The Star Early Edition
Ocean study shows decline in nutrients
A STUDY by a University of Cape Town researcher and international colleagues has found a 20 percent decline in the number of microscopic plants in the Indian Ocean over the past decade.
This is due to the surface of the ocean warming and its impact on fish, the study, published in the journal Geo- physical Research Letters by the Indian Institute of Tropical Meteorology, has found.
UCT researcher Marcello Vichi and other researchers contributed to the study which says the decline in microscopic plants could impact on food security in the Indian Ocean rim countries and the global fisheries markets in Japan, the US and several EU countries.
Vichi found this decline could affect the food chain, turning the biologically productive region into an ecological desert.
Primary production, the availability of organic compounds through photosynthesis by microscopic plants, is the basis of the marine food web.
The Indian Ocean, especially the western region, hosts one of the largest microscopic plant blooms in summer owing to the availability of nutrient-rich waters driven by the Monsoons, Vichi found.
He found the large-scale distribution of tuna and other fish are associated with the abundance of these microscopic plants.
“The ocean has absorbed the largest portion of the extra heat caused by increased atmospheric greenhouse gases,” said Vichi.