The following is a photo and video gallery of Brook lampreys Lampetra planeri spawning in a small tributary of Lough Derg in the River Shannon catchment, Ireland. These photos were taken on the afternoon of the 1st April 2014 when air temperatures exceeded 15 degrees Celsius and water temperatures began climbing over 10 degrees Celsius for the first time this spring. We have been monitoring this site, and a number of others, over the past 2 weeks and this is the first spawning activity that we observed this year.
This site is well known to us and we have observed brook lampreys spawning here as far back as the early 1990’s. However, as with many Irish watercourses, this stream and its lamprey populations have been affected by both agricultural pollution and drainage maintenance works and lampreys get little consideration in relation to the latter in Ireland. The lower reaches of this stream, where the nursery habitat is found, is regularly dredged and. as with many similar watercourses, the brook lamprey population here is in decline. Just as we accessed this site we disturbed two grey herons Ardea cinerea which were preying on these lampreys. We also saw a non-native mink Mustela vison while we were recording these videos. However, despite the pressures on this stream the brook lampreys were still here this week and this group were oblivious to us when we took these photos and videos!
The above photo gallery shows the brook lampreys nest building and spawning on the tributary of Lough Derg, Co Tipperary. Brook lampreys die shortly after spawning.
The above video gallery shows the brook lampreys nest building and spawning on the tributary of Lough Derg, Co Tipperary.
Brook lamprey is the smallest and perhaps most beautiful of the three Irish lamprey species. They are harmless and non-parasitic and most people do not even know they are present in streams. Unlike sea lampreys and river lampreys, brook lampreys only undergo localised migrations. In this stream in Co Tipperary they live out their whole life cycle in a few hundred metres of river.
Brook lampreys are the most common lamprey species in Ireland, but they are increasingly threatened due to an absence of any real protection, or indeed knowledge of their requirements. Their extended juvenile life cycle burrowed in sediments makes them especially vulnerable to river drainage and drainage maintenance works. They are also vulnerable to water pollution and eutrophication processes. Even small obstacles in rivers, such as bridge underpinning works or small weirs, can act as total barriers to migration to brook lampreys.
There is a real risk that brook lampreys will be lost going forward from streams like this one in Co Tipperary. We still have reasonably good populations of brook lampreys in Ireland but we need to urgently protect them or they will end up being as rare as they are in many other areas of Europe.
For further information on Brook lampreys please see our dedicated Brook lamprey page here.