Smelts in the city: help needed for rare London fish

The Zoological Society of London (ZSL), an international conservation charity, is calling for volunteers to help scientists find out more about a rare species of British fish, the smelt (Osmersus eperlanus), found in Central London. 

A new project by ZSL scientists, funded with a grant of £97,800 from the Heritage Lottery Fund, will launch in March 2015 and aims to discover where this silver-coloured fish breeds in the Thames. Smelt are an important fish species; not only as a potential food source for other animals but their presence indicates good estuary health. In the Thames there is a small but significant breeding population, one of the few remaining in the country. They also curiously smell of cucumber.

Smelt measuring

Joe Pecorelli, manager of the London's Rivers project at ZSL, said: “The Thames is London’s greatest wilderness yet still there are many things we don’t know about life in the river. The fact that the smelt, a nationally rare fish, returned to the Thames 20 years ago after more than a hundred years’ absence is a good sign. However, to ensure long-term survival of this species, we need to know where their key breeding grounds are in order to protect them. This project will be one of the most ambitious studies of the Thames yet and will see scientists and volunteers surveying the River from Chiswick to Greenwich.”

Once common in the Thames and beyond, pollution and habitat destruction caused the smelt to disappear from South East estuaries during the early 1800s. Improvements to water quality in the latter half of the 1900s lead to a gradual return of the smelt to a number of rivers in England, including the Thames. Today, the smelt is considered significantly threatened and still relatively rare.

In addition to providing scientists with important information about the smelt, this project will help more Londoners understand the rich ecology and history of the Thames and experience London’s aquatic wildlife first-hand. Londoners will also be able to learn more about conservation and the skills needed to ensure London’s wild residents continue to call the city their home.

To take part in the project or for more information, please contact or visit Training will be provided.

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