Biodiversity & Conservation

To assess the sensitivity of the biotope, the sensitivity of component species is reviewed. Those species that are considered to be particularly indicative of the sensitivity of the biotope, and for which research has been undertaken in detail are shown below (see selection criteria). The biology of other component species of the biotope is also taken into account wherever information is known to the researcher.

• Pholas dactylus
• Barnea candida

Laminaria digitata and Pholas dactylus are the key structuring species and also give the name to the biotope. The fronds, stipe and holdfast of the kelp plants create structural complexity within the biotope. The piddock Pholas dactylus is a key structuring species because of the refugia provided by the holes it makes. These have been known to increase species diversity (Pinn et al., in press). The burrowing polychaete Polydora ciliata is functionally important because tube building can modify the substratum and in areas of mud tubes can agglomerate, forming layers of mud that can sometimes be thick enough to eliminate the original fauna and flora, or at least can be considered as a threat to the ecological balance achieved by some biotopes (Daro & Polk, 1973). The understorey of red algae in the biotope is represented by Palmaria palmata which is frequently found both on rocks and sometimes on older Laminaria digitata stipes.