The question asked is "do microalgae cells talk to each other?" and if they do, "what do they communicate?". In the world of one-cell algae, communication is achieved through chemical compounds, produced by one cell and received by another cell of the same species or different species. In this project we wanted to know if cells of the same species communicated with each other to control their ability to survive and flourish. We found that they do. This is a remarkable finding that will change the way we interpret data from the ocean, where many microalgae species organize themselves in communities. As these algae make half of the planetÆs organic carbon (the other half is made by plants on land) understanding the factors controlling their abundance is great significance. Examples of microalgae diversity are shown in the images. To date the scientific understanding is that cells compete among each other for nutrients (or fertilizers) and that animals can feed on them, sometimes restricting their abundance. Phenomena such as harmful algal blooms or the quantity of food for animals are explained by these facts. The results of this project indicate that the relationship among cells can be more complex, and if so, we need to look at natural communities in a new light. Numerous experiments were performed in the laboratory, under controlled conditions, to first see if cells communicated, then to see how they communicated and finally to understand when they did. Several species have now shown the ability to communicate, indicating this phenomenon is widespread and not a rarity within marine algae, including species grown for commercial purposes. A Disclosure was filed with the Technology Transfer Office at the University of California San Diego as our discovery has potential for commercial applications. Under this Disclosure no details on the experiments can be provided at the time of the project completion. The Disclosure is also requiring a delay in publishing results in scientific journals. Once a provisional patent is filed, the results will be disseminated through established channels. In the meantime additional experiments are being performed in the laboratory to extend our understanding of this new form of communication among one-cell algae. Last Modified: 04/14/2014 Submitted by: Maria Vernet