Foresters aim to let stream life prosper: By analysing animal life in water, steps can be taken to improve its quality. Oliver Gillie reports

A TWO-INCH-LONG baby trout, two or three mayfly nymphs and some tiny beetles swam around in a tray - the catch from a fast-flowing stream near Capel Garmon in North Wales. Forestry workers, who usually take an interest in larger game, were studying the inconspicuous fauna of the stream.

'The small trout gives the game away,' said Gordon Patterson, a conservation officer with the Forestry Authority in Edinburgh. 'This stream is sufficiently alkaline to support a wide variety of animal life.'

The Forestry Authority is teaching foresters and the public how to recognise whether a stream is acid. By studying the insect life it is possible to tell whether there is enough animal life to support fish at the top of the food chain. A stream with insufficient insect life may be improved to increase the diversity of species.

'Acidity is one of the major factors which prevents a diverse fauna, including fish, flourishing in a stream,' Mr Patterson said.

To make it easy for people to diagnose the condition of a stream Mr Patterson, together with Brian Morrison, a scientist working with the Freshwater Fisheries Laboratory in Pitlochry, has published a guidebook.

'If there are water shrimps, limpets and snails (found under stones), and certain types of mayflies in a stream then we can be sure that it is relatively alkaline and will support fish,' said Mr Morrison. 'While stoneflies (which can be distinguished from mayflies because they have two rather than three tails) tolerate acid streams.'

The plant acids from bogs do not limit the insect life in the same way as the inorganic acids which enter the stream from acid rain.

Trees may increase the amount of acid rain and moisture being precipitated on to the land. But by arranging drainage channels so that rain water has to pass through an area of grassland some of this acid may be filtered out. The Forestry Authority now has guidelines for the management of forests which are designed to make it easier for a diversity of insect life to flourish.

'We avoid planting right up to the edge of a stream so that sunlight can reach the stream and the algae in it,' Mr Patterson said. 'We also do all we can to conserve the grass on the banks because it acts as a buffer against erosion. And we avoid stirring up silt from the bottom and try to stop soil washing into the stream because it damages fry and covers the bottom, killing off the important insect life.'

(Photographs omitted)

Suggested Topics
Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
ebooks
ebooksA special investigation by Andy McSmith
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Tradewind Recruitment: Science Teacher

£90 - £140 per day: Tradewind Recruitment: I am currently working in partnersh...

Recruitment Genius: Doctors - Dubai - High "Tax Free" Earnings

£96000 - £200000 per annum: Recruitment Genius: Looking for a better earning p...

Recruitment Genius: PHP Developer

£32000 - £36000 per annum: Recruitment Genius: A rapidly expanding company in ...

Recruitment Genius: PA

Negotiable: Recruitment Genius: A PA is required to join a leading provider of...

Day In a Page

Isis hostage crisis: The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power

Isis hostage crisis

The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power, says Robert Fisk
Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Maverick artist Grayson Perry backs our campaign
Missing salvage expert who found $50m of sunken treasure before disappearing, tracked down at last

The runaway buccaneers and the ship full of gold

Salvage expert Tommy Thompson found sunken treasure worth millions. Then he vanished... until now
11 best winter skin treats

Give your moisturiser a helping hand: 11 best winter skin treats

Get an extra boost of nourishment from one of these hard-working products
Isis hostage crisis: Militant group stands strong as its numerous enemies fail to find a common plan to defeat it

Isis stands strong as its numerous enemies fail to find a common plan to defeat it

The jihadis are being squeezed militarily and economically, but there is no sign of an implosion, says Patrick Cockburn
Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action

Virtual reality: Seeing is believing

Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action
Homeless Veterans appeal: MP says Coalition ‘not doing enough’

Homeless Veterans appeal

MP says Coalition ‘not doing enough’ to help
Larry David, Steve Coogan and other comedians share stories of depression in new documentary

Comedians share stories of depression

The director of the new documentary, Kevin Pollak, tells Jessica Barrett how he got them to talk
Has The Archers lost the plot with it's spicy storylines?

Has The Archers lost the plot?

A growing number of listeners are voicing their discontent over the rural soap's spicy storylines; so loudly that even the BBC's director-general seems worried, says Simon Kelner
English Heritage adds 14 post-war office buildings to its protected lists

14 office buildings added to protected lists

Christopher Beanland explores the underrated appeal of these palaces of pen-pushing
Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Scientists unearthed the cranial fragments from Manot Cave in West Galilee
World War Z author Max Brooks honours WW1's Harlem Hellfighters in new graphic novel

Max Brooks honours Harlem Hellfighters

The author talks about race, legacy and his Will Smith film option to Tim Walker
Why the league system no longer measures up

League system no longer measures up

Jon Coles, former head of standards at the Department of Education, used to be in charge of school performance rankings. He explains how he would reform the system
Valentine's Day cards: 5 best online card shops

Don't leave it to the petrol station: The best online card shops for Valentine's Day

Can't find a card you like on the high street? Try one of these sites for individual, personalised options, whatever your taste
Diego Costa: Devil in blue who upsets defences is a reminder of what Liverpool have lost

Devil in blue Costa is a reminder of what Liverpool have lost

The Reds are desperately missing Luis Suarez, says Ian Herbert