Amy Carrick – Ryevitalise Education & Engagement Officer
My friends in the world of fresh water have always tried to convince me that lampreys are beautiful creatures that are an essential part of our eco-system. I was somewhat unconvinced! Their slippery skin, suckers and razor teeth never quite made them the most attractive of animals. Having grappled with measuring elvers in plastic trays in the last Ryevitalise blog post, I was never convinced that neither eels nor lamprey were anything other than something out of a horror film. However whilst Riverfly monitoring on one hot sunny morning recently along with one of our (socially distanced) experienced volunteers, we came across one of the blighters. Even though notoriously difficult to catch, one landed right in our net after our 3 minute kick sample. As our volunteer excitingly popped it onto his hand and waved it in my face, I really wasn’t sure why he was that excited … so he explained how fantastic they were for our rivers.
So why the Rye?
Firstly we have three species of lamprey in this country – sea, brook and river lamprey. These have been a rare sight recently in this area until the past few years. As a result of an improvement in water quality, the removal of migratory obstacles and the installation of special tiles that help movement, the lamprey are navigating through the River Derwent. The population has become so important that the lower reaches of the Derwent now have protected status, reflecting the spawning distribution of the species in the catchment.
That this ancient species has made it back up to the River Rye towards the top of the Derwent catchment is very encouraging. Small numbers have been recorded in the past few years by our Riverfly monitors.
So why should we care?
Well over the past few decades high levels of pollution in our rivers has nearly wiped out any chance of seeing lamprey in the UK. All species of lamprey require clean sandy gravels to spawn. The young larvae then swim off to the soft marginal silt of the river to grow; feeding on the algae, bacteria and detritus. Sediments can also smother spawning gravel sites, also effecting other species of fish too. Dramatic changes in water flow and levels also affect these spawning sites. The migratory sea and river lamprey require good water quality to survive their long journey from sea to spawning sites.
This means that if you do have lamprey in your river, something is going right!
So what can we do to help?
Although the fate of the lamprey population depends on the goings on in the lower catchments, the more we can do in the upper catchments to keep lamprey here the better for our freshwater ecosystem, and that’s exactly what the Ryevitalise Landscape Partnership Scheme is trying to achieve. The reduction in sediments is one of the biggest factors; reducing Himalayan Balsam eroding our river banks, stopping cattle predation in rivers, changing the way riparian land is farmed to reduce runoff, all helps in the battle against sediment. Water level management and the planting of trees also helps with reducing the dramatic water level changes during the winter. And most importantly (slightly biased) is engagement! If people don’t know why we should care for lamprey, then they never will. Sharing the beauty and importance of this slippery creature with as many people as possible will help in protecting these quirky river species.
Did you know for example lamprey predate dinosaurs by 200 million years?! And my favorite – apparently during the Middle Ages, lampreys were widely eaten by the upper classes throughout Europe. It is thought King Henry I died from overindulging on lampreys.
So while I will still recoil in horror at seeing one, I now know how special lamprey are and I will attempt to make these as popular as the cuddly otter or water vole….well one can try…..