CHAPTER 6 . Coastal Environmental Management in Southeast Australia: The Roles of Ecology 101
Here, several examples of scientific problems are used to illustrate difficulties for
managers where ignorance prevents available scientific knowledge from helping. Examples are also given as case-histories of particular problems and how they were/are
managed, to illustrate some current practical issues. Finally, some recommendations
are made as to better ways ecological science could be included in bottom-up, participating programmes responsive to the needs of local community groups.
6.2
Decision-Making Against an Uncertain Background
6.2.1
Natural Ecological Systems
For far too long, managers and the general community have been misled by the quasiscientific - and very old-fashioned - view that ecological systems are equilibrial, that
there is a "balance of nature". This quasi-religious view of the "perfect" world, shaped
by external forces or sustained by well-tuned homeostatic mechanisms keeps appearing.
Its most recent manifestation is the Gaia view (Lovelock 19791988). Yet, we have known
for several hundred years that nature, when examined in any but a cursory manner, is
much more complicated than our beliefs and non-empirical views. This more flexible
and dynamic view goes back to Bacon (1620), but has perfectly respectable modern
support (e.g. for forest systems, Botkin 1990; for freshwater ecology, Likens et al. 1985).
One of the consequences of naturally varying systems is that temporal changes in
anyone place are not predictable and spatial differences are not possible to guess. Spatial
and temporal variation must be measured for components of coastal habitats. Increasingly, marine ecologists have been able to demonstrate three features of shallow-water
coastal habitats:
i. Interactions among species are complex and require considerable investigation before it is possible to describe, let alone explain and ultimately predict what responses
will be to any anthropogenic change (e.g. Dayton 1971; Paine 1980; Underwood et al.
1983).
ii. Life-histories and general ecology of the majority of coastal species (including fish
and other commercially exploited species) include pelagic dispersive stages, which
make predictions about future numbers very difficult because they depend on oceanographic processes and patterns of weailier which remain largely unpredictable at
any scale that currently matters ecologically (e.g. Coe 1956; Loosanoff 1964; Roughgarden et al. 1985, 1988).
iii. As a result of variable life-histories, recruitment of planktonic propagules (larvae,
spores, etc.) will be variable from place to place and time to time, in complicated
ways (e.g. Connell 1985; Underwood and Fairweather 1989). This, coupled with intense but complex interactions wiili other species (point (i) above), themselves varying greatly in local abundances, means iliat changes from time to time are generally
not consistent from place to place. Such complexity has coined the term "supplyside ecology" to identify the critical role of recruitment in ilie structure and dynamics
of coastal assemblages (e.g. Underwood and Fairweather 1989; Grosberg and
Levitan 1992).
Here, several examples of scientific problems are used to illustrate difficulties for
managers where ignorance prevents available scientific knowledge from helping. Examples are also given as case-histories of particular problems and how they were/are
managed, to illustrate some current practical issues. Finally, some recommendations
are made as to better ways ecological science could be included in bottom-up, participating programmes responsive to the needs of local community groups.
6.2
Decision-Making Against an Uncertain Background
6.2.1
Natural Ecological Systems
For far too long, managers and the general community have been misled by the quasiscientific - and very old-fashioned - view that ecological systems are equilibrial, that
there is a "balance of nature". This quasi-religious view of the "perfect" world, shaped
by external forces or sustained by well-tuned homeostatic mechanisms keeps appearing.
Its most recent manifestation is the Gaia view (Lovelock 19791988). Yet, we have known
for several hundred years that nature, when examined in any but a cursory manner, is
much more complicated than our beliefs and non-empirical views. This more flexible
and dynamic view goes back to Bacon (1620), but has perfectly respectable modern
support (e.g. for forest systems, Botkin 1990; for freshwater ecology, Likens et al. 1985).
One of the consequences of naturally varying systems is that temporal changes in
anyone place are not predictable and spatial differences are not possible to guess. Spatial
and temporal variation must be measured for components of coastal habitats. Increasingly, marine ecologists have been able to demonstrate three features of shallow-water
coastal habitats:
i. Interactions among species are complex and require considerable investigation before it is possible to describe, let alone explain and ultimately predict what responses
will be to any anthropogenic change (e.g. Dayton 1971; Paine 1980; Underwood et al.
1983).
ii. Life-histories and general ecology of the majority of coastal species (including fish
and other commercially exploited species) include pelagic dispersive stages, which
make predictions about future numbers very difficult because they depend on oceanographic processes and patterns of weailier which remain largely unpredictable at
any scale that currently matters ecologically (e.g. Coe 1956; Loosanoff 1964; Roughgarden et al. 1985, 1988).
iii. As a result of variable life-histories, recruitment of planktonic propagules (larvae,
spores, etc.) will be variable from place to place and time to time, in complicated
ways (e.g. Connell 1985; Underwood and Fairweather 1989). This, coupled with intense but complex interactions wiili other species (point (i) above), themselves varying greatly in local abundances, means iliat changes from time to time are generally
not consistent from place to place. Such complexity has coined the term "supplyside ecology" to identify the critical role of recruitment in ilie structure and dynamics
of coastal assemblages (e.g. Underwood and Fairweather 1989; Grosberg and
Levitan 1992).