How to determine the water quality based Benthos in these waters one of them is with a qualitative approach where we look at the types than Benthos that live in the water itself. The types of benthic waters based on the degree of damage put forward by Mulyanto (1995) as follows:
a) waters clean is Planaria, Perla, Isoperia, Leuctra, Nemoura, Eodyonurus and Ephemera.
b) organic light polluted waters is Caenis, Ephemerella, Baetis, Limnophillus and Hydropsyche.
c) an organic medium polluted waters is Simulium, Lymnaea and Physa.
d) the weight of organic polluted waters are Chironomous and Tubifex.
Pictures. Planaria
The use of macrozoobenthos as an indicator of water quality is expressed in the form of biological indices. This method has been known since the 19th century with the idea that there are certain groups of organisms that live in polluted waters. The types of these organisms are different from the types of organisms that live in the waters are not polluted. Then by biologists waters, this knowledge is developed, so that changes in the structure and composition of aquatic organisms due to changes in habitat conditions can be used as indicators of water quality.
Of the few studies that have been conducted, benthic organisms to migrate vertically in the substrate. Causes of migration allegedly because several possibilities, namely:
a) avoid predators,
b) avoid the intensity of light reaching the base,
c) avoid the presence of contaminants on the substrate surface.
Benthos organisms can also be divided into two groups, based on his habitat, among others:
Infauna, zoobenthos groups of various sizes and bacteria that live in the bottom sediments, which are included in this group are worms and clams. Although living in the bottom sediments of this group has a body shape that can connect to the water is by using that resemble organ pipes or make tunnels in the sediment.
Epifauna, zoobentos group who live cheek by jowl with a rough or hard surfaces (such as coral reefs, shellfish and piles of sand) or on the surface of the bay. Belonging to this group are oysters, clams, mussels, snails, starfish, sea cucumbers
Pictures. Teripang
Based on the consideration and the description above, the method of sampling benthic organisms can be classified as follows
Method of colonization (container sampler or core sampler)
Methods trap (trap sampler)
capture method immediately (impedite sampler, like surbur and Eikman dragde)