Stocks of the UK’s Atlantic salmon along with varieties of domestic brown trout could be under threat from a deadly parasite according to research led Bournemouth University (BU) published in the International Journal of Parasitology.
Lead author of the paper Dr Rodolphe Gozlan believes the disease is a rosette agent or parasite first identified in the UK in 2005. The agent - Sphaerothecum destruens – was originally found in the US and is closely associated with ‘invasive’ fish species including topmouth gudgeon and could prove deadly to native salmonids (Atlantic salmon, brown trout).
Dr Gozlan and his colleagues from the University of California, State University of New York, the UK’s Centre for Ecology and Hydrology and Cardiff University have found the first record of the new infective parasite rosette agent outside North America.
In his previous research (Nature, 2005), Dr Gozlan initially found that the parasite poses a severe threat to some freshwater fish species in Europe. The latest findings have serious implications in understanding the potential risk posed by the association in the UK of this disease, the rosette agent, with invasive fish species.
“Unlike in the US, the occurrence of this agent in invasive fish presents a major risk of spread from wild invasive populations to sympatric populations of susceptible native fish,” said Dr Gozlan, an associate professor in Conservation Ecology within BU’s School of Conservation Sciences. “As such it represents a risk for fisheries and commercial aquaculture, as movement of fish for stocking purposes is common practice.”
Scientists at Bournemouth University have so far found 26 populations of topmouth gudgeon across England and Wales in rivers, enclosed lakes and sites connected to the river network. Catchments at risk from invasion include the Kent, Yorkshire Ouse, Trent, Thames, Medway, Itchen, Test and Severn.
Further information is available in the attached press release. Photos are also attached showing the topmouth gudgeon which carries the parasite and a microscopic image of the rosette agent.
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