Big River Watch September 2024: A dive into the data
Take a deeper look at the data collected during our latest Big River Watch.
30/09/24
Earlier this month we held our latest Big River Watch week, a citizen science initiative where we encourage everyone in the UK and Ireland to spend time by their local rivers and share what they observe through our free app. This event saw a fantastic turn out, with 4,800 participants connecting with our rivers and submitting 2,700 surveys. Altogether, across a single week, we spent an incredible total of 50 days watching and monitoring our rivers.
The recent Big River Watch ran from the 6th-12th of September and here is what you reported from the river’s edge:
The start of autumn brought an array of wildlife sightings
Ducks once again take the prize for the river dwellers most commonly spotted by Big River Watchers, seen in over 1,200 times and featuring in 44% of all surveys. Fish were not far behind, appearing in 854 surveys. Less common but exciting sightings included 7 reports of beavers and 65 sightings of the elusive otter. The dazzling blue and orange flash of a kingfisher was recorded in 340 surveys whilst our elegant swans and herons appeared in 651 and 529 surveys respectively. We also had 146 sightings of the charming dipper and 378 reports of the small but mightily important riverflies – a useful indicator of a river’s water quality.
Pollution was present too
With sewage and chemical presence in our waterways frequently making the news this year, pollution remains a significant concern across our rivers. Citizen science can help to identify hotspots where restoration action and clean-ups can be targeted, so the Big River Watch also asks surveyors to look out for the less glamourous aspects of our river ecosystems too. Perhaps unsurprisingly, 62% of surveys (1,727) reported signs of at least one form of pollution. Silt, which can be washed into rivers during periods of rain, led the way as the most frequently observed pollutant, showing up in 858 surveys. Algal blooms, a tell-tale sign of nutrient pollution that may have come from agricultural run-off or sewage, were spotted in 250 surveys. Further evidence of sewage pollution was reported in 175 surveys, and 144 surveys recorded sightings of sewage fungus, another common sign of poor water quality. Other types of pollution included road runoff (which often presents as an oily sheen on the water surface) which was seen in 118 surveys and mine water which was reported in 29 surveys.
Plastic bottles, food packaging, wet wipes, shopping trolleys, vapes, and even bikes are all recurring sights in our rivers with 50% of surveys reporting signs of visible litter. Whether floating in the water or caught in vegetation, litter continues to contribute to the poor state of our rivers.
Barriers
One of the ways that human activity has significantly altered our rivers isthrough the installation of artificial barriers like dams and weirs. These modifications disrupt the natural flow and ecology of rivers. Fortunately, many of our local Trusts are actively working to reverse this damage by removing or mitigating these barriers, aiming to restore rivers to their natural state.
During the Big River Watch, we asked participants to record any barriers they encountered to help us highlight the prevalence and locations of these modifications. 645 surveys reported artificial barriers, while 144 surveys found a mix of natural and artificial barriers. Additionally, 1,007 surveys noted natural barriers such as fallen trees.
It's important to note that, unlike artificial barriers, natural debris can often benefit the river ecosystem by creating habitats and diversifying water flow. These natural obstructions can support wildlife and contribute to the overall health of the river.
Perception of river health
Despite the frequency of pollution and litter, 66% of surveyors felt that their river stretch looked healthy, whilst only 23% thought it looked unhealthy. While on the surface this may appear encouraging, it is important to recognise that many of the pervasive problems facing our rivers are not easily visible. For example, chemical pollution, known to be present in all our rivers, requires water sample testing and monitoring to detect it. It’s also probably a safe assumption that most surveyors prefer spending time outside when it isn’t pouring with rain, yet signs of sewage and litter are more likely to be spotted during or after heavy rainfall as it flushes them into our waterways. Additionally, while the Big River Watch app includes a handy ID guide for the commonly seen pollutants, spotting the signs can be tricky. These results may also indicate a need for further education around the issues facing our rivers, what to look out for, and what makes a healthy river.
If you’re interested in delving deeper into the disparity between perceived river health and the state of our rivers, our data explorer offers a detailed look. Each survey point on the map is color-coded—blue for healthy and red for unhealthy—based on the surveyor's perception. This can be compared to the colour of the river stretches themselves which are marked in blue or red to reflect their official ecological health status under the Water Framework Directive, with more detail visible when zoomed in.
Big River Watch also prompts participants to summarize their feelings when standing at their survey location with a single word. We gathered the most common responses and explored the connection between emotional reactions and the perceived health of the river. Similar to the previous two Big River Watches, participants observing a healthy-looking river were more likely to report positive emotions (calm, peaceful, relaxed), while negative feelings (sad, disappointed, frustrated) were more common among those surveying an unhealthy-looking river. There is a growing body of evidence that supports the importance of healthy green and blue spaces on our mental wellbeing, and these results continue to underscore the importance of prioritizing restoring nature for the benefit of community wellbeing.
Citizen science
Even though many Big River Watch-ers had taken part in one of our previous surveys, we are also pleased to see that 48% of participants were new to citizen science! This growing interest in protecting and monitoring our waterways is crucial in the fight for better river health. The Big River Watch not only provides valuable data but also aims to foster a deeper connection between individuals and their local ecosystems.
Has Big River Watch sparked your interest in Citizen Science? There are lots of other fantastic citizen science opportunities and projects you can join. You can find some in our blog ‘Citizen Science: 10 ways you can get involved in the fight for cleaner rivers’.
Other ways to help
If you participated in September’s Big River Watch, thank you for your contribution! Don’t forget that Big River Watch weeks take place twice a year and we’ll have another one coming in Spring. Until then, our app remains live year-round, and all the data collected (whilst not featured in the data explorer) is available and can be used by our local Trusts and other organisations to inform their projects and river restoration activities.
Find your local Trust
Use our member Trusts offer a great variety of activities to get involved in, from litter picks and tree planting to balsam bashing and riverfly monitoring. Find your local Trust and discovery opportunities in your area.
Want to learn more?
Use our interactive data explorer to delve into the survey data from all three Big River Watch events. If you’d like to download the full dataset or have any further enquiries, please contact [email protected].
Read our State of Our Rivers Report to learn about the issues facing our rivers, their current condition, and what needs to be done to improve them.