Publication Abstract

Managing Argulus foliaceus infections in stillwater trout fisheries

N.G.H. Taylor*, R. Wootten and C. Sommerville

Over 10 million people in the UK participate in recreational fishing (angling), a substantial proportion of whom fish for trout in stillwater systems. Such fisheries make an important economic contribution to the UK’s rural economy, with trout anglers spending over £25 million per annum fishing.

Infections by the ectoparasitic crustacean Argulus foliaceus are common in stillwater trout fisheries and constitute the most significant pathogen currently affecting these systems. The parasite is perceived to cause economic loss through a reduction in the number of anglers attending a fishery due to reduced capture rates and aesthetic appeal of fish, which can occur as a result of the infection. The extensive and heterogeneous physical, chemical and environmental nature of fisheries makes the management of pathogens within these systems difficult. A consequence of this is that a ‘one size fits all’ approach to control is unlikely to be effective. Fishery managers require a suite of options that can be used to develop a tailor made control programme that suits their business. 

This paper reviews currently available control strategies and suggests evidence based, novel management techniques that may reduce the parasite’s impact. Three years of field data have demonstrated that stock turnover and water clarity act as risk factors that can have a significant influence on the parasite’s dynamics. Manipulation of these parameters has the potential to reduce the impact of the parasite. Their use in parasite control is discussed together with chemical and biological control methods in relation to their effectiveness, limitations and ways in which their use can be optimised. By incorporating this information with our knowledge of the parasite’s biology, an integrated management plan, adaptable to many of the different fishery types found in the UK, has been developed.