Progress 06/15/17 to 02/14/18
Outputs
Target Audience:The target audience is aquaculturists, potential aquaculturists, shellfish farmers, shellfish constables, marine biologists, regulators, and all who are involved in shellfish production throughout the United States. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Multiple groups of stakeholders were kept in mind, and consulted throughout the Phase I project, and throughout the development of the Phase II project proposal. State and local regulators were contacted and consulted with through the planning process through direct meetings. Current and potential aquaculturists were consulted through direct meetings as well to help inform the Phase I project design, and to interpret and provide context for the results, and to help plan for future work. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Shellfish aquaculture in the United States has been expanding rapidly; providing jobs, promoting local economies, and yielding sustainable protein sources for a continuously growing human population. However, industry growth may be restricted in the future due to several issues which all directly relate to available food (microalgae) for shellfish growth. The issue is not that there is not enough microalgae available in most coastal and nearshore waters, as eutrophication and anthropogenic impacts have led to excess microalgae in many environments. The issue is being able to get the microalgae to the shellfish in a manner which matches their physiological demands. Shellfish are currently farmed using methods that are very risky (due to reliance on only nature-supplied water flow, and regular environmental disturbances, ie. harmful algae blooms (HAB), storms, etc.), which require large amounts of manual labor, and results in taking up large swaths of coastal water bodies which lead to stakeholder conflicts and a lack of space for expansion. The SBIR technology being developed presents a novel system for growing shellfish from seed to market within a modular platform, where ideal water flow and desired environmental characteristics are controlled, which results in greater yields, higher efficiency and reduced risk. Phase I findings The Phase I effort focused on two main objectives to evaluate the MAP concept: biological viability, and monitoring capacity. To evaluate the biological viability of the system throughout the culture cycle, four distinct trials were performed, with both eastern oysters and bay scallops, each for 30 days in June, September, October and November, 2017. Upwellers and downwellers have been demonstrated to be effective in shellfish aquaculture, and are standard industry protocol from shellfish size 1 mm through 30 mm. However, shellfish have never been raised to market size in an open-water system where flow is manipulated, and therefore, the shellfish utilized in the experiments were all between 30 mm and market size (75-90 mm). In each of the trials, the shellfish were stocked at three different densities relative to standard industry stocking densities (1X), and either 5 times greater (5X) or 10 times greater (10X), and deployed in either APDI bags in bottom condo cages (standard industry protocol), or in a tray within one of the tray packs within one of Ward Aquafarms' downweller systems. After 30 days, the ADPI bags were retrieved and the tray packs were removed from the downweller. Both bay scallops and oysters were analyzed for survival, shell height and volumetric increases. In all trials, the oysters and bay scallops were stocked at up to 10 times normal stocking density, and regardless of treatment, survival was very high (>90%), and no statistically significant differences were observed in mean percent survival in any of the trials for bay scallops or oysters (ANOVA, α=0.05, two-tailed P-value= 0.5111, R2= -0.02992). This means that if dissolved oxygen and food availability are kept high by increasing flow, both oysters and bay scallops can be cultured at a much higher density that was is standard industry practice, which can lead to much greater efficiency. Throughout all of the four bay scallop trials, the overall finding was that the 5X downweller treatment outperformed all other treatments consistently throughout the size range sampled from 27.2 mm - 45.4 mm. For example, in the first trial the bay scallops in the 5X downweller treatment had a mean growth rate of 0.20mm/day (SD, 0.21), which was significantly greater than all of the other treatments (α=0.05, Wilcoxon Ranked Sum, P=0.00028, df=5). At the conclusion of the fourth trial, the shell height of the bay scallops in the 5X treatment was 42.2mm (SD, 4.5), which was significantly bigger than the shell height of the bay scallops in the 10X bags, 5X bags, and the 10X downweller treatments (Tukey HSD, α=0.05, df =5, 174, P =0.0000752). This means that through overwintered market size, bay scallops can be grown at 500 per m2, which is 5 times greater than standard industry stocking densities, given the flow is increased and food and dissolved oxygen concentrations are sufficient. Throughout all of the four oyster trials, the overall finding was that there were no differences between the oyster downweller treatments, and that volume is the limiting factor when increasing flow to maintain optimal conditions. For oysters at the conclusion of both the first trial and at the end of the final trial, neither the mean growth rates of the oysters (ANOVA, α=0.05, two-tailed P-value=0.7159, R2= -0.0119), nor the final mean shell heights of oysters vary between treatments (ANOVA, α=0.05, two-tailed P-value=0.791, R2= -0.01474). The oysters could be stocked as high as 1,500 m2, which is 10 times higher than what industry practice for standard extensive ambient flow culture, without any reduction in growth or survival. However, the tray volume of 0.3 m3, was almost completely filled at the end of the final trial, and even though the lack of significant growth rate differences would indicate that stocking density could be increased, at the current flow rate, and food and dissolved oxygen, the volume available has been maximized. Increasing the stocking density requires greater vigilance over the system to ensure that the animals are consistently supplied with ideal growing conditions. To that end a cloud-based software platform was developed, which can store incoming environmental data, display it to the farmer and send alerts to the farmer based on user-specified thresholds. The testing downweller was equipped with 4 YSI EXO3 sondes (1 incoming water flow, three silos exiting water flow), which each measure water temperature, dissolved oxygen, and chlorophyll a (food availability), and 4 Flo-Tec flow velocity meters (1 incoming and three silos exiting water flow). From June through December of 2017, Ward Aquafarms collected real-time water condition data at the downweller using the sensors, which was then sent through a NexSens X2 data logger, over Verizon cellular to be stored remotely in the cloud. Ward Aquafarms setup a data repository on a Amazon Web Services (AWS) account, which also stores the app code to display the data to the user. Working with a software consulting firm (Zco, Nashua, NH), the app was developed for iOS to monitor chlorophyll, temperature, dissolved oxygen, and flow rates. The app is simple to use, bug-free, and can be downloaded from the Apple App store for free with a link supplied by Ward Aquafarms. Following the splash screen, the main screen shows the different incoming data streams, and the user can click on the dots above to switch between sensor (incoming, or the 3 different silos). The next available screen is the graphing function for either 24, 48 or 72 of the most recent hours, which is automatically re-scalable given the data to be displayed. The final screen is the settings, where the user can set thresholds for each of the different water parameters, set the number of alerts, frequency, and either through email or text.
Publications
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