Rocky Shores

Article | Updated 9 months ago

Rich red and grey rock piles or cliffs, which make up the rocky shore habitat, are found on many of the islands and along the mainland coastline of the Dampier Archipelago. These shores are affected by tides, becoming exposed to air and the sun when the water level drops. Rock pools are common in these areas, retaining water as the tide recedes.

Plants and Animals of Rocky Shore Habitats

Organisms that occupy the rocky shores are adapted to spending some period out of the sea due to the cycle of the tides. Generally, more species live lower down on the shore line, which remains underwater for longer periods of the day.

Many plants and animals inhabit rock pools that trap water as the tide goes out. Water temperatures in these rock pools rise as they are warmed by the sun and cool during the night. Therefore organisms that live in these pools must also cope with these changes in temperature.

Those animals left exposed on dry rock as the tide falls, such as periwinkles, resist drying out by retreating inside their shells or by moving into shaded crevices.

Methods for Sampling Rocky Shore Habitats

The sampling of organisms that live along the rocky shores is carried out when the tide is ebbing i.e. going out and the water level is low. During low tides, plants and animals are visible in the shallow waters and so can be counted, identified, or collected if further study is necessary.

Some animals hide under rocks as the water level drops to avoid predators and the risk of drying out. By turning over rocks, researchers can reveal the hidden organisms and record them. Researchers then replace the rock in its original position, to ensure the animals remain hidden.

As the tide drops, fishes may become trapped in rock pools, allowing researchers to identify or collect them.

Image of a researcher collecting specimens along a rock shore.

Researcher collecting specimens along a rock shore.
Image copyright Sue Morrison, WA Museum. 

Image of researchers collecting specimens along a rocky shores.

Researchers collecting specimens along a rocky shores.
Image copyright Sue Morrison, WA Museum. 

Image of Tetraclita squamosa, and Saccostrea cucullata.

The barnacle, Tetraclita squamosa, and rock oyster, Saccostrea cucullata.
Image copyright Clay Bryce, WA Museum. 

Image of the rocky shores of the Dampier Archipelago.

Rocky shores of the Dampier Archipelago.
Image copyright Clay Bryce, WA Museum. 

Image of the rocky shores of the Dampier Archipelago.

Rocky shores of the Dampier Archipelago.
Image copyright Clay Bryce, WA Museum. 

Image of the chiton, Acanthopleura spinosa, clings to a rock along the shoreline

The chiton, Acanthopleura spinosa, clings to a rock along the shoreline.
Image copyright Clay Bryce, WA Museum.