CHAPTER 6 • Coastal Environmental Management in Southeast AUstralia: The Roles of Ecology
105
mous distances (Mileikovski 1971; Scheltema 1971, 1986). Particular care is needed to
ensure that representative pieces of natural habitat used for breeding are not damaged
if populations elsewhere on the coast are to be sustainable.
The issue of appropriate scale is also of relevance to many progranIffies of monitoring
water quality. Some such progranIffies in Australia exist because of direct risks to human
health from sewage, pollutants, etc. Others, however, are done to evaluate managerial
changes proposed to improve "quality of habitats", "health of ecosystems" or to evaluate or increase sustain ability of local biodiversity (e.g. DEST 1997). Where the latter is
the aim, the projects are often (and probably usually) inept in conception because of
misplaced beliefs about scales and linkages in ecological processes. It is, for example
necessary to assume that measurements of physical (light, sediments) and chemical
(concentration of oxygen, nitrogen, phosphorous) variables are somehow tightly correlated with or are good predictors of sustainability of biological populations or diversity of species in that area. In southeast Australian coastal habitats, no such linkages
have been demonstrated and they are not likely, given that abundances and diversity
of species are unlikely to be under direct regulation by physical and chemical processes
without regard for biological interactions (Underwood and Peterson 1988; Menge 1995).
Above all, there have been (as discussed later for urban wetlands) repeated quantitative demonstrations of the relatively small spatial scales of patchiness of invertebrate
populations in coastal habitats. Generally, such scales are not easily inferred from simple
measurements (Underwood and Chapman 1996) and knowledge about them is not
necessarily transferable from one habitat to another - even for the same species
(Underwood 1996a). It is, however, the case that much routine measurement of physical and chemical variables (so-called "water-quality measures") is at temporal and
spatial scales entirely inappropriate to be related to known rates of change and scales
of difference of the very biological variables to which they are supposed to be related
(see Morrisey et al. 1992a,b for discussion of such scales).
Measures of water-quality (outside their use in assessments of risk to human health)
are a very poor tool to provide any useful information to managers and decision-makers. The widespread existence in southeast Australia of programmes of measurement
probably simply reflects the fact that participation of the community is desirable.
Members of community groups can usefully be involved in measurements of waterquality - even if the spatial and temporal scales of sampling are ill-conceived, there is
no demonstrable connection to any necessary biological variable and the information
itself is useless for any managerial decision. Participatory democracy does not, apparently, have to achieve any environmental improvement!
6.3.
Managerial Decisions as Experiments
6.3.1
Sewerage Outfalls on the Rocky Coast of New South Wales
Three sewage treatment plants served a population of 2.2 million people and discharged
directly into the sea. The amount of sewage and other domestic, commercial and industrial effluent was about 88% of the total in the Sydney region (Sydney Water
Board 1990). Between September 1990 and Aprill,991, the three outfalls were decom-
105
mous distances (Mileikovski 1971; Scheltema 1971, 1986). Particular care is needed to
ensure that representative pieces of natural habitat used for breeding are not damaged
if populations elsewhere on the coast are to be sustainable.
The issue of appropriate scale is also of relevance to many progranIffies of monitoring
water quality. Some such progranIffies in Australia exist because of direct risks to human
health from sewage, pollutants, etc. Others, however, are done to evaluate managerial
changes proposed to improve "quality of habitats", "health of ecosystems" or to evaluate or increase sustain ability of local biodiversity (e.g. DEST 1997). Where the latter is
the aim, the projects are often (and probably usually) inept in conception because of
misplaced beliefs about scales and linkages in ecological processes. It is, for example
necessary to assume that measurements of physical (light, sediments) and chemical
(concentration of oxygen, nitrogen, phosphorous) variables are somehow tightly correlated with or are good predictors of sustainability of biological populations or diversity of species in that area. In southeast Australian coastal habitats, no such linkages
have been demonstrated and they are not likely, given that abundances and diversity
of species are unlikely to be under direct regulation by physical and chemical processes
without regard for biological interactions (Underwood and Peterson 1988; Menge 1995).
Above all, there have been (as discussed later for urban wetlands) repeated quantitative demonstrations of the relatively small spatial scales of patchiness of invertebrate
populations in coastal habitats. Generally, such scales are not easily inferred from simple
measurements (Underwood and Chapman 1996) and knowledge about them is not
necessarily transferable from one habitat to another - even for the same species
(Underwood 1996a). It is, however, the case that much routine measurement of physical and chemical variables (so-called "water-quality measures") is at temporal and
spatial scales entirely inappropriate to be related to known rates of change and scales
of difference of the very biological variables to which they are supposed to be related
(see Morrisey et al. 1992a,b for discussion of such scales).
Measures of water-quality (outside their use in assessments of risk to human health)
are a very poor tool to provide any useful information to managers and decision-makers. The widespread existence in southeast Australia of programmes of measurement
probably simply reflects the fact that participation of the community is desirable.
Members of community groups can usefully be involved in measurements of waterquality - even if the spatial and temporal scales of sampling are ill-conceived, there is
no demonstrable connection to any necessary biological variable and the information
itself is useless for any managerial decision. Participatory democracy does not, apparently, have to achieve any environmental improvement!
6.3.
Managerial Decisions as Experiments
6.3.1
Sewerage Outfalls on the Rocky Coast of New South Wales
Three sewage treatment plants served a population of 2.2 million people and discharged
directly into the sea. The amount of sewage and other domestic, commercial and industrial effluent was about 88% of the total in the Sydney region (Sydney Water
Board 1990). Between September 1990 and Aprill,991, the three outfalls were decom-