Several aquatic organisms cause damages to submerged surfaces. Since this infestation has an economical importance, several studies are being made. Marine sedantary organisms may affect piles, floats, wooden dry docks and boats. These organisms are called foulers. Most of these organisms are distributed all over the world through the agency of ships.
They are of economic importance, since fouling of ships results in increased resistance to movement through water, reducing the efficiency, low-ering of speed, increasing fuel consumption and leading to wear and tear of engine. The efficiency of underwater sound equipments fitted on to commer-cial and naval vessels is also seriously affeceted as result of the accumulation of fouling organisms.
Pipes and conduits used to convey salt water in ships, industrial plants, oil refineries, nuclear power plants and aquaria become clogged and the flow is interupted by the growth of these organisms inside the pipe. Thus the problem of fouling organims is serious.
Several factors are known to influence the settlement of larvae of fouling organisms. The most important of which is recognised to be the formation of the primary film. It is composed chiefly of diatoms and algal spores with a relatively small portion of bacteria. The thin filaments of algae may afford foothold on the substratum for the larvae to settle. The algae and diatoms serve as food for these larvae.
The most important members of the fouling community include algae and representatives from almost all the invertebrate groups and the tunicata. Among the molluscs the mussels are the most important foulers. They settle heavily, especially in the pipe systems carrying seawater and obstruct the flow of water. Among Arthopoda, the barnacles are the dominant representatives of the fouling community. There are over 100 species of barnacles as foulers.
1. Using copper sheathing on wooden hulls of boats.
2. Applying suitable antifouling paint.
3. Chlorination in condenser system.
Since time immemorial, human beings have used animals for food and other purposes. While some animals are very useful to mankind certain others cause loss to the economy of man. Though every organisms has its own im-portance in nature, some of them such as a few mammals, birds, fishes, prawns and insects have become valuable. Some pests are competitors of human be-ings for natural resources and food. Thus a study of economically important animals will always be useful.