Monitoring the coast

A rock fall along Stonebarrow cliffs east of Charmouth. One stormA rock fall along Stonebarrow cliffs east of Charmouth.Monitoring the quality of a coastal geological site such as the Jurassic Coast is, at one level, very simple in that the coast is maintained by erosion and therefore so long as continues to erode, it is likely to remain in 'favourable condition'. Therefore the construction of coastal defences is the greatest single threat to the Site. A secondary consideration is fossil collecting. As discussed before; rapidly eroding sites are more robust (and more productive) in terms of fossil collecting, while slowly eroding cliffs are more sensitive. Many of these more slowly eroding sections are high, towering cliffs and therefore they are very unlikely to be effected by, for instance, irresponsible collecting while many of the important fossils have already been collected, typically in the course of scientific study many decades ago or even during as far back as Victorian times when the Natural Sciences were of great interest to many.

Natural England's site information system (ENSIS) is used to assess site condition. It asks a series of basic questions that apply to the full range of geological sites, not just cliffs:

Attribute Target
Exposure of features of Interest The features of interest are exposed or can practically be re-exposed if required
Vegetation Vegetation is not obscuring or damaging the features of interest
Tipping or landfill There is no unconsented tipping or landfill obscuring or damaging the features of interest
Tree planting There is no unconsented tree planting obscuring or damaging the features of interest
Engineering works There are no engineering works, including inappropriate restoration works, obscuring or damaging the features of interest
Planning condition Planning conditions and restoration agreements or plans are being observed on site
Geological specimen collecting

There is no irresponsible or inappropriate specimen collecting

The Ussher Society field trip into the Undercliffs from Axmouth Harbour, January 2012The Ussher Society field trip into the Undercliffs from Axmouth Harbour, January 2012The World Heritage Site team aim to visit every part of the Site at least once every three year period. That said; some parts of the Site are completely inaccessible and entirely subject to natural processes (Old Harry Rocks for example) and therefore there is no need to visit as there simply is no threat. Other parts require more intensive monitoring; the decline in the quality and number of large ex situ ammonites on Monmouth Beach for example has been evidenced by regular visits coupled with a simple photographic monitoring programme. Accompanying academic field trips is another useful way to monitor the site. So far none have raised any specific concerns.

In addition to using ENSIS, the World Heritage Team also specifically monitor the Geological Conservation Review sites and has been supported by the Joint Nature Conservation Committee who produced a unique monitoring database using the GCR sites. The Site is very complex; in places several GCR sites may overlap each other and extend across more than one SSSI. But as the GCR defines the core values of the World Heritage Site, it is these interests that provide the best and most detailed way to monitor the Site.

The GCR sites for stratigraphy; the rock record, are the simplest to monitor as this is basically about looking to see if the full rock strata in the cliffs are exposed. The only real threat to this interest would be through the construction of coastal defences and as discussed above, that threat is now outlined over the next 100 years through the Shoreline Management Plan. It is possible for some strata to be obscured through landslides but that is a natural process; the very process that maintains the Site and would therefore not be regarded as a problem warranting 'unfavourable' status. Feedback from the Science and Conservation Advisory Network, other visiting scientists and the public is also a useful way to provide additional information on site monitoring.

The fossil interests are far more difficult to monitor. The area around Lyme Regis for instance is a GCR site for fossil reptiles, fish and insects, but it is impossible to assess this interest by any one visit or to determine what may have been found between visits. However, it is more than reasonable to assume that the interest is in favourable condition if the site is still eroding (i.e. not hidden behind coastal defences). The West Dorset fossil collecting code aims to record what is being found through the recording scheme as discussed above.

A limited number of claims have been made by a very small minority, that collecting effort means that in many parts of the Site the ammonite zonation can no longer be demonstrated but these claims have never been supported with any evidence or, for that matter, any specific site where the claim could then be examined. These concerns do not appear to be shared by the academic community; indeed most successful researchers are simply getting on with their work and further refining areas such as zonation, through painstaking and committed fieldwork on the Site. The core of the issue here is that the fossil interest cannot be assessed on any one day. If a survey were to be carried out in the summer months after a period of very calm weather, it may not be possible to find any fossils but if the same survey were carried out directly after a winter storm, the results would be very different. Furthermore people tend to see what they want to see; a rapidly eroding coastline with prolific fossils that are being rescued just in time or a World Heritage Site plagued by over collecting where everything of interest is hovered up as soon as it becomes exposed.

Dunscombe Cliffs east of Sidmouth in June 2005Dunscombe Cliffs east of Sidmouth in June 2005Dunscombe Cliffs in August 2006Dunscombe Cliffs in August 2006

Monitoring the geomorphological GCR sites is similar to the stratigraphy; they are driven by natural processes and so long as no sea defences are in place, they will continue to evolve naturally. More of a challenge lies with trying to record the events for which the coast is so famed; particularly landslides, cliff falls and storms. The strategic monitoring programme now provides a useful source through repeat air photography and LiDAR and the West Bay wave rider buoy which records wave height, period and direction. This information and more, is freely available through http://www.channelcoast.org.

The result of all monitoring along the coast, together with the work on coastal defences, the fossil collecting recording scheme and other discoveries along the coast, is combined into an annual State of Conservation (SoC) report. The SSSI site monitoring data is available on Natural England's 'Nature on the map' web site.