Environmental Engineering Reference
In-Depth Information
international trade in traditional medicines. When we use the words use, exploita-
tion, hunting, harvesting, then unless otherwise stated we are treating them as
synonyms meaning killing an individual for gain. But we do not consider large-
scale commercial harvests, such as are common in the forestry and fisheries sector,
nor human-manipulated ecosystems such as plantations or fields. Instead we focus
on the conservation of species that are hunted in their natural habitat, and at a rel-
atively
small scale
. Our personal taxonomic bias is towards terrestrial vertebrates,
but most of what we say is equally applicable to other living organisms that are
similarly harvested; plants, corals, fish, fungi...It is also to some extent applica-
ble to commercial operations and to use that does not kill (e.g. harvesting plant
parts). Where methods are not broadly applicable, we point this out.
We necessarily take a
population-level approach
, because hunting is targeted at
populations. Even when it is relatively non-selective, there is a limited taxonomic
range taken in any one exploitation operation. This is another reason why we
exclude commercial forestry and fisheries, some components of which, such as
clear-cutting and bottom-trawling, destroy entire ecosystems. Of course even
targeted hunting can have profound ecosystem-level effects, but we focus predom-
inantly on studies that are concerned with the target organism itself. On the social
side we focus our attention at the level of the individual harvester and their
community, rather than at the national and international levels. Inevitably this
means that some issues are treated in a cursory manner, but we do point out where
processes at different scales have an important role to play in local sustainability.
Ignoring large-scale commercial operations does not imply that they are unim-
portant ecologically or socially. Commercial logging was a major factor in the 14%
reduction in tropical forest area between 1990 and 2000 (FAO 2001), the collapse
of the Grand Banks fishery had profound impacts on the local economy
(Ruitenbeek 2001), and the over-exploitation of marine megafauna in the last few
centuries has altered the ecology of the Caribbean beyond recognition (Pandolfi
et al
. 2001). But by focusing on the smaller scale, we aim to fill a gap. By and large,
commercial forestry and fisheries operations are overseen by professional managers
and scientists. In these systems, management may fail and science may confront
profound uncertainties, but the focus is strongly on the species as a resource to be
managed. Conversely, in situations where there is a conservation problem, there
are generally no resource managers overseeing operations. Instead
conservationists
must diagnose the problem and devise methods for improving the situation. These
are the people to whom this topic is addressed.
Because you are reading this topic the assumption is that the species you are inter-
ested in is exploited. However, it is a further step from observing that exploitation
is taking place to diagnosing it as the key threat to be tackled. Caughley and Gunn