Illegal aquaculture activities along with excess use of antibiotics have seriously affected life and livelihoods of the people around Chilika lake, the largest lagoon in Asia covering about a thousand hectare of land. It has also affected the rich ecological diversity of the lake.
The Chilika has over 400 vertebrates of both brackish and freshwater species, over a million migratory waterfowls and shorebirds gathering during winter, with several recorded as endangered and threatened and vulnerable species. A lake with a drainage basin of over 4,300 sqkm, it links with fisheries the lifeline of over a lakh fisher folks and contributes to foreign exchange balance through export of prawn and fish and tourism. Excessive population concentration in prawn culture areas over the years has brought a lot of pressure on the lake in terms of overfishing and extended agriculture in the lake margins. Along with marketisation and globalisation at the cost of local benefits, the national and global benefits have attained overriding importance.
It is important to note the changing aquaculture practices in this region. The lake provides an excellent brackish water environment with more than 6,000 hectare of area for prawn/fish culture which shares about 19% of the total available brackish water resources in Odisha. For centuries, the people of the region followed traditional methods of fishing. Prawn culturing in the lake is a relatively new activity, which stated during the early 1980s in a big way in and around the lake. large-scale conversion of traditional fishery sources has taken place after the advent of culture system of fishery. While diano and uthapani fisheries were converted to culture sources by non-fishermen and the Government, other fishery sources like bahani and jano areas were converted both by the Government and some primary fishermen cooperative societies either by themselves or through subletting to third parties. Under a programme for landless and rural poor, developed under the Brackishwater Fisheries Development Agency and supported by the State Fisheries Department, 1,550 ponds covering an area of 487 hectare were dug in the lake periphery. Several financial institutions invested over Rs 1.1 million in these projects. Besides, 165 private agencies developed their prawn farming projects in the lake through bank credit while 20 IRDP farmers were engaged in prawn farming under the Central Government's scheme "Area Development Approach Programme".
The Chilika had for decades been a steady source of livelihood for Scheduled Caste people residing in over 100 hamlets surrounding the lake in the districts of Puri, Khordha and Ganjam. The boom in the worldwide shrimp industry due to rising demand of shrimp exports was a golden opportunity for Indian industrialists and politicians to increase their foreign exchange earnings. "The indiscriminate use of chemicals and drugs, especially those which are banned have a negative impact on the environment and also incur penalties to the shrimp farming sector, including international trade difficulties arising from drug residues, the potential for loss of efficacy of prophylactics/ antibacterial agent and increased demand for and complexity of wastewater treatment. There is urgent need for sustainability in shrimp farming. The unscientific use of antibiotics, drugs and other pharmacologically active compounds has an adverse impact on human health and also the environment. Most of the countries importing marine products from us do not permit any residue level of banned antibiotics and chemicals. Therefore, from the export angle also we must ensure that the shrimp farmers do not use excess antibiotics, which have the potential to harm human health and adversely impact the environment," said SB Mishra, Chairman, Citizens' Action Forum.
Several 'aqua shops' in Odisha sell antibiotics, drugs and chemicals and other medical formulations unauthorisedly for shrimp culture, disregarding the ban on several of such products. Most of the products marketed are without label and any description of their composition/ usage.
The prawn industries in the Odisha coast and Chilika use feed and fertilisers for production of shrimps which get collected and accumulated at the bottom of the pond as waste known as sludge. Moreover, the higher export prices of shrimps are temporary and uncertain, but the losses in terms of the damage to environment and livelihood are of much more permanent in nature. Farmers usually expose their cultured organisms to medication regimes, for different purposes such as avoiding disease outbreaks and improving growth performance. There is high levels of a wide range of pharmaceuticals, including hormones, steroids, antibiotics and parasiticides in soils, surface waters and groundwater. "Aquaculture farms are sometimes abandoned by multiple problems and the soil from those farms remains hypersaline, acid and eroded. Therefore, those soils cannot be used for agricultural purposes and are unusable for long periods. In addition, the application of lime and other chemicals used in aquaculture to treat the soil can also modify its physicochemical characteristics, which could aggravate the problems," said Dr MR Dash.
(Written under the aegis of CSE Media Fellowship)