Back in October we worked with West Country Rivers Trust and Bristol Water to begin an eel escarpment study on Blagdon Lake reservoir in Somerset. It was a week of stunning autumnal mornings, so it was a treat to get out on the lake with beautiful views across the misty waters.
The first part of this study investigated the population of the critically endangered European Eel in Blagdon Lake reservoir to see how many eels enter and leave it as they migrate upstream from the sea. This is a crucial part of their life cycle as the eels migrate from where they are born in the Sargasso Sea, across the Atlantic Ocean to the west coast of Europe. From here they travel into estuaries and upstream into rivers where they can spend between 5-20 years feeding and maturing until they are ready to migrate back downstream to the Sargasso Sea to spawn. Barriers to migration are one of the main challenges that eels face, which is why this study is so important as it will show whether the eels are able to survive in the lake and eventually exit it as they migrate back downstream.
We used Fyke nets to fish for the eels overnight, which trap the eels as they swim into them. The nets do not harm the eels in any way, but simply prevent them from escaping until we come in the morning to count and measure them. Measuring the size of the eels will help us to age them, which is important to know as it tells us the stage of their life cycle. This project will help us to find the best ways to help this endangered species, so watch this space for more eel related research!