Ecology

Phase 1 survey of a brownfield site

phase 1 brownfield site

Derelict buildings sometimes require bat roost assessments

An extended Phase 1 Habitat Survey was commissioned for a site in south Norfolk. The site consisted of 0.3ha of unused land, including an old dilapidated building and several trees with bordering woodland, farmland and existing development. WFE undertook a site survey to classify the habitats to JNCC standards, and with the methods being ‘extended’ to include a general evaluation of potential habitats for any protected or valued species. The habitats on the site and surrounding area were classified, hedgerows were appraised, buildings and trees were inspected for bats and considerations were made concerning other protected species.

All the information we collected was mapped, supported by target notes and photographs detailing protected species issues. Further protected species issues were ruled out in this case and this fed into a final report for planning. If further surveys had been necessary, WFE could have produced what is known as a Preliminary Ecological Appraisal (PEA) and a final report produced after necessary surveys had been completed.

Preliminary appraisal used to inform project design

In March 2019 a small proposed housing development in Suffolk required a Preliminary Ecological Appraisal (or PEA) to understand ecological risks prior to our client making key planning and design decisions.  We would always advise doing this: issues flagged early can avoid significant delays and costs associated with seasonal survey constraints and re-design. Unfortunately an all too common occurrence when this advice is not followed.

In this case we were able to inform the client of the presence of great crested newts and reptiles in the surrounding area, both of which were flagged by a habitat survey and the data search we conducted. The data search also identified a sensitive grassland close by which was a County Wildlife Site.

ecological appraisal informs project design

A great crested newt found on site

The report we produced provided clear advice on the next steps, timings for necessary surveys, likely mitigation requirements and possible future licencing requirements. This information was fed into the design and planning stages.

Incidentally, the required great crested newt eDNA surveys were mobilised in April and we were able to complete our final report for planning by late May 2017 with no delay to the project timetable. If the client had come to us at the end of their design process, due to the seasonality of the surveys needed, the project would have been delayed until early-2020.

Wintering bird surveys in an SPA

  • January 27, 2020
  • Blog

WFE was commissioned to undertake a study of foraging wintering birds on the River Deben Estuary SPA (Special Protection Area) in Suffolk, focusing on a particular area where a freshwater flow was pumped from a sluice at night into the river from surrounding arable land. Natural England were concerned that plans to redirect this waterflow away from the estuary may impact non-breeding waterfowl species such as brent goose and redshank for which the Deben is an internationally important site. Water birds have been found to preferentially associate with freshwater flows over mudflats due to accessibility of fresh water for bathing and drinking and an increase in invertebrate prey densities.

wintering bird surveys

The River Deben is an internationally important site for bird species such as redshank and brent goose

The study compared the ornithological importance of the outfall site, which has intermittent flowing freshwater, with two control sites, one comprised an area of mudflat with no freshwater influence, while the other control was an area of mudflat with a permanent freshwater gravity flow. Two nocturnal surveys and one daylight survey were conducted per month between November and March on all three areas and involved the counting and identifying all bird species present with the assistance of thermal imaging cameras.

The study discovered that the area with the permanent freshwater flow hosted a significantly greater density of birds than the other two sites, which both had a very similar density of birds associated with both the nocturnal surveys and diurnal surveys. It was concluded that the site with the intermittent freshwater water flow had a negligible influence on the local bird communities providing equivalent habitat to a creek with no freshwater input and therefore the removal of the water flow would have no negative impacts on the wintering bird populations listed as interest features of the Deben Estuary SPA.

A new water pipeline at Thetford

  • January 27, 2020
  • Blog

In 2018 Wild Frontier Ecology undertook an extended Phase 1 habitat survey along a proposed water pipeline route around Thetford in Norfolk. The route was proposed to go through an industrial estate, agricultural fields, pastures, grasslands, hedges and trees.

To assess the habitats along the route, and the potential for any impacts on protected species, Wild Frontier Ecology first carried out a desk survey. This comprised a search for conservation sites within 2km of the proposed route and a data search with the Norfolk Biodiversity Information Service for species records. Fourteen statutorily designated nature conservation sites and 16 County Wildlife Sites were found with three of the County Wildlife Sites directly intersecting the route. 6,450 species records, including reptiles and a variety of bird species were also found within the 2km buffer.

Next the route was subject to a walkover survey where all habitats within a 100-250m buffer of the proposed pipeline were mapped and considered for their potential to host protected species such as great crested newts, reptiles and stone curlews. Ponds were also recorded and assessed for their suitability for great crested newts.

phase 1 water pipeline

An excerpt of a Phase 1 Habitat Map for the pipeline route

Based on the findings of the habitat survey, the client was advised that further great crested newt, reptile and stone curlew surveys should be undertaken to ensure impacts on these species were fully considered. No great crested newts were found in any of the surveyed ponds, a population of grass snakes was recorded at one County Wildlife Site and a stone curlew nest recorded just to the north of the route.

phase 1 water pipeline

Adam contemplates an early bath

Subsequent advice on how to avoid the recorded ecological features allowed the client to opt for directionally drilling under the County Wildlife Sites.

Wild Frontier’s final report then summarised the anticipated ecological impacts for the purposes of planning. Tailored construction methods and seasonal restrictions to the work were advised based on the survey findings. Altogether the package of survey works and clear practical advice meant that the project was assessed to have a neutral ecological impact in the long term, fulfilling the client’s ecological obligations.

Bats in a barn conversion

bats barn conversion Adam

Adam installs a receptor bat box on a tree as part of the mitigation for a bat EPS licence

As part of the works under a bat EPS licence, WFE provided an ECoW service for the conversion of a barn complex in Hindolveston, Norfolk in 2018.  Survey work over the summer of 2017 identified the presence of common pipistrelle, soprano pipistrelle and brown long-eared bat roosts within the barns.

The ECoW service included a “Toolbox Talk” to contractors prior to commencement of works on the site to ensure awareness of protected species issues and their responsibilities while working on the site, direct supervision of sensitive works, and consultation to ensure the correct installation of mitigation and compensation measures on site.

During the course of the supervised hand-stripping of roof tiles from the barns, two roosting bats were encountered; one common pipistrelle and one brown long-eared bat.  On each of these occasions the Natural England bat licensed ECoW was on hand to

bats barn conversion pip

A common pipistrelle was safely translocated during an Ecological Clerk of Works supervised roof strip

carefully remove the bat from the works site, give it a health check and relocate it to a receptor bat box in a suitable location elsewhere on site. 

Due to the effective ECoW service provided this project ran smoothly in accordance with the terms and conditions of the EPS licence, resulting in the prevention of harm to roosting bats and effective mitigation and compensation measures being implemented.

 

Water voles on a County Wildlife Site

WFE have had a long involvement with a site in South Norfolk where fishery ponds had been excavated on a County Wildlife Site. As part of the remedial works for restoring fen habitat in the area, a large pond supporting water voles was to be filled in.  

water vole surveys

Water voles were trapped and relocated away from the construction area

WFE consulted an associate who was experienced in water vole mitigation, and we worked in partnership to provide water vole surveys and a mitigation licence for this work. This required habitat management (scrub removal) across the rest of the site to provide new water vole habitat. Once the licence was obtained the pond was fenced and water voles were caught using suitable trapping equipment. Trapped animals were moved to soft release pens elsewhere on the site. Following a period in which no water voles were caught, a destructive search was undertaken, and one further water vole was removed. Pond infill then took place, with no further water vole casualties. 

We have monitored the site post infill, and noted continuity of water vole presence across the site. The infill area is showing signs of returning to good quality fen habitat, with water levels at or around ground level throughout. Managed areas of habitat are being used by water voles.

Botanical surveys for A47 expansion

WFE were commissioned to undertake a botanical survey along a section of the A47 trunk road to assist in scoping for dualling the road. A previous survey by a different consultant in 2016 had considered some areas of habitat to be of county value. WFE botanists revisited these areas and a number of other blocks of land within the proposal’s corridor, and recorded all plant species present, rating them for abundance. Several locally scarce species were found, and their locations recorded.

Hedgerows were surveyed, and assessed for their likelihood of being an important hedge from the botanical information collected.

Each area of habitat was then evaluated for ecological value. The aerial photography record and old maps were consulted to further inform the historical provenance of each area. From this it was possible to see that some areas had been incorrectly assumed to be ancient woodland of county value, while another previously un-surveyed area was determined likely to be ancient by WFE. 

botanical surveys A47 expansion

WFE’s surveys found a previously unidentified area likely to be ancient woodland

NVC surveys of a SSSI

WFE was commissioned by Norfolk Wildlife Trust to conduct an NVC survey of an extensive SSSI in central Norfolk – Rush Meadow. This is a substantial area of swamp, wet woodland and species rich grassland recently acquired by the Trust. The NVC survey was required to inform management decisions and influence grazing and scrub removal.

The site was examined using aerial photographs, and divided into areas of homogeneous vegetation. These areas were ground-truthed and quadrat sampled over several visits. Although visits were undertaken in good weather, there were treacherous ground conditions across the site and copious biting insects – a bit like the jungle had come to Norfolk!

The data was analysed using a number of different tools, including the NVC volumes, constancy tables and statistical tools to provide satisfactory assessment of vegetation communities. The final maps show complex geographical patterning through the site, with several important vegetation communities demonstrably present.

NVC survey

The final NVC map of Rush Meadow SSSI showing the complexity of habitats on the site

Assessing invertebrates along a new road route

Wild Frontier Ecology was commissioned to provide an assessment of invertebrate populations along the route of a new road scheme in Norfolk. The entire route was walked and appraised for habitat quality, and subsequently four selected areas were investigated in depth for terrestrial invertebrate diversity.

assessing invertebrate populations

Invertebrates sampled are brought back for identification

Vacuum sampling, sweep netting, aerial insect netting and beating tray sampling were used to collect specimens. These were preserved and identified using the relevant literature and online resources.

Over 380 species of invertebrate were recorded across four selected sites along the route. The assemblages were analysed using the Pantheon online tool, and the sites were assigned a geographic value. This led to a balanced assessment and proposal of suitable mitigation strategies for the scheme, including potential net gain scenarios.

Arboricultural report for 10km pipeline in Thetford

A project to install a new water pipe around the perimeter of Thetford was being designed. Wild Frontier Ecology were able to survey all the trees, groups, hedges and woodlands along the route to provide maps of these features. Within the zone of influence of the development around 200 individual trees were surveyed, as well as around 30 groups/woodlands and more than 10 hedgerows. WFE appraised the arboricultural value of these trees and any potential impacts from the proposal. Possible impacts such as root damage and removal of trees/hedgerows were identified.  

Trees Thetford pipeline

An impact assessment was carried out for trees along the pipeline route

Using WFE’s findings, the scheme was designed to minimise the impacts on trees. WFE provided advice on suitable mitigation methods such as tree protection fencing and ground protection. Methods of construction, tree protection and on site ‘tool box talks’ were also advised to ensure the identified trees were protected throughout the project.  

By working with the client from the early stages, WFE were able to minimise arboricultural impacts without delays to development.

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