Trout in the Town Blog

06/10/2014 - 15:30

Following on from the most recent blog entry (and very brief description of a method used by volunteers); please see the short 3-minute video below for a demonstration of how SPRITE members have successfully developed and implemented an efficient and robust technique for planting water crowfoot in freestone rivers (which would also work very well in more lowland settings too).

The method has a degree of resistance to grazing pressure during early phases of establishment and has also proven to be quite robust to the higher shear velocities experienced during spates on upland rivers.

Note the group's vital adherence to considerations for full permissions - including the requirement to source the plants from within the same river system and also from sites that are free from known biosecurity risk. Consultation with local Environment Agency (or equivalent local watercourse authority) is a way for volunteer groups to find out what permissions will be required in specific locations.

SPRITE methods for Ranunculus planting from Paul Gaskell on Vimeo.

29/09/2014 - 21:56



Here is a video showing just one of a long series of ongoing surveys on a site that was impacted by dredging activities. The Environment Agency re-introduced large boulders and also installed some marginal plants to help the site to begin to recover. Subsequent to that, volunteers from SPRITE- a group set up in Sheffield through the Trout in the Town project applied for permission and carried out re-planting of water crowfoot to improve the structural and invertebrate community diversity within the channel. The method for doing this in spate rivers is highly original and was developed primarily by Dave Woodhead - a central and long-standing SPRITE member, with Ranunculus collection from biologically clean headwater sites and planting work parties being run by Dave and Paul Hughes.

SPRITE also carried out some wildflower seed planting and have joined with other local volunteers to reduce the amount of Himalayan Balsam in reaches upstream of this section.

The video shows how important complex submerged cover is to trout (especially). In much simpler habitat almost all of the trout would have been caught at the upstream barrier after the activity of the survey team had flushed them all the way up through simple habitat that lacked refuge opportunities. However, whilst Ranunculus does not provide much defense against being stunned by a small electric field it (and other complex submerged cover such as tree roots, submerged fallen tree crowns and root wads) does provide significantly improved protection against natural visual predators.

Studies have shown that fish-eating bird predation efficiency drops greatly in the presence of complex submerged cover - and predators give up after a shorter duration to try elsewhere because their calorific return for the energy they need to expend to catch more prey makes the effort unprofitable.

Check out Richard Noble's survey team in action in the video above and see the fruits of volunteer labour (and note how most of the trout that are caught in the middle of the reach are hugging the Ranunculus!). This water plant is also excellent habitat for a number of aquatic invertebrate species and can contribute to improved diversity in flow velocities and associated substrate particle and nutrient-sorting over the cross-section of a channel.
 

18/09/2014 - 13:26

I was fortunate enough to contribute to Tuesday's launch event for the mammoth achievements that have been made (both in the river channel and within the local community) around Greater Manchester's River Medlock (see this piece from the BBC last year reporting part-way through the initial works http://www.bbc.co.uk/news/science-environment-24562282)

Although a great many people have contributed both to the overall project (and to Tuesday's launch event) - a lot of credit has to go to key personnel like Ollie Southgate of the E.A., Jo Fraser of Groundwork and Dave Barlow of Manchester City Council. The ongoing success of this project owes a lot to their drive and vision - both in the brutally difficult world of making such challenging projects actually happen in the modern economic and social climate and in the amount of effort to involve local communities by reconnecting people with their local river.


For my part I had the highly enjoyable task of introducing local primary school kids to the wonders of fly fishing (in this case Japanese fly fishing - known as tenkara!) in a river that, until recently, had been a smooth brick-lined chute that fish found it impossible to hold station against the current. Now, we might have only had minnows trying to take the fly, but that didn't matter because the kids really enjoyed trying their hand at casting, landing "Freddie the Rubber Fish"(!) and also fly tying. The kids and the fishing demos kept myself and Tom Bird well occupied in the hot late-summer sunshine (glorious!). The kids' experience with fishing and fly tying was coupled with an introduction to the real live invertebrates now inhabiting the channel by Matt Schofield of Irwell Rivers Trust.


After the kids had left, myself and Tom went on a hunt for a wild urban trout - but sadly for us - we didn't manage to find one on this visit. Who knows though, perhaps in time (and with the removal of the remaining kilometer or so (!) of brick channel-lining) we might see some more fish finding their way into this section of river.


07/09/2014 - 19:47

Look what the Wandle Trust have achieved now.

http://www.wandletrust.org/?p=5427

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 :-)

 

13/08/2014 - 13:46

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 answer to how the feat mentioned in the title of this post is achieved!!) - all offered in a wry, dry delivery of which Peter Ustinov would have been proud.

Enjoy...

04/07/2014 - 14:45



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 persisted at least 4 years and counting...Just a small amount of continuing ongoing care will readily control any re-establishment attempts made by balsam seed being imported into this reach. REMEMBER - work that has been noted in this blog previously (http://www.sciencecodex.com/global_plant_diversity_hinges_on_local_battles_against_invasive_species-105553) tells us that winning local-scale battles to preserve native biodiversity adds up to a significant conservation of overall biodiversity at landscape scales too. The work to control local patches of balsam, and its results show below, on the Don show that whilst the overall ideal scenario would be to systematically tackle all invasive plants from the top of the catchment downstream, there are still significant benefits to tackling local patches. This is true even with a future potential for re-invasion since there is still a substantial benefit to be had during the period between clearance and re-invasion (in this case at least 4 years)...AND it is much easier to "stay on top of" picking off a low number of re-invading plants than the initial great effort required to clear a large infestation that has already got out of control.

See the pictures below and ask yourself whether, even though there are sources of balsam upstream, the effort has been worth it so far...