Geoscience Reference
In-Depth Information
Here, an ecosystems approach to conservation is
more likely to bring real benefits for biodiversity
and for human communities than attempting to
impose more traditional 'western' views of nature
conservation (Abell and Bryer, 2009; Mathooko
et al
., 2009; O'Keeffe and Thirion, 2009).
management options for rivers along a spectrum of
decreasing conservation value. At the high-quality
end of the spectrum there is a case for
preservation
of
those few remaining examples of natural or near-
natural river systems. Where river 'quality' remains
high but where human pressures are evident,
the preferred option changes from preservation
to
limitation
of catchment development; further
along the spectrum the need is for
mitigation
of
damage, then for
restoration
of degraded stretches,
and finally, at the end of the spectrum, for
dereliction
- giving up and accepting the status
quo when improvement is impossible or when
the costs outweigh the benefits. The science of
river restoration has made significant progress since
1990 (Kondolf, this volume). Yet there are still
difficult policy decisions to be made. For example,
should time and money be spent on restoring the
worst rivers to a level of mediocrity or to ensure
that the rivers of the highest quality are kept in that
condition? Can the restoration of rivers in Europe
to 'high ecological status' be justified when the
WFD only requires the target of 'good ecological
status' to be met? Where rivers are already at high
ecological status how can they be maintained at
that level when resources are limited?
River restoration is one area where an ecosystem
services approach can pay dividends for nature
conservation. However, this requires a careful
analysis of the costs of restoration and the
benefits both for biodiversity and for human
communities, and needs an understanding of the
relationship between ecosystem services and the
hydrogeomorphic character of the river section
under consideration (Thorp
et al
., 2010).
Rivers as protected 'sites'
Nature conservation has always relied on the
idea that parcels of land can be protected from
human development and activity by some form
of legal designation, and the practice of selecting
nature reserves or other 'sites' for protection occurs
universally. In the European Union an extensive
network of Special Areas of Conservation ('
Natura
2000
') has been established to safeguard particular
types of habitats and threatened species. Some of
these SACs are rivers, with examples from the
UK including the Avon in England (Plate 5a), the
Tweed in Scotland (Plate 5b), the Tywi in Wales
(Plate 5c) and the Upper Ballinderry in Northern
Ireland (Plate 5d). Taken together, however, the
'qualifying interests' for these four high-quality
rivers cover only a very small proportion of
their plant and animal communities - the river
habitat in Annex I (described earlier), otter (
Lutra
lutra
), Atlantic salmon, sea lamprey (
Petromyzon
marinus
), river lamprey, brook lamprey (
Lampetra
planeri
), bullhead (
Cottus gobio
), freshwater
pearl mussel, Desmoulin's whorl snail (
Vertigo
moulinsiana
) and floating water-plantain (
Luronium
natans
). In addition, the difficulty of trying to
squeeze rivers into the traditional mould of
terrestrial site protection has long been recognized,
because legal designations rarely extend to entire
catchments and often stop at the top of the river
bank. Consequently, more is expected of legislation
that supports river basin management (e.g. the
WFD) as a way of securing some of the aims of
nature conservation. The role of protected areas in
future strategies for river conservation is a topic
ripe for debate and action.
River management versus river conservation
Boon (2000) suggested that there are clear
distinctions between what is usually considered the
role of river 'managers' and those interested in
river 'conservation'. Nature conservation highlights
the intrinsic value of the special or extra-ordinary
(the natural, the rare, the threatened, the diverse)
yet still appreciates the ordinary. It lays stress on
'non-use' (e.g. aesthetic) values while realizing
the importance of 'use' (e.g. economic) values.
River management focuses on the ordinary but
Restoration or conservation?
In the broadest sense, river restoration can be
considered a form of river conservation. At the
rivers conference in 1990, Boon (1992) set out five
