As a Site of Special Scientific Interest Bushy Park supports a highly diverse wildlife community including those species associated with its waterbodies and watercourses.
The Longford River, as it flows from west to east across Bushy Park, separates out into several channels and is at its most intricate when flowing through the Woodland Gardens. Whilst this area makes an important contribution to the aquatic habitat across the park it is not realising its full biodiversity potential.
In 2018 an ecological survey of the four main ponds (Fisher’s, Triss’s, Waterhouse and Witch’s) and associated watercourses was undertaken thanks to support from players of People’s Postcode Lottery. The results clearly showed that some of the waterbodies held large amounts of silt and were nutrient-enriched and poorly oxygenated. This reduces the biodiversity value of the ecosystem, with relatively few species able to survive in these conditions. Fisher’s Pond was found to be in particularly poor condition, only supporting a very limited community of invertebrates (those able to survive high concentrations of nutrients and low oxygen levels).
So, in January 2021, we embarked on a major project to restore Fisher’s Pond. The first significant step was to reduce the huge silt deposits that had accumulated in Fisher’s Pond and its two feeder streams over many years. A whopping 500m3 of material was removed – equivalent to over 3.5 double-decker London buses!! The majority of the silt was used to reshape and create shelves along the margins of the channels and pond. Giving the channels a more sinuous form helped to vary water flow along them, introducing more oxygen to the water and creating more varied conditions for wildlife. A remarkable 1,200 wildflower plants were added to the new margins, including yellow flag iris, water forget-me-not, flowering rush, marsh marigold and purple loosestrife. These provide structure, shelter, food, and egg-laying opportunities for many species from dragonflies to newts.
The challenging ground conditions at the time of the works (an extremely wet winter) and the necessary use of large machinery means that disturbance is inevitable and during the works the site did look a mess! But an area of approximately 1,000m2 was sown with a wildflower seed mix. These areas have already shown incredible recovery and are more species rich as a result.
By improving water and habitat quality and creating more favourable and stable conditions for wildlife we expect existing species to flourish, new species to colonise, and the ecosystem to thrive again. Although it is too early to confirm this, certainly the water looks much clearer and we will monitor the changes in the habitats and species which live there and learn from the experience. As well as helping biodiversity in its own right, projects like this also help increase the resilience of habitats and species to better withstand the impact of climate change and help us to manage the network of ponds and streams in a more holistic and sustainable way.