1 - Cochin University of Science and Technology

1. 1. Importance of benthos
Chapter I. Introdllclioll
As a result of the environmental complexity exhibited by the
shallow waters, the benthos of the region show different feeding habits and
constitute one of the major links in the marine food chain. Benthos play an
important role in the regeneration and recycling of nutrients between
pclagic and benthic realms, as they form an important source of food item
for the demersal fishes and an indispensable link to higher trophic levels
and provide food both directly and indirectly through the detritus food
chain for various micro-consumers at the lower trophic level. Food and
feeding habits of benthos differ mainly according to the substratum. There
are filter feeders, suspension feeders, detritus feeders, carnivores,
scavengers, and epiphytic grazers. Thus benthos with different functions of
this kind occupy a certain domain according to their contributions and form
a community in which certain species occur together in an area. The
benthos are important as indicators of the health of the habitat and play a
critical role as a major source of energy to economically and ecologically
important demersal fishes.
The concept of indicator species is of great importance in biological
monitoring and benthic invertebrates are recognised as useful tools.
Benthic invertebrates like Capitella capitella, Nereis caudata and Ba/anus
amphitrite have been identified as possible indicators to show the presence
of certain chemical substances in the marine environment. Therefore many
of them are treated as sentinel organisms and biomarkers in the assessment
of health of the marine ecosystem. Thus they are the pollution indicators
of marine environment because of their direct relationship with the type of
bottom and the physical nature of the substratum. Thus benthos may be
treated as sensitive indicators of the condition of accumulation of organic
matter and its nature in the sediments (Bordovsky, 1964). Apart from the
above, some of the macrobenthic organisms like gastropods, crabs, prawns,
etc. contribute well to the economy of the region.
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