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Northey Island historical change
In 1840 the tithe map shows that most of the island to have been used as pasture
or arable land. After a major storm in 1897, large (approximately 2/3 of the
island) became flooded following breaches to the sea wall, which were not repaired
(Burd 1994). By 1901 these areas were reported
to have reverted to saltmarsh (see report by the Institute
of Estuarine and Coastal Studies 1992 and Figure below). The saltmarshes
that became re-established showed substantial erosion
between 1973 and 1988 (Burd 1992)
The retreat site
In 1991 a small 0.8ha site in the Blackwater Estuary was the first deliberate
attempt at an experimental managed realignment. The area affected was enclosed
after 1840 but before the storms of 1897. The engineered realignment was a collaborative
effort between the owners of the site, the National Trust, NRA (now Environment
Agency) and English Nature. One of the aims of breaching and lowering of the
sea wall was to see if saltmarsh could be recreated. A study of the recolonisation
showed that by 1993 a pioneer saltmarsh community had developed. By 1994 there
were a total of 25 species including the rare Suaeda
vera and other recognisable communities forming mosaics with the pioneer
marsh (Dagley 1995).
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Guidance: This island provides an insight into the changes which
have taken place over the last 150 years or so as tidal land was enclosed,
and then abandoned as sea walls failed. It also represented a significant,
if small, step towards developing managed
realignment as an alternative to continuing strengthening of
existing sea walls.
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References
Burd, F.
1992.
Erosion and Vegetation Change on the Saltmarshes of Essex and North Kent between 1973 and 1988.
Research & survey in nature conservation, 42
Nature Conservancy Council, Peterborough.
Burd, F.
1994.
Sites of Historical Sea Defence Failure - Phase II Study.
English Nature.
Dagley, J.R.
1995.
Northey Island managed retreat scheme. Results of botanical monitoring 1991 to 1994.
English Nature Research Report, 128
English Nature.
Institute of Estuarine and Coastal Studies
1992.
Historical Study of Sites of Natural Sea Wall Failures in Essex.
English Nature Research Report, 15
English Nature.
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