Stop the spread of non-native species and diseases

At the British Fly Fair International show on the 11th February, we listened to Stuart Crofts talk in the Fly Fair Forum, entitled “Why invertebrates are important to your fly fishing”. Stuart started with a short section on non-native invasive species and biosecurity and focused on the killer shrimp (Dikerogammarus villosus) first discovered in the UK at Grafham Water in Cambridgeshire in September 2010. These are ecosystem engineers and will either eat or out compete everything else that you end up left with little else but shrimp. These invasive shrimp are difficult to eradicate as chemical or biological means will also impact native species. At present the best course of action is to stop their spread by ensuring that fisherman do not inadvertently transport them to new locations – hence the campaign to Check, Clean & Dry your equipment. The shrimp can survive out of water in damp conditions for up to 14 days and up to 2 days in dry conditions so if you are unable to dry your equipment for at least 2 days at 20ºC before the next time you fish then Stuart noted 2 options you can use: Clean your equipment thoroughly and then (1) use a disinfectant (see the CEFAS guide) or (2) bathe your equipment in hot water for 15 mins. Not boiling water but water that is above 45ºC, i.e. run the hot water tap and when it is getting too hot to hold your hand in it then it is hot enough. Then stick it on the radiator to dry out completely. The gold standard would be to have two sets of gear that you do not need to use equipment that is not dry and safe to use. While this post has focused on the killer shrimp and non-native species, there are a whole array of diseases that are likely spread in the same way and the impacts that these have on the aquatic environment and our quarry can be devastating.