980). Gippsland Regional Environmental Study: Heavy Metals in Biota and Sediments" of the Gippsland Lakes. Ministry for Conservation, Environmental Studies Series Publication No. 279, Victoria, Australia. Harris, J. W., Fabris, G. J., Statham, P. J. & Tawfik, F. (1979). Biogeochemistry of selected heavy metals in Western Port, Victoria, and use of invertebrates as indicators with emphasis on Mytilus edulis planulatus. Aust. J. Mar. Freshwat. Res. 30, 159-178. Luoma, S, N. (1990). Processes affecting metal concentrations in estuarine and coastal marine sediments. In Heavy Metals in the Marine Environment (R. W. Furness & P. S. Rainbow, eds), pp. 5166. CRC Press Inc., Boca Raton, FL, USA. McKenzie, J. A. & Goudey, R. (1991). Assessment of Coastal Discharges for their Potential Environmental Impact. Environment Protection Authority of Victoria, Scientific Report Series, Report No. SRS 91/ (106, Victoria, Australia. Nicholson, G. J., Fabris, J. G. & Gibbs, C. F. (1990). Heavy Metals in the Sediments of Corio Bay. Environmental Protection Authority of Victoria, Scientific Report Series, Report No. SRS 90/003, Victoria, Australia. Talbot, V., Magee, R. J, & Hussain, M. (1976). Distribution of heavy metals in Port Phillip Bay. Mar. Pollut. Bull. 7, 53-55. Wilkinson, L. (1990). SES'TAT: The System for Statistics. Systat, Inc., Evanston, IL, USA. Wright, L. D., Nielsen, P., Short, A. D, Coffey, F. C. & Green, M. D. (1982). Nearshore and Surfzone Motphodynamics of a Storm Wave Environment: Eastern Bass Strait, Australia. Coastal Studies Unit Technical Report No. 82/3, Coastal Studies Unit, University of Sydney, Australia.
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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 consequence, 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,
1992) and direct analysis of metal concentrations in the < 6 3 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 offshore 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 subsampled. 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
Fig. 1 Sediment sampling locations, Ninety Mile Beach, Victoria. W, Woodside Beach; S, Seaspray Beach; D, Delray Beach.
414
148 E
Volume 3 0 / N u m b e r 6/June 1995
~tm nylon mesh. The fraction passing through the mesh was split into two portions and freeze-dried in polythene Whirl-pacs. One dried portion was analysed for Hg, and the other for Cu, Cr, Cd, Pb, Fe, Ni and Mn. A nitric/perchloric acid digestion (Anon., 1984) was carried out on the fine sediment fraction ( < 63 Ixm) in order to obtain an estimate of the background concentrations of acid-digestible (total) metals within this fraction of the sediment. Acid-digestible or total metal concentrations are defined here as those metals that are in the exchangeable, adsorbed or lithogenic phases, and not part of the silicate matrix of the sediment (Anon., 1993). This digest was also carried out on the entire sediment sample for comparison purposes. Concentrated nitric acid (5 ml) was added to 1 g of each of the dried sediment samples and allowed to stand overnight. Digestion mixtures were heated to 95°C, cooled and then refluxed at 95°C with perchloric acid. The resulting solution was filtered through an acid-washed Whatman No. 541 filter paper into 10 ml of concentrated hydrochloric acid, diluted with deionized water, and analysed with a Varian SpectrAA-400 atomic absorption spectrophotometer. Each analysis was carried out in duplicate and the mean of the two results is reported here. The concentrations of acid-digestible (total) Hg present in the fine (< 63 ~tm) and the entire sediment fractions were determined using the digestion procedure of Elrick and Horowitz (1987). Approximately 1 g of dried sediment was weighed and added to a mixture of concentrated nitric and hydrochloric acids, and heated to 150°C for 30 min. Potassium dichromate (5 ml of 5%) was added to each solution, before dilution with deionized water and analysis for mercury with a Varian SpectrAA-400 atomic absorption spectrophotometer. Each analysis was carried out in duplicate and the mean of the two results is reported here. Blanks and a certified reference material (National Bureau of Standards Standard Reference Material 1646, Estuarine Sediment) were analysed concurrently with the sediment samples to ensure consistency of recoveries over the 3 years of sample collection (Table 1). A two-way (Model 1) hierarchical analysis of variance (ANOVA) was used to compare metal concentrations in the < 6 3 ~tm fraction over time, and
between sampling locations. Data were inspected for gross deviations from normality and transformed (log~) where necessary, before analysis. Where concentrations were less than the detection limit, values were assigned at half the detection limit (this was necessary only for some Hg analyses, for samples collected in 1992). A Tukey HSD multiple comparison procedure with an experimentwise type 1 error probability of 0.05 was used to locate any significant differences in metal concentrations. Pearson correlation coefficients and Bonferroni adjusted probabilities associated with each coefficient were calculated for metal concentrations in the < 63 ~tm fraction. All computations were carried out using the SYSTAT V5.03 statistical package (Wilkinson, 1990). Significant spatial and/or temporal differences existed in the concentrations of all metals assessed in the < 63 ~m sediment fraction (Table 2). Of the eight metals analysed, only Pb and Hg exhibited a significant interaction term for the main effects. Sediment samples from Woodside Beach contained consistently higher average concentrations of all metals excluding Fe, Pb and Hg over the 4-year survey period, although this difference was not statistically significant in all cases (Table 3). Fe occurred at highest concentrations in sediments from the Seaspray stations, although the average concentrations was not significantly higher than at the Woodside stations (Table 3). There was no consistent pattern in differences in mean metal concentrations over time (Table 3), although group comparisons suggested that there may have been an increase in average Fe, Ni and Mn concentrations with time. No significant difference in mean Pb concentrations in sediments was detected between sites in 1989 and 1992, but in 1991 the concentration was significantly higher in Seaspray Beach sediment samples than in those collected from Delray Beach (Table 4). No significant difference in mean Hg concentrations in sediments was detected between sediments collected from the three sites in 1989 and 1991, but in 1992 the Hg concentration was significantly higher in Woodside Beach sediments than in samples collected at the other two sites (Table 4). Statistically significant correlations (following a Bonferroni adjustment) were found between Cr and Pb
TABLE 1 Mean recoveries of sediment standards using nitric/perchloric and nitric/hydrochloric acid digestions.* < 63 ~tm Sediment fraction
Total sediment fraction
Metal
NBS reference material 1646
1989
1991
1992
1989
1991
1992
Cadmium Chromium Copper Iron Lead Manganese Mercury Nickel
(i.36 _+(/.(t7 76 _+3 18_+3 3.35 _+0.10 28.2 __+1.8 375 -+ 20 0.063 _+0.012 32_+ 3
0.46 33 15 2.33 13.8 171 0.077 18
0.36 53 15 2.60 20.0 203 0.068 22
(/.34 38 15 3.(13 17.4 276 0.064 23
(t.32 35 13 2.4(I 15.0 220 (I,(t5(t 18
0.36 33 18 3.12 29.9 238 0.088 21
(I.36 36 20 3.02 28.4 24 I 0.087 24
*Values reflect the degree of consistency of metal recoveries over the period of sample collection. All results are shown as {tg g-~ dry wt, except iron (wt %),
415
Marine Pollution Bulletin TABLE 2 Total cumulative concentrations of metals from the < 63 i,m sediment size fraction following extraction by nitric/hydrochloric and nitric/ perchloric acids and summary of results of two-way ANOVA on metal concentrations.* Year
Site
Station
Copper
Chromium
Cadmium
Lead
Iron
Nickel
Manganese
Mercury (A)
1989
Woodside
W1 W1 W2 W2 W3 W3 W4 W4
28.5 35.0 19.0 16.8 14.2 6.6 10.7 8.6
20.0 19.5 19.4 18.4 22.4 24.6 24.1 26.5
0.30 0.40 0.10 0.34 0.20 0.05 0.35 0.25
4.6 5.8 5.8 4.0 6.1 10.7 4.2 5.4
8900 69011 10 120 8700 9800 8800 11 000 9300
9.0 12.0 8.0 8.2 9.8 5.9 9.0 11.0
103 128 124 l 18 1S 128 139 119
0.36 IS 0.16 0.16 (/.39 0.14 0.12 0.22
Delray
D1 D1 D2 D2 D3 D3 D4 D4
NS NS 19.0 14.3 12.0 22.7 11.8 16.4
NS NS 27,1 18.9 21.4 19.1 14.6 19.7
NS NS 0.20 0.25 0.40 0.24 0.15 0.15
NS NS 7,1 5,5 4,1 8.6 3.1 4.1
NS NS 10 5011 10 i 00 8600 8200 13 200 9800
NS NS IS IS 7.8 10.2 6.0 6.9
NS NS 69 67 66 74 66 88
NS NS 0.22 0.16 0. l 5 0.25 0.11 0.13
Seaspray
S1 $1 $2 $2 $3 $3 $4 $4
14.3 11.0 9.6 8.0 6.3 6.5 11.8 11.3
21.0 16.6 15.4 14.2 15.4 20.3 24.3 28.2
0.35 0.25 0.60 0.30 0.40 0.10 0.30 0.25
3.6 1.6 0.1 2.5 2.1 6.8 6.0 10.0
10 800 11 100 l 0 200 9100 10 300 11 100 13 200 14 300
8.0 6.0 6.0 5.4 6.4 10.4 10.3 15.0
107 115 124 76 66 76 IS 216
0.16 0.15 0.13 0.32 0.16 /).21 0.13 0.15
Woodside
W1 W1 W2 W2 W3 W3 W4 W4
11.1 10.5 NS 21.2 10.0 26.4 10.0 5.2
75.6 58.4 NS 67.1 62.6 55.4 39.5 49.8
0.23 0.51 NS 0.10 0.48 0.24 0.07 0.07
44.3 13.5 NS 11.6 14.6 13.1 8.1 10.6
16 000 16 100 NS 16 401) 16 000 15 800 11 200 13 800
21t.5 16.1 NS 18.2 16.8 13.8 7.9 10.6
635 172 NS 377 192 3211 323 557
0.05 0.05 NS 0.86 0.66 IS 0.26 0.05
Delray
D1 D1 D2 D2 D3 D3 D4 D4
10.0 4.3 4.7 7.0 5.0 5.9 7.0 10.0
40.6 41.1 30.0 46.9 44.0 49.0 48.5 50.0
0.11 0.08 0.12 0.12 0.33 0.21 0.11 0.11
12.0 12.0 5.1 7.6 3.5 6.4 7.6 6.5
12 600 10 400 7500 12 000 13 100 13 600 10 500 10 600
8.9 5.9 5.6 8.5 10.0 10.8 5.9 6.9
1311 144 77 136 102 103 120 130
0.17 0.84 0.59 1.10 0.10 0.87 1.2/) 1t.93
Seaspray
$1 S1 $2 $2 $3 $3 $4 $4
8.2 10.7 6.3 6.3 8,0 7,6 8,1 10,2
58.8 47.1 51.5 46.l 46.0 46.9 43.7 47.1
0.11 0.12 0.18 0.15 0.10 0.12 (/.07 0.1 l
11.7 9.3 17.8 18.9 18.2 18.0 15.4 17.7
13 17 15 14 14 14 13 17
900 5011 900 800 400 800 2110 200
9.9 14.4 11.9 11.8 9.9 11.5 10.4 14.0
208 117 1117 152 256 193 258 236
0.88 1t.95 0.15 0.05 IS 0.05 0.05 0.05
Woodside
W1 W1 W2 W2 W3 W3 W4 W4
15,8 23.9 7.8 4.8 12.4 4.8 25.5 6.3
44.4 44.5 56.6 61.5 35.4 21.6 41.2 33.3
0.45 0.77 0.33 0.21 2.04 1.01 0.70 0.51/
10.8 7.9 13.8 5.8 7.4 6.6 13.2 10.1
18 19 17 10 19 17 20 20
500 300 700 300 900 500 600 000
13.6 15.5 11.5 6.3 12,7 1(1.4 20,6 19,0
252 344 478 183 331 243 665 447
0.36 0.28 0.26 0.06 0.13 0.16 t).23 0.25
Delray
D1 D1 D2 D2 D3 D3 D4 D4
7.1 19.5 4.6 9.4 13.1 6.1 9.3 7.1
46.9 35.8 31.8 35.3 35.8 47.5 47.2 48.5
0.33 0.39 0.22 0.14 0.24 0.13 0.17 0.34
18.4 21.8 8.6 10.9 15.0 12.6 12.5 12.2
17 16 15 20 17 17 16 16
000 000 000 000 700 000 400 700
10,6 10,2 10.0 13.3 10.7 10.7 9.6 9.8
134 155 115 126 81 155 177 140
0.06 < 0.05 < 0.05 < 11.05 < 1t.1t5 < 0.05 < 0.05 0.11
Seaspray
S1 SI $2 $2 $3 $3 $4 $4
6.8 1.1 4.2 6.9 7.8 7.2 9.1 7.5
36.7 41.1 30.6 45.4 38.1 40.2 30.6 30.9
1.54 IS IS 0.28 0.44 0.26 0.16 0.34
12.5 12.5 7.1 12.0 9.2 11.6 10.4 14.5
19 19 20 l9 20 20 20 21
900 600 000 300 100 200 4110 200
13.0 12.0 12.2 13.8 12.8 15.0 14.6 15.4
204 235 437 660 205 201 189 205
< 0.05 11.07 < 0.05 0.15 < 0.05 < 0.05 < 0.05 < 0.05
1991
1992
Source of variation Year Site Year × site
Station (year, site)
F value 5.54* 5.45* 1.34 1.50
88.18"** 0.90 2.18 1.08
14.51"** 2.94 2.64 1.73
16.11"** 0.38 3.36" 1.80
56.07*** 7.56*** 2.62 1.25
7.56** 6.11"* 1.69 2.36*
21.34"** 21.66"** 1/.37 0.17
12.63"** 4.21 * 4.01 * 2.48**
*All concentrations are shown as ~tg g-I dry wt. NS = Not sampled, IS = insufficient sample for analysis. (A) Nitric/hydrochloric extraction only. *0.01 < p < 0.05; **0.001 < p < 0.01; ***p < 0.001.
416
Volume 3 0 / N u m b e r 6/June 1995
TABLE 3 Summary of Tukey multiple comparison testing, <63 pm sediment fraction.*
TABLE 4 Summary of Tukey multiple comparison testing, mercury' and lead, < 63 ~tm fraction.*
Metal
Metal
Year
Lead
1989
Seaspray
Site multiple comparison
Time multiple comparison
Site multiple comparison
Copper
Seaspray Delray Woodside
1992 1991
Chromium
Seaspray Delray Woodside
1989 1992 1991
1991
Delray
Cadmium
I)elray Seaspray Woodside
1991
1992
Woodside
Iron
Delray Woodside Seaspray
1989 1991
1989
Delray
Nickel
Delray Seaspray Woodside
1989 1991 1992
1991
Seaspray
Manganese
Delray Seaspray Woodside
1989 1991
1992
Delray
1989
1989 1992 1992
1992
*Sites and years joined by a horizontal line showed no significant difference in metal concentration.
(r----0.601, 0.01 < p < 0 . 0 5 ) and Ni and Fe ( r - 0 . 7 6 6 , 0.001 < p < 0.01) at Woodside Beach; between Cr and Pb (r=0.868, p<0.001), Cr and Fe (r--0.817, 0.001 < p <0.01) and Ni and Fe (r=0.883, p < 0 . 0 0 1 ) at Seaspray Beach; and between Cr and Mn ( r - 0 . 8 4 5 , 0 . 0 0 1 < p < 0 . 0 1 ) at Delray Beach in the < 6 3 ~tm fraction of the sediment. Inter-metal correlations differed with locality, which may be indicative of differences in the origins of the metals, particularly in the vicinity of Seaspray Beach, which is adjacent to a freshwater creek discharge. Correlations along the eastern seaboard of Australia are more complex (deForest et al., 1978), with sediments having a higher degree of inter-element correlation than that found in the present study. Metal concentrations in sediments along the New South Wales coast are, however, probably influenced by inputs from industrial complexes in the Wollongong-Port Kembla area (deForest et al., 1978). Most results of the nitric/perchloric and nitric/ hydrochloric acid extractions for the entire sediment fraction were below detection limits, with the exception of Cr, Fe and Mn (Table 5). Nearshore sediments from the Ninety Mile Beach west of Lakes Entrance have generally low acid-extractable (total) concentrations of metals compared with other nearshore sites sampled around the Australian coastline (Table 6). Approximately 3 0 0 x 106 1 per annum of untreated domestic sewage originating from the Yarram township (population 2100) is discharged over the beach 5 km to the west of the sampling stations at Woodside Beach. The effluent contains relatively high concentrations of metals, including Cd, Cu, Pb and Zn, and is highly toxic to the amphipod test species Allochestes c o m p r e s s a (McKenzie & Goudey, 1991). There is a net easterly current movement along the Ninety Mile Beach (Wright et al., 1982) and the results of the < 63 {tm sediment fraction analyses suggest that it is likely that the Yarram outfall has resulted in minor metal contamination of the sediments in the vicinity of Woodside Beach.
Mercury
Delray
Woodside
Woodside
Seaspray
Seaspray
Seaspray
Woodside
Woodside Seaspray
Delray
Delray
Woodside
*Sites joined by a horizontal line showed no significant difference in metal concentration.
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Marine Pollution Bulletin The staff of Marine Science & Ecology Pty. Ltd collected sediment samples from the Ninety Mile Beach. Steve Shinners (Gippsland Water) is thanked for providing useful discussions, Gus Fabris and Geoff Nicholson (Marine Science Laboratories, Queenscliff) provided advice on metals analysis during the course of this study and reviewed a draft manuscript. Gerry Quinn (Monash University) is thanked for advice on statistical analysis of the data.
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Anon. (1984). Digestion Procedures for the Determination of Heavy Metals in Sediments by Atomic Absorption Spectrophotometry and ICP Emission Spectroscopy. Unpublished Report of the Rural Water Commission of Victoria. Rural Water Commission, Armadale, Victoria, Australia. Anon. (1993). Guidelines for the Sampling and Analysis of Contaminated Sediments. Draft report prepared for the Australian and New Zealand Environment and Conservation Council. Environment Protection Authority, Victoria, Australia. Black, C., Bolger, M. & Schaap, H. (1983). Background Levels of Trace Elements at the McGauran's Beach Outfall Site and Interaction of Ash Effluent with Seawater. State Electricity Commission of Victoria Report No. SO/83/66, Victoria, Australia. Bryan, G. W. & Langston, W. J. (1992). Bioavailability, accumulation and effects of heavy metals in sediments with special reference to United Kingdom estuaries: a review. Environ. Pollut. 76, 89-131. deforest, A., Murphy, S. P. & Pettis, R. W. (1978). Heavy metals in sediments from the central New South Wales coastal region. Aust..l. Mar, Freshwat. Res. 29,777-785. Elrick, K. A. & Horowitz, A. J. (19871. Analysis of Rocks and Sediments for Mercury by Wet Digestion and Flameless Cold Vapour Atomic Absorption (Varian Notes, No. AA-72). Varian Analytical Instruments, Palo Alto, CA, USA. F6rstner, U. (1989). Contaminated Sediments: Lectures on Environmental Aspects of Particle-Associated Chemicals in Aquatic Systems (Lecture Notes in Earth Sciences, Vol. 21). Springer, Berlin, Germany. F6rstner, U. & Wittmann, G. T. W. (1981). Metal Pollution in the Aquatic Environment (2nd edn). Springer, Berlin, Germany. Glover, J. W., Bacher, G. J. & T. S. Pearce (1980). Gippsland Regional Environmental Study: Heavy Metals in Biota and Sediments" of the Gippsland Lakes. Ministry for Conservation, Environmental Studies Series Publication No. 279, Victoria, Australia. Harris, J. W., Fabris, G. J., Statham, P. J. & Tawfik, F. (1979). Biogeochemistry of selected heavy metals in Western Port, Victoria, and use of invertebrates as indicators with emphasis on Mytilus edulis planulatus. Aust. J. Mar. Freshwat. Res. 30, 159-178. Luoma, S, N. (1990). Processes affecting metal concentrations in estuarine and coastal marine sediments. In Heavy Metals in the Marine Environment (R. W. Furness & P. S. Rainbow, eds), pp. 5166. CRC Press Inc., Boca Raton, FL, USA. McKenzie, J. A. & Goudey, R. (1991). Assessment of Coastal Discharges for their Potential Environmental Impact. Environment Protection Authority of Victoria, Scientific Report Series, Report No. SRS 91/ (106, Victoria, Australia. Nicholson, G. J., Fabris, J. G. & Gibbs, C. F. (1990). Heavy Metals in the Sediments of Corio Bay. Environmental Protection Authority of Victoria, Scientific Report Series, Report No. SRS 90/003, Victoria, Australia. Talbot, V., Magee, R. J, & Hussain, M. (1976). Distribution of heavy metals in Port Phillip Bay. Mar. Pollut. Bull. 7, 53-55. Wilkinson, L. (1990). SES'TAT: The System for Statistics. Systat, Inc., Evanston, IL, USA. Wright, L. D., Nielsen, P., Short, A. D, Coffey, F. C. & Green, M. D. (1982). Nearshore and Surfzone Motphodynamics of a Storm Wave Environment: Eastern Bass Strait, Australia. Coastal Studies Unit Technical Report No. 82/3, Coastal Studies Unit, University of Sydney, Australia.
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