​The River Mole and the 4Bs Biodiversity Initiative

The River Mole and its tributary streams are a vital component of the 4B’s landscape and it supports an extensive network of interlinked habitats and ecosystems. The valley also comprises the most diverse mix of habitats including the river itself, the tributary streams, standing waterbodies, banksides, woodland, scrub, hedgerows, mixed farmland, and managed areas such as golf-courses, gardens, greens and commons. The river and its itributaries are classed as a Biodiversity Opportunity Area because of the variety of habitats, plants and animals they support and the potential for enhancing biodiversity.
 
The river and streams, when in a healthy condition, support a complex web-of-life within and around them. Plants in the river provide food and shelter for invertebrates, including fly larvae, as well for fish and, as food, for birds such as ducks and swans. The smaller invertebrates provide food for larger invertebrates (such as crayfish) and vertebrates including fish and amphibians. These, in turn, provide food for birds, including kingfishers and heron, and mammals such as mink (which we hope will one day be replaced by our native otter). When the aquatic fly larvae hatch into adult flies they become food for fish, birds and mammals including bats. There are few lovelier places to be than by a healthy stream on a summer evening watching fish and bats feeding on hatching and egg-laying flies.

The stream-side vegetation, when free of invasive species, will have a diverse range of plants which provide homes, feeding and resting places for a host of animals.  The tree-like network of tributary streams and connected ditches allow this richness and diversity to reach all areas of the river valley. The main river forms a natural corridor, allowing the movement of species from upstream to downstream and vice versa. Such natural corridors are vital in a time of climate change where plant and animal populations will need to be able to respond to changing conditions by shifting their distribution within the country.
 
The River Mole and its tributary streams are a vital component of the 4B’s landscape but many of the habitats and ecosystems have been degraded by pollution and human activities. A concerns for the quality of water in the river and a desire to campaign and act for improvement has inspired a group of volunteers to form River Mole River Watch - a charity whose purpose is to connect individuals and groups who care about the river, to work together to return it to a good ecological state for wildlife, plants and people.
 
Restoring the river and its tributary streams to a healthy condition is essential to the 4Bs Biodiversity Initiative goal of a healthy, biodiverse landscape, rich in habitats that enable wildlife to flourish. River Mole River Watch volunteers already sample the main river and tributaries of the Mole - Tanners Brook, Betchworth Brook, Shag Brook, Gad Brook and Wallace Brook - for the monthly Catchment-wide ‘citizen science’ water quality testing programme.  Their data can inform the habitat monitoring activities of the 4Bs biodiversity initiatove.
 
Further information about River Mole River Watch, including their latest water quality monitoring data, can be found at: https://www.rivermoleriverwatch.org.uk/​
  
Nigel Bond
River Mole River Watch Trustee

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​World Rivers Day worldriversday.com/ will be celebrated on Sunday September 22 this year. It brings people together to raise awareness about the importance of rivers and how they are threatened by human activities.