Madhuparna Bhattacharjee Zawya 10 Apr 11;
The rise in surface temperature of the Oman Sea has led to a 40 per cent decline in sardine landings in the past ten years, according to the data from the Ministry of Agriculture and Fisheries.
Due to the continuous rise in the surface temperature over the past 40 years and the development of zooplankton that consumes phytoplankton, fish stocks have been suppressed, the data said.
Speaking to Muscat Daily, Dr Sergey Piontkovski, associate professor at the department of Marine Sciences and Fisheries at Sultan Qaboos University, said, "The rise in temperature decreases the productivity of phytoplanktons in the stratified waters, as mixing is reduced, thus blocking the penetration of nutrients from the deep to the upper layers."
He said that in the Muscat region the plankton-consuming sardines comprise 50 per cent of the total annual landings in Oman.
Piontkovski with his team of researchers from various institutes and countries is currently working on a project to study the patterns in the Oman Sea and what might be expected in the next few decades.
"This is a strategically important issue for the country," he said revealing that the team has collected data from over 90 research expeditions, which will enable the scientists to evaluate term tendencies in any sort of changes in the sea. "The retrospective analysis of historical data on measurements will be complemented by 15 years of data on remote sensing of physical, chemical and biological characteristics of the Oman Sea."
In any sea, the physical, chemical and biological processes work in a complex way and in the long run are affected by climate change. At present, 'oceanographic satellite' images are enabling the scientists to monitor the region on a daily basis. "We receive images on sea surface temperature, ocean currents and red tide developments and analyse them on a day-to-day, week-by-week, month-by-month and also year-by-year basis," he said.
In the images, the concentration of phytoplankton is given in the form of colour spectrum, in which the blue range of colours identify low concentration. As the concentration goes up, the colour shifts from green to red. Chlorophyll is the indicator of the amount of phytoplankton in the water.
Piontkovski said that the rising sea surface temperature, decline in the oceanic primary production, dwindling fish stocks and expanding red tides are matters of great concern. "What we have to do is to understand what could be done to prevent this or how much more environmental management has to be optimised."
