River Reflector June 2019

Its has been another fantastic year for Our Love Your Magnificent Severn Campaign with many people dedicating their time to clean up their streets and rivers. Unfortunately, the flooding that happened at the beginning of the month meant our annual river trip was cancelled but what did the flood mean for wildlife that live and depend on rivers to survive?

Love Your Magnificent Severn Campaign 2019

It won’t have come to any surprise that our Love your Magnificent Severn river trip was cancelled this June. The aim of the trip was to collect as much litter as possible whilst spreading awareness of water pollution in our rivers. Unfortunately, foul weather and rapidly deteriorating river conditions meant safety to our volunteers and crew were at high risk.

However, no matter how dismal the weather, volunteers and crew members instead dedicated their time into a mass litter pick along the river banks of the Severn and Reabrook collecting over 20 bags of rubbish! Plastic wrappers, bottles and cigarette butts were some of the most prevalent pieces of litter found. We also held a litter picking event at Whittington castle before finishing our campaign at Pam’s Pools where we showed visitors some of the amazing wildlife found in our rivers.

Although our main event was cancelled, we have more than made up for it in the amazing response of groups and individuals around the county doing their own litter picks in their area.  Friends of Wesley Brook located in Shifnal is just one of the many communities that have joined together to clean up their local area.  They managed to collect up to 60 bags of rubbish demonstrating how much litter is on our streets and by our watercourses. 

Our campaign has now come to a close this year but we are still encouraging everyone to get out there and do their own litter pick whether it’s big or small. Please contact rivershub@shropshire for more details.

What happens to our wildlife in floods?

The start of June was no doubt a washout, potentially breaking June 2012 for being the wettest on record.  The persistent heavy rain prevented many of us from getting out and about and has especially taken a toll on many planned outdoor events, including our very own Love Your Magnificent Severn River Clean Up!

Floods are seen as destructive to both property and infrastructure. They can cause loss of life and affect our day to day routines. However, the impact it has on our freshwater wildlife is sometimes overlooked. With a changing climate and more unseasonal floods how does our wildlife cope in these high, turbid waters?

River Reflector

Firstly, rivers need floods to create unique habitats and support biodiversity. A disturbance such as a flood or drought is an important natural part of an ecosystem.  Therefore; there is nothing unusual about a flooded river. However, the problems occur when a flood is extreme and unseasonal.

When a river floods, fish usually spread out as the river spreads, finding refuge at the edges of the river. More mature fish will stay deep in the water avoiding the fast flowing water above them. Younger fish however, (less than a year old) may get washed downstream by the current but it’s generally only for short distances.  The young fish will find edge waters where the water is slower and shallower and, as the water recedes, they will follow it back to the main river channel. However, it’s not uncommon to find mass stranding’s of fish after floods; especially depending on how extreme they are. As floodplains become submerged by water, water flows can be strong and depending on the size of fish they can either be washed out or choose to explore the large expanses of flood water. Invertebrates also have the same strategy as young fish.  However they are more prone to becoming washed away. Invertebrates will take refuge under rocks and vegetation moving to deeper areas where they are out of the way from the current.

A seasonal flood that occurs in spring and winter is in fact beneficial for the fish and invertebrate environments. Floods can clean the river bottom by washing out all the sand and silt that has built up over time and moving it downstream. This exposes gravels that most trout and salmon species need in order to successfully spawn.  It is not uncommon to see an increase in young fish in years immediately after a flood. However, when floods are unseasonal and extreme such as this June it can have a number of negative impacts. June is the time of year when birds are nesting, farmers are spraying and nymphs are hatching. Therefore disturbances in these cycles can be detrimental to the health of a river and the wildlife that depend on it.

Floods increase surface runoff, erosion to banks and riverbeds and introduce more soil, organic matter and pollutants into the watercourse. Studies have shown that plant biomass and the abundance of both fish and invertebrates can be dramatically reduced by extreme floods. For example, the endangered freshwater pearl mussel found in the River Clun can be washed away and removed from the river bed as well as been subject to increase of water pollution.

Floods that occur in June don’t only have an impact on the wildlife that live in the water it also impacts water birds such as dippers, kingfishers, sand martins and grey wagtails. Many of these birds nest in the river banks and crevices close to the water relying on clear waters to catch their fish and invertebrates to survive. The timing of Junes flood would have affected many of these birds either by washing away their nests or preventing fledged chicks from finding food to build up strength. Despite this, many birds normally have 2 broods a year therefore depending on the weather; the next brood should be more successful.

What we can do

Flooding is a sensitive topic to many but as our climate changes floods are becoming more frequent. It has been found that many aquatic organisms have reduced resilience to extreme events such as flooding due to human activities such as urban development, farming on floodplains, river flow disruptions and pollution. These all contribute to frequent flooding.  

Here at the trust, we are working to reduce flooding in areas such as the Corvedale by using natural flood management techniques which not only reduce flooding but also create new habitats. We are also involved in projects such as Depave which encourages people to replace unnecessary tarmac with green space so that surface runoff onto roads, rivers and drains can be reduced.

Other ways to reduce the impact of flooding to wildlife are to:

River Reflector