"A Clear Future for our River"


New BART/University research students

BART are pleased to welcome our newest University research students this month from the University of Bristol who will be continuing our water quality monitoring along tributaries of the Bristol Frome, this time looking at potential urban sources!:

“We are from the University of Bristol, School of Geographical Sciences currently studying towards our BSc in Geography. We are working in partnership with Bristol Avon Rivers Trust to assess for pollution levels from the two brooks running from separate neighbouring housing estates. During this research we will be implementing various different techniques and procedures in order to collect the data required to research this aim and test it effectively.”

Thank you and we are looking forward to seeing your results!

Walkover surveys find room for improvement!

BART have been very busy recently, travelling all over the catchment doing walkover surveys and writing advisory reports for river improvement projects including the Corston, Newton, and Nunney Brooks and the River Somer. Jess, our Aquatic Scientist, has found many issues on the Nunney Brook including channel straightening and re-enforced banks which means there is limited bankside and in-stream habitat. She also found sections of the brook were overly deepened, sluggish, full of sediment and heavily shaded, preventing light from reaching the channel. These factors will reduce water quality and productivity in the channel, suppressing invertebrate populations due to lack of habitat and food sources which in turn reduces populations of other river wildlife.

Over-deepend, straightened and channelised section of the Nunney Brook

More survey work took us to a section of the River Avon near Sherston, Wiltshire, where we spent a beautiful evening assessing numbers of spawning Brown trout. We marked the locations of ‘redds’, which are depressions dug by the Brown trout into which they lay their eggs. This survey followed concerns of reduced numbers of the fish each year along with lower water levels. We are planning to put in some woody debris structures here next year to increase the diversity in water depth and flow, which will also help to scour the riverbed gravels of sediment which can smother the fish eggs and reduce spawning success.  To best position the woody debris structures to give the greatest benefit we are going to be monitoring locations of the redds over the winter.

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A beautiful evening for survey work!

Eel surveying on Blagdon Lake

Back in October we worked with West Country Rivers Trust and Bristol Water to begin an eel escarpment study on Blagdon Lake reservoir in Somerset. It was a week of stunning autumnal mornings, so it was a treat to get out on the lake with beautiful views across the misty waters.

The first part of this study investigated the population of the critically endangered European Eel in Blagdon Lake reservoir to see how many eels enter and leave it as they migrate upstream from the sea. This is a crucial part of their life cycle as the eels migrate from where they are born in the Sargasso Sea, across the Atlantic Ocean to the west coast of Europe. From here they travel into estuaries and upstream into rivers where they can spend between 5-20 years feeding and maturing until they are ready to migrate back downstream to the Sargasso Sea to spawn. Barriers to migration are one of the main challenges that eels face, which is why this study is so important as it will show whether the eels are able to survive in the lake and eventually exit it as they migrate back downstream.

Fyke netting

We used Fyke nets to fish for the eels overnight, which trap the eels as they swim into them. The nets do not harm the eels in any way, but simply prevent them from escaping until we come in the morning to count and measure them.  Measuring the size of the eels will help us to age them, which is important to know as it tells us the stage of their life cycle. This project will help us to find the best ways to help this endangered species, so watch this space for more eel related research!

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Electrofishing surveys on the Wellow Brook

Thanks to funding from the Bristol Avon Catchment Partnership, BART carried out electrofishing surveys on the Wellow Brook this summer.  The study was undertaken to provide part of a set of data being collected to monitor improvements made by the boulder weir removal (read more about this here) and also a number of in stream habitat improvements made following funding from the Environment Agency.

On 6th and 7th June 2017, BART worked with Five Rivers Environmental Contracting to conduct electrofishing surveys on the Wellow Brook between Stoney Littleton and Wellow.  Electrofishing is a fish surveying technique combining a mixture of electrical current with a known water conductivity to temporarily stun fish in order to measure and document the population and community fish statistics at a freshwater location.

The following fish were found during the survey:  Brown trout, European eel, Brook lamprey, Stone loach, Common bullhead, Minnow, 3 spined stickleback and 9 spined stickleback.  During the surveys, most fish were found at pinch points where both fish cover and flows increased significantly compared to otherwise straightened and canalised sections.  Recommendations were made to increase pinch points in these straightened sections of the river and introduce woody debris.  The findings of the electrofishing study were used to inform the river restoration works carried out by BART on the Wellow brook in September and October 2017. Read about the river restoration work to improve fish habitat here!


A summer of ecological surveys

BART’s ecologist, Jessy Grant, has been busy this summer with lots of exciting ecological monitoring projects for both BART and external clients.  Here’s more information about some of our ecological work!:

  • Case study:  Wellow brook pre-restoration surveys – Summer 2017

BART carried out a suite of surveys on the Wellow brook at Stoney Littleton in summer 2017 to assess the ecological conditions of the brook before beginning river habitat restoration works in September 2017.  (To read about the habitat restoration project please click here). The area where restoration was going to take place was divided into an upstream and downstream section.  In each section Jess undertook one macroinvertebrate survey, one 100m macrophyte survey and a 400m River Corridor Survey covering the whole section.  It is hoped that with further funding post restoration, monitoring will be carried out one year after the river restoration works to measure the changes. 

Analysis of the data found that the Wellow Brook at Stoney Littleton has a good diversity of macroinvertebrates and macrophytes present.  Water Framework Directive (WFD) classification results found the brook to be at “good status” for macroinvertebrates and macrophytes in the downstream stretch and “high status” for macrophytes and macroinvertebrates in the upstream stretch.  Recommendations were made for river restoration works in the straight sections of the brook where flow is slow, the substrate is predominantly silt and there is heavy shading.  The findings of the surveys informed the September in-stream restoration works, which helped to increase sinuosity and channel diversity in straighter sections of the channel where the flow is slower and decreased over-shading of the channel. 

  • Case study:  Corston and Newton Brooks’ environmental assessment and walkover surveys – Spring and Summer 2017

In spring and summer of 2017 the Duchy of Cornwall funded BART to undertake environmental monitoring on the Corston and Newton Brooks, west of Bath.  The aim of the monitoring was to record and assess the current environmental conditions of the brooks within the Duchy of Cornwall’s land and to make recommendations for potential improvements to the waterbodies.  Monitoring included macrophyte surveys, macroinvertebrate surveys, water quality surveys, waterbody assessment walkover surveys, wet weather walkover surveys and tree surveys.  The data and findings are being put together in a report for the Duchy of Cornwall, so watch this space for further information!