PROJECT DESCRIPTION
BACKGROUND
The Broads Natura 2000 network site is situated near the eastern English coast in the county of Norfolk. It is an internationally important wetland ecosystem and covers an area of 5 889 ha. Its lakes are a key biodiversity and iconic landscape feature that have suffered from a legacy of water quality issues. The Broads has a long-term restoration programme, which includes a Lake Restoration Plan that identifies and prioritises restoration actions.
Hoveton Great Broad and Hudson’s Bay have been flagged as a priority for lake restoration work. These sites comprise 12.5% (36.51 ha) of the Broads Natura 2000 site and host naturally eutrophic lake habitats listed in Annex I of the Habitats Directive. The sites' conservation status has been in an ‘Unfavourable No Change’ condition for at least 40 years mainly due to historic nutrient inputs from sewage works and diffuse sources. This has resulted in high algal biomass, loss of aquatic macrophyte biodiversity, turbid water, large amounts of fluid nutrient-rich sediment and shallow water depths, leading to an overall decline in the associated biodiversity, particularly birds and invertebrates.
OBJECTIVES
The main aim of the Bure LIFE project was to restore the naturally eutrophic lake habitat to a species-rich, clear-water state through minimal carbon footprint project actions. The restoration work benefitted EU priority habitats, such as calcareous fens with Cladium mariscus (7210*), and Annex II-listed Habitats Directive species such as otters, as well as waterfowl including wigeon, gadwall and shoveler.
Specifically, the project aimed to:
- Improve the ecological condition of the naturally eutrophic lakes with Magnopotamion or Hydrocharition habitats (3150) within Hoveton Great Broad and Hudson’s Bay, bringing them to a ‘Unfavourable Recovering’ conservation status by 2020. This involved:
- Sediment removal from both waterbodies;
- Biomanipulation of both lakes to achieve clear-water conditions, leading to an aquatic macrophyte dominated state.
- Re-use the sediment to create new areas of fen vegetation corresponding to the previous extent of marginal lake edge habitats, including calcareous fens with Cladium mariscus habitat and to help restore eroded river banks.
- Monitor the recovery process and disseminate best practice guidance associated with the restoration techniques to managers of similar habitats both within the SAC and elsewhere in the UK and the rest of Europe.
- Raise awareness of anthropogenic impacts, improve physical and intellectual access and increase appreciation of biodiversity amongst local communities, visitors, land managers and a range of other target audiences.
RESULTS
The project ran from September 2015 to June 2023 and was delivered by Natural England in partnership with the Environment Agency. The project mostly delivered its objectives and the restoration activities implemented resulted in moving Hoveton Great Broad and Hudson’s Bay from unfavourable-no change condition to unfavourable-recovering condition. This was achieved without fully implementing the foreseen restoration action of biomanipulation (fish removal). However, monitoring of the habitat condition will continue as part of the After-LIFE Plan to ensure the recovery of the habitat is sustained.
Main achievements:
- Removal of 54,000m3 of sediment from the lakes.
- Re-use of dredged sediment to create 3.7 ha of new fen habitat. Established using translocated fen turf from a nearby source.
- Opening up of two dykes to promote nutrient flushing though the lakes.
- Moderate improvements to macrophyte species richness and abundance were recorded as well as improvements in water quality including a reduction in Total Phosphorous and zooplankton.
- The project improved the visitor infrastructure of the Nature Trail providing public access to Hoveton Great Broad which was used extensively for public engagement and environmental education during the project. This included additional education spaces and platforms, new interpretation signs, a new bridge, tern raft, and periscope to view the changes underwater.
- Visitor numbers to the Nature Trail increased by 22%, 75 volunteers participated during the project and the project targeted a range of local community groups as part of the engagement activities.
- Establishment of an After LIFE Steering Group to oversee and implement the After-LIFE plan.
