A novel method to achieve seeding density of cultivated dulse

What is the problem?Aquaculture is Agriculture, and globally the seaweed aquaculture business has an annual value of over $17 billion USD and is projected to grow at a rate of 8.2% (CAGR) over the next decade. Despite its value and potential to be an economic engine in coastal communities, the United States grows less than 0.1% ofcultivated seaweed. In fact, we import the majority of the seaweed consumed in this country. Most of these imports come from Asia, creating a trade deficit. While there is a nacent seaweed aquaculture industry here in the US, it is almost entirely focused on growing kelp, a large but relatively low value group of brown seaweeds. At the same time, there is strong global demand for dulse (Palmaria palmata), a red seaweed which commands a much higher price, as much as $96 per dried pound. Currently this seaweed is almost exclusively wild harvested from wave-swept points, and supply far outstrips demand. Unlike kelps which are relatively easy to cultivate, the life history of dulse was not well understood until the early 21st century and it has not been grown at commercial scale.The current barrier for commercial dulse production is in the nursery phase. Traditional seaweed cultivation methods often have an early-stage mortality rate of around 90%. This is primarly because the large amount of reproductive material needed also introduces biological contamination.Why does the problem matter?This is an economic opportunity to develop a lucrative industry and bolster our working waterfronts. There is unmet demand for dulse both domestically and as a potential export which cannot be met by wild harvesting. Currently, traditional methods for cultivating this seaweed from propagules remain unsuccessful due to low spore concentration and high contamination loads.How does this project address this problemThe overarching goal of phase I can be summarized in two workds: Concentration and Purification. In order to inoculate rope with dulse spores, we need to concentrate these spores shortly after release from a large volume of water. The main challenge whenever concentrating a solution is that it also tends to increase the number of biological contaminants - including bacteria and micro-grazers that feed on dulse spores. To achieve both of these goals we are going to investigate flow cytometry with in-line sorting to produce incredibly pure spore solutions. Originally developed to sort blood cells, flow cytometry has been adapted to isolate plankton from ocean water. To our knowledge this is the first time this approach will be used on dulse tetraspores.What should the outcome be?The primary outcome of this project will be a spore solution which is more concentrated than the origional, and which has had over 99.9% of all contaminants removed. Looking further downstream, this very pure, highly concentrated spore solution will be used to inoculate aquaculture lines in order to grow dulse at a commericial scale. We anticipate that purified, more concentrated spore solution will result in much higher spore survival rates, which means that we can grow a lot more dulse with the same amount of reproductive material.Why does the outcome matter?In order to grow dulse we need better cultivation methods. Our biggest challenge by far is that most spores die within the first few days and never grow large enough to be harvested. By concentrating and purifying the spore solution we should increase both the quality of the lines which go out to farmers as well as increase the number of lines we can seed at one time.