General coastal industry impacts
Heavy metal and other discharges/activities from coastal industries are potentially very damaging, and although usually requiring an environmental licence to do so, industrial waste frequently flows directly into the coastal/marine environment (Commonwealth of Australia 1991). The impacts of coastal industries on the coastal zone vary significantly between industries, but many impacts are similar in nature to those of mining activities which were summarised earlier, particularly 'black sands' mining. However, once again data on coastal impacts are limited. Although more studies have been undertaken on the topic of industrial coastal pollution when compared to other uses of the coastal zone, Batley (1995) queries the sampling methods used, and suggests that the data are unreliable in some instances. Most information is also drawn from international research which makes it difficult to place into the unique Australian context (Richardson 1995). There is little known, for example, about the full effects of PCBs (Richardson 1995, Zann 1995, Burzacott 1996), and there is still little information on the short-term and long-term effects of oil discharges on the coastal environment, despite the frequency of occurrence (Connell 1995). But in general, impacts from coastal industries and associated infrastructure, which are numerous and both direct and indirect (Young 1996), can be summarised as:
• generally poor groundwater and coastal water quality
• concentration of toxic chemicals in fish and other marine fauna, and the cumulative effects on the broader food chain
• long-term sediment contamination where toxins accumulate in the sediments, and can be re-released via dredging operations
• land subsidence and localised sea level rise (not just related to industrial development). As noted in previous sections, in the Port Adelaide area of South Australia, there is local sea level rise as a result of subsidence. This land subsidence is associated in part with land or wetland reclamation for industrial and other developments, groundwater extraction from industrialisation, and port development, among other things. Belperio (1993) noted that as a result of groundwater extraction from these reclamation and other activities, the result is soil compaction and soil acidification via substratum leaching
• loss of important ecological and economic resources including damage to fisheries due to the impacts of contaminants and the reclamation of mangroves and sea grasses; algae can also be lost in this process
• increased toxic algal blooms from excess nutrients and eutrophication
• creation of deformities and breeding abnormalities in fauna (e.g. organochlorines can cause deaths in fish and thinning of eggs, and the contaminants are passed on between generations, e.g. in dolphins)
• petroleum hydrocarbons or oil discharges from coastal petrochemical plants are usually only small-scale, but large discharges (also from shipping) can have severe adverse effects, for example, on coral reefs, seagrasses and mangroves (e.g. deaths in seeds, drowning of pneumatophores, defoliation), abnormal growths in gastropods, and death in fauna such as seals and birds. There may also be some effects on the larval stages of some marine species, but this has not yet been fully studied. In marine biota, levels of petroleum hydrocarbons are reported by Connell (1995) for seabirds, fish in the Great Barrier Reef, and clams, mussels and oysters; high contamination was found in fish and birds in Queensland, and low contamination in Port Phillip Bay, Victoria
• increased water turbidity arising from sedimentation with the creation of ports (dredging) to support industry, in addition to port pollution by oil and toxic chemicals, litter, and the spread of antifouling paints (see also section on shipping impacts, page 156)
• greater strains on existing infrastructure, such as roads and power
• loss of public access and recreational amenity
• visual, aesthetic and noise impacts
• human health impacts for coastal residents from air emissions and consumption of contaminated seafood (RAC 1993, Connell 1995, Richardson 1995, Zann 1995).
While there is an understanding of the general types of coastal impacts that can occur from industries, the actual degree and nature of these impacts is not widely understood because it also depends on the nature of the immediate coastal environment. For instance, in Cockbum Sound, Western Australia, the coastal environment is unable to adequately mitigate industrial contaminants because of poor flushing conditions, and a minimal tidal influence which may dilute and draw the contaminants out to open sea (Hails 1982). Similarly, in the Upper Spencer Gulf of South Australia, aerial emissions from industries tend to be trapped over the Gulf's waters because of local climate conditions (Reilly 1991). In addition, limited fresh water inputs and minimal mixing of Gulf waters with the open sea has resulted in the accumulation of metals in the Gulf (Bell 1983).