Sea lampreys began spawning on the Lower River Mulkear during early June 2013. The photos below show some of the activity at this site at this time. Water levels were very low in early June 2013 and this coupled with persistent sunshine did not provide ideal conditions for these lampreys. There was evidence of disturbance at this site due to people entering the water for swimming or paddling.
The weir shown in the pictures below is the site of Mulkear Life’s ‘lamprey pass’. We still remain very concerned that this ‘pass’ does not actually work. Although we are fully supportive of much of the work that this organisation does, there is no scientific evidence that this pass can be used by lampreys. It is time to provide such information on the efficacy (or likely otherwise) of this pass. Sea lampreys are poor swimmers, cannot jump, and cannot climb obstacles using the “attach-twitch-attach” strategy of Pacific Lampreys. We cannot see how they can use this ramp, and indeed based on our knowledge of the scientific literature and capabilities of sea lampreys do not believe that this ‘pass’ provides any benefits. Of course, we would very much like to be proved wrong; but consider that this is very unlikely.
This ‘pass’ clearly would offer no benefit to the other two lamprey species in the River Mulkear. Likewise, this structure would not provide any assistance to the European eel.
ECOFACT are Ireland’s leading aquatic ecological consultancy and we consider ourselves experts in fish pass design and implementation. If you have a requirement for designing or installing a fish pass, please contact us to discuss.