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Status of Ongoing
Research
Since 2004, the Central Marine Fisheries Research Institute has undertaken pioneering research on the impact, adaptation and vulnerability of Indian marine fisheries to climate change under the ICAR Network Project. A brief summary of 8 years of research is as follows:
- There were marked spatial and seasonal differences in SST anomaly within each state. Among other parameters, seasonal wind speed has strengthened in several regions, and chlorophyll concentration has increased during southwest monsoon along Kerala coast.
- From a large amount of data collected along the entire Indian coast on climatic, oceanographic parameters, fish catches, biological characteristics, changes in distribution and abundance, phenology, especially spawning of important fish stocks are evident. In general, low value, small sized, short-lived species with quick turnover of generations such as oil sardine and mackerel are able to adapt to seawater warming by extending their distributional boundaries to northern latitudes. About 20% of fish in the Indian seas fall under this category. The mackerel, being a tropical fish, are expanding the boundary of distribution to depths as they are able to advantageously make use of increasing temperature in the sub-surface waters. Hence catches in the bottom trawl are increasing.
- SST between 27.5-28.00C may be the optimum for thread fin breams and when the SST exceeds 28.00C, the fish shift the spawning activity to seasons when the temperature is around the preferred optima.
- Impact of climate change on the three major lake systems Vembanad Lake (Kerala), Chilka Lake (Orissa) and Pulicat Lake (Tamil Nadu-Andhra Pradesh) was studied. Results point that spawning will be moderately affected in Vembanad Lake, mild–moderately in Pulicat Lake and strongly in Chilka Lake.
- An increase in SWT beyond 100C reduces the hatching rate, larval survival of Cobia and Pompano. The hatched larvae had deformities.
- Vulnerability of corals to climate change will result in the following changes
| Region |
Decade at which corals begin to decline |
Decade at which corals would be remnant |
| Andaman |
2030 - 2040 |
2050 - 2060 |
| Nicobar |
2020 - 2030 |
2050 - 2060 |
| Lakshadweep |
2020 - 2030 |
2030 - 2040 |
| Gulf of Mannar |
2030 - 2040 |
2050 - 2060 |
| Gulf of Kachchh |
2030 - 2040 |
2060 - 2070 |
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- CO2 emission by marine fishing boats has been estimated. It is found that the emission has increased substantially in the last 30 years due to increase in number of fishing boats and mechanization. Highest CO2 emission (as tonnes per t of fish catch) was by trawlers (1.2), followed by mechanised boats (1.1), dolnetters (0.96), gillnetters (0.93).
The vulnerability of the coastal districts of Maharashtra, Kerala and Tamil Nadu was assessed to climate change using indicators demography, infrastructure, occupation, climate variabilites and fishery. Raigad and Thane in Maharashtra, Alappuzha and Kozhikode in Kerala, Ramnathapuram and Tirunelveli in Tamilnadu were found to be the most vulnerable.
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