Eroded rock crevices provide good hiding microhabitats for marine organisms.

The deep groove indicates that erosion is severe.

Rock pool may form on the hard shore. It keeps sea water even during low tide.

The rock pool may be quite shallow, in which case physical factors  

(e.g. temperature, salinity) fluctuate very much. 

Salinity may increase

to the point of saturation, then the pool liquid becomes brine

until finally salt crystals are formed.

This example indicates that physical factors fluctuate in smaller rock pools. 

It is a temporary microhabitat only. When physical conditions become too extreme,

organisms are unable to survive.

These rock pools do not hold a lot of life forms as they are easily dried up.

A relatively sheltered part of the rocky shore.

An exposed part of rocky shore.

Rocky shore organisms menu