Every ecological assessment starts with a desktop study. But most ecologists are still doing it the slow way.
If you're an ecologist working in the UK — whether you're preparing a Preliminary Ecological Appraisal (PEA), scoping an Ecological Impact Assessment (EcIA), or doing pre-construction ECoW work — your desktop study is the foundation everything else builds on. Get it right, and you save hours in the field. Get it wrong, and you miss constraints that blow up timelines.
This guide covers every publicly available data source for ecological desktop studies in England, Scotland and Wales — what each one gives you, how to access it, and how to actually use it efficiently.
What Is an Ecological Desktop Study?
A desktop study is the first step in any ecological assessment. It involves gathering existing data about a site and its surroundings to identify ecological constraints before anyone sets foot on site.
A typical desktop study identifies:
- Statutory designated sites (SSSIs, SACs, SPAs, Ramsar, NNRs, AONBs/National Landscapes, LNRs)
- Non-statutory designated sites (SINCs, Local Wildlife Sites, County Wildlife Sites)
- Protected species records within a defined buffer of the site
- Priority habitats (Ancient Woodland, lowland heath, floodplain grazing marsh, etc.)
- GCN District Level Licensing Risk Zones
- Any other ecological constraints relevant to the proposed works
Under CIEEM guidelines, a desktop study should always be undertaken as part of a PEA, and the results inform whether Phase 2 surveys are required.
The Problem With the Traditional Approach
Here's how most ecologists do a desktop study in 2026:
- Open MAGIC Map. Search the site. Toggle layers on and off. Screenshot SSSIs, SACs, SPAs. Note Ancient Woodland. Check Priority Habitats.
- Open NBN Atlas. Search by grid reference. Filter by species group. Check bats, dormouse, otter, water vole, badger, reptiles, GCN. Note records, dates, resolution.
- Open Natural England's GCN Risk Zone mapping separately. Check Red/Amber/Green.
- If the site is in Scotland, open NatureScot Sitelink and repeat the designation search.
- If the site is in Wales, open DataMapWales and repeat again.
- Order a LERC data search (£100–375, takes days to come back).
- Compile all of it into a report.
This process takes 30–60 minutes per site. For a single PEA, that's manageable. For a corridor assessment along 20km of railway with 15 check points, it's a full day of mind-numbing repetition.
Every Free Data Source for Ecological Desktop Studies in the UK
Here's the complete list, organised by what they give you:
Statutory Designations
MAGIC Map
magic.defra.gov.uk
MAGIC — the Multi-Agency Geographic Information for the Countryside — is the main portal for statutory designation data in England. It's run by Defra and Natural England.
What it covers: SSSIs, SACs, SPAs, Ramsar sites, NNRs, National Parks, AONBs/National Landscapes, Ancient Woodland Inventory, Priority Habitat Inventory, SSSI Impact Risk Zones, Countryside Stewardship agreements and more.
Limitations: England only (despite claiming GB coverage, its Scottish and Welsh data is patchy). The interface is slow and clunky. No API access for batch queries. You can't easily search multiple locations at once.
NatureScot Sitelink
sitelink.nature.scot
Scotland's equivalent of MAGIC. Provides designated site boundaries, citations, and condition assessments for Scottish SSSIs, SACs, SPAs and other designations.
Limitations: Separate system from MAGIC. Different interface, different data format. If you work across the border you need to check both.
DataMapWales
datamap.gov.wales
Wales' geographic data portal. NRW publishes designation data through DataMapWales via WFS services.
Limitations: Again, a completely separate system. Requires different search methods and has its own quirks.
Natural England Open Data Geoportal
naturalengland-defra.opendata.arcgis.com
This is where the underlying GIS data behind MAGIC actually lives. Natural England publishes designation boundaries as ArcGIS feature services that can be queried programmatically. If you know what you're doing with GIS, this is faster than MAGIC.
Data available: SSSI boundaries, SAC/SPA/Ramsar boundaries, SSSI condition assessments, SSSI Impact Risk Zones, Ancient Woodland Inventory, Priority Habitat Inventory, National Character Areas, and more.
Protected Species Records
NBN Atlas
nbnatlas.org
The National Biodiversity Network Atlas is the UK's largest repository of publicly available biodiversity data. It aggregates records from hundreds of data providers including the BTO, Mammal Society, Bat Conservation Trust, local record centres and citizen science platforms.
What it gives you: Species occurrence records with date, grid reference, resolution, data source and licence type. You can search by location and filter by species group.
Limitations: NBN Atlas is not a substitute for a LERC data search. Many high-resolution records from local recording groups are held exclusively by LERCs under CC-BY-NC licences. NBN provides a useful screening layer but won't give you the full picture. Record resolution varies hugely — a 10m resolution record from a licensed surveyor is far more ecologically significant than a 10km citizen science record.
Licence note: Most records on NBN Atlas are published under OGL, CC0 or CC-BY licences which permit commercial use. A subset carry CC-BY-NC (non-commercial) licences. Always check the licence type before using records in commercial reports.
Local Environmental Records Centres (LERCs)
There are around 50 LERCs across the UK, each covering a specific geographic area. They hold detailed, high-resolution species records that often don't reach NBN Atlas. A LERC data search is still considered best practice for PEAs and should be obtained where possible.
Cost: Typically £100–375 per search depending on the LERC and search area. Turnaround: usually 5–10 working days.
Find your local LERC: alerc.org.uk
GCN Risk Zones
District Level Licensing Risk Zones
Natural England publishes GCN District Level Licensing Risk Zones as a separate ArcGIS layer. Zones are classified as Red (high likelihood of GCN presence), Amber (moderate) or Green (low).
This data is accessible through MAGIC Map, but you need to know which layer to toggle on — it's not immediately obvious.
Habitats
Ancient Woodland Inventory
Published by Natural England as part of the open data geoportal. Shows areas of Ancient Woodland (land continuously wooded since at least 1600 AD) and Ancient Replanted Woodland. Ancient Woodland is classified as an irreplaceable habitat under the NPPF.
Priority Habitat Inventory
Also published by Natural England. Shows areas of Priority Habitat as defined under Section 41 of the NERC Act 2006. Priority Habitats are habitats of principal importance for the conservation of biodiversity in England.
Flooding and Other Constraints
Environment Agency Flood Map
While not strictly ecological, flood zone data is relevant for ecological assessments — floodplain habitats, wetland connectivity, and water vole/otter habitat are all influenced by flood risk. The Environment Agency publishes flood risk data through the Flood Map for Planning service.
The Faster Way: Combining All Sources in One Search
The reason the traditional approach takes so long is that each data source lives on a separate website with a separate interface. You're essentially doing the same search — "what's ecologically significant within 2km of this point" — five or six times across different platforms.
What if you could enter a grid reference, postcode or coordinates once and get every designation, every protected species record, every GCN zone, and every priority habitat in a single search?
That's exactly what EcoCheck does.
EcoCheck queries Natural England, NatureScot and NRW designation layers, NBN Atlas species records, GCN Risk Zones, Ancient Woodland and Priority Habitat data — all live, in real time, for any GB location. Results come back in seconds, not minutes.
For linear infrastructure projects, the Corridor Search feature lets you paste multiple grid references along a route and get a complete constraints picture for the entire corridor in one go — perfect for rail ECoW work, highways assessments, or pipeline routes.
What EcoCheck Doesn't Replace
EcoCheck is a screening tool for desktop assessments. It does not replace:
- LERC data searches — LERCs hold detailed local records that don't appear on NBN Atlas. A LERC search should still be obtained for formal PEAs.
- Phase 1 Habitat Surveys — Desktop data tells you what's been recorded. It doesn't tell you what's actually on site today. A walkover survey is always required.
- Phase 2 Protected Species Surveys — If your desktop study or PEA identifies potential for protected species, detailed surveys by licensed surveyors are required.
- Professional ecological judgement — EcoCheck provides the data. Interpreting it, assessing significance, and making recommendations is your job as an ecologist.
Desktop Study Best Practice: A Checklist
Before submitting any desktop study, check you've covered:
- All statutory designations within your search buffer (typically 1–2km for a standard PEA, up to 5–10km for HRA screening of European sites)
- Protected species records from NBN Atlas or LERC search
- GCN District Level Licensing Risk Zone assessment
- Ancient Woodland Inventory check
- Priority Habitat Inventory check
- SSSI condition assessment for any SSSIs within the search area
- SSSI Impact Risk Zone check (for planning-related assessments)
- NatureScot data if the site is in Scotland
- NRW data if the site is in Wales
- Date stamp on all data sources consulted
Summary
The ecological desktop study hasn't changed in principle for decades — you still need to identify what's designated, what species are recorded, and what habitats are present before you go to site. What has changed is how efficiently you can gather that data.
Whether you use MAGIC Map, NBN Atlas and NatureScot individually, or use a tool like EcoCheck to combine them into a single search, the important thing is that your desktop study is thorough, properly referenced, and clearly identifies the ecological constraints that will shape your assessment.
Patrick O'Connor is a Freelance Ecologist at Kinterra Consulting and the developer of EcoCheck — an instant ecological desktop assessment tool for any GB location. Try it free for 3 days at ecocheck.co.