Dear Marie & estuarine Science List Members,
There are a couple of references that I am aware of about the Chinese Mitten
Crab in the Thames. I have the full abstract for the first:
Attrill,MJ; Thomas,RM (1996): Long-term distribution patterns of mobile
estuarine invertebrates (Ctenophora, Cnidaria, Crustacea: Decapoda) in
relation to hydrological parameters. Marine Ecology Progress Series
143(1-3), 25-36. Between 1977 and 1992, semi-quantitative samples of
macroinvertebrates were taken at fortnightly intervals from the Thames
Estuary (UK) utilising the cooling water intake screens of West Thurrock
power station. Samples were taken for 4 h over low water, the abundances of
invertebrates recorded in 30 min subsamples and related to water volume
filtered. Abundances of the major estuarine species have therefore been
recorded every 2 wk for a 16 yr period, together with physico-chemical
parameters such as temperature, salinity and freshwater flow. Annual cycles
of distribution were apparent for several species. Carcinus maenas exhibited
a regular annual cycle, with a peak in autumn followed by a decrease in
numbers over winter, relating to seasonal temperature patterns. Conversely,
abundance of Crangon crangon as consistently lowest in summer, responding to
seasonal changes in salinity, whilst Liocarcinus holsatus, Aurelia aurita
and Pleurobrachia pileus were only present in summer samples, with P. pileus
often in vast numbers (>100 000 per 500 million l). The estuarine prawn
Palaemon longirostris showed no obvious sustained annual pattern, but
evidence for a longer cycle of distribution was apparent. During 1989-1992
severe droughts in southeast England severely disrupted annual salinity
patterns and coincided with a large increase in the Chinese mitten crab
Eriocheir sinensis population. This included the first synchronised
migration of adults in the UK. Settlement of young crabs during low-flow
periods is suggested as an explanation for this population increase.[BROWN
SHRIMP; CRANGON CRANGON; DISTRIBUTION; ERIOCHEIR SINENSIS; FLOW; LIFE CYCLE;
LIOCARCINUS HOLSATUS; PLEUROBRACHIA PILEUS; SALINITY; TEMPERATURE; THAMES
ESTUARY]
Clark,PF; Rainbow,PS; Robbins,RS; Smith,B; Yeomans,WE; Thomas,M; Dobson,G
(1998): The alien Chinese mitten crab Eriocheir sinensis (Crustacea:
Decapoda: Brachyura) in the Thames estuary. Journal of the Marine Biological
Association, UK 78, 1215-1221. [CHINESE MITTEN CRAB; ERIOCHEIR SINENSIS;
MARINE; NON-NATIVE SPECIES; THAMES]
These will have some useful distributional and life cycle data, but probably
won't help regarding control.
We have found extremely high densities of juvenile mitten crabs near low
water on a survey for a client, just downstream from Tower Bridge. They were
under various size rocks, reaching densities of about 300 per square metre.
I may be able to dig out some further details from our report if that would
be helpful.
I am not aware of Chinese mitten crabs causing problems in gravel - has
anyone else knowledge of this? I know they can dig substantial holes in
mudbanks. Can't immediately think of any mitigation/control methods that
might be effective, apart from changing the gravel into something more
substantial that they can't burrow into.
Good contact points would be at Paul Clark at the Natural History Museum,
Philip Rainbow at Queen Mary and Westfield College and Myles Thomas at
Environment Agency Hatfield.
Hope this helps,
Phil Smith
Dr Phil Smith, AEC/3E Ltd, The Limes, Creedy Park, Crediton, Devon, EX17
4EB, UK
Tel +44 1363 776456 fax 774656 e-mail [log in to unmask]
BOOKMARK THE 3E DATABASE OF ENVIRONMENTAL EXPERTS AT http://www.3eltd.com/
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