Prince Albert Angling Society view conservation as an absolute priority and this consideration echoes through our committee and our conservation officer, Mr Ian Doyle. Over the past few months, Ian has worked on a tremendous amount of projects to improve habitat, remove invasive non-native plant species and work side by side with other like minded clubs and organisations.

Chinese Mitten Crab

I have recently attended a seminar with the North Wales Wildlife Trust to discuss the invasion of the Chinese mitten crab, another threat to our fishing. We are, as a direct result from this meeting monitoring our river system and urge any fishermen, members or not to report any sightings to myself and also the website dedicated to tackle them.

I regularly take salinity and temperature measurements and pass them over to the trust ,this data will hopefully help us understand key factors to the mitten crabs life cycle and may in the future be used to find a method to control the creatures that threaten our river systems.

Should you come across one please treat it with extreme caution as they have vicious claws and are quite capable of giving you a nasty nip. In 1912, a large male mitten crab was discovered in a river in Germany. It was the first of many. During the 1920s and 1930s the crab flourished, spreading throughout Europe. It has since invaded waterways from Scandinavia in northern Europe to the Atlantic coasts of France and Portugal in the south.

The crabs are now rife in the Thames and have been evident for some years but now can be located in the River Mersey and also in the Welsh Dee. The crab pictured above was caught at dock road in Connah’s Quay by a junior member. To give you an idea of size, the shell measured roughly 4 inches across.

Mitten crab facts

  • The mitten crab breeds in estuarine waters and travels upstream into fresh water returning to the estuary to breed.
  • In china they are known to travel up to 1500 kilometres upstream .
  • They can walk across land.
  • Part of their diet consists of fish eggs. worrying for the salmon redds,particularly when you consider the crabs ability to travel upstream.
  • They live in burrows in the river bank and are known to undermine flood banks this causes concern on the Dee in particular as a large amount of her banks are used to alleviate local flooding.
  • They are an import from China (the clue is in the name) and are believed to have been introduced in either ships bilges or by people for use as a food source.

Simple Identification

The white tooth like claws are a good identifying pointer, so to are the mittens which cover them.


Ian Doyle

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