Thiruvananthapuram: An ongoing study by the department of aquatic biology and fisheries of Kerala University has found that pollution in the Amayizhanjan canal has destroyed the ecosystem of Akkulam-Veli lakes . This has led to the mass destruction of fish wealth , an alarming decline in oxygen levels in the water, and an excess presence of microplastics in fishes. The study found that the polluted Amayizhanjan canal water reaches the lake through Paravathyputhanar, making it the most polluted lake in the state.
There were 35 fish varieties in the lake and it has now decreased to less than 10. The level of oxygen is zero in most parts of the lake. The average oxygen level in much of the area of the lake is below 4 mg/litre of water.
This is the minimum oxygen level required for fish growth. Polluted water from the Amayizhanjan canal has brought a wide variety of nutrients, which are conducive to the growth of water plants, to the lake. As a result, water plants grow exponentially, and the level of oxygen has come down drastically, the study has found.
The study team also traced over a hundred microplastics in fish samples collected. This is the highest number of microplastics ever recovered from fish samples in the state. The number of people who used to fish from the lake was over 50 some 20 years ago, but it has now decreased to less than 10.
The lack of fish wealth has forced them either to give up fishing from the lake or to shift to other jobs. Since the taste of the fis.