Restoring and revitalising to ensure a more resilient River Kent and its species

PROJECT DESCRIPTION

BACKGROUND

The River Kent is a 225 km² catchment dominated by the Kent, Gowan, Mint and Sprint tributaries. The River Kent Special Area of Conservation (SAC; almost 89 ha) is designated for the habitat 3260 (Water courses of plain to montane levels with Ranunculion fluitantis and Callitricho-Batrachion vegetation) and 3 species listed in Annex II of the EU Habitats Directive – the critically endangered freshwater pearl mussel (Margaritifera margaritifera), the endangered white-clawed crayfish (Austropotamobius pallipes) and the bullhead (Cottus gobio). It is the only major English river system where white-clawed crayfish populations are still abundant throughout and the only UK river where the crayfish and freshwater pearl mussels are found together. Both white-clawed crayfish and bullhead are at the northern extent of their range. Freshwater pearl mussels require a stable riverbed with sand or clean gravel to support the buried stage of their life cycle. The suitability of habitat for salmon and trout is also important as the mussels’ larvae (glochidia) depend on them as host species. Freshwater pearl mussels formerly occurred more widely throughout the SAC, but the population is now near to extinct with 34 individuals across 2 locations.

The project, together with complementary actions in the wider catchment, will address issues highlighted in Article 17 reports (required under the Habitats Directive), Site Improvement Plans (SIPs; developed in the previous LIFE project LIFE11 NAT/UK/000384) and condition assessments. These issues are: water quality and siltation; physical and morphological modifications; decline in species condition and extent; invasive alien species (IAS) and diseases including signal crayfish, a vector for Aphanomyces astaci (crayfish plague), which, whilst not currently present in the SAC, are now present only 7 km away; and lack of awareness and understanding amongst stakeholders. These issues have led to a failing SAC condition: less than 0.4% is classed as favourable but not secure, and the remainder is unfavourable (83.32% is unfavourable- recovering but not secure, and 16.31% is unfavourable- no change).

OBJECTIVES

The LIFE R4ever Kent project will focus on restoring and revitalising the River Kent SAC, making it more resilient to environmental pressures and securing the survival of the species with the most demanding habitat requirements. The project will move the SAC towards favourable recovering/favourable secure condition by using a range of best practice methods for river/riparian restoration and invasive species control. It addresses river and wider catchment issues and actions outlined in the relevant SIPs and thematic plans drawn up in the earlier project IPENS (LIFE11 NAT/UK/000384).

The project’s key objectives will improve the resilience of the river's habitats and species to future pressures and threats. Its specific objectives are to:

1. Restore the SAC: provide optimum conditions for the Annex I water course habitat for which the UK has a special responsibility and its 3 Annex II indicator species;
2. Revitalise Annex II species populations: increase the critically endangered freshwater pearl mussel population (by 4,000); expand its range in the SAC; reinforce the site’s population with donor stock from other suitable freshwater pearl mussel sites; improve breeding facilities to secure England’s long-term freshwater pearl mussel population; ensure the long-term future of the endangered white-clawed crayfish from crayfish plague; provide optimum conditions for the freshwater pearl mussel's salmonid hosts; and maintain bullhead populations;
3. Trial new techniques: use IAS biocontrol; assess the sensitivity of eDNA surveying techniques to detect key species movement/distribution and provide an early warning system for crayfish plague; carry out research to investigate fish/mussel interactions; and prove the effectiveness/sustainability of these methods;
4. Secure the long-term sustainable management of the River Kent’s catchment: use targeted advice/training/demonstrations for more than 50% of adjacent landowners, and for the agricultural/forestry sector, to improve practices and reduce nutrient/sediment inputs entering the SAC; and
5. Ensure replication/communication: transfer knowledge/skills and replicate conservation actions to 5 sites; and inspire and raise awareness of the value and function of more natural riverine systems across a wide-ranging audience (30,000) in the UK and mainland Europe.
   

The project supports the Habitats Directive through the protection and restoration of an SAC and safeguarding 3 Annex II species as well as the EU IAS Regulation regarding the control and removal of invasive alien plants and signal crayfish. It also supports Regulation (EC) No 1100/2007 on the recovery of eel stock, the EU Water Framework Directive and various other related biodiversity and freshwater policies and strategies.

RESULTS

Expected results:

• 88.9 ha of SAC restored, addressing SIP issues, with 15.75 km achieving favourable-recovering condition and the remainder moving towards favourable-secure condition through:

• Upper headwater sections functioning more naturally:
• 15.75 km of riparian or in-channel improvements;
• 30 km of fencing;
• 75 anchored trees or 350 m of green engineering;
• 2,000 trees planted;
• 500 m of embankment improvements;
• 500 m of deculverted becks;
• 1.1 km of revetment works

• 3 small weirs removed;
• 300 m² of gravel cleaned;
• Fish spawning refuges doubled;

• Hatchery improvements:
• More than 4,000 freshwater pearl mussel juveniles bred for release;
• Over 3,000 juveniles released during the project with 1,000 retained for reintroduction once they have attained a larger size;

• Management plans in place:
• 50% of key landowners or managers targeted, with 50 farm walkovers and 30 new agreements made;
• 15 case studies and catchment-specific guidance documents produced;

• IAS strategy in place:
• 20 km of bankside IAS plants removed;
• Biocontrol of rust fungus successfully implemented;
• Signal crayfish confirmed as not present; and
• eDNA surveying utilised.