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What lies beneath: protecting rare plants on the Montgomery Canal

Nestled in the heart of Mid-Wales and the English border, the Montgomery Canal has always been popular with nature lovers. Known as the Monty, this rural canal is home to a fascinating array of flora, and lurking beneath its waters is one of the rarest aquatic plants in Europe. The elusive Potamogeton, a type of pondweed, has found its own little niche within this unique man-made ecosystem. Yet, without intervention, this remarkable plant could soon disappear forever.

Montgomery Canal - Aston Locks

Built over 200 years ago, in its heyday the Monty would have been bustling with narrowboats laden with coal, limestone and grain. Sadly, by the latter half of the 19th century, traffic on the canal began to dwindle, as Britain's agricultural industry faltered and railways became increasingly prevalent. Following a serious breach near the aqueduct on the River Perry, the canal was finally abandoned in 1944.

Over the ensuing years, the Monty gradually succumbed to nature, with large sections being taken over by plants and wildlife. While restoration efforts began in the 1960s, and continue today, more than half of the canal remains unnavigable. It's in these pockets of wilderness that Potamogeton has persisted, popping up in ideal open water refuges where the water quality is high. Often this is in areas that closely mimic natural habitats, such as the slow river backwaters.

“These pondweeds will be absolutely teeming with life,” says Andy Shaw, from The Rare British Plants Nursery in Wales, “pike will be hiding in it, preying on other fish, and it'll provide cover for a whole range of invertebrates… If the pondweeds weren't there many of the invertebrates wouldn't be there, so these plants are a vital part of the food chain.”

Potamogeton seen underwater

What's more, some species of the Potamogeton found in the Monty, such as Potamogeton praelongus are particularly scarce, declining in Britain and endangered across much of Europe, leading to the areas of canal where they are found being designated as Sites of Special Scientific Interest (SSSI). “They're already extinct in some European countries,” Andy confirms, “so we've got an international responsibility to preserve them here in the UK.”

But it's a delicate balancing act. These rare plants sprang up in the wake of the canal's closure, finding refuge in the silt-laden waters. But while the Monty's protected status has provided a haven for these remarkable plants, populations are small and habitats are shrinking. Without careful management, these plucky pondweeds could disappear from our waterways altogether.

A man holding up an example of a rare pondweed

That's why we've partnered with Andy Shaw and his team at The Rare British Plants Nursery to conduct a comprehensive study of this fragile pondweed and cultivate more plants for relocation in the canal.

With Andy and the team's help, we've already begun improving sites along the canal, including adjacent wetland reserves, where Potamogetons can survive and thrive. As Andy explains, “A little bit of boat traffic might actually be beneficial when the canal is restored, and the new wetlands act as nurseries to grow more of the species, to help it spread even further along the canal. By restoring cultivated plants to the canal, we'll give the pondweed a helping hand, allowing it to jump over roads, bridges or a field and expand its range.”

The initiative should help us strike the difficult balance between restoring the canal to full navigation and preserving and enhancing its unique ecosystem. Our long-held vision for the Monty is a thriving and sustainable canal that benefits people and nature alike, providing a safe haven for plants and wildlife for years to come.

And if all goes to plan, not only will we succeed in propagating Potamogetons along our canals, we'll also contribute to the recovery of this wonderful species worldwide.

Last Edited: 28 July 2023

photo of a location on the canals
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