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P. Genovesi
11 years (Panzacchi et al. 2006). The Ruddy duck eradication campaign
launched in the United Kingdom is predicted to cost € 5–13 million. Even
small-scale eradications can sometimes be very costly: for example, the
removal of only twelve Himalayan porcupines from Devon cost a staggering
€ 230,000.
One of the problems in assessing how much eradications have cost on average
is that the available literature (either scientific or “grey”) often does not
report such data, and the results of prompt eradication projects (cf. removals
carried out in the early stages of invasions) are often not published at all. If it
is complex to assess costs, it is even more difficult to compare costs with benefits
of eradications, because these depend on parameters which have very
high levels of uncertainty, such as the probability of the target species, if not
removed, to establish, expand and cause damage. The eradication of the Canadian
beaver (Castor canadensis) from France required only one operator
working for a limited amount of time but likely prevented very costly impacts
if the species had been allowed to expand (Rouland 1985). In an attempt to
compare costs of eradication vs. permanent control, Panzacchi and coauthors
(2006) showed that the successful eradication of the coypu from East
Anglia, costing about € 5 million in 11 years, may have prevented much more
severe economic impacts in the long term, considering that permanent control
of the species in Italy causes losses of over € 3.4 million per year and that
future annual costs are predicted to exceed € 12 million (see also Chaps. 18
and 19).
In the case of the invading alga C. taxifolia, successful eradication from
California required (converted into €) over € 2.5 million in 3 years, and additional
costs will be necessary for medium-term monitoring. In Europe, when
the species was initially detected, it could have been removed within a few
days of work (cf. above) – nowadays, it is widespread, and permanent control
in many areas of the Mediterranean basin is costing huge amounts of money.
In the case of the black-striped mussel from Cullen Bay in Australia, the decision
of eradicating the invasive – at a cost of (converted into €) over € 1.3 million
“only” – was taken because of the risk that an expansion of the alien mollusc
could have impacted the local € 24 million pearl fishery.
More comprehensive economic assessments of eradications are evidently
needed, in order to provide state governments with critical data for revising
their policies on the issue, and to assist the authorities competent of taking
decision about when to start an eradication (see also Chaps. 18 and 19).
22.2.5 Legal and Organizational Constraints
Invasive alien species are a cross-cutting issue, involving many different
aspects (such as agriculture, forestry, horticulture, aquaculture and hunting),
and implementation of eradications is often regulated by different laws. For