The seven species are lamprey, Arctic char, vendace, spined loach, allis shad, twaite shad and smelt. All seven species of fish are a conservation priority at a national and international level. The reasons for their previous decline include historically poor water quality, barriers to migration and a changing climate. But now, all seven are starting to thrive again thanks to work by the Environment Agency and other conservation groups.
Alastair Driver, Environment Agency national biodiversity manager, said: “These rare fish are the unknown jewels of our rivers, lakes and coastline. The Environment Agency has a range of projects to support them and although England’s rivers are the healthiest for 20 years, there is still more to be done to improve their chances. Reintroducing meanders, breeding fish and removing weirs are among our key work to help these little-known fish thrive.”
Lamprey were regarded as a luxury food by monarchs, served poached in red wine by Romans.
Lampreys are eel-like creatures once eaten by Vikings, and pre-dating dinosaurs by more than 200 million years. Thanks to the lowest levels of pollution seen for more than 100 years and the removal of barriers to their spawning migrations they are returning to many UK rivers. Where barriers cannot be removed, Environment Agency fisheries staff have fitted lamprey ‘tiles’ to existing weirs to help them get upstream. River and sea lamprey have now been found in the Yorkshire Ouse, where only 30 years ago they were absent. But lamprey are very secretive creatures and very little is known about their life at sea. Lamprey can be found in all our Cumbrian rivers, most notably in the Eden and Derwent where they are designated features of the Special Areas of Conservation. They are also a designated feature of the Solway Firth Special Area of Conservation.
Arctic Char in the River Liza
It is widely recognised that the majority of UK Arctic char populations are in decline with increasing temperatures considered to be one of the greatest threats to their existence in UK waters. In England they are native only to the Lake District where they are present in seven lakes: Windermere, Coniston Water, Wast Water, Buttermere, Crummock Water, Haweswater and Thirlmere. In 2005, the Environment Agency, together with partners including the Forestry Commission, United Utilities and Wild Ennerdale, set about trying to reverse their decline in Ennerdale Water. A barrier to migration was removed, some charr restocking was undertaken, and land-use changes were implemented in order to improve water quality in an important charr-spawning stream. Recent surveys have shown that charr numbers in Ennerdale are now showing a marked increase which is a tremendous success following lots of hard work.
The vendace is the rarest native freshwater fish species in the U.K
The herring-like vendace is the rarest native freshwater fish species in the UK. This silver fish is native to just two English lakes (Derwentwater and Bassenthwaite Lake in Cumbria). Their populations are impacted by lake siltation and the introduction of non-native species and, like char, they are also threatened by climate change. The Environment Agency has been working with others to improve river habitats upstream of Derwentwater and to prevent the introduction of more non-native species than could harm the vendace.
While the populations in Derwentwater remain healthy, it is unclear whether or not the Bassenthwaite Lake population still exists – only one vendace has been found there since 2001. However, surveys have shown that vendace from this lake have established in Loch Skeen after being introduced there. So, if conditions in Bassenthwaite improve sufficiently, we may be able to reintroduce them back to the lake.
The spined loach spends most of its life in and around the silty beds of rivers and lakes.
The spined loach is found in just five river catchments in the east of England – the Trent, Welland, Witham, Nene and Great Ouse. The easterly flowing direction of all these rivers is an indicator of the origins of the species. All these rivers were once a part of the Rhine catchment, at a time when the North Sea was a land mass. But when the North Sea cut off Great Britain off from mainland Europe the spined loach was stranded and hasn’t moved much since.
The Twaite Shad is a herring which enters fresh water to reproduce each May.
At one time, twaite shad were commonplace throughout the Severn Estuary and its rivers. During the 19th century many rivers were modified which has restricted shad to the lower reaches of the river by preventing access to their historic spawning habitat. There are now only four spawning twaite shad populations in the UK – the rivers Tywi, Usk, Wye and Severn. The Environment Agency is working on a project to secure funding for a project that will open up more than 230 km of historic spawning ground to support shad populations in the Severn Estuary. Allis shad is the twaite shad’s larger cousin and can grow up to four kg in weight. Shad are occasionally found off of the Cumbrian coast, particularly in the Solway area.
The smelt is a small species related to the trout and the salmon.
The smelt lives in coastal areas of Britain including the Solway. By the end of the twentieth century there were fewer smelt populations due to the effects of pollution in river estuaries and the construction of weirs which stop fish moving upstream to spawn. The situation is improving due to better water quality – investment in sewage treatment has reduced instances of low oxygen levels in estuaries. Work to improve fish passage, by the removal of weirs or the installation of fish passes, has benefitted all species of migrating fish, including smelt. In addition, smelt have been given additional protection by the creation of Marine Protected Areas.
