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North west coast USA - summary
The northwest coast of America has a temperate climate and high-energy shorelines.
The coastline is rocky with headlands and small estuaries. Saltmarshes are relatively
restricted by comparison with their southern counterparts, though problems associated
with Spartina invasion are also significant,
as for example in Pugit Sound. Here the Washington State Noxious Weed
Control Board (http://www.nwcb.wa.gov/)
have classified both Spartina anglica and
S. alterniflora as class B weeds which are
designated for control by state law.
Restoration efforts in the north west seek to redress the problems associated
with habitat loss, pollution and invasive species (including Spartina)
and are concentrated on estuarine habitats. As on the north east coast here
restoration of coastal wetlands is being undertaken by improving tidal exchange
where this has been restricted though construction of roads and other obstructions
to tidal movement. One site in Washington was opened to tidal flushing in 1987
after being enclosed for approximately 70 years. Rapid development of saltmarsh
took place between the first and fourth years but with change slowing after
year 6. Based on accretion rate data from previous studies it was predicted
that full recovery of the system would take between 75 and 150 years (Thom
et al. 2002).
| Guidance: Of particular interest are the attempts to restore tidal
wetland on the west coast using dredged
material, which may have lessons
that can be applied to the UK and the rest of northwest Europe. |
References
Thom, R.M., Zeigler, R. & Borde, A.B.
2002.
Floristic development patterns in a restored Elk River estuarine marsh, Grays Harbour, Washington.
Restoration Ecology, 10., 487-496.
Abstract...
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