Sensitivity to human activities

Activities listed are those which influence, or are likely to influence this habitat and which are assessed in the UK marine SAC project review. The sensitivity rank may require amendment in the light of new information becoming available.

Sensitivity to:

Human activity



Synthetic compound contamination Uses: boats/shipping (anti-fouling)


The toxic affects of tributyltin (TBT) on molluscs, especially the dog whelk Nucella lapillus, are well-documented (Bryan et al. 1986, 1987). TBT was extensively used in antifouling paint specifically to kill marine fouling organisms. Unsurprisingly, it therefore had a major ecological impact. Very low concentrations of TBT can lead to the condition known as imposex (the development of male sexual characteristics) in dog whelks. Dog whelks are an important predator on rocky shores and their decline might be expected to have a profound effect on the rest of the community. TBT also affects mussels, an important space-occupying species on rocky shores and may therefore have important effects on community structure.

Synthetic compound contamination

Uses: boats/shipping (oil spills)


Modern dispersants have a low toxicity and are unlikely to do any more harm than the oil. However, since the oil will become dispersed into the water it may contaminate areas below the water level that were previously unaffected, unless it can be trapped and removed.
Hydrocarbon contamination Uses: boats/shipping (oil spills)


The sensitivity of a rocky shoreline to oiling is dependent on its topography and composition as well as its position. For example a vertical rock wall on a wave exposed coast is likely to remain unoiled if an oil slick is held back by the action of the reflected waves. Some shores are well known to act as natural collection sites for litter and detached algae and oil is carried there in the same way. On exposed coasts these sites are usually boulder/cobble beaches at the backs of bays or gullies which act as traps for the oil. As on all types of shoreline, most of the oil is concentrated along the high tide mark while the lower parts are often untouched. It is not long before the waves and tides that carried the oil onto the shore are gradually removing it again, but the rate of such weathering is dependent on weather conditions and shore characteristics. On a shore exposed to strong wave action a patch of oil will usually not remain there for long.
Changes in nutrient levels Waste: sewage discharge

Not sensitive

The effects of sewage discharge on high-energy rocky shores are negligible.
Abrasion Recreation: popular beach/resort


The effect of people simply walking on the shore can be damaging. This is particularly apparent when the topography of the shore causes people to follow a limited number of routes, leading to the appearance of paths characterised by reduced cover of fauna and flora (Fletcher 1997). Light trampling pressure has also been shown to damage and remove barnacles (Bronsan & Crumrine, 1994).

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