Environmental Engineering Reference
In-Depth Information
and income. Attitudes to the resource, including cultural importance and
knowledge of its conservation status.
●
Existing institutional framework
. The ownership and control of the resource
and its habitat. Legislation at the national, international and local levels.
Traditional and de facto use rights. Cultural mores concerning the resource.
●
Additional threats to the system, potential or actual
. These include both biolo-
gical and socio-economic threats, such as land use change and habitat loss,
aliens and invasives (both immigration of users from outside and alien
species), hybridisation and disease.
Box 6.1
Examples of factors influencing management interventions.
The issue of concern—the Tanimbar corella
Just because the use of an endangered population is high profile does not neces-
sarily mean that it is the most significant cause of the population's predicament,
nor that stopping it will be the most effective way to ensure population
persistence. For example, banning the international commercial trade in the
Tanimbar corella (a type of parrot,
Cacatua goffini
) was largely counter-productive
(Jepson 2002). This endemic species is listed as near-threatened on the IUCN
Red List (IUCN 2006) because of ongoing population declines and its small pop-
ulation size. However, it is locally abundant and the commercial trade provided
some compensatory benefits to local people from its crop-raiding activities. The
removal of this benefit reduced incentives to conserve the species, and provoked
considerable resentment and mistrust of conservationists.
Resource type—High-value products in international trade
Rhino horn is a good example of an attractive export commodity because it has a
high value per unit, the units are conveniently sized for transport, it is non-
perishable, and has a high cultural value for traditional medicines in the Far East and
for dagger handles in Yemen (Martin and Martin 1982). Shark finning, involving the
disposal at sea of the rest of the shark (usually still alive), is prevalent because only the
fins have a high enough value-volume ratio to make transportation cost-effective
(Fig. 6.1). Current initiatives for improving the sustainability of this trade include
ensuring that sharks are landed entire, with the fins still attached to the body, thus
reducing the economic value of the catch while aiding monitoring (IUCN 2003).
By-product mortality—gaharu harvesting
Examples of bycatch of non-target organisms in commercial fisheries are numerous
and well documented (Lewison
et al
. 2004). A forestry example of by-product mor-
tality is the harvesting of gaharu resin, a valuable fragrant wood produced by trees
of the genus
Aquilaria
as a response to fungal attack. Traditional harvest methods
involve detailed checks to see if an encountered tree contains gaharu before felling;
in Indonesia, this practice is much less common and the trade is highly commer-
cialised. Harvesters now cut down virtually all
Aquilaria
trees encountered, healthy
or not (Soehartono and Newton 2002).
