Devonshire magazine takes a look at bird life on the…
Can you believe it, these beautiful, tropical-looking fish are being taken from our reefs in Devon, driven by lorry to Scotland to work as parasite cleaning agents in the salmon farming industry, denuding local reef habitats for a very long time afterwards of a valuable part in the ecological chain
This summer, a new threat to Devon’s marine environment emerged. Thousands of local fish, from a family of fish known as wrasse – are being removed from waters just off the south Devon coast.
The fish are then transported alive to Scottish salmon farms where they are being used as a ‘natural’ control against parasites, such as sea lice. Scottish salmon farms have an increasing problem with sea lice in intensive farming operations. Sea lice are naturally occurring parasites which attach themselves to salmon and can reduce their health and growth. When fish are farmed in high densities the problem is magnified.
Sea lice are controlled in conventional fish farms through the use of chemicals and other techniques such as washing with warm water. Every three or four years, the parasites become resistant to chemical treatments and new ones need to be found. Currently there are no new chemical treatments on the horizon so there is an increased emphasis on use of ‘cleaner fish’. Wrasse have been targeted for use as ‘cleaner fish’ and have been caught in very high numbers from other parts of the UK and transported to fish farms to reduce lice infections.
Devon’s tropical-looking wrasse are long lived fish that thrive on the rocky shores of Devon, Dorset and Cornwall. They are carnivorous and mostly feed on shellfish. They are very variable in size: Ballan wrasse can grow up to an amazing 4kg in weight but most species are much smaller. The cuckoo wrasse is one of our most colourful UK fish and wouldn’t be out of place in the Great Barrier Reef. Males have a bright blue head and tail and a mixture of orange and blue coloured body. Wrasse are highly territorial species and reproduce slowly which means populations are very slow to recover after over-fishing.
This summer, wrasse are being trapped in Plymouth Sound and Wembury Bay. Most of these waters are part of a Marine Protected Area known as Plymouth Sound and Estuaries Special Area of Conservation.
The removal of live wrasse for Scottish fish farms is thought to be a relatively new practice. Until now wrasse have not been commercially fished in Devon, however, demand from Scotland for parasite control has meant that five species are now being targeted, including: Corkwing, Ballan, Goldsinney, Cuckoo, and Rock Cook wrasse.
A WRASSE CAMPAIGN
Devon Wildlife Trust (DWT) launched a campaign in June calling for a ban on the live capture of Wrasse from Devon’s Marine Protected Areas (MPAs) – places which have been recognised for the richness of their marine nature.
The campaign gives Devon residents the chance to voice their opposition by signing an on-line petition which asks for action to be taken by the county’s MPs.
Recent controls on Devon’s wrasse fishery have been implemented by the Inshore Fisheries and Conservation Authority (IFCA), but DWT believes that these do not go far enough. It points to a similar wrasse fishery which took place in 2015 in Dorset which saw 57,000 of the fish taken during just one 18-week period. Now the fear is that a similar operation is underway in Devon.
Devon Wildlife Trust is concerned about the impact this will have on local wrasse populations and the wider marine environment. The charity’s Director of Conservation and Development, Peter Burgess said:
“We’re calling for an immediate stop to this fishery. Wrasse are long-lived and highly territorial fish, so the removal of large numbers along the Devon coast will severely disrupt their populations – it could take decades for them to recover.
“Nobody yet knows what impacts wholesale removal of wrasse will have on our fragile marine reef ecosystems and the natural balance could be thrown into chaos. This could be devastating for not only the wrasse but habitats and species which depend on them for their survival.”
DWT believes the recent moves by the Devon IFCA to partially control the fishery are an acknowledgement of the problem but don’t go far enough.
Peter Burgess added:
“It’s vital that we exercise the precautionary principle and halt the capture and removal of Wrasse from our most precious marine environments before long term damage is done.
“Devon wrasse populations are being threatened to solve the problems caused by commercial salmon fish farms hundreds of miles away in Scotland. There is very little understanding of its longer term impacts on the health of this fascinating native species and the fragile reef environments the wrasse help to sustain. This is why we’re asking the people of Devon to help us stop the removal of thousands of wrasse from the county’s Marine Protected Areas by signing our on-line petition.”
Sign the petition now! http://wtru.st/DWTwrasse
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