WTT Blog

Rise of the Wandle

Posted on September 07, 2014

Look what the Wandle Trust have achieved now.


The major connectivity AND channel habitat morphology improvements are hugely significant milestones in the ongoing assisted recovery of this London chalkstream.

It is, also, on the site of the impounded reach I used on this video to illustrate the problems that weirs pose for habitat quality (not only fish passage, but river corridor biodiversity as  whole).


I'm looking forward to going back to take some footage of the 'after' shot :-)


Roger Wotton's Exopolymer Extravaganza: Turning S*** into Swifts and Swallows

Posted on August 13, 2014

Each year the WTT hosts a weekend event of talks, food, drink and fishing. This June's Annual Get Together (for members and non-members alike), saw some terrific talks from all speakers. Perhaps the one that surprised the audience the most is the one that is reproduced in full in the video below. A wide-ranging talk that drew on Professor Wotton's fascinating research career on how vitally important to life in rivers (and also all aspects of human existence - from tooth decay to safe drinking water!) are the tiny, stringy "chains" of molecules exuded by cells at the microscopic level.

Now retired, Roger Wotton can look back across a career of teaching and learning to give us a great "taster menu" of anecdotes relating to the surprising invisible world around us. From fish, to invertebrates to the way that classic chalkstream water weeds orchestrate themselves a supply of slow-release fertiliser right on top of their root stock (whilst keeping their leaves swaying just sub-surface for maximum photosynthesis) - the 25 minute talk has it all. Make sure to watch it right the way through because there are wonders of the natural and human world explained like never before throughout (like the...

Volunteer Action on Urban River Corridor Biodiversity: It works!

Posted on July 04, 2014

Back in 2010 the photo above is what an area of Sheffield's urban River Don looked like. Later that year, local Trout in the Town group "SPRITE" organised a day that combined their own volunteer force with a group of University of Sheffield staff that had been released for the day to contribute to volunteer works in the local area. The volunteers cleared a substantial section of the urban Don of all the balsam that they could get their hands on. You can see that, where the balsam had been removed, there was not much else in the way of vegetation that was able to survive...

Then in 2011, as the video below shows, one of SPRITE's activities was to follow up on previous clearance work by removing any re-growth of balsam and then to consolidate that with sowing of a seed-mix of species native to the Don corridor.

SPRITE Winter Working Parties from Paul Gaskell on Vimeo.

Now, in 2014, the photographs below clearly tell the story of how local volunteer action has significantly improved the floral (and associated faunal) biodiversity within the river corridor. These benefits, initiated in 2010 have...

Sleep-walking into Flooding Fragility

Posted on May 20, 2014

In just one of many illustrative examples in his book "Antifragile - things that gain from disorder" author Nassim Taleb talks about the irony of sports-shoe makers touting that their most advanced models are those that most closely replicate the bare human foot. This is fascinating since it highlights that attempting to smooth out and cushion the shocks experienced during running actually had the effect of massively increasing muscular and skeletal injuries from running.

In barefoot running, the toes and arches of the feet act as shock absorbers and - crucially - allows them to be exposed to the action of running that actually strengthens them in this function. By contrast, the attempt to eliminate those specific stresses resulted in humans striking the floor with their heels rather than their toes and the additional padding robbed our feet of the varied "training" that prevents things like fallen arches and plantar fasciitus.

Another example favoured by Nassim Taleb is that of "regulators"; devices that were fitted to smooth out some of the slightly erratic running of steam engines. The idea was to make them more efficient - and for much of the time this is the effect that they had. However, on the...

Sheffield Has a Formal Strategy for its Waterways; Incorporating its Urban and Rural Catchment areas

Posted on May 12, 2014

Some readers may have already seen the various pieces that I've contributed on managing surface water in urban and rural catchments (e.g. videos embedded at the bottom of this post) alongside the organisational role to Sheffield's first One Big River event. This was a week of activities focused on the rivers of the Steel City and was timed to coincide with both the River Restoration Centre's Annual Conference (held for the first time at Sheffield Hallam University) as well as the formal signing (and Cabinet adoption) of the Waterways Strategy.

The various community and volunteer events that formed the week-long programme (https://sites.google.com/site/sheffieldonebigriver/main-events-program included a family-day of riverside events run by the Sheffield branch of the Trout in the Town project (SPRITE) and the Wild Trout Trust. Everyone involved really enjoyed talking to local residents and visitors and showing them the life that abounds in the river via both bug sampling displays and also a demonstration of the "Mayfly in the Classroom" apparatus. This also provided an excellent opportunity to hand out the materials containing contact details and descriptions of SPRITE's monthly activities to people who have been living...

Sheffield Beneath The Waterline

Posted on April 17, 2014

Wildlife photographer and videographer Jack Perks visited Sheffield yesterday as part of his bid to document as many of Britain's freshwater fish species as he can. Some of these species face an uncertain or bleak future - and Jack's project (http://www.btwlfishproject.com/) could be the last time that they are possible to document on film. On this, his first recce visit, I took Jack on a whistle-stop tour of a number of locations spread across the city; ranging from retail/city-centre areas, heavy industry zones and suburban sites. Jack's VLOG gives a snapshot of his visit below:


Meeting United Utilities with Salford Friendly Anglers - part of the Trout in the Town family

Posted on February 19, 2014

Valuable proof that anglers and community interest groups can be taken seriously by large companies (as well as government bodies) was ably demonstrated yesterday during a meeting convened by the formidable Mike Duddy of Salford Friendly Anglers (centre of picture above).

Discussions over the current (and future-planned) status of a range of Combined Sewer Outfalls on the Irwell system were held at Mike's offices in Salford. Presentations by network managers and external affairs representatives of United Utilities (the local water supply company) were combined with debate over conditions in and around the river.

I'm pleased to have been able to support the group in getting to the stage in the discussions through some assistance in data crunching and interpretation that allowed the "priority" discharges affecting their rivers to be identified based on reported chemical discharge information. Coupled with detailed local knowledge from anglers such as Arthur Hamer on the observed performance of outfalls - a useful exchange of information occurred; enabling plans for exploring collaboration and partnership efforts for the benefit of the condition of Greater Manchester rivers to be made.

Great stuff - and an inspiration to all who...

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

Posted on January 08, 2014

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

Posted on January 02, 2014

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/assets/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 prohibit the stocking of fertile hatchery-bred trout from 2015) is to set up their own wild broodstock programme. Especially as the stripping of wild brood stock removes the natural reproduction that would otherwise have taken place(and which would, consequently, have been subjected to the relevant...

Bank erosion - a matter of balance

Posted on October 23, 2013

You can always have too much or too little of a good thing. When it comes to revetments (re-inforcements) of river-banks; there are a whole host of pitfalls.

On the one hand, many sections of river suffer from excessive grazing of the land surrounding them that leads to a dramatic reduction in the variety of bugs, plants as well as fish populations that can be supported. In addition, many rivers that run through towns and cities often pass through quite intensively used land upstream of urban reaches. The excessive inputs of fine silt and sand where bank-erosion is rampant and extensive often end up being accumulated in the engineered sections of channels in towns and cities. As well as causing maintenance problems,this can smother what may, otherwise, be perfectly good spawning gravel.

Conversely, where efforts to "lock" a river channel in one place are over-zealous; the result will be the strangulation of supply of spawning gravels and a variety of cobbles and other river-bed material. Each of the different diameters of gravels/cobbles/boulders that come from eroded banks form a unique and vital habitat either for particular species or particular stages within the lifecycle of a species.

So the optimum for biodiversity (and, consequently...

Unintended de-stabilising consequences of dredging...

Posted on October 07, 2013

The WTT borrowed the fabulous Emriver kit from Severn Rivers Trust during the 2013 CLA gamefair. It allowed us to set up a whole range of common river-channel scenarios in an accurate scaled-down simulation. Dredging was one of the things we modelled:

Dredging river-bed material is something that is of particular relevance to the urban/heavily-modified channel environment. As is so often the case with rivers, what seems like the obvious and correct thing to do can actually blow up in your face (or someone else's face several miles up or downstream!).

Just as intriguing are the potential knock-on impacts of ad-hoc dredging in rural environments in an effort to increase the capacity to drain land...

Nature abhors a vacuum and removing accumulated material from a river channel can have far-reaching and unintended consequences. The first principle effect is to increase the demand for eroded river-bed and river-bank material from upstream. This can dramatically increase the rate of erosion in upstream reaches.

It also rapidly leads to the re-filling of the dug-out channel... (back to square one, so you dredge again....)

The other major/worrying effect is the interruption of the transport of sediment downstream of the dredged reach. Whilst the bed material is being re-accumulated in...

Introducing the Emriver: the "model railway" of river habitat processes

Posted on September 19, 2013

The Wild Trout Trust very gratefully benefited from the generous loan of Severn Rivers Trust's "Emriver" at this year's CLA gamefair. As well as proving to be a great way to engage game fair attendees of all ages, it provided a fantastic opportunity to accurately simulate many scenarios that we routinely encounter in our river habitat works. This first video introduces some of the basics - and shows the effect of two common habitat installation techniques: marginal brash and log flow-deflectors.

There will be a series of short videos that follow this first introductory piece. Each subsequent film will look at specific scenarios and model their outcomes - which are often highly unexpected unless you have quite a lot of existing experience with geomorphology...