Making a difference during Loddon Rivers Week

Almost a year to the day that the South East Rivers Trust constructed a backwater on the River Loddon in Charvil Meadows, we were back to do further enhancements as part of Loddon Rivers Week 2021.

This was just one of a series of river work that took place during this celebration of the River Loddon and its tributaries, between 18th-26th September. The work to co-ordinate the week was funded by the Environment Agency.

During the week, volunteers planted native plants to stabilise the banks of the previously constructed backwater, put in gravel to a chalk stream, tackled invasive species and enjoyed learning about bats.

Several partners were involved in the week, including Hampshire and Isle of Wight Wildlife Trust, the Loddon Fisheries and Conservation Consultative, Blackwater Valley Countryside Partnership, Hampshire County Council and Dinton Pastures County Park.

Planting to stabilise riverbanks

With the help of volunteers and our partners LFCC, more than 500 native plants were installed to stabilise the banks of the backwater and bring about biodiversity benefits. The plants included yellow flag iris, sedge, purple loosestrife and water mint.

We also distributed two tonnes of gravel at the downstream mouth of the backwater. This has shallowed up the area and has also provided some potential spawning habitat for local fish species such as barbell.

LFCC also took the opportunity to carry out a brief fish survey on the backwater. The results were very promising, with more than 100 individual fish found in the backwater. There was a good mix of different species and notably, a lot of the fish were juvenile species of under  a year old, all of which nicely demonstrated the benefits of backwaters as excellent nursery habitat for juvenile fish.

We were continuing our work with Hampshire and Isle of White Wildlife Trust to restore the chalk stream habitat found in Bassetts Mead LNR near Hook.

During a habitat improvement event on the River Whitewater – with a little assistance from the HIWWT tractor operator – we put in a whopping 30 tonnes of new river gravels, funded by Hook Parish Council, to depleted areas. Clean, gravelly river beds are a classic feature of chalk streams, providing fantastic spawning areas for fish like trout as well as refuge for many invertebrate species.

An example of wetlands planting, run by SERT on the Loddon backwater planting

Rewarding removal of invasive species

The physical demands of spending a day in a muddy swamp, compared to the work inserting gravel, was not lost on the volunteers who spent a day tackling floating pennywort at Wyndhams Pool at Yateley.

This invasive species, native to North America, was introduced widely across Europe as an ornamental pond species. It has now become established in the wild, with serious economic and ecological consequences, because it can grow up to 20cm a day, producing 70kg of wet weight per square metre. This high growth rate means pennywort can quickly cover a water body, smothering the wildlife underneath, blocking out sunlight and reducing oxygen levels.

At the end of a hard day’s work, the results were very satisfying. The second sweep through the affected area produced very few plants. This work was part of an ongoing initiative to attempt to totally eradicate this plant from the Yateley area. Monitoring and further removals, both by Hampshire County Council volunteers and contractors funded by the Environment Agency as a  Fisheries Improvement Project, will continue on this site into next year.

Inserting gravel into the Loddon

Walk to assess further work

The work to remove pennywort was followed up with a walk along parts of the River Blackwater near Farnborough, to further assess the extent of water hawthorn (aka Cape Pondweed) in the river.

This plant, not officially classed as an invasive species, is nevertheless not native to Europe, and there are concerns that it could outcompete some of the indigenous species and potentially disrupt the biodiversity of the River Blackwater and further downstream.

Completing the Water Hawthorn Safari means the Loddon Catchment Partnership can record presence of this plant within the river and keep an eye on its spread. Thanks to those who helped the Loddon Fisheries and Conservation Consultative to conduct the monitoring.

Pennywort, an invasive, non-native species

Captivated by bats

Bat experts Steve and Bernard from the Blackwater Valley Countryside Partnership led a party of 18 adults and children around Hawley Meadows, an area of riverside floodplain near Camberley. As darkness fell, a few pipistrelles were spotted along the tree belts in the Meadow, but when they reached the River Blackwater activity really took off.

Everyone was captivated for half an hour, watching the many close passes of Common and Soprano Pipistrelles and the Water Bats (aka Daubenton’s bats) feeding over the river.

In addition to the bat walk, an Emm Brook guided walk was incredibly well received. There is a real sense of community in the Woosehill area and participants were very enthusiastic about hearing what is planned for their stretch of the Emm Brook.

The walk also gave an insight into the river’s hidden potential, highlighting both the habitat features that enable it to support wildlife and some of obstacles river species face. The expertise and local knowledge from participants enhanced the walk with wildlife sightings and local history.

A common bat Photo by HitchHike from Pexels