Geoscience Reference
In-Depth Information
and Culver, 2009). This, together with the
Groundwater Directive, has stimulated research
on the HZ in European countries such as Ireland
(Arnscheidt
et al
., 2009; Kibichii
et al
., 2009). In
addition, regulatory bodies have taken a direct
interest in the HZ for the first time in the UK.
However, despite these policy developments there
has been no move to develop monitoring networks
for the HZ in the UK, probably because of a lack
of incentives and compulsion for such networks
and a general lack of knowledge regarding the
functional
have been updated with a growing number of
records from the Environment Agency, records
compiled by the national subterranean Crustacea
recorder (Lee Knight) and additional published
sources (Davy-Bowker
et al
., 2006; Stubbington
et al
., 2009) providing a comprehensive database
of fauna collected within the HZ and other
hypogean habitats (Robertson
et al
., 2008). These
data are now publicly available via the UK National
Biodiversity
Network
(NBN)
Gateway
which
contains
more
than
1300 records
of
hypogean
significance
of
the
HZ
(Buss
et al
.,
macrocrustaceans.
Most significantly this database has allowed the
distribution of HZ fauna to be studied in detail
for the first time at a national scale in relation
to underlying geology and glacial history (Plate
17) (Robertson
et al
., 2008). A NERC funded
knowledge transfer 'Hyporheic Network' has also
made major advances in stimulating awareness of
the HZ and in sharing ideas (Buss
et al
., 2009;
Krause
et al
., 2011).
2009).
The start of the 21st century saw researchers
in the UK stress the importance of hyporheic and
benthic meiofauna within lotic foodwebs and in
secondary production (Stead
et al
., 2004). Research
at the river-channel scale also showed how benthic
fauna in the HZ are associated with upwelling and
downwelling water within riffles (Davy-Bowker
et al
., 2006) and marked the beginning of a period
of significant growth in HZ research.
Significant advances in the understanding of HZ
ecology in the UK were made through the Natural
Environment Research Council (NERC) LOwland
CAtchment Research (LOCAR) programme
(2000-2006). This was designed specifically to
address hydrological, hydrogeological, geomor-
phological and ecological interactions in permeable
river catchments (Wheater and Peach, 2004). This
inter-disciplinary programme resulted in a series of
projects on the natural functioning of the HZ and
on human impacts. These included the temporal
variability in temperature regimes at the scale of
individual riffles (Hannah
et al
., 2009), spatial and
temporal variability in HZ fine sediment storage
associated with the growth of aquatic macrophytes
(Heppell
et al
., 2009), and the occurrence of
methanogenesis within the HZ of streams with
extensive macrophyte growth and subject to
increased sedimentation from agricultural runoff
(Sanders
et al
., 2007).
More recently, reviews of HZ ecology and
biodiversity have been published for Scotland
(Gilvear
et al
., 2006; Pryce
et al
., 2010) and for
England and Wales (Robertson
et al
., 2008). The
historic distribution data for England and Wales
The current status of HZ
research and its importance to
understanding biodiversity and
ecological functioning in rivers
Although much of the research on HZ ecology in
the UK appears to have been directed historically
towards obligate hypogean organisms, most of the
organisms recorded in terms of abundance and
diversity are of benthic origin (Proudlove
et al
.,
2003). This pattern is similar to that reported for
most other regions of the world where the HZ
has been studied in detail (Marmonier
et al
., 2010;
Olsen
et al
., 2010; Wood
et al
., 2010). The following
section summarizes how research in the UK is
contributing to international scientific research on
the wider functioning of the HZ in relation to
salmonid fisheries, the HZ refuge hypothesis, the
role of hydrogeology, and the impact of nitrate
loading. It also describes how recent research has
begun to unlock the 'hidden' fauna of the HZ in
the UK through a national-scale survey of Scotland
(Pryce
et al
., 2010).
