Geoscience Reference
In-Depth Information
refugium during adverse environmental conditions
highlighted (Williams and Hynes, 1974).
During the 1980s and early 1990s there was
an increasing acknowledgement of the interaction
between surface water and groundwater systems
(Danielopol, 1980; Hynes, 1983; Valett
et al
.,
1993) resulting in a proliferation of ecological,
hydrological and biogeochemical research centred
on the HZ (Grimm and Fisher, 1984; Stanford
and Ward 1988; Triska
et al
., 1990). This growing
awareness and research effort culminated in the
HZ being firmly integrated within stream ecosystem
theory (Ward, 1989; Boulton
et al
., 2010) and
landscape ecology (Gibert
et al
., 1990; Datry
et al
.,
2008). However, many of the reported patterns
and hypotheses advanced have still not been
formally tested in the UK. This chapter considers
developments in HZ research, and achievements
in the UK during the last 20 years. In particular
it highlights how current research is contributing
to wider international research agendas centred on
the HZ.
Table 13.1
Water mites recorded in the UK associated
with the hyporheic zone.
Acari
HYDRACHNIDIA
HYDRYPHANTOIDEA
Hydryphantidae
Thyasella mandibularis
(Lundblad, 1924)
Wandesia (Wandesia) racovitzai
Gledhill, 1970
Tartarothyas romanica
Husiatinschi,1937
LEBERTIOIDEA
Torrenticolidae
Monatractides (Monatractides) madritensis
(K.Viets,
1930)
Torrenticola (Megapalpis) thori
(Halbert, 1944)
HYGROBATOIDEA
Hygrobatidae
Atractides (Tympanomegapus) acutirostris
(Motas &
Angelier, 1927)
Atractides (Atractides) denticulatus
(Walter, 1947)
Atractides (Atractides) latipalpis
(Motas &Tanasachi,
1946)
Feltriidae
Feltria (Azugofeltria) motasi
(Schwoerbel, 1961)
Feltria (Feltria) cornuta
Walter, 1927
Feltria (Feltria) denticulata
E.Angelier, 1949
Feltria (Feltria) subterranea
K.Viets, 1937
Aturidae
Barbaxonella angulata
(K.Viets,1955)
Albaxona lundbladi
Motas & Tanasachi,1947
Aturus brachypus
K.Viets, 1936
Kongsbergia (Kongsbergia) clypeata
Szalay, 1945
Lethaxonidae
Lethaxona (Lethaxona) cavifrons
Szalay, 1943
ARRENUROIDEA
Momoniidae
Stygomomonia (Stygomomonia) latipes
Szalay, 1943
Neoacaridae
Neoacarus hibernicus
Halbert, 1944
Hungarohydracaridae
Hungarohydracarus subterraneus
Szalay, 1943
HALACAROIDEA
Halacaridae
Lobohalacarus weberi
(Romijn & Viets, 1924)
Parasoldanellonyx parviscutatus
(Walter, 1917)
Soldanellonyx chappuisi
Walter, 1917
Soldanellonyx monardi
Walter, 1919
Porolohmanella violacea
(Kramer, 1879)
The state of knowledge in 1990
Research on the HZ in the UK until recently
lagged behind that of North America, Australia
and other parts of Europe (Proudlove
et al
., 2003;
Robertson
et al
., 2008). Before 1990 research on
the HZ of UK rivers was based on collecting and
describing fauna rather than on ecological studies.
A total of 35 taxa are recognized as obligate aquatic
hypogean organisms in the UK. Taxonomically
water mites contribute the greatest biodiversity
to the hyporheic zone (Table 13.1). In contrast,
Crustacea dominate other groundwater habitats
(numerically and in species richness) including
caves, springs and boreholes in aquifers (Table
13.2). However, most groundwater hypogean taxa
have also been recorded inhabiting the HZ. It
is somewhat surprising that five of the seven
obligate subterranean macroinvertebrate species
(stygobites) in the UK were described during the
19th century (Robertson
et al
., 2009; Knight and
Gledhill, 2010).
