Event Title

Session C7: 'Dodgy' Barriers: Conservation Implications and Mitigation Outcomes for Sea Lamprey in Irish SACs

Location

Groningen, The Netherlands

Event Website

http://fishpassage.umass.edu/

Start Date

24-6-2015 11:20 AM

End Date

24-6-2015 11:35 AM

Description

Abstract:

Anthropogenic structures in rivers can impede fish passage. In Ireland, weirs were commonly installed on major and minor rivers to harness water power to operate machinery. Many such structures are now derelict. Many had fish passage facilities installed, the target species being Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.). A combination of Water Framework Directive and Habitats Directive provides a lens to critically examine anthropogenic barriers and their possible impacts on fish species of conservation significance, particularly in channels designated as Special Area of Conservation (SAC) for anadromous species. In Ireland, these species include sea lamprey (Petromyzon marinus L.), Twaite shad (Alosa fallax Lacepede) and Atlantic salmon. Surveys have identified substantial clustering of sea lamprey nesting sites below the most downstream major weirs on the Irish SACs and limited upstream penetration, as recorded in catchment-wide larval sea lamprey distribution. Ireland has a conservation management objective of achieving unimpeded access to 75% of the main stem channel length for spawning anadromous lamprey migration. The potential for achieving this target was examined in two SAC rivers – the Mulkear (Lower River Shannon SAC) and the Munster Blackwater SAC. Barrier passability or porosity was examined using the SNIFFER barrier tool and information on the status of sea lamprey was generated from spawning site surveys and from catchmentwide electric fishing surveys of larval lamprey. Implementation of barrier management strategies was associated with substantial increase in numbers and degree of dispersal of Petromyzon redds on the Mulkear. The two major Blackwater weirs are scheduled for modification and scope for enhanced dispersal of migrating adult sea lamprey is examined in the context of the design of proposed modification and of available sea lamprey larval records in the Blackwater catchment.

Comments

Presenting Author Bio: Lead scientist on Inland Fisheries Ireland’s (IFI) investigations on Annex II Habitats Directive fish species (lamprey, shad and whitefish (pollan)) and Red Data Book Fish (char and smelt). Leads strategies in IFI to examine connectivity and anadromous fish; to improve hydromorphology (under WFD) in arterially-drained rivers; oversees works and monitors impacts of strategies on fish community and on riparian zone.

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Jun 24th, 11:20 AM Jun 24th, 11:35 AM

Session C7: 'Dodgy' Barriers: Conservation Implications and Mitigation Outcomes for Sea Lamprey in Irish SACs

Groningen, The Netherlands

Abstract:

Anthropogenic structures in rivers can impede fish passage. In Ireland, weirs were commonly installed on major and minor rivers to harness water power to operate machinery. Many such structures are now derelict. Many had fish passage facilities installed, the target species being Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.). A combination of Water Framework Directive and Habitats Directive provides a lens to critically examine anthropogenic barriers and their possible impacts on fish species of conservation significance, particularly in channels designated as Special Area of Conservation (SAC) for anadromous species. In Ireland, these species include sea lamprey (Petromyzon marinus L.), Twaite shad (Alosa fallax Lacepede) and Atlantic salmon. Surveys have identified substantial clustering of sea lamprey nesting sites below the most downstream major weirs on the Irish SACs and limited upstream penetration, as recorded in catchment-wide larval sea lamprey distribution. Ireland has a conservation management objective of achieving unimpeded access to 75% of the main stem channel length for spawning anadromous lamprey migration. The potential for achieving this target was examined in two SAC rivers – the Mulkear (Lower River Shannon SAC) and the Munster Blackwater SAC. Barrier passability or porosity was examined using the SNIFFER barrier tool and information on the status of sea lamprey was generated from spawning site surveys and from catchmentwide electric fishing surveys of larval lamprey. Implementation of barrier management strategies was associated with substantial increase in numbers and degree of dispersal of Petromyzon redds on the Mulkear. The two major Blackwater weirs are scheduled for modification and scope for enhanced dispersal of migrating adult sea lamprey is examined in the context of the design of proposed modification and of available sea lamprey larval records in the Blackwater catchment.

https://scholarworks.umass.edu/fishpassage_conference/2015/June24/71