"Although a record catch of nearly four lakh tons of oil sardine was registered in the state in 2012, a gradual decrease was recorded in the landings during the following years owing to the development of El Nino", said E.M. Abdussamad, scientist at CMFRI.
A sharp decline to about 46,000 tons was experienced in 2016 following a strong El Nino year in 2015. With the reduced intensity of El Nino, the sardine catch registered an increase in 2017.
The scientists at the CMFRI are of the view that as El Nino is gaining momentum, sardine stock in Kerala waters may be severely affected leading to a substantial drop in catch.
Though there was a marginal increase in the production of sardine in 2017 after a record-low harvest in 2016, once again the El Nino, which began to gain pace before the sardine stock revived to its normal level from an earlier depletion, may spell disaster for Kerala's fisheries sector with a dwindling catch, scientists said.
After studying the data of fluctuations in the production of oil sardine in last 60 years, the scientists at the Pelagic Fisheries Division of the CMFRI concluded that El Nino is the major factor that caused depletion of the oil sardine stock.
"The Climate Prediction Centre of the National Oceanic and Atmospheric Administration (NOAA), which is an international agency focusing on the conditions of the oceans, warned in December last year (2018) that El Nino is expected to strengthen during the coming seasons. The World Meteorological Organization (WMO) and Indian Meteorological Department (IMD) also stated that 2018 was an evolving El Nino year and that 2019 may be warmer due to El Nino and global warming", said Abdussamad.
He added that with the El Nino getting strengthened, the catch of sardine from the Kerala coast might decrease. Last year (2018) also saw a stagnation in the catch of sardine from the state compared to the previous year.
"Indian oil sardine is a sensitive pelagic fish whose biological cycle can easily be upset even due to slight differences in the ocean ecosystem. The impact of El Nino is more evident along the Kerala coast than other areas of the country. Hence, the fluctuation in oil sardine catch is always high along the south-west coast", he added.