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Showing posts from January, 2014

Detailed introduction to how Erosion and Deposition in rivers provides a home for wildlife

Perhaps topical given current examples of river-bed-transporting extreme flows happening in many parts of UK...

In a striking similarity to the widespread lack of understanding of the impacts of dredging on flood risk - the problems caused by weirs that choke off the downstream progression of river gravels, cobbles, sands etc. are not widely appreciated.

The presentation below gives a basic outlining of why everything that lives in our rivers depends on the capacity for river channels to continually transport (and periodically deposit) river bed material from the hilltops to the sea. If we work better with (rather than against) these processes it would be far better for both societal needs/costs and the natural world.

Universal nature of risks with Wild Brood Stock, egg-boxes and similar supportive breeding schemes

Although extremely counter-intuitive upon first sight; trying to help wild populations of (for example) trout by boosting their reproduction actually has many more chances to go wrong than to actually help. There is a lot of coverage devoted to the various aspects of this in some of our WTT guidance pages (http://www.wildtrout.org/sites/default/files/library/Stocking_position_2012_final.pdf)

But as a really readily understandable example from the world of bird conservation; we can see just one of the prominent pitfalls of giving an artificial helping-hand to breeding success. The nub of it is that if the boosted numbers are made up of individuals that the natural environment would otherwise kill off; you risk actually pushing the population closer to extinction (or permanent reliance on human intervention). The story below and trout-specific research should give serious pause for thought to any club assuming that the best response to the Trout and Grayling Strategy (which will prohib…