Declawing Crabs- Not Sustainable

It is a case of one law for vertebrates, and another for invertebrates. In Europe and the US fishermen are allowed to "declaw" edible crabs - remove one, or in the UK, both claws - and toss the animals back into the sea. Because crabs can regenerate the limbs, the fishery industry considers the practice sustainable. But is it? Bob Elwood of Queen's University Belfast, UK, and colleagues measured how much declawing increased stress and affected crabs' survival. Crabs with one claw removed showed a greater physiological stress response - release of glucose and lactate into the blood - than crabs allowed to shed a claw naturally. And they were still stressed 24 hours later. Of 28 crabs that had one claw removed, five died, whereas no crabs died after shedding their claws naturally (Marine Biology, DOI: 10.1007/s00227-007-0681-5). In the UK, fishermen can legally remove both claws. "There is a suggestion that the practice makes the fishery sustainable but the data on mortality would put this into doubt," says Elwood...