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Biological Factors


The environment affects the daily life of every organism on the shore. How individuals react to that environment affects their chances of survival.

Most creatures have quite specialised behaviours locked away in their nervous systems, so that they act appropriately when reacting to an environmental stimulus. If not, their chances of survival are diminished, and they may die.

Animals actively move toward a favourable stimulus and actively avoid unfavourable stimuli. Animals do not think and make decisions as humans do, but tend to react to stimuli in predetermined "locked-in" ways. Mostly this behaviour leads to a favourable outcome, but occasionally the behaviour is totally inappropriate for the occasion, and the animal dies. An example is when whales or dolphins strand themselves on a gently sloping beach and will not return to deeper water no matter how hard humans try to assist them.

Planktonic crustacean's daily activity consists of four periods. In the morning they rise towards the water's surface. As the day grows hotter, they sink to an optimum level. In the evening they again move upward towards the water's surface. After sunset, they gradually drift down in a passive state. This cycle is repeated daily.

Animals select sheltering places, hunt down desirable food, avoid harmful situations, search our favourable living places, select suitable mates to produce fertile gametes and avoid predators. The way an animal behaves has a major effect on its continuing existence.

Behavior is an extremely complex topic and is the province of animal behaviorists (usually from America) and ethologists (usually from Europe).


Bennett, I. (1987) W. J. Dakin's classic study: Australian Seashores. Angus & Robertson, Sydney.

Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. New Holland, Sydney.

Underwood, A. J. & Chapman, M. G. (1993) Seashores: a beachcomber's guide. New South Wales University Press, Sydney.

Biological Factors
Oxygen & Respiration
Food and Predation

Home Page
Rocky Shores
Tidal Levels
Intertidal Zonation
Environmental Factors
Biological Factors
Feeding Relationships


photo of Keith DaveyLife on Australian Seashores
by Keith Davey (C) 2000

Learning Consultant - Media
The University of Newcastle

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Scientific Consultant: Phil Colman
site created 01.01.98 : updated 01.04.2000