Environmental Engineering Reference
In-Depth Information
per unit effort for the species. It might include changing the selectivity of gear types
and seeing how that affects the size and composition of the catch. A control area
might be harvested under business as usual to address the confounding effects of
climate or ecosystem change on the outcome of harvesting. The major structural
uncertainties in our models of how our system works can then be tested and
reduced, allowing much better management.
However, active adaptive management is not easy to implement, particularly
when conserving exploited species in poorer countries. Learning has a cost in terms
of the yields foregone while testing out the system, rather than going straight for
the hypothesised best management strategy. It may be risky, because the aim is to
push the system into situations where it might not otherwise go, which could
include very heavy harvesting risking population collapse or changes in harvesting
strategy risking livelihood collapse. It may be hard to get stakeholders on board,
given that the approach is relatively scientific and may seem rather divorced from
the day-to-day concerns of resource users. There is always going to be a trade-off
for managers between the scope of change that is politically and socially feasible
and the potential benefits that could be gained from improved system perform-
ance. Finally, in rapidly evolving systems, an adaptive approach may fail because
the rate of learning is slower than the rate of change; a simple precautionary
approach (such as a no-take area) may be more robust in these situations.
Generally, active adaptive management has been much talked about but little
implemented outside developed country fisheries (Lee 1999). One example in a
developing country is the use of adaptive learning by stakeholders in deciding on
stocking rates for aquaculture ponds in south-east Asia (Garaway and Arthur
2004), which is an exciting new development, but is in a context which is much
easier to control than harvesting wild resources.
7.5.2.7 The scope of decision analysis
Decision analysis is a way to formalise management decision-making so that the
process is transparent. However, while a logical and quantitative approach to
decision-making is powerful, the approach will still not produce a magic answer to
difficult problems. Weighting of outcomes will always be subjective and results are
still limited by our understanding of the system. It is important that the quantita-
tive nature of the approach doesn't give false confidence. In the end it is only
by monitoring outcomes and adapting to circumstances, and by involving all
stakeholders in the process, that management can be effective.
7.6 Contextualising management
It's easy to get caught up in the local and short-term detail of implementing
conservation management. However, local issues are embedded within a wider
context, which can derail the best conservation actions if it is not taken into
account.
 
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