Enhancing biodiversity in urban areas can be achieved through larger garden ponds rich in native plants, as revealed by a recent study. The research, led by Dr. Matthew Hill, a Lecturer in Ecology at Bournemouth University, offers key recommendations for effectively managing garden ponds to create thriving habitats for aquatic species in urban environments. The findings, published in the journal Insect Conservation and Diversity, emphasize the significance of pond size, the presence of aquatic plants, and the management of conductivity—a measure of water’s electrical current passage. The study also considers the potential impact of fish predation.
Dr. Hill stressed the importance of managing garden ponds for wildlife alongside aesthetic or fishkeeping considerations. With an estimated two and a half to three and a half million garden ponds in the UK, correctly managed ponds could serve as vital freshwater resources in urban areas. The study, conducted in Oxfordshire, involved surveys of thirty ponds by the Freshwater Habitats Trust to assess habitat composition and species diversity. Based on the analysis, recommendations were made:
- Opt for larger ponds: A minimum pond surface area is suggested to increase the diversity of aquatic species, though safety implications should be considered.
- Increase native plant variety: Native plants play a crucial role in providing food and maintaining a balanced ecosystem. While some non-native plants may be chosen for ornamental reasons, their presence should be limited due to the associated risks.
- Use rainwater to reduce water conductivity: Lower conductivity levels support the thriving of environmentally sensitive species. Rainwater is recommended to top up ponds, as various contaminants from fish food, potting compost, and other sources can affect conductivity.
The study did not find evidence of ornamental fish negatively impacting biodiversity, provided the pond had low to moderate fish numbers. However, the researchers suggested that plants could offer hiding places to reduce the risk of predation by fish.
Dr. Hill highlighted the need for collective pond management, proposing the formation of community groups. Instead of individual management, he encouraged the management of ponds collectively to create a diverse range of environmental conditions for aquatic species, emphasizing both larger ponds with diverse species and smaller, ecologically unique ponds.
Photo by Tatiana Syrikova: https://www.pexels.com/photo/wild-ducks-swimming-in-calm-water-of-lake-in-park-3933384/