Rocky Shores

Exposed Rocky Shores

Two shores: on the left is one very exposed to wave action; right, a very sheltered shore. Note the high density of barnacles on the exposed one. See the Ballantine Exposure Scale

Usually face into the open sea and the prevailing wind. This means they generally have bigger waves than sheltered shores which face away from the open sea and the prevailing wind. The prevailing wind in Britain is from the south-west and so here on the west coast of Wales our exposed shores are usually on south to south westerly facing shores and our sheltered shores are usually on north to north easterly facing shores. South to south westerly facing exposed shores get more sunlight than sheltered ones, are more susceptible to desiccation and in general are not hospitable places for most inter-tidal organisms. Because reality is never as simple as we imagine there are exceptions. Off-shore reefs or islands for example can shelter shores that would otherwise endure heavy wave action.

On a flat calm day in mid-summer an exposed shores can be idyllic but have a look at the species living here:

• Splash Zones can be enormous - the more waves the higher the splash zone goes
• Dominated by species that can cling on tight: limpets, barnacles, mussels
• Few seaweeds
• Zonation is often clearer on exposed shore as the species stand out more
• Biodiversity can be low
• Biomass is low

Find out more about the zones by clicking below: