BELLAMBI OUTFALL

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Monitoring Results

## Biological Communities

Outteridge (1992)

Found that sewage effluent:

- increased faecal coliform levels on beaches close to sewage outfalls compared to beaches further away.

- Bellambi Beach was found to be the most affected beach on the Wollongong coastline. Bellambi Beach and Corrimal Beach (north and south of Bellambi outfall) were found to have higher levels of coliforms more frequently than fairy Meadow Beach (several kilometers away). Fishermans Beach (north of Port Kembla outfall) was found to have higher levels of coliforms more frequently than Port Kembla Beach (directly south of the outfall). Perkins Beach (4 km south of Port Kembla outfall) had similar faecal coliform levels to Fairy Meadow Beach [a nominal control site].

General findings (not necessarily related to outfall):

- increased concentrations of chromium, copper and zinc in pipis near Port Kembla.

- lower concentrations of metals were found in pipis from beaches around Bellambi outfall (that is, other sources of pollutants (e.g. creeks, lagoons, industry, atmospheric fallout and Port Kembla Harbour) may contributed to the observed patterns of trace metal concentrations.

- Spatial and temporal variability in the beach fauna was high and no definitive outfall effects could be inferred.

Methods:

Outteridge (1992) investigated the effect of sewage outfalls on sandy beach fauna in the Illawarra region. She analyzed Water Board faecal coliform data 9from 9 beaches), independently collected coliform data, trace metal levels in pipis (Donax deltoides) and the community structure and distribution of intertidal fauna from 6 beaches in the Illawarra region.

Roach et al (1995)

Found that sewage effluent:

- increased trace metal concentrations above background levels in P. stolonifera body and muscle tissue and C. tramoserica tissue at outfall locations.

- lowered the rate of recruitment (colonization by living organisms) of algae and limpets that graze on these algae at the Bellambi outfall location compared to the control locations (Bulli Point & Towradgi Point)

- effected the patterns of colonization of denuded patches at outfall and control locations.

Found no effect on:

- numbers of taxa at either Bellambi or Port Kembla outfall (reduced number of taxa often a characteristic of heavily polluted systems)

General findings (not necessarily related to outfalls):

- no difference in most kelp holdfast invertebrates between outfall and control locations.

- significant differences between locations were found for the abundance of some kelp holdfast invertebrates, however, the abundance often varied between and within sites at both outfall and control locations.

- that the effects of effluent discharge on the composition of kelp holdfast communities, if any, were small compared with natural variation.

- No organochlorines were detected in any of the tissues analysed.

- concentrations of selenium, zinc and DDT were significantly higher than background concentrations on one occasion at Port Kembla and concentrations of chlordane and DDE were significantly higher at Port Kembla and Bellambi on two occasions and two control locations (Shellharbour and Bulli), that is, when contaminants in the body tissue of P. stolonifera were measured on four occasions at two outfall locations (Bellambi and Port Kembla).

- the accumulation of trace metals and organochlorines above background levels was small compared to data collected on the accumulation of metals and organochlorines in similar organisms from other studies of areas affected by sewage outfalls.

Methods:

Roach et al (1995) investigated differences in kelp holdfast invertebrate communities, accumulation of metals and organochlorine pesticides by intertidal invertebrates (limpet (Cellana tramoserica), the barnacle (Tesseropora rosea) and muscle and body tissue from the cunjevoi (Pyura stolonifera) and patterns of recruitment of intertidal invertebrates near Bellambi (and Port Kembla) outfall.

Banwell (1996)

Found that sewage effluent:

- effected species composition at the outfall compared to control sites Particular species occurred at two sites near the outfall, but were absent at the third outfall site and at all control sites.

- 60% of the difference was due to the occurrence of three species (Chaetomorpha aurea, Polysiphonia spp. and Ulva lactuca) at the outfall sites and four species (Corallina officinalis, Montfortula rugosa, Laurencia pinnosa and Sargassum spp.) at the control sites.

Methods:

Banwell 1996 investigated the impact on intertidal flora and fauna of shifting the discharge from Sydney’s major sewage outfalls (at North Head, Bondi and Malabar) from shoreline discharge to offshore (deep water) discharge. The intertidal communities at two of these outfalls (North Head and Malabar) were compared with the intertidal communities at two other outfalls (Potter Point and Bellambi) to see if there was any evidence of a recovery once the sewage at North Head and Malabar was diverted offshore. A number of control locations were also included in Banwell’s (1996) design.

TEL (1994)

General findings (not necessarily related to outfalls):

- the fish fauna were dominated by small mobile fish species.

- species of economic importance and tropical origin also occurred in small numbers.

- assemblages of macrobenthos were dominated by macroalgae, Ecklonia radiata, turfing and encrusting algae and the sea urchin Centrostephanus rodgersii.

- the introduced green alga Caulerpa filiformis was relatively abundant at Bellambi outfall.

- multivariate analyses revealed few differences between assemblages of fish from outfall and reference locations, but large, inconsistent variability within locations. This variability was significant at individual times for Bellambi and between habitats for Port Kembla.

Found that sewage effluent:

- reduced individuals and species of fish - an absence of Trachinops taeniatus and fewer Parma microlepis and Parma unifasciata at the Bellambi outfall site.

- increased the percentage cover of Caulerpa filiformis, reduced the percentage cover of encrusting algae and sea urchins (Centrostephanus rodgersii), as well as fewer Australium tentoriforme shellfish at Bellambi.

Methods:

TEL (1994) investigated the fish communities and macrobenthic assemblages in the Illawarra coastal zone. This study was specifically targeted at the abundance and species richness of fish and macrobenthic assemblages at Bellambi and Port Kembla outfalls.

AWT (1998)

Found that sewage effluent:

- either positively or negatively affected the abundance or percentage cover of a number of intertidal species at Bellambi and Port Kembla STPs.

- Ulva, red turf algae and the limpets Siphonaria denticulata and S. virgulata increased their abundance or percent cover while Sargassum spp. and cunjevoi (Pyura stolonifera) showed decreased abundance or percent cover (AWT 1998).

- lowered the species diversity around the outfalls compared to the reference locations.

- increased the percentage cover of red algae and the green alga Caulerpa filiformis around Bellambi outfall.

- decreased the percentage cover of brown algae such as kelp (Ecklonia radiata) at the Port Kembla outfall.

- increased the percentage of ‘Brown Fuzz’ (a mixture of alga, hydrozoa and bacteria that forms a fine tufting cover over the reef) around Port Kembla outfall.

- kelp (E. radiata) was absent from the nearshore environment at Bellambi and Port Kembla (primary treated effluent), however kelp occurred within 5 m of the discharge point at Wollongong (secondary treated effluent).

Methods:

AWT (1998) investigated the effects of primary treated sewage effluent on intertidal and subtidal rocky reef communities around Bellambi and Port Kembla ocean outfalls and on the subtidal communities around Wollongong ocean outfall. Intertidal communities around Bellambi and Port Kembla ocean outfalls were sampled four times during 1992-1993 and subtidal communities were sampled at four times between 1992-1994. These sites were sampled again in 1998. Subtidal rocky reef communities were sampled near Wollongong ocean outfall in 1998. A number of control sites were also sampled. Sampling of intertidal communities was undertaken using a 50cm X 50cm quadrat. Sampling of subtidal communities was undertaken using an underwater camera and a 30cm X 40cm quadrat.

Outfall Pipe

Faecal Coliform

Outfall Pipe

Bellambi

(Bell_7) Last updated June 2000