Trout & Salmon (UK) - - Know How | Invasive Species -

What’s the prob­lem? Dikerogam­marus vil­lo­sus was found in Cardiff Bay, Grafham Wa­ter and Eglwys Nun­nyd reser­voir in 2010, and the Nor­folk Broads by 2012. D. haemobaphes was found in the Sev­ern in 2012, fol­lowed by the Thames, Trent, Witham, and Ken­net and Avon Canal. Both Ponto-caspian shrimp are a very se­ri­ous threat to na­tive species, they can live in a wide range of aquatic habi­tats, with low oxy­gen lev­els and even 20 per cent salin­ity. Grow­ing up to 30 mm long, D. vil­lo­sus are much larger than na­tive fresh­wa­ter shrimp, and have been dubbed “killer shrimp” for their ten­dency to shred prey with­out eat­ing it. Other in­ver­te­brates, fish eggs and ju­ve­nile fish may be at­tacked, with vul­ner­a­ble species driven into lo­cal ex­tinc­tion. Re­search on the River Chur­net shows that D. haemobaphes, the “de­mon shrimp”, is likely to have a sim­i­lar im­pact.

What you can do

Take care­ful biose­cu­rity mea­sures when you leave an area where Ponto-caspian shrimp are present. Apart from strin­gent biose­cu­rity, no ef­fec­tive means of con­trol are cur­rently known. NB: If you sus­pect you’ve seen th­ese shrimp in any other lo­ca­tions, email de­tails and a pho­to­graph to alert_non­na­tive@ ceh.ac.uk as soon as pos­si­ble.

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