Below 8m the rocks are less well colonised partly due to reduced light levels but also due to the activities of the edible sea urchin which exists here in huge numbers. On its underside, the urchin has a beak-like mouth and as it steadily progresses across the rocks, the beak grazes the surface. Very few encrusting animals can resist this and many rocks remain bare as a result. However, this does mean that other creatures which occupy this area are more easily visible. The common topknot - a type of flatfish that lives exclusively on rocks - can be found here. It relies on total immobility to avoid detection and it is very easily overlooked. So confident is it that it will not be seen that it does remain still even when you are just centimetres from it allowing superb opportunities to observe and photograph it. The lesser octopus is often seen here and nowadays is extremely common due to the overfishing of cod which were one of its main predators. The grotesque angler fish is common in some years around this depth but again is a master of disguise as it lays in wait for its prey. Capable of swallowing fish up to its own size by inflating its body with water, these fish (which grow up to 25kg) are known on occasions to swim up to the surface and take sea birds with one powerful gulp!

Text and Images by Jim Greenfield.