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Essex Coast and Estuaries CHaMP - summary
The main habitats
to be found along this coastline include mudflat, salt marsh, and grazing marsh.
The land surrounding the estuaries which make up the bulk of the site is low-lying
and prone to flooding. This threat partly derives from the fact that much of
the land has been 'won' by the enclosure of extensive areas of tidal land for
agriculture, which now lie below mean sea level. At the same time there has
been a measurable loss of intertidal habitat, notably saltmarshes
which appears to be related to the relative rise in sea level of 1.7mm/year
(historical rise at Harwich). Given the predicted rise of 5mm/year based on
the MAFF advised allowance for sea defence purposes, then the trend of habitat
loss seems set to continue and with it the coastal
squeeze .
This CHaMP provides important information and examples of four key approaches
to habitat restoration, namely:
- Re-creating mudflats and saltmarshes to seaward by developing saltmarsh
restoration sites (1980s);
- Maintaining the existing tidal habitat using dredged
material;
- Re-creating mudflats and saltmarsh landward through managed
realignment;
- Re-creating coastal
grazing marsh.
| Guidance:
The Essex sites help to show how important the contribution of saltmarshes
and mudflats can be to coastal defence. The fact that this is now much
more widely recognised is partly due to the examples of restoration of
these habitats through managed
realignment, which is of special significance
in this area. Examples of historical
failure of sea defences also provide
valuable information as to the likely course of habitat restoration behind
an engineered sea wall breach (Crooks
et al. 2002). |
References
Crooks, S., Schutten, J., Sheem, G.D., Pye, K. & Davy, A.J.
2002.
Drainage and elevation as factors in the restoration of salt marsh in Britain.
Restoration Ecology, 10., 591-602.
Abstract...
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