May 2025

The Trym near Westbury on Trym
Photo credit: Peter Coleman-Smith

Pollution in Badock’s Wood Local Nature Reserve (LNR)
Photo credit: Peter Coleman-Smith

Installing an eel rope in Westbury Wildlife Park
Photo credit: Peter Coleman-Smith

The River Trym is a small stream packing a big punch. Though only 10k from springs near Filton and Cribbs Causeway to the tidal Avon, it’s waters flow through historic villages (Henbury, Westbury on Trym), a wooded limestone gorge (Blaise Castle Estate) and also several deprived communities. The river joins up the key local green and blue space for the approximately 80,000 Bristolians who live within a couple of kilometres. Potentially it’s a huge asset.
 
The focus of the Trout in the Trym initiative has always been on the whole catchment, top to bottom. It’s almost pointless tidying a short stretch, and it’s fun joining up with volunteers from other areas. Over 450 tonnes of rubbish have been removed (which Bristol City Council’s Parks team take away - thanks!) This includes 15 motorbikes, dozens of carpets, furniture, many tonnes of plastic and (in Henbury) lots of shopping trolleys.
 
Including balsam pulling action, volunteers have invested more than 5,000 hours in the river. Many locals have heard about Trout in the Trym and thank members for the improvement when they see them at work. Some older ones share stories about fish they caught and adventures they had in the stream back in the day. A couple of primary schools take pupils for walks along the stream as part of their environment teaching.
 
Despite flowing in recreational areas, pollution is a huge problem. Volunteers have reported at least 30 separate incidents since 2021. This is from misconnected drains, paint/plaster down drains, road and building-site run-off – and spills from CSOs.

Under Riverblitz and Riverfly monitoring schemes (coordinated by Bristol Avon Rivers Trust, BART) ongoing citizen science sampling has confirmed high levels of Phosphates / Nitrates and low abundance and diversity of macro-invertebrates. In both 2024 and 2025, University of Bristol Geography 2nd year students found micro-plastics.

Another issue is the roughly 30 weirs on the Trym/Hazel Brook, each hampering eel and fish movement (Wild Trout Trust Advisory Report, 2019). Climate change means connectivity is ever more important, the dry spring this year being just another reminder.
 
In 2024, BART completed a successful walkover survey and identified key barriers with worthwhile habitat upstream. Hopefully, once properly planned, fish passes can be installed. Ahead of that, in April 2025 volunteers at Westbury Wildlife Park and from Trout in the Trym created and deployed biodegradable straw and hemp eel ropes on 2 of the weirs in the park. Lots of fun and practical learning took place. The hope is to do more next January (when elver migration picks up) so this red listed, BAP Priority species is helped.

Locals and volunteers love this river. Grassroots groups are doing everything they can to help it and some wildlife is being observed, kingfishers, otters, eels, brown trout and most recently (while river cleaning in May 2025) a perch.
 
The BACP has helped fund progress to date - which has been really helpful. What’s needed now is a strategic programme of investment in the Trym catchment for: i) Sewage infrastructure/rain management/pollution control; ii) Fish passes/habitat improvement; and iii) Concerted community engagement and education.
 
If these steps are taken, a really exciting opportunity exists to make a difference for communities and nature in the heart of the BACP area.
 
Peter Coleman-Smith. Trout in the Trym volunteer.

Many thanks to Peter from Trout in the Trym, for providing this month’s Project Spotlight. If you’d like to read more about this community group or get involved, please visit Trout in the Trym. 

From 7th-15th June, the Natural History Consortium are running their annual Festival of Nature. This is the UK’s largest free celebration of the natural world and the theme for this year will be water. There will be a week of both in-person and online events for all ages, with film screenings, guest appearances, arts and crafts, experiments, screenings, walks, talks, tours, exhibitions, music and much more.

The full Programme of Events for this can be found here.

The Community Programme of Events can be found here.

This event is part funded by the Bristol Avon Catchment Partnership Fund. You can read more about the Fund here.

On 3rd July, the Severn Estuary Partnership (SEP) will be hosting their annual Forum in Weston-Super-Mare, involving presentations and talks on the latest projects, research and policy developments taking place around the Severn Estuary.

Read more about this event and book your ticket here.

Image credit: Severn Estuary Partnership (SEP)

New Forest in Winter
Photo credit: Freshwater Habitats Trust

Freshwater Habitats Trust have recently launched ‘The Freshwater Network’, which aims to increase freshwater biodiversity by reconnecting landscapes and creating a network of high-quality waterbodies. Small water bodies and wetlands will be a key focus of the strategy, as they make up 80% of the freshwater environment. Organisations working with the Freshwater Habitats Trust on this include: the National Trust (NT), Natural England (NE), Natural Resources Wales (NRW), Environment Agency (EA) and private landowners across England and Wales.

Read more about the Freshwater Network here.

A new citizen science app has been developed for the public to report sightings of blue-green algae.

Blue-green algae are a type of bacteria (Cyanobacteria), which can produce toxic chemicals harmful to both human and animal health. They are naturally present in lakes, ponds, canals, rivers and reservoirs. During the warmer summer months, they can be a serious health risk when their concentrations increase and can result in blue-green algae blooms.

This app requests you to take a photo of the algal blooms, and detail what types of activities take place in the location you are in. The potential public health risks can then be reported to the relevant authorities or landowners.

Find out more about the app and blue-green algae here.

Bloomin' Algae app logo
Image credit: UK Centre for Ecology & Hydrology (UKCEH)

A Water Vole Feeding
Photo credit: Peoples Trust for Endangered Species (PTES)

The National Water Vole Monitoring Programme (NWVMP) is now open between the 15th April-15th June for citizen scientists to record and monitor water voles at a chosen site. Following the release of American mink, water vole populations have decreased by approximately 90% over a ten-year period. As a result, People’s Trust for Endangered Species have been running the NWVMP since 2015 to establish water vole presence/absence, and abundance to guide conservation work for this species.

Find out more about volunteering here.

30 Days Wild is The Wildlife Trusts annual nature challenge event, which aims to inspire people of all ages to connect with nature throughout this June. The Wildlife Trusts have free activity packs available for both adults and children to take part in various activities such as bird watching and planting wildflowers.

Find out how to participate here.

Image credit: The Wildlife Trusts

Chalk stream springs, which feed the River Cam at Nine Wells Wood, Cambridge
Photo credit: Robert Macfarlane

Robert Macfarlane has recently published a new book, ‘Is A River Alive?’, where he explores rivers as living beings, and considers how rivers should be recognised by both the imagination and the law. Furthermore, he discusses river health, the Big River Watch, and rivers he has visited internationally, including in Ecuador, Quebec and southern India.

Find out more about the book here.