Fen Management Handbook - Scottish Natural Heritage

Problems for invertebrates area are created by:
– Carp can stir up mud to produce murky water with few plants or invertebrates: a bad problem in
newly dredged ponds where carp have been introduced
– Excessive clearance of water crow-foot etc from chalk rivers
– Removal of woody debris
– Treatment of ponds and lakes against fish-louse. Or ‘temporary’ drainage to eliminate fish/fish
lice, and then restocking with fish
– Fishermen excessively removing aquatic and aquatic marginal vegetation, and further destroying
the wetland/water transition by building up the bank
1.1.1 Spined Loach
The following management recommendations for spined loach are taken from English Nature
(undated).
– Management which causes a reduction in habitat diversity e.g. channelization of rivers and
streams should be avoided.
– Regulate excess stocking of omnivorous course species such as roach and bream
– Prevent introduction of non-native species such as carp to the river system
– Limit any unregulated manipulations, such as the removal of pike, which in turn causes an increase
in course fish species such as roach and bream
– Adopt sensitive weed cutting practice. For example cutting down the centre, or perhaps one side
of a channel to create a heterogeneous habitat suitable for spined loaches.
– Long term management of macrophytes, through tree planting where appropriate to create shade
along one bank
– Dredging should not be undertaken across the whole length of the channel at a given time.
Dredging in the centre of the channel, leaving undisturbed refuges may be acceptable
– Dredging should not be more than once every 4 years to enable populations of spined loach to
recover and achieve maximum lifespan.
– Frequency of dredging maybe increased to once every 2/3 years where a rotational regime is
adopted, always leaving suitable refuge areas.
References and sources of further information
Ausden M., Sutherland W.J. & James R. 2001 The effects of flooding lowland wet grassland on soil
macroinvertebrate prey of breeding wading birds. Journal of Applied Ecology, 38: 320-338.
Bradbury, R.B. & Bradter, U. 2003. Habitat associations of Yellow Wagtails Motacilla flava flavissima
on lowland wet grassland. Ibis 146: 241 – 246
Langton, T., Beckett, C and Foster, J. 2001. Great Crested Newt Conservation Handbook. Froglife,
Halesworth.
Smart, M. & Coutts. K. 2004. Footdrain management to enhance habitat for breeding waders on
lowland wet grassland at Buckenham and Cantley Marshes, Mid-Yare RSPB Reserve, Norfolk,
England. Conservation Evidence 1: 16-19)
Strachan, R & Moorhouse, T. 2006 The Water Vole Conservation Handbook, Second edition. The
Wildlife Conservation Research Unit.
Youngs, T. 2005. Wet grassland practical manual: breeding waders. RSPB, Sandy, UK.
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