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Showing posts from November, 2010

Going all the way on the Cray

A little London Chalkstream near Sidcup which has been diligently looked after in recent years by Thames21's Ashe Hurst got another shot in the arm on Thursday and Friday last week. Two of the WTT's conservation officers (Andy Thomas and Paul Gaskell) did two days of specific habitat improvement works in order to train the Thames21 staff and volunteers (including local youngsters who have been excluded from schools). A variety of uses of woody debris, brash bundles, wire, stakes and metal pin fixings were used to promote localised scouring of the stream bed, sorting and cleaning of spawning gravels and submerged "brashy" cover for juvenile fish.

The videos below show the increase in flow and change from "concreted" immobile gravels (with dark algal growth) to mobile and silt free (light coloured)particles at the pinch point created by an upstream "V" flow deflector


The flows prior to the installation of the upstream V were much more sluggish and fav…

Highlighting trout spawning and what to avoid when wading in winter

An example of some of the useful communication of highly relevant information that can be passed directly to grass roots participants just by contributing to an online specialist forum. Click the link below:

http://www.flyforums.co.uk/826909-post86.html
In summary - don't trim/remove debris that produces localised gravel scour:

This trailing branch debris is cleaning and "sorting" gravel for spawning - note the brighter patch of gravel

and don't tread on redds (trout "nests") containing eggs:

Newly formed redd which will allow eggs to hatch and emerging tiny fish (alevins) to shelter in the gaps between the pebbles below the surface of the gravel bed


Trout cutting a redd - photo Peter Henriksson