A scientific study on atmospheric transport has revealed that a surprising number of micro-organisms have reached Bermuda in air that has travelled across the Atlantic Ocean.

The research, carried out by the Bermuda Biological Station for Research, plays an important role in the international study of atmospheric transport of land-based organisms and other particles over and into the ocean.

Scientists believe the micro-organisms eventually settle on the surface of the ocean and may be responsible for some diseases in marine organisms and even people.

Each year, winds in the earth's lower atmosphere transport several hundred million tons of soil dust over the Atlantic Ocean from North Africa. Studies in Barbados and other sites in the Caribbean have shown that microbes such as fungi and bacteria accompany this dust.

BBSR scientists Dr. Peter Sedwick and Dr. Tony Knap began the study in 2002, using the refurbished air-sampling tower at Tudor Hill in Southampton to collect the samples.

Last year, BBSR researchers undertook a weekly time-series study to collect and examine microbes in samples of marine air in an effort to discover how many of these micro-organisms reach Bermuda and to better understand their biological and chemical significance.

Dr. Sedwick and other BBSR researchers have been conducting ongoing laboratory analysis of the samples since the first round of sampling at the tower was completed in September, 2003.

“We found airborne microbes, including fungi and bacteria, to be far more numerous than we had expected, with as many as one million micro-organisms per cubic meter of air,” said Dr. Sedwick.

“This shows us that there is a very active transport of micro-organisms from North Africa to our area of the Atlantic Ocean.”

Based on these findings, Dr. Sedwick has submitted a proposal to the US National Science Foundation for further research.

He suspects airborne microbes may play an important role in the delivery of dust-derived iron to ocean surface waters. Fungi and soil-dwelling bacteria produce chemical compounds in order to capture iron.

These chemical compounds may, in turn, affect the biological availability of iron, which is an essential nutrient required for the growth of plants in the ocean, said Dr. Sedwick.

“The results of this research will bolster our ability to predict how the ocean will respond to future climate changes, such as changes in rainfall and atmospheric dust transport, and perhaps even alter these changes because of the influence that changes in the supply of iron may have on marine organisms.”