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Declawing Crabs May Lead To Their Death

Date:
October 10, 2007
Source:
Queen's University, Belfast
Summary:
The future sustainability of fishermen who declaw edible sea crabs has been questioned. Marine scientists studied crabs' reaction to declawing. Crabs felt increased stress and had a lower survival rate after the removal of one claw.
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Professor Bob Elwood with a crab at a Singapore restaurant.
Credit: Image courtesy of Queen's University, Belfast

The future sustainability of  fishermen who declaw edible sea crabs has been questioned by a Queen’s academic.

Professor Bob Elwood, from the School of Biological Sciences studied crabs’ reaction to declawing. Crabs felt increased stress and had a lower survival rate after the removal of one claw.

He said: “Should a crab survive declawing it will not be able to feed effectively and may subsequently die of starvation.”

Under current UK laws, fishermen can legally remove both claws and then put the animal back into the sea. According to Professor Elwood, this can result in stress and a high mortality rate for crabs.

Professor Elwood said: “We found a strong stress response within ten minutes of taking off one claw and this stress remained after 24 hours. The stress response was greater if the crab was declawed rather than being induced to cast off a claw. So, the stress is not due specifically to claw loss but to the manner of the claw loss.

“In the past, declawing has been defended because it has been likened to claws being naturally cast off, but this study shows clearly the two are very different.

“Of particular concern was that claw removal resulted in a substantial mortality within 24 hours that appeared to occur when the wound size was large. The typical fishery practice of removing two claws is likely to result in a much higher mortality than that observed in these experiments and so will have marked implications for the sustainability of crab claw fisheries.”

Looking at the declawing process around the world he concluded: “A fishery in the USA only allows removal of one claw. This is difficult to regulate because it cannot easily be determined if two claws are from the same crab or different crabs. In most other places the whole crab is used for food not just the claws.”

“In our experiments we were aware of ethical concerns about repeating the practice of claw removal in a scientific investigation. We believe though that the small number of animals is justified as it gives important data that might save very large numbers of crabs from this experience.”


Story Source:

The above post is reprinted from materials provided by Queen's University, Belfast. Note: Materials may be edited for content and length.


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Queen's University, Belfast. "Declawing Crabs May Lead To Their Death." ScienceDaily. ScienceDaily, 10 October 2007. <www.sciencedaily.com/releases/2007/10/071007210836.htm>.
Queen's University, Belfast. (2007, October 10). Declawing Crabs May Lead To Their Death. ScienceDaily. Retrieved July 30, 2015 from www.sciencedaily.com/releases/2007/10/071007210836.htm
Queen's University, Belfast. "Declawing Crabs May Lead To Their Death." ScienceDaily. www.sciencedaily.com/releases/2007/10/071007210836.htm (accessed July 30, 2015).

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