A 400-million-year-old rare blood-sucking creature once eaten by Vikings and a relic from the Ice Age top the Environment Agency’s ‘secret seven’ list of England’s rarest fish, which it unveiled today.
The seven species are lamprey, Arctic charr, 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.
The smelt is a small species of fish, related to trout and salmon, that lives in coastal areas of Britain. 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 the 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.