Environmentalists in Jersey say the number of dead spider crabs found on the north east of the island is "deeply disturbing".
Since August hundreds of them have been found dead by divers in St Catherine's.
A local diver has told ITV News he is finding more and more trapped in nets under the water.
Initially there was confusion as to whether the crabs were dead or had simply shed their shells, which is something that spider crabs do as they grow, however environmentalists say they have noticed an increase in underwater nets trapping the crabs.
It is thought that fishermen are trapping the spider crabs under water until they can be sold and are sometimes used as bait for whelks.
- Anna Geary spoke to Kevin McIlwee and Don Thompson to find out more...