Highways Agency

Ecology

Overview of Effects

Disturbances from the existing motorway already impact on existing habitats and species. In order to minimise effects on habitats and species the Scheme includes a variety of mitigating measures. These include low noise surfacing, environmental barriers, sustainable drainage and new planting, together with habitat reinstatement and enhancement. These mitigation measures are in line with the Highways Agency Biodiversity Action Plan.

Designated ecological sites remain largely unaffected by the Scheme. There is little or no change compared with the current situation. However, new lighting has a negative impact on certain species in some locations.

A programme of mitigation and a Construction Environmental Management Plan controls construction effects and ensures improvements are implemented.

The creation of new species-rich grassland, together with the reinstatement of plantation and hedgerows, improves the connection between habitats.

Species-specific measures including bat boxes, ponds and reptile refugia further improve many areas for wildlife.

Badgers

Badgers and their setts are protected under the Protection of Badgers Act (1992). The Badgers Act was implemented mainly to protect badgers from baiting and deliberate harm or injury, but also contains restrictions that apply more widely. Badgers are also protected under the Badgers Act of 1990 against killing or injury. Detailed surveys were done within 150m of the motorway which revealed badgers to be present throughout the Scheme. Evidence includes setts, latrines, prints, trails and signs of foraging.

Any work likely to involve disturbance to active badger setts requires licensing. Section 4 contains suitable areas for supporting badgers and the location of setts, runs and foraging areas has been established. Suitable mitigation will be implemented before construction commences.

Bats

All native species of bat in the UK are protected by the Wildlife and Countryside Act (1981 [Schedule 5]), as amended by the Countryside and Rights of Way (CROW) Act (2000). They also receive protection through the Conservation (Natural Habitats, & c.) Regulations (1994 [Schedule 2]), implementing the EC Habitats Directive 92/43/EEC in the UK. Seven species of bats were recorded during surveys.  No active roosts were found although potential roosting trees and 8 carriageway crossing points were identified. Species recorded were common pipistrelle (Pipistrellus pipistrellus), soprano pipistrelle (Pipistrellus pygmaeus), unidentified pipistrelle (Pipistrellus spp.), noctule (Nyctalus noctula), noctule /serotine (Eptesicus serotinus), Myotis spp and unidentified spp. Although all bats are protected by European legislation, none of these species is considered rare or restricted in this locality.

Features which have potential for bats to either roost, forage or commute would be retained. Treatment ponds would be more numerous and these may provide additional foraging habitat for bats.

Upgraded lighting to high pressure sodium lamps and an increase of the number of light columns throughout the Scheme would have negative effects on bats close to the motorway although the proposal includes cut-off lamps which would help reduce light spillage. However the lighting proposals could have some benefit as insects are attracted to the brighter light and preyed upon by some species of bat.

Breeding Birds

All bird species are protected under the Wildlife and Countryside Act (1981) as amended by the Countryside and Rights of Way (CROW) Act (2000). Species listed under Schedule 1 of the Wildlife and Countryside Act are protected at all times. Numerous breeding birds were identified in the study area including Schedule 1 species. These included kingfisher (Alcedo atthis), barn owl (Tyto alba), woodlark (Lullula arborea), fieldfare (Turdus pilaris) and redwing (Turdus iliacus). Very few breeding birds were recorded in motorway verges. Several locations within Section 4 are considered ideal habitat for breeding birds.

Sensitive habitats such as woodlands (where the majority of breeding birds occur) would be protected from construction noise by a buffer zone of vegetation and temporary fencing. However the removal of habitat would result in a slight loss of areas suitable for foraging and shelter and in the opening year new planting and reinstated habitats would be immature. As time progresses this vegetation will mature and help reduce impacts to breeding birds.

Deer

The Deer Act (1963, amended 1980 and 1991) prohibits the taking or killing of deer listed on the schedules within the act during the close season for that species. Deer are common outside of the highway boundary due to the presence of woodland habitat and linear corridors. Records show muntjac (Muntiacus reevesi) and fallow deer (Dama dama) are present in the area. As deer do not regularly occur in the motorway corridor specialist deer surveys were not undertaken for the Scheme. However, records of deer are most abundant around Junction 28.

Deer moving through the study area are not expected to be affected by increased noise due to the use of low noise surfacing and changes in lighting are not likely to affect deer as most activity occurs away from the motorway corridor. No increase in deer mortality is predicted as signage and fencing will be used where necessary and deer are expected to continue using the existing underpasses and over bridges to cross the motorway.

Dormouse

The dormouse (Muscardinus avellanarius) is legally protected under Annex IV (a) of the EU Council Directive 92/43/EEC on the Conservation of Natural Habitats and Wild Flora and Fauna (the Habitats Directive). This Council Directive was brought into law in the UK through the Conservation (Natural Habitats, and c.) Regulations (1994). In addition, the dormouse is also specially protected under Schedule 5 of the Wildlife and Countryside Act (1981, plus subsequent amendments), reinforced by the Countryside and Rights of Way Act (2000). No dormice were recorded at any of the sites targeted for surveys in the study area.

Suitable dormouse habitat is present in ancient woodland blocks outside the highway boundary. Suitable habitat usually consists of woodland edge habitats, dense and open scrub where it backs onto ancient woodland and hedgerows (often ancient and overgrown) with good connections to scrub and woodland habitats. Woodland management and new hedgerow planting will benefit dormice through the creation of new habitat.

Fish

A decision was made with Natural England and the Environment Agency not to undertake fish surveys as there is a low historical occurrence of aquatic species within the study area and no watercourses or culverts will be altered by the Scheme.

Water quality is expected to improve due to proposed drainage, which will ultimately benefit any aquatic species that may be present.

Great Crested Newts

The great crested newt (Triturus cristatus) is protected by the Wildlife and Countryside Act (1981, plus subsequent amendments). This Act has been further amended by the Countryside and Rights of Way Act (2000). Newts also receive legal protection under the Conservation (Natural Habitats, and c.) Regulations (1994). A total of 59 ponds were surveyed for great crested newt within 250 metres of the motorway. The species was recorded in 32 of these ponds along the motorway.

There will be a temporary loss in terrestrial habitat during construction although new scrub, woodland and species-rich grassland will be planted within the new motorway verges. In general the new drainage system will improve water quality within the areas that receive runoff, indirectly benefiting amphibians. If great crested newts colonise the treatment ponds, highway maintenance would follow best practice guidelines and legislation to safeguard the species.

Invertebrates

Some invertebrates are protected by the Wildlife and Countryside Act (1981) including the white-clawed crayfish.  Levels of protection vary, but normally prevent killing, injuring, disturbance or trade of protected species. Surveys on aquatic invertebrates except white-clawed crayfish were not undertaken for the Scheme as there is a low historical occurrence of aquatic species within the study area. Five locations were surveyed for terrestrial invertebrates but only low numbers of common glow-worm (Lamptyris noctiluca) larvae were discovered. Observations also include a number of dragonfly and damselfly (Odonata) species around ponds and watercourses. Stag beetles have previously been recorded at an orchard between Junction 29 and 30. 

No watercourses or culverts will be altered and the water quality of the road surface runoff is expected to improve due to the new drainage system, benefiting any aquatic invertebrates which may be present in the area. Areas with good potential for terrestrial invertebrates such as patches of species-rich grassland within the verges would be retained where possible and where mature woodland with dead or dying trees is adjacent to the highway boundary fence the buffer zone between the two will be maintained or strengthened through careful planting.

Otters

The otter is protected by Wildlife and Countryside Act (1981 [Schedule 5]), which has been amended further by the Countryside and Rights of Way Act (2000). It also receives legal protection under the Conservation (Natural Habitats, and c.) Regulations (1994). 28 areas within 50m of the M25 carriageway were searched for evidence of otters which includes food remains, faeces and footprints. Observations of the streams and ditches in the area showed that most are unsuitable for otters however they are present in some rivers and tributaries throughout Section 4. 

The Scheme will not affect any river bank habitat however pollution events could result in reduced water quality that may indirectly affect otter habitat and food resources. Measures will be used to ensure that pollution events near watercourses are avoided or appropriately managed. The provision of secure crossings and continuous natural habitat will benefit otters. 

Reptiles

The slow worm (Anguis fragilis), common lizard (Lacerta vivipara), grass snake (Natrix natrix) and adder (Vipera berus) are protected from being killed, injured or traded under Wildlife and Countryside Act, (1981 [Schedule 5]). Reptile surveys were carried out in nine areas to establish which species of reptiles are present in the motorway verges and where they occur. 
Four species were found within the motorway verges: common lizard (Lacerta vivapara), slow worm (Anguis fragilis), grass snake (Natrix natrix) and adder (Vipera berus). 

Planted grassland and scrub within the new verges will regenerate and replace any vegetation lost during construction. Reptile hibernacula will be placed in the verges to make them more attractive for reptiles and scattered scrub will be planted to provide both shade and cover from aerial predators. Recreating habitats will increase available foraging areas and connect existing isolated pockets of habitat.

Water Vole

Water vole (Arvicola terrestris) habitat is protected under Schedule 5 of the Wildlife and Countryside Act (1981, plus subsequent amendments). This prohibits damage or destruction of place of shelter or protection and disturbance while in a place of shelter only. Surveys for water vole were carried out along watercourses with suitable habitat. River banks and vegetation were searched to look for evidence of water voles. The evidence discovered consisted of burrows, latrines (faeces), food stores and footprints.  Evidence of water vole was discovered in eight locations.

Additional surveys will be carried out close to construction areas at the appropriate time.  If water voles are found, a clearance exercise will be undertaken to move them to a more suitable area. Any destroyed bank habitat will be restored and where possible, mammal ledges will be installed at culverts to create safe crossing points. The new drainage proposals and treatment ponds are predicted to improve water quality in the area which is expected to benefit water voles.