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Restoring mudflats for birds
There are two important issues when considering the effectiveness of re-creating
or creating tidal sand and mud flats for birds:
- The speed with which newly created mud flats are used by birds and the numbers
involved. This has been studied at Seal Sands, Teesmouth (Evans
et al. 1998; Evans et al. 2001).This
and other studies of managed realignment sites suggests that usage by waterfowl
occurs quite rapidly, especially where invertebrate
prey quickly colonise in reasonable numbers. However the assemblage
may be different to that occurring in more natural areas due, in part to less
diverse range of sediment types and the height of the enclosing sea walls
remaining on the site. [Many waterfowl species prefer open situations where
they are able to see potential predators, some distance away.];
- For some species which graze plants in the inter tidal and tidal zones the
restoration
of Zostera beds will also be significant.
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General guidance: Because of these delays it is important when
considering mitigation schemes designed to replace tidal flats for birds
that the habitat is created some months or even years prior to the loss
of the habitat it will replace.
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References
Evans, P.R., Ward, R.M. & Bone, M.
2001.
Seal Sands Northwest Enclosure Intertidal habitat re-creation: Invertebrate Recolonisation and use by waterfowl and shorebirds. Final report, Department of Biological Sciences, University of Durham.
INCA Projects and English Nature.
Evans, P.R., Ward, R.M., Bone, M. & Leakey, M.
1998.
Creation of temperate-climate intertidal mudflats: factors affecting colonisation and use by benthic invertebrates and their bird predators.
Marine Pollution Bulletin, 37/8-12., 535-545.
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