RED POINT OUTFALL

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Monitoring Results

### Nutrients and Indicator Bacteria

Sampling indicated that 400m offshore of Red Point concentrations of ammonia and orthophosphate exceeded ANZECC guidelines and faecal coliform bacteria levels exceeded guidelines for primary and secondary contact recreation (MHL769 1997). [Note that these latter results were obtained before the commissioning of the chlorination-dechlorination system].

### Biological communities

Outteridge (1992)

Found that sewage effluent:

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

- affected Bellambi Beach the most on the Wollongong coastline with Bellambi Beach and Corrimal Beach (north and south of Bellambi outfall) having higher levels of coliforms more frequently than fairy Meadow Beach (several kilometers away).

- affected Fishermans Beach (north of Port Kembla outfall) more frequently than Port Kembla Beach (directly south of the outfall).

Other findings (not necessarily related to outfall):

- peak concentrations of chromium, copper and zinc were found in pipis from beaches near Port Kembla with lower concentrations of metals in pipis from beaches around Bellambi outfall. Outteridge (1992) concluded that other sources of pollutants (e.g. creeks, lagoons, industry, atmospheric fallout and Port Kembla Harbour) may also have 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 (from 9 beaches), independently collected coliform data, trace metal contamination of pipis (Donax deltoides) and the community structure and distribution of intertidal fauna from 6 beaches in the Illawarra region.

TEL (1994)

Found that sewage effluent:

- Affected the boulder habitat with fewer species of cryptic fish at Port Kembla outfall, greater abundance of rock cale (Crinodus lophodon) and red morwong (Cheilodactylus fuscus) and lower abundance of hula fish (Trachinops taeniatus) and seaperch (Hypoplectrodes mccullochi).

- Decreased abundance of sea urchins (Centrostephanus rodgersii) and increased abundance of Cabestana spengleri shellfish at the outfall site.

General findings (not necessarily related to outfall):

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

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

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

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

- 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.

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.

Roach et al (1995)

Found that sewage effluent:

- indicated 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.

- had a small, if any, effect on the composition of kelp holdfast communities, compared with natural variation.

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

- Significantly increased concentrations of selenium, zinc and DDT above background concentrations on one occasion at Port Kembla and concentrations of chlordane and DDE at Port Kembla and Bellambi on two occasions.

Found no effect on:

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

- most kelp holdfast invertebrates between outfall and control locations (Bass Point and Coalcliff).

General findings (not necessarily related to outfalls):

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

Methods:

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

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.

- lowered the species diversity around the outfalls when 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 Site

Faecal Coliform

Sea Urchin

Caulerpa

Outfall

Barnacles

Outfall

Limpets

Kelp

Ulva

Red Point

(Redp_7) Last updated June 2000