Training Manual Application of Genetics and Biotechnology in ...

BIOREMEDIATION OF COASTAL AQUACULTURE WATER
K. K. Krishnani
Aquatic contamination - Health Hazards to aquatic animals
Aquaculture, particularly culture of tiger shrimp Penaeus nzonodon , has
extensively been practiced all along coastal regions of India. However, during the
past 20 years, there has been a revolutionary change in the aquaculture industry. The
increasing impairment of coastal water quality has affected the aquaculture
profitability in certain areas. The marine environment has become a dumping ground
for discharge of wastes of heavy industries carrying metals, chemicals, pesticides and
other hazardous pollutants, which is likely to result in deterioration of coastal water
(Sakthivel and Ramamurthy, 2003). Pesticides that are primarily of agricultural
origin may pose a serious environmental hazard because of their persistence, toxicity
and lipophilic nature (Krishnani, 1998). Heavy metals which are discharged from
electroplating industry, metal finishing, leather tanning and chrome preparation, to
coastal waters has got an adverse impact on the aquatic species as they are among the
conservative pollutants which are not subjected to bacterial attack or decomposition
and are permanent additions to the marine environment (Krishnani et al. 2003). The
pollution of soil and water with xenobiotics is widespread in the environment and is
creating major health problems.
Apart from xenobiotics, the culture of marine and brackishwater organisms in
aquaculture systems may result in metabolic loads in the ponds and may reach the
environment through drained waste. Accumulation of organic matter, solids,
nitrogenous compounds and other nutrients may cause stress and DO depletion,
which are unfavourable tb the animals but favourable to the disease causing agents,
particularly when the intake and drainage systems of the aquaculture farms are both
based on the same water source. The control of water quality is therefore the key
factor for success in shrimp farming. In general, effective management of water