River Reflector December 2018

Read the latest news from our Rivers Team.

Rounding off the year at River Clun

To round off a busy year, the Rivers Team revisited the river Clun to provide our second River Health Training event. Despite the wet and rainy weather, we found a mixture of aquatic life including mayflies, freshwater limpets and even a bullhead! The abundance and variety of invertebrates is a crucial indicator into the health of a river. In the case of the river Clun it scored a moderate value, stipulating that it could be better. However, for rivers to improve, it is important for people to be aware of the factors that influence water quality such as runoff, leaching of pesticides or misconnected drains. If people are able recognise the threats to our rivers and understand ways to prevent them, river health scores like the Clun will increase. Not only will it benefit invertebrates, it will benefit, communities, mammals and birds such as otters, kingfishers and dippers. To see how you can benefit your river go to our Shropshire Rivers Hub at www.shropshirewildilfetrust.org/rivers.

How does aquatic wildlife survive in winter?

As we escape out of the cold and bitter winter weather and into our well heated homes. Some of us may wonder how fish and other organisms survive these wintery conditions in our local streams. Unlike many mammals, frogs and newts; fish and invertebrates do not hibernate. In fact they are cold blooded and have the ability to go into an inactive state where they lower their heart rate and do not eat or excrete waste but only consume oxygen to survive. Many small fish and invertebrates will remain in these smaller brooks and streams all year-round, hiding under undercut banks and logs, while larger fish will move to deeper pools downstream.

River Reflector

Photographed by Dom Egerton 

As we escape out of the cold and bitter winter weather and into our well heated homes. Some of us may wonder how fish and other organisms survive these wintery conditions in our local streams. Unlike many mammals, frogs and newts; fish and invertebrates do not hibernate. In fact they are cold blooded and have the ability to go into an inactive state where they lower their heart rate and do not eat or excrete waste but only consume oxygen to survive. Many small fish and invertebrates will remain in these smaller brooks and streams all year-round, hiding under undercut banks and logs, while larger fish will move to deeper pools downstream.

In extreme cold, water becomes less dense when frozen than the free water itself and therefore, floats. This aspect is critical for aquatic life, for if water bodies froze from the bottom up, stream habitat features would become largely uninhabitable for organisms. This is because many fish and invertebrates live under and among the gravels and cobbles in the stream bottom and are partially protected during most winters. Furthermore, the presence of groundwater and springs entering into streams can provide a refuge for fish and other organisms in winter. The temperature of groundwater is usually equal to the mean air temperature above the land surface. This means areas where groundwater seeps into streams can provide temperatures well above surface water temperature in winter. Fish are also known to seek this during summer too. Where groundwater provides a cooling effect from summer warming, and protects species that prefer cool water (e.g., dace and bullhead).

River Reflector

Winter Stonefly 

In addition to rural extremes, people also have their effect on nature, even in winter. Urban areas where there are a lot of "impervious" surfaces (e.g., roads, concrete, and roofs) can pose a particular hazard for aquatic life. Heavy rains or thawing snow can add to this, resulting in rapid runoff leading to "scouring" of streams occurring when fish and insect larvae are relatively inactive causing damage or death to animals in vulnerable habitats. Another problem in urban areas in late winter and spring is high levels of road salt that can wash into streams creating toxic conditions and contaminating soils and groundwater. Although winter can be harsh, some organisms rely on and thrive in the colder months. "Winter Stoneflies" (Family Capniidae) are so named because they emerge and mate during the winter months and can sometimes be found crawling on the snow near streams. They have the opposite strategy of most aquatic invertebrates in that the nymphs burrow into the stream bed and become inactive in summer, rather than in winter.

Unsurprisingly, winter is a tough time for invertebrates and fish but it can also be crucial for species like the winter stonefly. Winter highlights the challenges that rivers face all year round such as pollution, weather and runoffs. Despite this, our aquatic life is has an incredible ability to adapted and evolve new ways to survive these challenging conditions for the next upcoming generation in spring.

Cry Me A River- by Antony W Shaw

I didn’t know what to expect as I arrived at the HQ of Shropshire Wildlife Trust this Thursday evening. I was welcomed by Jenna Shaw and Chloe Howard whose warm smiles and immediate offer of hot tea and biscuits soon helped me forget the cold fog. I was lead to a room where members of the public were gathered to hear a talk by Pete Lambert of SWT, Guy Pluckwell and Richard Teague, both from the Environment Agency (EA), on the improvement, maintenance and health of Shropshire waterways.  As the presentations got underway it soon became clear that Shropshire’s waterways, and all others, are in need of everyone’s care. The effect of pollution and neglect of our waterways by industry, farming and the general public, was graphically presented throughout the scheduled two hour talk that easily became three hours.

River Reflector

Many of the signs that a watercourse is in trouble are obvious - discolouration, unpleasant odours, oil films, dead fish, wildlife depletion, excessive foaming, fly-tipping, shopping trollies, blocked pipes, sanitary product build up, and condom trees (I’m not kidding). I learned that I share the same ‘blindness’ with the population regarding water use at home. Many of us simply flush away tons of micro-plastics, detergents, cooking products, food waste, fats, paints and oils, everyday without regard for where it goes or its environmental effects. It’s not that we don’t care, we do. It’s just — we don’t know.

For instance, did you know that buildings and dwellings built after 1922 have two drainage systems? One that takes water directly to the rivers and a second system that takes contaminated water to the local water company for treatment? Kitchen and utility extensions are often built with incorrect drainage connections, sending contaminated water to our rivers. Even housing developers have been found to plumb-in new builds incorrectly. 

Fresh water is precious. Globally, 844 million people don’t have access to fresh water. Global warming is set to exacerbate the problem. Increased sea levels will flood fresh water tables with brine, reducing fresh water availability and driving up costs. Here’s another thing that I did not know. All objects and fluids, most of which are undetectable to our eyes, that find their way onto the nation’s roads and motorways will be washed by the rain into drains and into our rivers. That got me thinking.

I’m an average driver with an average car. I replace my tyres annually, wearing into the roads about 24mm depth of rubber a year. That turns out to be about 2,256 cubic centimetres of tyre products deposited onto the UK’s roads per year by an average car.  A standard eraser is about 6.3 cubic centimetres, so my tyres throw onto the roads the equivalent of about 358 erasers a year. Now, there are 31.5 million registered cars* on the UK’s roads. So, using my car as the average, that’s an equivalent volume of around 11.3 billion erasers making their way to our rivers every year. Not including emergency vehicles, motorcycles, farming vehicles or trucks. Add to that other pollutants from vehicles, such as oil and other fluid spills and leaks; hand car wash chemicals, etc. and the picture is pretty bleak.

As I drove home in my fossil-fuel burning, rubber depositing average car, a simple question crossed my mind. ‘So, what’s the good news?’ 

The following morning I realised, it’s simply this. The Wildlife Trusts, The Environment Agency and organisations like them exist and want to hear from us. Like the environment, they need everyone’s help. They will educate, train and support us for free. Whether it be thinking about how better to dispose of used cooking oils, checking our homes’ water drainage system, driving less, being careful with plastics and  litter, volunteering, or calling 0800 807060 to inform the Environment Agency that we’ve spotted a problem, our impact will be significant. 

Thursday night’s Shropshire Wildlife Trust presentation sent me home better informed and empowered to circulate information to others. It’s comforting to think that my, and your, actions can benefit every living thing.   

River Reflector

Upcoming Events

  • Friday 18th Jan 2019 at 10am—12pm. Meeting at Carding Mill Valley, Church Stretton. Lower stretch of Carding Mill Valley. Parking at National Trust car park for Carding Mill.
  • Monday 18th Feb 2019 at 10am—12pm. Meeting at River Perry, Gobowen. Located on a stretch of River Perry adjacent to the playing field of the Village Hall on St Martins Road.  Parking Available at Village Hall car park on St Martins Road.
  • Monday 18th March 2019 at 10am – 12pm. Meeting at Cantern Brook, Bridgnorth. Located on a Stretch of Cantern Brook adjacent Dingle View, WV16 4JL. Suggested parking: Dingle View.