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.