Event Title

Session D6 - Management of migrating European eel (Anguilla anguilla) in Irish rivers used for hydropower generation.

Location

UMass Amherst

Event Website

http://fishpassage.ecs.umass.edu/Conference2012/

Start Date

7-6-2012 3:25 PM

End Date

7-6-2012 3:45 PM

Description

An extensive decline in European eel stocks, which prompted the European Union to provide a legislative framework (E.U. Regulation No. 1100/2007) for conservation of the species, has been recognised in Ireland for over two decades. In 2008, a National Eel Management Plan (EMP) was adopted which required specific actions to be initiated. Prior to development of the eel management plan, an attempt was made to estimate the current and historical spawner biomass escapement from Irish river systems and this lead to the conclusion that particular eel conservation measures were needed in Ireland. Among the actions specified in the National EMP were: closure of eel fisheries and markets; improvements to eel habitats, including water-quality; reduction in adverse effects of barriers and hydropower generation. Results of research undertaken on migrating eel populations in three Irish river systems (River Lee, River Shannon and River Erne), regulated for hydropower generation, and current eel conservation programmes, will be outlined in this presentation. The stocking of juvenile eels, undertaken since the 1960's for fishery enhancement reasons, has declined due to poor natural recruitment. Therefore the main focus of recent research has been on determining the numbers, biomass and spawner quality of the downstream migrating silver-phase eels. Monitoring of population dynamics and turbine passage mortality rates has involved: analysis of daily and annual catches at eel fishing weirs; mark-recapture experiments; population surveys undertaken using DIDSON acoustic cameras; acoustic telemetry and mathematical modelling. Capture of silver-phase eels for release downstream of dams is currently the main hydropower mitigation measure. In the period 2009-2012, over 135 t were safely released. Options for development of alternative conservation measures, such as deflection to spillways, are being explored. However, spawner quality issues (fat content, parasite infection and maturation status) are of increasing concern.

Comments

Dr T. Kieran McCarthy has been researching Irelands freshwater ecosystems for over 40 years. He and his research team have undertaken extensive studies on the biology of European eel in Ireland. The current focus of his eel research is on determination of the effective spawner biomass escapement from Irish rivers used for hydroelectricity genereation.

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Jun 7th, 3:25 PM Jun 7th, 3:45 PM

Session D6 - Management of migrating European eel (Anguilla anguilla) in Irish rivers used for hydropower generation.

UMass Amherst

An extensive decline in European eel stocks, which prompted the European Union to provide a legislative framework (E.U. Regulation No. 1100/2007) for conservation of the species, has been recognised in Ireland for over two decades. In 2008, a National Eel Management Plan (EMP) was adopted which required specific actions to be initiated. Prior to development of the eel management plan, an attempt was made to estimate the current and historical spawner biomass escapement from Irish river systems and this lead to the conclusion that particular eel conservation measures were needed in Ireland. Among the actions specified in the National EMP were: closure of eel fisheries and markets; improvements to eel habitats, including water-quality; reduction in adverse effects of barriers and hydropower generation. Results of research undertaken on migrating eel populations in three Irish river systems (River Lee, River Shannon and River Erne), regulated for hydropower generation, and current eel conservation programmes, will be outlined in this presentation. The stocking of juvenile eels, undertaken since the 1960's for fishery enhancement reasons, has declined due to poor natural recruitment. Therefore the main focus of recent research has been on determining the numbers, biomass and spawner quality of the downstream migrating silver-phase eels. Monitoring of population dynamics and turbine passage mortality rates has involved: analysis of daily and annual catches at eel fishing weirs; mark-recapture experiments; population surveys undertaken using DIDSON acoustic cameras; acoustic telemetry and mathematical modelling. Capture of silver-phase eels for release downstream of dams is currently the main hydropower mitigation measure. In the period 2009-2012, over 135 t were safely released. Options for development of alternative conservation measures, such as deflection to spillways, are being explored. However, spawner quality issues (fat content, parasite infection and maturation status) are of increasing concern.

http://scholarworks.umass.edu/fishpassage_conference/2012/June7/23