What are SSSIs?

Sites of Special Scientific Interest (SSSI) are protected areas within England. They are designated (legally protected) to maintain and protect a specific aspect of biological or earth heritage interest. The individual aspects that make the site special, and for which the site is designated are called features of interest. These features can be wide ranging from individual species of interest, both plant and animal, to habitats and geological formations of national or historical landscape importance. As the government’s adviser for the natural environment in England Natural England is the responsible authority for notifying and assessing the condition of SSSIs in England. Natural England notifies a SSSI when an area of land has features which are of special interest according to scientific guidelines which identity diversity of habitats, geology and wildlife. As of February 2023 there are 4127 SSSIs across England, with the number slowly increasing as new sites are designated. Across all these sites there are approximately 13,000 features of interest. More information on how these sites and features of interest are distributed across England , and the condition of these features can be found on the other tabs at the top of this page.

Why do we monitor sites?

Natural England (NE) undertakes monitoring to gather evidence on the condition of features of interest within SSSIs, alongside evidence on any pressures that may be affecting them. Undertaking this monitoring is the statutory function of Natural England for all SSSIs as well as other sites with different designations. Natural England use the evidence gathered to advise land managers, partners and stakeholders. The condition of SSSIs are also reported as a key metric in the government’s 25 Year Environment Plan and the Environmental Improvement Plan.

In particular, site monitoring enables Natural England to:

• Ensure that the right management is in place to deliver the best environmental outcomes on a site.
• Evaluate and improve the effectiveness of our interventions.
• Report on our corporate plan targets and statutory responsibilities.
• Contribute to our understanding of long-term changes in the natural environment.

Since April 1st 2023, Natural England produce a single condition for each feature of interest within a SSSI, using data gathered from across the feature's extent. Alongside this whole feature condition, Natural England can also assign conditions, if needed, to specific units where the feature is found. This will allow NE to record variation in a features condition across SSSIs, and better inform management through unit-specific comments.

Our Monitoring Tools

The tools we use for monitoring are listed below.

Monitoring specifications – These are documents that set out the monitoring parameters for each feature on the site. The monitoring specification provides the guidance and rational for surveyors to determine the condition of each of the features for which the site is designated. The variables that Natural England measure and assess for each feature (called attributes), are based on JNCC Common Standards Monitoring. Each attribute has an associated target, which is used to determine the condition of the feature. The attributes and the equivalent targets outlined in the monitoring specification, are tailored to the specific SSSI.

Common Standards Monitoring (CSM) – Guidance developed to provide an agreed approach to the assessment of condition on statutory sites designated through UK legislation and international agreements. This guidance is divided into habitat and species features with separate guidance for earth science features. This guidance is followed when completing a condition assessment. The JNCC CSM guidance is continuously being improved with the latest iteration produced in 2022, outlining the risk-based approach that should be adopted by all statutory nature conservation body’s (SNCBs).

Common Standards Monitoring Compliance – There are multiple common standards monitoring guidance documents, each tailored to different habitats or species. Within this guidance, some attributes are categorised as mandatory, where others are considered supportive attributes to take into consideration. If all the mandatory attributes, as outlined in the relevant JNCC CSM Guidance, have been addressed in the assessment, then the condition assessment is said to be CSM-compliant. If however, the assessment has not addressed all the mandatory attributes, then it is categorised as ‘non CSM-complaint’. Compliance is not dictated by data collection methodology, but only whether the mandatory attributes have been assessed or not.

Natural England field surveys - Information gathered by Natural England, is usually undertaken through field surveys using the monitoring specification as the basis for targets. The Natural England Site Survey (NESS) app is used to record survey data and upload it to Natural England’s internal database.

Desk-based assessment – In some scenarios, a desk-based assessment is undertaken to review the data available on a SSSI. This desk-based assessment involves the use of any available information including previous surveys, site visits, file notes or remote observations such as earth observation, moorland change map etc.

Data gathered externally – Natural England do not only rely on the data they gather first hand. Natural England use data collected by land managers and partners such as members of the Major Landowners Group, as well as evidence from 3rd parties including citizen science projects such as e.g. WeBS, BSBI, etc. Other sources of data may come from include Local Records Centres, local interest groups, or national biodiversity groups such as Butterfly Conservation, Amphibian and Reptile Conservation Trust etc. The data gathered by these external sources, contribute to the decision on condition made by Natural England.

Condition assessment - The results of field visits, specialist surveys and other data sources are used to assign a condition category based on the attributes and targets set out in a SSSI’s monitoring specification. The condition categories are: favourable, unfavourable recovering, unfavourable no change, unfavourable declining, partially destroyed and destroyed. Definitions for these conditions are provided in the glossary page.

Field data collection methods – When collecting data on species, more often than not, there is a species-specific survey technique that Natural England use. When data collecting for habitats however, there are three main data collection methodologies, used by Natural England when on-site. These are:

• Structured walk with pre-assigned stops

  The method involves planning a structured walk cross the feature’s extent, incorporating pre-assigned sample points, where detailed attribute information is gathered. This approach helps reduced bias and ensures data is collected from across the entire feature.

• Rapid Assessments

  The rapid assessment method requires a skilled surveyor familiar with common standards assessment methodology. This approach does not require a structured walk or preassigned stops. The surveyor's professional judgement is used and data on condition is recorded with a clear explanation of the reasoning behind the decision made.

• Random Sampling Approach

  In some scenarios, the structured walk approach isn’t applicable particularly if the feature extent is large or fragmented. Similarly, the rapid assessment might not be applicable as multiple survey groups are needed due to the extent/fragmentation of a feature. In this scenario, surveying staff can use a random sampling method to gather the required data. This is a pragmatic solution to undertaken large and complex site monitoring.