Dead Dolphin ashore May 2016

Dead Dolphin ashore May 2016

Thursday, 25 March 2010

Mitten Crab off Ramsgate ?


In between today's showers I managed to slip in a quick survey on the strandline on the short stretch of sand between the groynes of the Western Undercliff , Ramsgate. For the first time since I started surveying the Western Undercliff as part of the Thanet Coast project, I found more mermaid purses (thornback ray egg cases) than dogfish egg cases. Numbering 39 mermaid purses to 19 dogfish egg cases. The strandline had more weed than usual and there was a fair amount of small pieces of sea coal mixed amongst it. I did manage to find three bead size pieces of Amber which is becoming more of a norm than a rarity.

However, I did manage to find a claw from Chinese Mitten crab and it was a fresh one too which in itself a unusual find for the area. The Chinese Mitten crab is an invasive species causing concern over its population growth in our waters. To make the position clearer I have copied an extract from a marine enviromental website.


"The Chinese mitten crab has increased markedly in the last 10 years in the UK. This invasive species can cause serious structural degradation and pose a significant threat to native communities in estuarine systems. As a consequence, it has been placed on the IUCN 100 of the World's worst invasive alien species list. The largest UK population of mitten crabs is located in the Thames region."

"This invasive species can cause degradation of river banks by burrowing and pose a significant threat to native communities in catchment systems. As a consequence, it has been placed on the IUCN 100 of the World's worst invasive alien species list. In England, although the population in River Thames had remained low, recent evidence suggests that it is increasing. It is perceived that increasing numbers of this crab will have a significant adverse impact on the natural balance of the Thames ecosystem. Therefore the purpose of this project is to determine if the population of mitten crabs in the River Thames can be controlled by commercial exploitation
"
Picture is the claw and next to it is a one pound coin for scale.

2 comments:

Tony2 said...

Thats an interesting find. It would be interesting to see a what whole one looks like.

Tony Beachcomber said...

Tony, There bodies appear rounded and they are vicious little sods.
They have a growth of on both claws that looks like seaweed and looks like a pair of gloves, I suppose that was where the name comes from.