TROUT

The Wild Trout Trust contributes to several Aire Rivers Trust projects and initiatives, such as the Better Becks programme. It helps that Prof Jonny Grey, the WTT Research & Conservation Officer, is an Airedale resident and has a good working knowledge of his local system. One of his projects (TROUT), independent from ART but with similar aspirations and goals as the Better Becks project, is producing some very encouraging data.

TROUT – or Tackling Resilience on Underperforming Tributaries – is a 5-year project funded under the Yorkshire Water Biodiversity Enhancement programme. It aims to do what it says on the tin by improving habitat both instream and within the riparian zone and boosting trout fry numbers as a result. The WTT use brown trout as a sentinel species – if there is a healthy, wild, sustainable population of trout in a stream or river, it suggests that there is sufficient water of sufficient quality flowing through a mosaic of sufficient quality habitat to fulfil the various requirements of the trout life-cycle. And being in the middle of the food chain, lots of trout suggests plenty of food (mostly riverine and land-based invertebrates such as mayflies, shrimp & worms) and also plenty of food for predators of trout (otter & heron etc).

What form might habitat improvement take? Because I have been focussing mostly on headwater tributaries to boost spawning, it generally involves methods to sort and keep gravel free from silt so the trout can lay eggs and they’ll incubate safely. Adding wood, wiggling channels, providing cover and shade, and preventing fine sediment from washing in are all important, as is ensuring adult fish have free access in and out!

TROUT involves 3 sites in each of the Aire, Nidd & Wharfe catchments and I measure success against a number of control becks. I will focus on the Aire outcomes here, but it’s useful to place these in the wider context of other Dales rivers – see my summary of the overall project on the WTT pages, here.

One site is the goit in Hirst Woods at Seven-Arches and it is slightly atypical to the other sites in the project in that the focus is for ‘coarse’ species rather than trout per se. I posted a blog about early developments last year, here. In a nutshell, the work resulted in a doubling in the species count and increased the abundance of fish from 10s to 1000s! Build it and they will come…..

Haw Beck flows between Embsay and Skipton behind the Skipton Quarry and from there into Eller Beck. Tarmac Ltd and another local landowner have allowed us to exclude livestock, plant trees, introduce wood and generally diversify the habitat, as well as remove a redundant low-head weir. Indeed, ART volunteers helped me with the trees. In 2 years, we have boosted the trout fry numbers by 10x.

The third site, Flasby Beck, flows into Eshton Beck and ultimately into the Aire below Gargrave. It just needed a good dose of wood, big wood, to kick the channel about a bit and provide refugia. So it wasn’t terrible, to begin with, but it was underperforming! There are now 6x the number of trout fry able to reside at the site.

Relatively simple interventions give rise to big wins over a relatively short time frame. TROUT runs for 2 more years and I will be monitoring until the end to see if those population boosts are sustainable. More information is available, here.