Introduction
The Great Crested Newt (GCN) Survey and Mitigation Guidelines 2025 (GCN SMG 2025), authored by James Grundy, represent a comprehensive update to the longstanding guidelines first introduced in 2001. Developed in collaboration with over 100 ecologists, this document integrates decades of field experience, advancements in scientific methods, and evolving legislative contexts. The guidelines address critical challenges in surveying and mitigating impacts on Grear Crested Newt Triturus cristatus populations, with an emphasis on preserving biodiversity while accommodating development.
Context and Rationale
The original guidelines served the ecology sector for nearly 25 years but required modernization to reflect contemporary practices, such as the widespread adoption of environmental DNA (eDNA) surveys. This transition has notably reduced hands-on training opportunities for early-career ecologists, creating a field skills gap. The GCN SMG 2025 aims to balance traditional and modern methodologies, ensuring both practical applicability and robust ecological data collection.
Legislative Framework
GCNs are protected under multiple legislative instruments:
- Conservation of Habitats and Species Regulations 2017: Protects GCNs from deliberate harm and habitat destruction.
- Wildlife and Countryside Act 1981: Addresses intentional or reckless disturbance of GCNs and prohibits the sale of certain amphibians.
- Animal Welfare Act 2006: Mandates humane treatment of captured GCNs.
These laws emphasise the need for licensed activities when conducting surveys or implementing mitigation measures.
Survey Methodologies
Traditional Methods
- Leaf Fold/Egg Searches: Involves inspecting submerged vegetation for eggs, which are distinguishable by size and color. This method is crucial for establishing breeding site presence but must cease once eggs are identified to avoid unnecessary disturbance.
- Torch Surveys: Conducted after sunset using high-powered torches to observe newts along waterbody margins. Conditions such as air temperature and water clarity are critical for success.
- Bottle Trapping: While effective in certain conditions, this method is controversial due to animal welfare concerns and inherent data variability.
- Hand Netting: Useful for capturing larvae or adult GCNs in shallow waters, though it risks damaging aquatic habitats.
Environmental DNA (eDNA)
Since its adoption in 2016, eDNA sampling has become a preferred method due to its efficiency and minimal disturbance. By analyzing water samples for traces of GCN genetic material, this method can confirm presence or absence without requiring multiple site visits. However, it cannot determine population size, necessitating supplementary traditional surveys.
Habitat Suitability Index (HSI)
HSI assessments evaluate the quality of aquatic habitats based on factors such as water quality, shading, and terrestrial connectivity. While useful, HSI scores should not replace direct surveys for confirming GCN presence.
Mitigation Strategies
Mitigation strategies aim to balance development needs with GCN conservation. Key approaches include:
- Licensing Schemes:
- Natural England’s district-level licensing streamlines approvals by compensating for habitat loss through offsite mitigation.
- Site-specific mitigation licenses ensure tailored conservation efforts.
- Temporary Amphibian Fencing and Pitfall Traps: These physical barriers prevent GCN movement into construction zones, facilitating safe capture and relocation efforts.
- Habitat Creation and Management: Post-development, habitats must be restored or created to support sustainable GCN populations. Monitoring ensures long-term success.
Biosecurity and Best Practices
Biosecurity protocols, such as those outlined in ARG UK Advice Note 4, mitigate the spread of amphibian diseases and invasive species. Measures include:
- Using disposable gloves and disinfecting equipment.
- Avoiding unnecessary handling of amphibians.
- Ensuring proper disposal of survey materials.
Challenges and Recommendations
The guidelines acknowledge several challenges, including:
- The potential misapplication of eDNA and HSI data.
- Variability in GCN behavior linked to climate change, such as earlier breeding periods.
- The need for ongoing updates to methodologies and training resources.
To address these, the GCN SMG 2025 recommends:
- Regular review of legislative and scientific developments.
- Enhanced training programs for ecologists to build field expertise.
- Collaboration among stakeholders to refine mitigation techniques.
Conclusion
The GCN SMG 2025 serves as a vital resource for ecologists, developers, and regulatory authorities. By blending traditional methods with innovative tools like eDNA and aligning with legislative mandates, these guidelines promote effective conservation of GCN populations. The document’s practical advice and emphasis on sustainability underscore its role as both a reference and a training resource, ensuring its relevance in the evolving ecological landscape.
The new guidelines can be found here.
How we can help you with great crested newt mitigation
If you need assistance with great crested newts on your project including survey methods, district or traditional licensing please contct us on 02920 650 331 or enquiries@acerecology.co.uk