For Invasive Species Week, the MSA highlights Salmon Fluke – A fish parasite listed with top fifteen invasive species that are most likely to invade the UK in the next 10 years
Research published by Centre Ecology and Hydrology (CEH) includes Salmon fluke Gyrodactylus salaris in the top fifteen invasive species that are not yet established in the UK, but pose a significant threat to native biodiversity, the economy and human health.
Invasive non-native species (INNS) are defined as species, introduced through human action outside of their native range, that have the ability to spread causing damage to the environment, the economy, our health or the way we live. Over the last century there has been a dramatic increase in the movement of non-native species around the world as a consequence of increasing international trade and travel.
Salmon Fluke Treatment
Salmon fluke is a small parasite barely visible to the naked eye which infects the skin, gills and fins of salmon, trout, grayling and other fish in freshwater. It presents one of the greatest threat to Atlantic salmon populations in the UK.
It occurs naturally in the Baltic rivers of Finland and Russia where the native fish are tolerant to the parasite. However, Atlantic salmon outside of this native region have no or little tolerance to it, resulting in collapses in fish stocks in rivers where it is introduced.
In Norway, 50 rivers have so far been infected, losing around 98% of their salmon within five years of invasion. To control the spread of the parasite, infected rivers must be treated with rotenone to remove all potential fish hosts and barriers put in place to prevent salmon entering the river to spawn and generate more hosts. These extreme but necessary measures are highly destructive, expensive and take many years to undertake.
Our principle worry is the accidental introduction of the parasite into the UK. The parasite is very hardy and can survive for 5-7 days without a host in damp conditions such as damp angling equipment (nets, waders and bags). This means it could be unintentionally brought into the UK on angling equipment that isn’t thoroughly cleaned and dried before being used again in UK waters.
“This priority list confirms the major and imminent threat that salmon fluke presents to fish populations in the UK. It is critical that we all work together to keep this devastating parasite out of the country. Research has demonstrated the effectiveness of the check, clean dry measures to kill invasive species and diseases present on damp angling nets. Following these simple measures after every fishing trip, anglers can help to prevent this invasive species, and others from being accidentally spread into our waters”
What can I do?
Prevention is better than cure. It only takes one infected fish to start an epidemic Always carry out the three ‘Check clean dry’ steps. Whilst we may not be undertaking many or any trips abroad at the moment due to Covid-19, it is essential that we clean and dry our equipment and boots thoroughly after any fishing trip in the UK or returning from abroad to ensure gear are clean of any parasites, plants and aquatic materials. Following this best practice, will help to prevent the spread of any invasive species or disease between our waters.
© Jannicke Wiik Nielsen
As an Alliance of five organisations, we will build on the existing work of our partners and maximise our impact by taking a coordinated approach and vital action in order to halt and reverse the decline of wild Atlantic salmon.
The goal of the Missing Salmon Alliance is to build an evidence-base to influence national and international decision-makers to regulate activities that adversely impact wild Atlantic salmon.
The Missing Salmon Alliance
The MSA is comprised of the following members:
Game & Wildlife Conservation Trust, Atlantic Salmon Trust, the Angling Trust with Fish Legal, The Rivers Trust and Fisheries Management Scotland.
https://www.missingsalmonalliance.org