Excessive growths of green seaweeds (often referred to as algal or seaweed blooms or "green tides") can cause many environmental problems, some of which are thought to be a result of toxins produced by the seaweeds. These toxins can dramatically affect other plants and animals; however, little is known about their production. Toxins that have already been identified include dopamine, and two breakdown products of dimethylsulfoniopropionate (DMSP): acrylic acid, and dimethyl sulfide (DMS). In this study, we will address the following questions: 1) What triggers the production of dopamine and DMSP? Are the amounts of these toxins constant or do they change in response to changes in the environment? Is production different in different seasons or in different places? 2) Where and how are these toxins produced and stored in the cells? 3) Why is dopamine toxic? Does it produce additional damage when it degrades to dopamine quinone? and 4) If new toxins are identified, what triggers their production and how do they work?
A better understanding of how seaweed toxins are produced and work will help determine if, when, and where seaweed blooms will affect marine communities or harm economically and ecologically important species. Because these seaweeds are found around the world, our results will apply beyond the Pacific Northwest. DMSP produced by phytoplankton is important in global sulfur cycles. Since DMSP production in seaweeds and phytoplankton are likely to be similar, knowing more about DMSP in seaweeds should result in a better understanding of DMSP in phytoplankton and, therefore, the role of DMSP in the global sulfur cycle.
Graduate and undergraduate training will be an important part of this work. At least three undergraduates and two graduate students will work on the study and will learn electron and fluorescence microscopy and chemical separation and identification techniques.
