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1.
This paper examines concentrations of trace contaminants in oysters placed in inshore and offshore waters before and after the change to offshore disposal of sewage near Sydney, NSW, Australia. The ability to compare inshore and offshore concentrations before and after the event allows the formulation of unconfounded conclusions about the impact of sewage on the availablity of trace contaminants in the coastal environment and the effect of the change in the method of disposal of Sydney's sewage on the availability of those contaminants.

The data show clearly that the diversion of sewage from nearshore to offshore areas has resulted in a significant drop in the concentrations of organochlorines in oysters deployed near sewage outfalls in the nearshore region. In offshore areas, there were no differences detected among regions prior to the commissioning of deepwater outfalls. In the post commissioning period there were a number of instances when trace metal concentrations in the regions were different from each other, but these differences were not correlated with proximity to the sewage outfalls nor was a particular metal consistently elevated, so it was concluded that the causes of difference were not related to the presence of the sewage outfalls.

This study has demonstrated that oysters were useful indicators of trace metal and organochlorine contamination of marine waters; that relatively high levels of contamination of inshore waters near sewage outfalls prior to deepwater sewage disposal were reduced, to be not different from other parts of Sydney's coastline after the commencement of deepwater discharge, and that there was no concommitant increase in accumulation of contaminants in offshore waters. Further, preliminary indications are that Sydney's coastal waters are not very heavily contaminated by trace contaminants in comparison to areas of NSW with much lower levels of development. Concentrations of organochlorines are, however, high in comparison to data from similarly developed areas of the USA.  相似文献   


2.
The New South Wales Environment Protection Authority has recently completed a programme to evaluate the impact on near-shore shelf sediments, following the commissioning of three new deepwater sewage outfalls off Sydney, Australia. These outfalls discharge a total of around 1300 ML day−1 of primary treated sewage derived from domestic and industrial sources. The study compared three locations that were close to the outfalls (likely impacted) and three locations far from the outfalls (likely non-impacted). Four zones were sampled within each location to provide estimates of spatial variability. Three samples of surface sediment were collected from each zone at six monthly intervals over a three year period which encompassed the commissioning of the outfalls. The results of the study suggest that, associated with the commissioning of the three deepwater outfalls, there has not been a significant effect on the concentration of trace metals in the sediments surrounding the outfalls. The concentrations of trace metals in the whole sediment generally were close to the world-wide background levels quoted in the literature, and generally reflected the distribution pattern of the sedimentary fines (< 62.5 mm). When compared to a number of sediment quality guidelines, the concentrations of trace metals were found to be below a level considered to have the potential to cause biological effects or (in the case of As, Ni, Cr) at a level that could be tolerated by the majority of benthic organisms.  相似文献   

3.
For many years, sewage was continuously discharged via inshore outfalls into shallow subtidal habitats around Sydney (New South Wales). In 1990, deepwater ocean outfalls were commissioned and inshore discharge ceased. This study examined the assemblage of organisms found on subtidal cliffs at one inshore outfall to examine differences in, or recovery by, the biota when sewage was no longer discharged. This assemblage was primarily composed of filter-feeding animals (sponges, ascidians, bryozoans, anthozoans) and encrusting algae. Differences and changes in the assemblages at a number of different spatial scales, relative to the assemblages at two reference locations, were examined four times over a 20 month period. Although most taxa showed significant changes over the study period, most of these were unpredictable and varied interactively according to the taxon, plot, depth and location. For most measures, however, the location where sewage had been released lay within the natural variability shown by the reference locations. The implications of these findings are discussed with respect to other studies on the effects of sewage on intertidal and shallow subtidal habitats.  相似文献   

4.
Sydney's sewage disposal problems have been the catalyst for wider questioning by the community about the management of the water cycle in the Sydney Basin. Public concern over the deepwater ocean outfalls generated an involvement in the Environmental Monitoring Programme (EMP) which provided a number of insights into the marine environment offshore Sydney, interactions between agencies and the role of public interest groups. The EMP has not provided sufficient information to make decisions about the value of higher levels of treatment. However, public interest in these outfalls is being subsumed by demands for the greater recycling of water and mechanisms for reducing water use.  相似文献   

5.
Environmental variables and their association with faecal coliform and streptococci densities were investigated at a number of Sydney's metropolitan beaches. High variability in faecal coliform and faecal streptococci densities was observed at most beaches. The ability of the various models to explain the observed variation in faecal coliform or streptococci levels was relatively low, although they did provide an insight into the more influential environmental factors involved. Rainfall has the single most important effect on faecal coliform and streptococci densities at Sydney beaches. Whether this is due to increased stormwater runoff at the beaches, increased discharge through the outfalls (both the deepwater ocean outfalls and the few remaining shoreline outfalls), or a combination of both is unclear and is likely to depend on the individual beach being considered. Elevated levels of faecal coliforms and streptococci are still occasionally observed at some beaches, but these levels are usually not as high nor as frequent as they were prior to commissioning of the deepwater outfalls. The significant associations of current and plume entrapment with faecal coliform and streptococci densities at some Sydney beaches suggest that under certain conditions, effluent from the deepwater ocean outfalls can still influence faecal coliform and streptococci densities at these beaches.  相似文献   

6.
To overcome the problems of beach pollution Sydney Water constructed three deepwater sewage outfalls off North Head, Bondi and Malabar. The outfalls were commissioned over the period September 1990–July 1991. A 5-year multi-disciplinary environmental monitoring programme was set up to assess the impacts on the demersal fish and soft-bottom macro-invertebrate communities. Assessment of impact was based on an asymmetrical analysis of variance which provided an a priori orthogonal contrast between a single outfall and multiple control sites sampled before and after commissioning. Impacts were detected in both communities, included several commercially and recreationally important species of fish, and occurred with the greatest frequency in the soft-bottom community. The results are summarized, and several examples are presented and show that the direction and magnitude of the impacts varied among outfalls and taxa. The results are then discussed in terms of the needs of future monitoring and the implications for the assessment of human-induced impacts in other parts of the world.  相似文献   

7.
This paper summarizes the results of a large-scale ‘beyond BACI’ designed assessment of the influences of effluent discharges from Sydney's deepwater sewage outfalls on assemblages of larval fishes. Larval fishes were sampled at three outfalls and at multiple control locations three times before and three times after the deepwater outfalls were commissioned. Sampling was stratified to account for time of year, oceanography and plume behaviour. Large numbers of fish larvae were caught near the outfalls and were thus exposed to sewage plumes. Results indicated that some larvae that normally occur at depth were displaced upwards by rising plumes, particularly when plumes surfaced. No predictable positive or negative numerical responses of larvae to outfalls were evident. Rather responses varied depending on the taxa, outfall and season. The large inherent level of natural spatial and temporal variability in abundances of larvae swamped the detection of possible impacts for many taxa. Future field based studies need to track larvae through plumes to assess changes in numbers, but also to test effects on the health and condition of larvae.  相似文献   

8.
A quarterly sampling programme was conducted during 1973–1974 off the coast of Delaware to provide an environmental baseline for two ocean sewage outfalls. Extensive physical measurements and water quality data, together with biological data (fish, invertebrates, bacteriological samples), were collected. Based on this research the design of sewage treatment for one of the outfalls was improved.  相似文献   

9.
Health of red morwong, Cheilodactylus fuscus and rock cale, Crinodus lophodon was assessed using histology to determine effects of the Sydney cliff outfalls on these two species. Ten individuals of each species were sampled from three outfall sites and three control sites. Benign epitheliocystis, presence of metazoan parasites, epithelial lifting, telangiectasis, haemorrhage and inflammation were found in the gills of some individuals. Hemosiderin was present in melanomacrophage aggregates in liver and spleen of some fish and also in kidneys of a few fish collected in Malabar outfall site. Hyaline droplets were present in tubular epithelium in kidney of some fish, particularly in the individuals collected from Malabar. Although for some changes there was a trend of greater prevalence at the outfall sites, there was no statistically significant difference between the fish from outfall sites and control sites. Most changes were species specific and the differences were statistically significant. This suggests problems with extrapolating results from one species to others. Greater replication, smaller range of size, chemical analysis of tissue residues as well as better knowledge of the fate of sewage and oceanographic processes would improve interpretation of any future surveys. A multidisciplinary approach would be most beneficial for pollution studies.  相似文献   

10.
In order to predict the behaviour of plumes from three deep ocean outfalls for sewage off Sydney, three-dimensional numerical modelling was used. The modelling suite was driven by data generated by an oceanographic monitoring station measuring wind, ocean currents, temperature and wave characteristics. Three different modelling phases are implemented daily, a nearfield model, a hydrodynamic model and a water quality model. Model output can be used by the New South Wales Environment Protection Authority to predict water quality at ocean beaches and inform the community.  相似文献   

11.
With the possible exception of copper and zinc, eight trace metals in muscle tissue of five popular benthic-feeding sportsfishes caught near the Los Angeles County municipal wastewater outfalls were not concentrated above levels measured in island and coastal control specimens. In contrast, the edible portions of five invertebrate seafood organisms collected from the highly contaminated bottom sediments in this discharge zone did concentrate some of the metals several-fold above control values. The maximum contamination observed was a 10-fold elevation of chromium in abalone and scallop muscle.  相似文献   

12.
Since the commissioning of the three major deepwater outfalls in Sydney, there has been a dramatic improvement in general beach water quality at Sydney's ocean beaches. This has required the NSW Environment Protection Authority's Beachwatch Programme to shift from assessing the impacts of gross sewage pollution due to nearshore outfalls to more diffuse pollution from stormwater and sewer overflows.

The visual indicators of gross sewage pollution originally used by Beachwatch for the daily assessment of bacterial water quality are now of limited value. General linear models (with multiple effects) were constructed to identify the secondary indicators which best describe the levels of bacterial contamination due to stormwater pollution. Data from four representative Sydney beaches were modelled separately due to the site-specific effects of pollution sources and hydrodynamics. Factors which were built into the models and were known on the day of prediction were rain amount, presence of stormwater material, the maximum daily stormwater rating, drain or lagoon flows at the time of sampling, and the drain/lagoon bacterial concentration two days before sampling.

Results indicate that there is a general linear relationship between visual indicators and bacterial density; however, the reliability of the prediction on a daily basis is poor and rainfall alone as a predictor is equivalent to or better than visual assessment alone. The primary source of information for the preparation of Beachwatch daily pollution bulletins now is rainfall reports from a telemetered network of rain gauges along the coast. This is a more cost-effective approach and has allowed the reallocation of resources to address more directly the problem of stormwater pollution at higher risk beaches.  相似文献   


13.
Little is known about the impacts of mine waste disposal, including deep-sea tailings, on tropical marine environments and this study presents the first account of this impact on deepwater fish communities. The Lihir gold mine in Papua New Guinea has deposited both excavated overburden and processed tailings slurry into the coastal environment since 1997. The abundances of fish species and trace metal concentrations in their tissues were compared between sites adjacent to and away from the mine. In this study (1999-2002), 975 fish of 98 species were caught. Significantly fewer fish were caught close to the mine than in neighbouring regions; the highest numbers were in regions distant from the mine. The catch rates of nine of the 17 most abundant species were lowest, and in three species were highest, close to the mine. There appears to be limited contamination in fish tissues caused by trace metals disposed as mine waste. Although arsenic (several species) and mercury (one species) were found in concentrations above Australian food standards. However, as in the baseline (pre-mine) sampling, it appears they are accumulating these metals mostly from naturally-occurring sources rather than the mine waste.  相似文献   

14.
Sydney Water has completed a risk assessment to assess the risks to human health and aquatic organisms in creeks, rivers, estuaries and ocean waters affected by wet weather sewage overflows, stormwater and sewage treatment plant discharges. The risk assessment methodology consists of a comparison of measured and predicted concentrations of chemicals with toxicity reference values. Estimates of receiving water chemical concentrations were derived using data from a 10-year period so that the variable rainfall pattern was represented. Computer models were used to simulate and predict wet weather discharges during this ten year period. Risks were validated by bioassays and bioassessments. Risks to aquatic life from wet weather discharges were attributed to 14 chemicals at one or more of the sites and stormwater was the predominate source of the chemicals. There were no risks to people engaged in water based activities. Noncarcinogenic risks from fish ingestion are predicted at three sites. Predicted cancer risks for most individual chemicals were relatively small. Carcinogenic risks were typically associated with organochlorine compounds, polycyclic aromatic hydrocarbons, dichlorobenzene, and arsenic. The predicted cancer risks also appear to be largely the result of stormwater rather than sewage overflow inputs and largely due to historical contamination by organochlorine pesticides. It is expected the concentrations of these chemicals will decrease over time.  相似文献   

15.
The Sydney Environmental Monitoring Programme (EMP) measured the environmental performance of Sydney's new deepwater sewage outfalls against a wide range of criteria related to impacts on marine ecosystems and on human use of marine resources. It consisted of a number of interacting studies conducted during the period 1989 to 1993. Given that all the studies have now been finalized and the data analysed and presented (see papers in this volume), it is appropriate to review the program as a whole and identify, with the benefit of hindsight, where things could have been done better. This paper focuses mainly on the experimental design and statistical treatment of the studies conducted, although management problems are also briefly addressed. Overall it is concluded that the studies making up the EMP contributed greatly to enhancing our understanding of the marine environment of the coastal shelf off Sydney, an area which had previously received only limited attention. Most of the studies, however, suffered from deficiencies in experimental design, which was difficult to overcome when analysing the data. It will be important, in designing future integrated monitoring studies, to draw on the experience of programs such as this to avoid some of the pitfalls which appear to be inherent in these types of large programs.  相似文献   

16.
Residues of DDE, DDD, DDT and PCB were measured in different tissues of fourteen sperm whales caught in the waters off Spain's north-western coasts. Unlike what seems common in other marine mammal species, females appear to be more contaminated by organochlorine compounds than males. Pollutant levels in this species were found to be intermediate to other cetaceans, probably due to their feeding habits mainly based on squid and bottom fish. Concentrations of total DDT and PCB in blubber were similar to most of those determined in sperm whales from other areas of the northern hemisphere.  相似文献   

17.
Sediment cores from the vicinity of sewage outfalls off McMurdo Station as well as surface grab samples from different locations in the McMurdo Sound, Antarctica were analysed for coprostanol (5β-cholestan-3β-ol) and epicoprostanol (5β-cholestan-3-ol) to assess the degree of sewage addition to the Sound. Sediment samples close to the point source contain as much as 3 mg g−1 dry sediment of coprostanol, whereas samples farther from the source, for example from New Harbour and Granite Harbour, contain only trace levels to 40 ng g−1. Coprostanol in the sediments of latter locations most likely originates from seals rather than from sewage outfalls. It appears that sewage particles are very quickly incorporated into the sediment layers close to the discharge point in the eastern Sound. However, significant levels (930 ng g−1) of fecal sterols were detected in Cape Armitage surface sediments, indicating that the sewage plume could also have reached the seawater intake station, situated in between the outfall and Cape Armitage sampling site. These results suggest the need for a sound environmental monitoring and assessment of the existing wastewater practices in the region.  相似文献   

18.
Point-source impacts such as sewage plumes can cause significant degradation of larval habitat. Data on larval abundance, current speed and the shape of surface and subsurface sewage plumes off the coast of Sydney, Australia, indicated that long-shore currents can transport large numbers of larvae through plumes that can potentially affect the health of larvae. Deformities to the notochord, eyes and head were found in samples of preserved wild larvae. Some deformities (e.g. Lateral curl of the notochord) were probably caused by preservation and ‘packing effects’ (shaped by organisms and objects in the sample), while others (e.g. half-pigmented eyes and corrugated notochord) were unlikely to have been caused by sampling artefacts. Deformed larvae were found in waters around Sydney that are influenced by multiple sewage outfalls, and at locations up to 250 km from Sydney. It was concluded that deformities were caused by natural and potentially anthropogenic factors. Cyto- and histopathological studies of larvae are required. Moreover, relationships between oceanography and concentrations of pollutants in plumes are needed to further assess impacts of pollutants on assemblages of vulnerable planktonic animals.  相似文献   

19.
The discharge of sewage to the ocean can be an issue of public and scientific concern. Such has been the case in Sydney over at least the past 25 years. In this paper, the history of Sydney's sewage discharge is outlined, and the decisions taken to address concerns about the environmental effects of shoreline discharge of large volumes of primary treated sewage effluent are described. Design criteria are described for deepwater outfall systems that, since 1990–1991, have discharged 80% of Sydney's sewage after primary treatment at North Head, Bondi and Malabar Sewage Treatment Plants (STP). The integrated elements of a comprehensive five year Environmental Monitoring Programme (EMP) are set out. Other papers in this volume describe the result of EMP component studies. The five year EMP was designed to provide the basis to assess the environmental performance of the new deepwater outfall systems during the first two years of their operation and to provide a baseline against which further change may be measured.  相似文献   

20.
The levels of DDT residues, dieldrin and PCBs have been determined in the tissues of 15 species of marine animals from the Liverpool Bay area of the Irish Sea. In general, the concentrations of these compounds are somewhat lower than those reported earlier for fish from other British inshore areas, despite the fact that the Bay is subject to pollution, not only from the River Mersey, but also from extensive sewage sludge dumping. This difference may reflect recent controls on the use of these compounds.  相似文献   

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