Cuckoo Wrasse © COAST
A new Open Seas article published this week looks at the threat of rising commercial demand on wild wrasse stocks – due to their use as ‘cleaner fish’:
Cleaning up the cleaner fish
Wrasse are beautiful, charismatic fish that play a key role in the ecosystems of Scottish inshore waters. However, as Scottish salmon farmers now look to ‘cleaner fish’ as a way to address the industry’s sea lice problem, rising commercial demand is having potentially negative impacts on wild stocks of wrasse.
We take a look at the issue, find out what we know, what we don’t know and what we really should know about the environmental costs of the unprecedented demand for ‘cleaner fish.’ Our research indicates there is a systemic flaw in current fisheries management, which has failed to take precautionary steps to regulate this new fishery.
The sea lice problem
A big commercial concern for salmon farmers is sea lice: natural parasites that biologically weaken the health of salmon by feeding on their flesh and also transmit pathogens which affect growth rates and survival. They can therefore decimate farmed salmon harvest rates.
The rising costs for health treatments then affect the cost of farming, estimated to be £30 million annually. Crucially, aside from being just a business challenge for salmon farming companies, the problem spills out beyond the open net salmon cages into the sea.
For years, the salmon farming industry has been trying to deal with lice using chemical therapeutants, vaccines and disinfectants, but unsurprisingly chemical treatments aren’t a hit with consumers – and they aren’t particularly good for the environment either.
In recent years, the situation has slowly come to greater public attention, and the industry, following pressure from regulators and campaigners, notably Salmon and Trout Conservation Scotland, recognised the need to stop or reduce the discharge of hydrogen peroxide and other treatments into our sea lochs.
Read the full article at Open Seas
Tags: Fisheries, Marine, Salmon Farm, Seafood