Marine Biology

Salinity

           It is also an important factor deciding the distribution of fouling communities. Many of the forms are stenohaline and some are euryhaline forms. The euryhaline forms representing the Estuarine algae and plants are euryhaline form. Many of the alagal species such as Enteromorpha,and Chaetomorpha are represented in the bottom of the boats which frequently visit estuarine regions. There are many forms such as mussels and barnacles which are strictly marine forms , which can however survive or tolerate the low saline conditions by some behavioural adaptations like tightly closing their valves for quite some time till the high tide resumes.

            Many groups of animals and plants are recognized as foulers. Even though they are from entirely different groups, they show some common characteristics. They are chiefly intertidal and are mostly sedentary when adult. These organisms together form a community, known as the fouling community. These attach in a clearly recognizable sequence to a particular substratum. This succession starts with the primary film constituted by benthic diatoms, various filamentous algae and bacteria. The subsequent succession varies according to conditions prevailing in each area. Usually Bryozoa appear next, followed by mussels, whereas in certain other situations, hydroids, barnacles, tube worms or tunicates attach at an early stage. Many other organisms join this community later to take advantage of the presence of the early settlers which provide shelters as well as food. The ultimate outcome is the establishment of a complex community of animals and plants. Those that settle in the beginning may not be represented at all in the final fouling community. The animals and plants that settle first may perish in large numbers, owing to the great struggle for space. Some, however, succeed and form a pioneer community. This provides a new environment which may then shelter the young ones of other individuals. Thus, step by step, the fouling community develops in numbers and in the variety of organisms represented changing from one type of community to another. In the end the slow-growing, long-living and larger species alone survive to represent the climax association of fouling organisms which may continue for a long period of time.