Introducing Ken and a new service..Intertidal surveys

Intertidal surveys focus on the zone that is exposed at low tide, and which is covered with seawater when the tide is high. Supporting an incredible range of habitats and species, the intertidal zone is a hotspot for biodiversity and forms part of an important ecological network around our coastline, much of which protected is by environmental legislation e.g. under designations such as Marine Conservation Zones (MCZs), Special Protection Areas (SPAs), Special Areas of Conservation (SACs), Ramsar sites or Sites of Special Scientific Interest (SSSI’s). Any plan or project which could impact upon the intertidal zone therefore needs careful consideration.

Below are some examples where intertidal surveys may be required:

• Assessing the condition of designated sites;
• To establish a baseline ahead of installation of infrastructure such as outflow pipes, cables or larger developments such as marinas, ports or harbours; or,
• To assess impacts after coastal installations and/or developments.

When undertaking an intertidal survey, the first thing to consider is the timing of survey, which depends to some extent on the habitat present.  Surveys of rocky shores and saltmarsh are best done in the summer when the algae and plants have had a chance to grow to facilitate identification and also to obtain a realistic estimate of cover. In contrast, surveys on sand or mud shores can be undertaken at almost any time of year but with consideration that in winter low water on a spring tide may not occur in daylight.  Surveys should ideally be undertaken around low water on a spring tide so that the maximum area of intertidal habitat is revealed.

Another consideration is in regard to taking samples – these are in the form of quadrats on rocky shores and saltmarsh but on sand or mud shores it would be necessary to take core samples if there is a requirement to precisely determine the sediment type and invertebrate community composition.

There are many health and safety concerns with intertidal surveys: e.g. being cut off by the rising tide; becoming trapped in soft sediments; or falling onto deep water to name just a few.  These can all be mitigated for, by working in pairs, wearing PPE such as lifejackets but crucially not entering areas that appear too risky to the surveyor – dynamic risk assessment is crucial.  On very large expanses of intertidal sediment, an amphibious vehicle such as a hovercraft or Argocat is helpful or indeed essential, not to mention being rather good fun!

Please do contact Burton Reid if you need (or think you may need) an intertidal survey and Ken will be more than happy to run through the process and discuss your requirements.