Marine Biology

Introduction

Inter tidal areas having solid rocky bottom, large boulders and igneous rocks are called rocky coasts. Rock types may vary from the hard, impervious granite type to the more porous soft rocks such as limestone, sand stone and chalk. The softer rocks degrade more easily to form cracks, crevices and rock pools. Generally rocky intertidal shore will have steep slopes as the structures are like vertical structures. Rocks provide a hard surface on which marine organisms can attach themselves. When the tide is out, the rocks are exposed and during this period large number of organisms such as seaweeds and other attached organisms are visible to the naked eye of the observer. A unique characteristic feature of the rocky inter tidal shore is the formation of zonation by various organisms with varying capacities to tolerate dessication and predation pressure. Generally, rocky intertidal shores have three distinct zones comprising the ‘supralittoral fringe’ zone (splash or spray zone), ‘littoral’ ( mid- littoral) zone , and ‘sublittoral fringe’ zone.