Floating Wetlands

This project is funded by Welsh Government’s Local Places for Nature Challenge Fund, administered by WCVA.

A pilot study across three Ynys Môn lakes

A Floating Wetland in place in Llyn Maelog

the project goals.

  1. Design, permit, and install two floating wetlands to combat water quality issues.

  2. Research the impact on local zooplankton populations and quantify the scale at which water quality could be affected and improved.

  3. Engage the public on the health of the lakes.

  4. Explore opportunities for an expanded installation across Wales.

North Wales Rivers Trust staff monitoring the Floating Wetland

the pilot

In partnership with Ynys Mon Local Nature Partnership program, we are conducting a pilot study involving three lakes to better understand the impact of floating wetlands on water quality and the mitigation of harmful algal blooms. This study includes:

  1. Control Lake: This lake is equipped with sondes that monitor nutrient levels but has no floating wetland installed. It serves as a baseline to compare the effectiveness of the interventions in the other lakes.

  2. Lake with Floating Wetland: This lake has a floating wetland installed to absorb nutrients directly from the water, aiming to reduce the nutrient load and control algal blooms.

  3. Llyn Maelog: This lake not only has a floating wetland but also additional upstream interventions designed to reduce nutrient inputs from agriculture and sewage. These combined efforts aim to tackle the nutrient pollution at its source and further enhance the effectiveness of the floating wetland.

    We are hoping the learnings from this study will help to inform design and planning for future floating wetlands to support biodiversity and water quality.

the problem

Cyanobacteria can become a problem in lakes like Llyn Maelog under certain conditions, leading to harmful algal blooms (HABs) that produce toxins dangerous to humans and animals. Some cyanobacteria produce cyanotoxins, which can be harmful to animals and humans.

Cyanobacteria can become a problem in lakes like Llyn Maelog under certain conditions, leading to harmful algal blooms (HABs) that produce toxins dangerous to humans and animals, including dogs. Here are the conditions that can contribute to cyanobacterial problems in such lakes:

  1. Nutrient Enrichment (Eutrophication): Excessive nutrients, particularly nitrogen and phosphorus, from agricultural runoff, sewage, and other sources can lead to nutrient-rich waters that promote the growth of cyanobacteria.

  2. Warm Temperatures: Cyanobacteria thrive in warm water temperatures, typically during late spring to early fall. Higher temperatures accelerate their growth and bloom formation.

  3. Calm Water Conditions: Still or slow-moving water provides an ideal environment for cyanobacteria to accumulate and form blooms. Windless days and limited water circulation contribute to these conditions.

  4. Sunlight: Cyanobacteria need sunlight for photosynthesis, so prolonged periods of sunny weather can enhance their growth.

  5. Water Chemistry: Certain chemical conditions, such as higher pH levels and low water hardness, can also favor cyanobacterial growth.

Blue-green algae causing problems for North Wales lakes

The Science

We kicked off the project at the beginning of the year with a webinair to explain the science behind the project and how the community can get involved. You can watch the recording below.

community

The success of our environmental initiatives hinges on the active involvement of the community. Local residents, educators, and students are the most important stakeholders in monitoring, co-designing, and collating data for our floating wetland projects. By participating in these efforts, the community not only contributes to the scientific understanding of their local ecosystems but also takes ownership of sustainable solutions to protect and improve their water bodies.

North Wales Rivers Trust delivering a Floating Wetland education session

education


As part of this pilot programme, we collaborated with teachers, educators, and students in Ynys Môn to help them create their own floating wetlands.

Developed in partnership with the Charles River programme and with support from the LNP team, WCVA, and the Welsh Government, the STEAM Activity Kit offers a hands-on opportunity to learn about the lakes' ecology, pollution, and water quality.

The booklet and lesson plans, designed for a four-week course for grades 3-6, include lessons and activities that fit within a one-hour period. The Activity Kits explore the lifecycle of daphnia and demonstrate changes in water when daphnia, spirulina, and a wetland are present in the same environment. This engaging and educational programme helps students understand the importance of maintaining healthy aquatic ecosystems and the role of innovative solutions like floating wetlands in water quality management.

“Our STEAM EDUCAtION PRoGRAMME INSPIRES YOUNG PEOPLE TO UNDERSTAND WATER QUALITY, POLLUTION AND NATURE BASED SOLUTIONS TO AID RECOVERY.”

— Poppy Backshall ,Community Engagement Officer

work so far…

phase one

Launched the project

We launched the project with an event at the Oyster catcher in Rhosneigr, followed by a webinair and talk at the Menai Strait Partnership Forum in Menai Bridge. This was followed by numerous meetings with local schools, Natural Resource Wales and other stakeholder groups and organisations

Wetland design

Dr Antony Smith initially devised the wetlands and locations in partnership with landowners based on scientific data and access. We then sent out a tender for procurement and we selected Biomatrix Water Solutions to design the plant system and install the wetland.

Education

Poppy launched the DIY floating wetland project by launching a wave of school assemblies across Ynys Mon and gave talks on the wetland. Poppy signed up ten schools to our DIY floating wetland programme.

Phase 2

In phase two, we installed sondes across three Ynys Môn lakes to collect data on nutrient levels. This information will help us understand the issues affecting these lakes and target interventions to improve water quality. The sondes were installed at the end of May. Additionally, our community volunteers are gathering data on cyanobacteria levels and sending samples to an accredited laboratory. This alerts local residents when the water may be dangerous and allows us to monitor key months when cyanobacteria levels are likely to rise, linking these patterns to nutrient inputs and weather conditions. You can view the latest cyanobacteria levels below.

Launch of our DIY Wetland Kit

We connected with our friends at the Charleston Project in Boston, USA, who shared their innovative DIY floating wetland kit. Inspired by this, the North Wales Rivers Trust team developed a bilingual STEAM resource, available for download below. Pupils across Ynys Môn used these materials to design, build, and monitor their own mini floating wetlands in the classroom over a four-week program. They introduced Daphnia to observe the effects of zooplankton on water quality, mimicking the cleaning effects of our Llyn Maelog wetland.

Ysgol Rhosneigr Pupil measuring the water depth of their Floating Wetland model
Ysgol Rhosneigr pupil looking at Daphnia through a microscope

phase three

In phase three, an additional wetland in Llyn Penrhyn on Ynys Mon has been installed. This will allow the results of the two lakes containing wetlands to be compared.

During Autumn/Winter 2025, we are collaborating with several farmers on best land management practices and implement farming interventions to reduce nutrient runoff at the source.

Check back soon for more updates!

faq’s

Protecting Ynys Môn lakes