Experimental Studies on the Ecology of Intertidal Environments at Heron Island. I. Exclusion of Fish from Beach Rock.

Abstract

The zonation of dominant organisms on the beach rock at Heron Island was reinvestigated following the work of Endean, Stephenson, and Kenny (1956) and three zoning algae were noticed. Field indications suggested the apparent sparsity of the biota was due to the browsing activities of fish.

Fish-proof enclosures were constructed, some containing browsing molluscs, and the fauna and flora therein were compared with the surrounding areas by means of detailed general observation, and by estimation of the chlorophyll concentration per unit area of surface. The results confirmed that browsing fish are the most important single controlling factor.