Professor Christopher J Gobler. (Photo: SOMAS/Miriam Godfrey, NIWA)
Vitamins may advance harmful algal blooms: study
Monday, December 06, 2010, 00:30 (GMT + 9)
Vitamins B-1 and B-12 may promote harmful algal blooms (HAB’s), according to a study by Stony Brook University scientists recently published in Proceedings of the National Academy of Sciences (PNAS).
Professor Christopher J Gobler, PhD, research scientist Ying Zhong Tang and PhD candidate Florian Koch of the School of Marine and Atmospheric Sciences at Stony Brook ran experiments to learn whether the species of phytoplankton that constitute HAB’s need B-vitamins to develop. The blooms are formed by phytoplankton and adversely affect coastal ecosystems and fisheries across the globe, costing the US alone hundreds of millions of dollars yearly.
In recent decades, HAB’s and their effects have worsened.
Most research has concentrated on chemical nutrients such as nitrogen and phosphorus as the cause, and “the importance of coenzymes and particularly vitamins (vitamins B-1, B-7 and B-12) in regulating and stimulating harmful algal blooms has rarely been considered,” the researchers wrote.
“[HAB’s] can harm humans by causing poisoning from shellfish contaminated with algal toxins and can damage marine ecosystems by killing fish and other marine life,” Gobler said. “The distribution, frequency and intensity of these events have increased across the globe and scientists have been struggling to determine why this is happening.”
Every US coastal state suffers from harmful algal blooms, he told.
“New methods have recently been developed to measure concentrations of vitamins B-1 and B-12 in the ocean and we discovered that vitamin levels were co-varying with the occurrence of HABs,” Gobler continued.
The scientists looked at more than 40 harmful algal bloom species in the laboratory and said that all but one of the species tested (96 per cent) required vitamin B-12 to grow, and that 20 of 27 (74 per cent) required vitamin B-1. Further, the toxic algae was found to need higher concentrations of vitamins B-1 and B-12 than those reported in the past for other phytoplankton.
Scientists found that the concentrations measured as needed for growth correspond to vitamin concentrations observed in coastal waters, implying that HAB demands for vitamins may deplete their available supply in hours to days, they said.
The vitamin requirements of HAB’s were larger than expected partly because most such blooms are caused by algae called dinoflagellates, which often devour large organic molecules like amino acids and proteins which are similar to vitamins.
“Vitamins are among a suite of organic compounds dinoflagellates exploit for growth. Since dinoflagellates are notorious for the ability to form HAB’s, this study suggests vitamins are key organic compounds that may influence the occurrence of HAB’s of dinoflagellates,” the authors wrote.
But discovering the chief source of vitamins to HAB’s may be challenging, Gobler warned.
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By Natalia Real