This video says about itself:
Sparling (or smelt) spawning run in the River Cree in 2010, this is the last population of Osmerus eperlanus known on the West coast of Scotland. This footage was taken as part of a larger project working on rare fish in the River Cree.
From Wildlife Extra:
Breeding ground sought of small Thames fish that smells of cucumber
There is a call-out to Londoners for volunteers to help scientists find out more about a rare species of British fish, the smelt (Osmersus eperlanus), which curiously smells like cucumbers. It is found in the Thames in central London.
The project by scientists from the Zoological Society of London (ZSL), funded by a grant of £97,800 from the Heritage Lottery Fund, will launch in March, with the aim of discovering where this silver-coloured fish breeds in the river.
Smelt are an important fish species; not only as a potential food source for other animals but because their presence indicates good health in an estuary.
In the Thames there is a small but significant breeding population, one of the few remaining in the country.
Joe Pecorelli, manager of the London’s Rivers project at ZSL, says: “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.”
Pollution and habitat destruction caused the once-common smelt to disappear from South East estuaries during the early 1800s.
Improvements to water quality in the latter half of the 1900s led to a gradual return of the fish to a number of rivers in England, including the Thames.
Today, the smelt is still considered significantly threatened and continues to be relatively rare.
In addition to providing scientists with important information about the smelt, it is hoped this project will help more Londoners understand the rich ecology and history of their river and experience London’s aquatic wildlife first-hand.
To take part in the project (training is provided) or for more information, contact firstname.lastname@example.org or visit www.zsl.org/smelt.