Plymouth’s National Marine Aquarium, which manages the site in Whitsand bay, believes that the 100m-long net could have been “set illegally close to the reef by unlicensed fishermen”, before getting snagged on the wreck and “destroying a large section of the reef”.
The wreck, says the NMA, is home “to more than 250 species of marine life – many of which have not been found on other dive sights around the UK”.
It fears that “some of these uncommon species have now been destroyed, and may take many years to return”.
“Numerous crabs and fish” have been found trapped, some of which have been released alive by the divers.
It was known that “licensed fishermen are not to blame for the net”. Various authorities are working “to try to establish why this has happened and who is responsible”.
For the moment, the NMA is advising “against any dives over the reef, until further information is available”.
Diving operations to clear the netting are being run by local company Diving and Marine Solutions.