Essay on Algae as bio-indicators of water pollution
Bio-indicators are organisms or communities of organisms, their
reactions evaluate a situation, giving clues for the condition of the whole
ecosystem. Bio-indicators are used for assessing environmental health
and bio-geographic changes taking place in the environment, either
positive or negative, and their subsequent effects on human society.
Good bio-indicators provide measurable response (sensitive to the
disturbance or stress but does not experience mortality or accumulate
pollutants directly from their environment). It reflects the whole
population/ community/ ecosystem response and also response in
proportion to the degree of contamination or degradation. Bio-indicators
is in wide distribution and abundant and has a constant metabolism rate.
It is relatively stable despite moderate climatic and environmental
variability. Taxonomically, bio-indicators are well documented and
stable. It is easy for sampling, sorting and storage. Easily culturable in
laboratory. Low cost and man power effectiveness.
Algae are third most important group applied for monitoring
purposes after invertebrates and bacteria. They are suited to water
quality assessment as they are main primary producers in aquatic
system. They have greater sensitivity to pollutants than many other
organisms. And also respond rapidly and sensitively to environmental
stresses. They are easy to culture and use in assays which make algae as
a suitable bio-indicators of water pollution. Similarly, algae are valuable
indicators because of their nutrients needs, rapid reproduction and very
short life cycle. Sampling is easy and in-expensive which requires few
persons for assessment and has a lesser impact on other organisms.
Some examples of bio-indicator algae are listed below;
