Changes in the Marine Environment

Data on water quality, sediment quality and aquatic organisms in Port Kembla Harbour from the 1970s to the 1990s are reviewed. In the 1970s, the marine environment of Port Kembla Harbour was in poor condition as a result of pollution from heavy industries. Elevated concentrations of pollutants were found in water, sediment and fish in the harbour; aquatic biodiversity was limited and many fish kills were reported. With the implementation of pollution reduction programs (required by legislation changes) by the industries surrounding the harbour since the 1970s, pollution in the harbour has been reduced dramatically, and the quality of the marine environment of the harbour has noticeably improved. Large reductions in the concentrations of certain toxic wastes and heavy metals in water have occurred. Marine life has returned to the whole harbour (parts were described in 1977 as abiotic). Contaminants in fish have decreased. Despite this achievement, however, there is still considerable room for improvement in the quality of the marine environment of the harbour.

Port Kembla Harbour is an artificial harbour on the east coast of New South Wales, Australia, 71 km south of Sydney (at 34°29' S, 150°54' E). It is one of four major ports on the New South Wales coast, the others being Newcastle Harbour, Sydney Harbour and Botany Bay. It is a major industrial port with Australia's largest steel works (5 Mt/annum production) adjacent to the harbour and a large (20 Mt/annum) coal exporting terminal, a grain exporting terminal (6 Mt/annum), a copper smelter and a fertiliser manufacturing plant in the immediate vicinity of the harbour. Port Kembla ranks ninth in Australian ports, with an average of 25 million tonnes of cargoes moving annually through the port, carried by some 1300 ships.

The port consists of an outer harbour formed adjacent to a headland to the southeast by the construction of breakwaters and an inner harbour formed by the dredging of Tom Thumb Lagoon. The Outer Harbour is an area of 137.5 ha, with depths from 4 to 16 m, while the Inner Harbour is an area of 56.5 ha, with depths from 9.2 to 16.3 m. Entrance to the Inner Harbour is through a 155 m wide channel known locally as 'the Cut' (Port Kembla Port Corporation, 1995).

Allans Creek is the major drainage system to the harbour. It has a catchment area of 23 km2 and extends 8 km from the Illawarra escarpment in the west to Port Kembla Inner Harbour in the east. The land use within the catchment comprises an array of heavy industry, light industry, commercial, urban and rural zones. Other drainage systems to the harbour are the Town Drain from the north and some small creeks from the south. The Town Drain receives significant urban runoff from Wollongong City (Hanson, 1982; Rhoden, 1990).

Industrial effluents have been the major cause of water pollution in Port Kembla Harbour for many years. Pollution reduction programs were implemented by the heavy industries adjacent to the harbour, beginning in the 1970's. Since then, there have been numerous studies on water and sediment quality, marine organisms and water pollution control in the harbour.

In this paper, we summarise the results of various studies of Port Kembla Harbour from 1975-1995, on water and sediment quality, benthic organisms and pollution levels, and comment on trends in the environmental health of the harbour and pollution reduction practices of local heavy industries.

Reports, data and other information on water quality, sediment quality and aquatic organisms in Port Kembla Harbour from the 1970s to the 1990s available from the New South Wales Government Departments, Broken Hill Propriety Steel (BHP Steel, including BHP Integrated Steel, BHP Flat Products Division, and BHP Sheet and Coil Division), University of Wollongong, Wollongong City Council and other organisations and individuals were collected and reviewed. In order to develop a system for examining changes, sites were selected which were equivalent to the current BHP harbour survey stations. Relevant data on water quality and sediment quality from these sites were used to look for temporal trends. Only data for which some assessment of quality could be made were used in the analysis. Indications of data quality utilised were: clear statement of methods used; naming of laboratory carrying out the analyses, particularly for registered laboratories; inclusion of data quality information (replicates, reference materials data) in the report; and discussion of data collection with the scientists involved.

Water quality parameters considered were dissolved oxygen (DO), ammonia (NH3), cyanide (CN), phenol and the metals Cd, Cu, Fe, Pb and Zn. Yearly values of the water quality parameters from each source were obtained by averaging the appropriate values for a site from all data sources in a given year. For sediments, data on the heavy metal parameters As, Cd, Cr, Cu, Fe, Hg, Pb and Zn were considered, and all results were recalculated to mg/kg on a dry weight basis. Interpretation of the sediment results must be carried out with caution since dredging programs have taken place in the harbour throughout the period under investigation.

For aquatic organisms, data on intertidal epibiota, subtidal epibiota and chemicals in fish were examined to see if any changes in the marine fauna in the harbour could be identified over this period. Data on industrial pollution effluents and pollution control practices of the heavy industries were collated to assess the effectiveness of water pollution reduction programs of the industries in improving the harbour marine environment.

The data used in the following analysis was taken from reports showing evidence of some quality control procedures being in operation. The methods used were considered 'good' at the time of measurement, but, particularly for heavy metals in water, there is evidence that much of the work carried out globally in the 1970s produced results that were unreliable at low (< 5 µg/L) concentrations, due to problems with blanks, contamination of samples and detection limits (e.g., see Batley, 1999). Most of the concentrations used in this analysis were above 5 µg/L.

The data show that the water quality in the 1970s was poor compared with the Australia and New Zealand Environment and Conservation Council (ANZECC, 1992) guidelines for protection of aquatic ecosystems (marine waters). The average concentration of dissolved oxygen in the upper water columns (samples taken from depths < 10 m) of the Inner Harbour was 20% lower than the guideline concentration while those of cyanide and phenol were 200 times and twice, respectively, the guideline concentrations. Concentrations of zinc in the upper water columns of the Inner Harbour and around Site 4 were 2-3 times the ANZECC (1992) guideline concentration, while those of lead were 1.5 to 3 times the guideline value, and cadmium in the upper water columns of the Outer Harbour was three times the guideline concentration. The concentrations of copper in the lower water columns (depth > 10 m) were high, reaching up to 9, 6 and 7 times the guideline concentration in the Inner Harbour, the Cut (Site #4) and the Outer Harbour respectively (Table 1).

From the 1970s to the 1990s, there were substantial reductions in the concentrations of cyanide, phenol, iron and zinc. For dissolved oxygen (DO), the concentrations in the Inner Harbour increased by about 20% from the 1970s to the 1990s, while for ammonia, small reductions appear to have occurred over the same period. The concentrations of zinc decreased markedly over most of the Harbour, while for copper, decreases were recorded for the lower water column concentrations between the 1970s and the 1990s, but the surface waters showed no pattern of change. The concentrations of cadmium and lead showed no significant changes from the 1970s to the 1990s.

Comparison of the average heavy metal contents in the harbour sediment samples with those from areas of New South Wales with similar geology and sediment types (SPCC, 1986b), but unaffected by waste disposal or other pollution, showed that Port Kembla Harbour sediments contained elevated concentrations of heavy metals. Batley and Low (1986) showed that concentrations of iron, lead and zinc were about an order of magnitude higher than in sediments from areas unaffected by waste disposal. Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc all lay within the ranges found in other polluted systems (Batley and Low, 1986). The relatively large concentrations of iron in Port Kembla sediments were expected because large quantities of iron ore are shipped into the harbour and stored in the surrounds.

S ediment	Sources	As	Cd	Cr	Cu	Fe	Hg	Pb	Zn

Port Kembla	1977 a			276	953	100429		409	2043
Harbour	1986 * b	45	15	174	95	73000	0.5	269	2220
Average	1990 c	14	4.5				0.2	151
	1991 c	34	4				2.9	479
	1992 c	46	0.8				0.4	453
	1993 c	43	5.6	203	1468		0.6	484	1209

Sediments unaffected	NSW Central Coast	-	0.5-5	-	3-20	2100	-	3-20	0-140
by waste disposal d,e	Average for East Coast, Australia	-	1.6	38	6	900	-	21	40
	World Average	40	0.3	100	48	6000	-	20	95
	Port Hacking	-	-	<10	<10	3500	-	-	10

Table 1 - Heavy Metal Concentrations (mg/kg) in Sediments from Port Kembla Harbour, environments unaffected by waste disposal and other polluted systems

Determination of the temporal changes in sediment metal concentrations from the 1970s to the 1990s was difficult to define as the data was derived from a number of different reports. In many of the reports, the original authors did not attempt to examine temporal changes and did not relate their data to that of earlier workers. Thus it was difficult to relate individual sediment metal concentration changes to specific activities in the surrounding industries, as at least three major industries are involved, each with a different schedule of environmental improvement.

A decrease did occur in the zinc concentration, and possibly for cadmium, but for the other metals no real patterns of change were observed, except possibly for copper where an increase in sediment concentration is indicated.

An attempt was made to assess changes in biodiversity and marine faunal health in the harbour by examining data on intertidal epibiota, subtidal biota and chemicals in fish. The ability to interpret the data from many of the studies was severely compromised because studies were often based on short investigations (< 1 week), no suitable control sites were considered, and details on replication and statistical analysis techniques used were not always fully presented. There were few data to examine any seasonal variations, and consequently only very general statements can be made about temporal patterns in biota.

Studies in 1977 indicated that no epibiotic growth was present in the Inner Harbout between the level of the High Water Spring Tide (HWST), and 1 m below the Low Water Spring Tide (LWST) (MSE, 1978). This abiotic zone extended to 2 m below LWST at sites close to Allans Creek. Similar studies in 1991 found polychaetes, ascidians and algae at sites which had been abiotic in 1977 (MSE and CEC, 1991).

An attempt was made to obtain data on chemicals in fish over the study period. In April 1976, an investigation of fish in the harbour by NSW Fisheries found "high levels of cyanide and heavy metals in the fish" (NSW Fisheries File #F75/1437, as reported in EPA (1994)), which led to the renewal of fishing closures on the harbour at that time. The 1976 raw data were not available for comparison with more recent studies (J. Burchmore, NSW Fisheries, pers. comm, 1994).

Two studies were carried on chemicals in fish in the early 1990s (MSE and Cec, 1991; EPA, 1994). Heavy metals and polycyclic aromatic hydrocarbons were analysed in 1991 from 8 species of fish and one invertebrate species from 14 sites in the Inner Harbour and 4 sites in the Outer Harbour (MSE and CEC, 1991). It was found that chromium, manganese and lead in fish and crab tissue were below detection limits (detection limits of chromium, manganese and lead were 1.0, 1.0 and 0.5 mg/kg, respectively) while tin was detected in 4 of 8 fish species, and iron and zinc in all species. Levels of polycyclic aromatic hydrocarbons (PAHs) in fish tissue were low (all < 20 ng/g) in comparison with industrialised areas in other countries (MSE and CEC, 1991).

Heavy metals, organochlorine compounds, dioxin and furan were analysed in 3 fish species collected in 1992 from 5 sites in the harbour to provide a "snapshot" assessment of toxic chemicals in fish (EPA, 1994). The results indicated that, for the 17 non-PCB organochlorines and 12 trace metals analysed, contaminant levels in fish samples were very low with the exception of selenium. The analytical method used, however, appeared to be overestimating the concentration of selenium actually present (T. Lewis, University of Wollongong, pers. comm., 1995).

The study also indicated that 44% of the mullet samples analysed had concentrations of PCBs exceeding the National Food Authority Maximum Residue Level (0.5 mg/kg). No specific source of the PCBs has been identified. Dioxin and furan concentrations in fish were very low (all < 2 pptr) (EPA, 1994).

Comparison of these two data sets is limited because of the selection of fish species and the different metals and organic compounds studied. For example, only 2 metals (lead and zinc) and only 3 fish species (blackfish - Girella tricuspidata, sea mullet - Mugil cephalus, and yellowfin bream - Acanthopagrus australis) were common to both studies. For zinc, concentrations in blackfish (9-10 mg/kg wet wgt) and bream (4.8-6.1 mg/kg) were fairly consistent, but for sea mullet the EPA (1994) study gave a mean of 3.4 mg/kg while the MSE (1991) study gave 14-22 mg/kg. The EPA data were consistent with data from Bebbington et al., (1977) who found that bream along the NSW coast had a mean zinc concentration of 4.2 mg/kg. No explanation for the higher zinc values found by MSE in 1991 is forthcoming. For lead, all three fish species in both studies had concentrations < 0.5 mg/kg.

The results from the analysis show that the marine environment of Port Kembla Harbour was in poor condition in the 1970s. Elevated concentrations of toxic wastes (ammonia, cyanide and phenol) and heavy metals (iron, zinc, copper, lead and cadmium) were found in the water, particularly ammonia, cyanide and phenol in the upper water columns of the Inner Harbour, iron, zinc and lead in the upper water columns of the Inner Harbour and the Cut, and copper in the lower water columns of the whole harbour (Table 1) (SPCC, 1977). At the same time, evidence was observed of low biological diversity and productivity, especially in the Inner harbour. No epibiotic growth was present in the intertidal and shallow subtidal areas of the Inner Harbour (MSE, 1978). Fish were contaminated and in 1976 high levels of pollutants in the fish were found (NSW Fisheries File #F75/1437, as reported in EPA (1994)). Very few fish were observed in the harbour and many fish kills were reported (MSE, 1978; Moran, 1984). It was reported that the major polluters were large steel and copper industries surrounding the harbour (SPCC, 1977; MSE, 1978).

Since 1974, under the direction of the New South Wales SPCC/EPA and their enabling legislation, and, in particular, in accordance with the NSW Clean Waters Act of 1970, pollution reduction programs have been implemented by the industries surrounding Port Kembla Harbour. These programs were aimed at providing a mutually acceptable mechanism so that the company holding a licence issued under the NSW Pollution Control Act (1970) can put practical, cost effective and efficient emission controls in place. This was particularly relevant where emissions contain more than the desired concentration of contaminants, because existing plant and equipment are unable to achieve the desired levels when operated and maintained in the best manner and conditions (M. Pease, NSW EPA, pers. comm., 1995).

The majority of the emission control programs were initiated in 1977 (Moran, 1984) and a variety of measures have been introduced to reduce the levels of heavy metals and other toxic wastes, particularly ammonia, cyanide and phenol, in effluents discharged into the harbour. As a result, flow rates and pollutant concentrations in effluents have been reduced significantly, e.g., the average cyanide concentration in the steel mill main drain was 4.0 mg/L in 1975, but has been below 0.1 mg/L since 1990.

Figure 1. Changes in the cyanide concentration 1970-1994 in the BHP Steelworks Main Drain (located 800 m upstream of harbour on Allans Creek)

Implementation of pollution reduction programs by the industries surrounding Port Kembla Harbour, has led to a noticeable improvement in the quality of the marine environment of the harbour. From the 1970s to the 1990s, the concentrations of some heavy metals and toxic wastes in harbour waters were reduced while that of dissolved oxygen increased. As a result, marine life has returned to the whole harbour. Population, biomass and species richness of epibiota appear to have increased at sites nearest to Allans Creek. Contaminants in fish were at low concentrations by the early 1990s (EPA, 1994).

Although pollution reduction programs have been implemented and significant positive changes in the quality of the marine environment have been found, the marine environment of the harbour requires further improvement. Comparison of the water quality in the 1990s with the ANZECC (1992) guidelines for protection of aquatic ecosystems (marine waters) showed that the guideline concentrations were exceeded in the water for cyanide, zinc, copper, lead and cadmium in the 1990s, especially for cyanide in the upper water column of the Inner Harbour. Despite the average dissolved oxygen concentration in the 1990s achieving the guideline value, DO concentrations in the Inner Harbour and the Cut in specific years did not. Phenol was the only contaminant for which the guideline concentration has been consistently achieved (Table 1).

Increases in heavy metal contents of sediments at certain locations (Site 8) have been found since the 1970s. Major increases in copper concentrations were recorded at most sites. The heavy metal concentrations in the sediments in the 1990s were similar to those found in other polluted systems (Chester, 1990) and about an order of magnitude higher than those from sites unaffected by waste disposal. The elevated concentrations of these metals pose a potential threat to aquatic species in the harbour.

Since the 1960s, a number of major dredging operations have been carried out in Port Kembla Harbour, which mainly covered the Inner Harbour (Sites 1, 2 and 3), the Cut (Site 4), the channel of the Outer Harbour (Site 5) and the Outer Harbour Entrance (Site 6) (NSW PWD, 1969, unpub. document; West Ham Dredging, 1975; SPCC, 1983; SPCC, 1986a; EPA, 1992). This dredging may have contributed to the reductions in the sediment heavy metal concentrations. Site 8 is close to the copper smelter drain and no major dredging operations have been reported at this site. This may be one factor contributing to the significant increases in the contents of copper, lead and zinc in the sediment at this site, which is now the subject of further investigation.

The marine environment of the harbour is affected not only by the surrounding heavy industries but also by a variety of other pollution sources. Coal handling, oil spillage and vessels using the harbour are potential pollution sources. Apart from the heavy industries, other likely point pollution sources are a diversity of light industries and commercial activity, including manufacturing, construction, mechanical and electrical engineering, steel fabrication, car servicing, farms and general development activities (Rhoden, 1990). Many of these operations are located in the lower catchment of Allans Creek and in small industry zones located in the catchment of the Town Drain. The relative contribution of these small point sources has not, to date, been adequately assessed. The small industries are required to comply with the NSW Waste Minimisation and Protection of the Environment Legislation (the latter supercedes the previous Clean Waters and Clean Air Acts), but enforcement has been difficult. This arises partly from a lack of resources, but also when a pollution incident is observed in a waterbody, it is often very difficult to identify the specific source of the contaminant.

Rural and urban non-point source pollution is also created in the Allans Creek Catchment from stream bank and bed erosion, land slips, poorly managed landfill sites and subdivision works, which affect the harbour via Allans Creek. For example, urban and rural runoff carried high levels of ammonia, nitrate and nitrite from upstream areas of the Allans Creek catchment, leading to high concentrations, especially of ammonia, in the lower Allans Creek system (Kininmonth, 1993). There is an urgent need to assess the relative contributions of the diffuse and point sources to pollution of Port Kembla Harbour.

Currently, the industrial discharge licences are based on a combination of environmental goals, finance and technologies available to the industries (NSW EPA, pers. comm., 1998), which are mutually acceptable to the industries and the NSW EPA. For the continued improved management of the area, however, there is still no satisfactory scientific basis for determining the long term limits for the industrial discharges, but state and local government agencies are currently addressing this situation.

During the 1970s, the marine environment of Port Kembla Harbour was heavily polluted by the surrounding industries. High concentrations of toxic wastes and heavy metals were found in the water. The sediments also contained elevated concentrations of heavy metals. Aquatic organisms were highly impoverished. High levels of pollutants were found in the fish. Very few fish were observed and many fish kills were reported.

Increased public pressure has led, since the 1970s, to the implementation of pollution reduction programs by local industries, with the result that pollution discharges to the harbour have been markedly reduced. During this time, there has been a noticeable improvement in the quality of the marine environment of the harbour. Reductions in the concentrations of toxic wastes and heavy metals in the water have been measured and there has been an increase in marine biodiversity and aquatic organism productivity in the harbour.

Despite the improvements over the last 20 years, the marine environment of Port Kembla harbour is still in need of enhancement. The ANZECC guideline concentrations for protection of aquatic ecosystems (marine waters) are exceeded for many pollutants in the water. The sediments still contain elevated concentrations of heavy metals and epibiota richness and phytoplankton activity are still at low levels compared to non-industrial sites along the NSW coast. Continued improvements in the marine environmental quality of the harbour are still required.

The authors would like to thank the following for their contributions to this study: H. Urban, C.M. Wong, P. Giles, M. Hale and M. Sajdek of BlueScope Steel; W.J.J. Hoogendoorn, C. Haley and L. White of the Port Kembla Port Authority; P.J. Moran, formerly of the Australian Institute of Marine Science; G. Clarke of NSW Department of Land and Water Conservation; J. Nevill, C. Ferguson, T. Jones and M. Pease of the NSW EPA; R. Divakarla of Southern Copper Ltd. Valuable comments on the draft manuscript by Dr. P. Hutchings and an anonymous referee are gratefully acknowledged.