June 9, 2008
Lyon College News Bureau

Dr. Han Chuan Ong, assistant professor of biology at Lyon College, was a member of a research team studying the genetics of a toxic algae that forms large blooms in the Pacific and Atlantic oceans. Their work, published recently in the May 8 issue of BioMed Central Genomics, characterized the chloroplast genomes of two strains of the same alga.

Brown tides involving the Pacific and Atlantic strains of Heterosigma akashiwo are responsible for causing significant losses to fish hatcheries around the world, especially in the Pacific Northwest regions of the US and the coastal regions of Japan. For example, the devastating 1997 bloom in central Puget Sound almost led to a complete loss of the local salmon aquaculture industry. These deadly blooms are primed for another appearance in the near future – they bloom a few times each decade – as they last occurred in the Puget Sound area in 2006.

In the published study, the scientists reported that both H. akashiwo strains have small and large differences in their chloroplast genome sequences, possibly because of adaptations to different oceanic conditions. Whether the small differences in DNA sequence affect their bloom behavior remains to be seen. However, the most startling discovery is that their chloroplast genomes are completely shuffled and also contain large pieces of DNA of unknown origin, unlike the chloroplast genomes of other closely related organisms.

Presently there are no precise methods for predicting the formation of brown tides or methods to eradicate the blooms once they are formed.

The National Science Foundation and the National Institutes of Health funded this research. Other scientists involved in this project are from the University of Washington and Vanderbilt University.