Skip to main content

Hull International Fisheries Institute Electric Fishing Survey of Trout in the Town Ranunculus Planting Site



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.

Comments

Popular posts from this blog

Why Presume to Remove Weirs? (with River Dove Case Study)

Weirs and the Backwards Ways that Rivers Work One of my favourite sayings on river restoration is a mangled quote from a movie "... boxing is an unnatural act. Everything in boxing is backwards: sometimes the best way to deliver a punch is to step backwards...but step back too far and you ain't fighting at all ". So my mangled version starts out "Everything in rivers is backwards...". Basically, I never seem to run out of new examples of "what SEEMS to happen in a river is actually the complete opposite of what really happens". The rest of this article looks at many of the "backwards" things about weirs and rivers - and finishes off with a real-world case-study that is playing out right now on the River Dove . One spoiler alert is that, from an ecological point of view, it is almost always safe to assume that: The best biological outcome for a river is the removal of some or all of an artificial weir.  Now, I don't exp

The Wild Trout Trust: A Film by Chalkstream Fly

Here is a great short piece that captures what the work of the Wild Trout Trust is all about. It was made for (and broadcast on) the very first "World Fishing Day" - a 24hr live fishing programme created by FishingTV.com . It features TV personalities (and WTT President & Vice President respectively!) Jon Beer and Matthew Wright as well as Director of the Trust, Shaun Leonard. You can see more work by the film-makers on Chalkstreamfly.co.uk  and, of course, you can join the Wild Trout Trust here: WTT Membership Paul Gaskell (Trout in the Town Conservation Officer)

Birmingham and Coventry's Urban Waterways

It's about time for a new blog post and I thought it would be good to flag up some of the investigations that I've been doing in conjunction with Waterside Care (which, in itself, is supported by Keep Britain Tidy ). As well as initial investigations on the River Cole around the Shire Country Park and Burberry Brickworks, more recent forays to the little Westley Brook, River Sowe, Stonehouse Brook and a little stream in the Holly Wood Local Nature Reserve (between Great Barr and Queslett) have seen me criss-crossing the M6 and M69 and the surrounding areas. What always surprises me is just how much of the Black Country/Coventry area is essentially "floating" on a vast network of underground watercourses which suddenly pop up into daylight in surprising places. Of course this puts a lot of pressure onto the biology of these streams - not only from the physical "encasing" of their channels in brick and concrete (both above and below ground). It is t