chapter  21
19 Pages

Development and Application of Environmental Indicators in Sea

An indicator is used to show that a change has occurred, for example, in

chemistry, litmus paper turns red under acidic conditions. If we want to know

whether or not the wind is blowing we can look to see if the plants are swaying.

This is a good indicator of the wind. But what this tells us depends on who we

are and what we want to know. It may mean it is a good day for sailing or that

the weather is about to change. But it will never tell us why the wind is blowing

or what complex environmental changes are occurring to cause the wind to

blow. Indicators can tell us that conditions are changing, but it is up to us to

discover why and what we should do about it.