This project has two (2) overarching research objectives supported by four (4) strategies:
1) Conduct a spatiotemporal analysis of nutrient availability and crop characteristics for kelp farms in Casco Bay
a. Characterize relationships between observed nitrogen availability and the morphological characteristics of kelp on existing kelp farms in Casco Bay
b. Model spatial and temporal variability in bioavailable nitrogen throughout Casco Bay
2) Generate siting and harvesting recommendations for current and prospective kelp farmers
a. Explain how nitrogen incorporated into kelp tissue over a growing season compares to nitrogen dynamics both observed at specific sites and projected throughout the bay
b. Summarize observations about environmental conditions that support peak biomass or other desirable characteristics of kelp
The purpose of this project is to support value-added siting of kelp farms. Despite its popularity in eastern Asia, kelp farming is relatively new to the United States. In 2009 the first kelp farm was launched in the coastal waters of southern Maine. During the past 10 years, the number of kelp farmers in the state has risen from a handful to dozens but decisions regarding where to site kelp farms are still somewhat haphazard. Farmers currently take into account parameters like access to the coast, potential user conflicts, benthic composition, depth, and wave exposure, but very few, if any, are equipped with the instruments or methodology that allows them to consider the role that nutrients play in the growth and composition of their kelp. This is akin to a terrestrial farmer not knowing the nutrient composition of their soil or the fertilizing regime applied to their crop. Although not a plant, kelp is a primary producer and thus it requires ample amounts of nitrogen to produce biomass via photosynthesis.
Approximately 35 limited purpose licenses or standard leases for kelp aquaculture in Casco Bay have already been approved by the Department of Marine Resources. This is the highest density of farms in Maine and, likely, the entire United States. As such, a spatiotemporal analysis of coastal nitrogen data for Casco Bay will provide a large group of kelp farmers with substantially more knowledge about how the Bay’s nitrogen varies in space and time. These patterns in nitrogen dynamics can then be compared to observations of morphology and kelp growth at specific farms in the Bay to shed light on how farmers might increase net farm income through informed siting or harvesting. Results from this effort will also help to validate the ecosystem services offered by kelp farms (i.e. improved coastal water quality for fisheries and recreation). This information can be used by kelp farmers to promote the sustainability of their activities and influence future initiatives or policy around kelp farming activities.
I am currently conducting statistical analyses to examine the relationship between ambient environmental conditions and the morphology, biomass, and tissue composition of kelp cultivated in Casco Bay.
I have been working with Kyle Brennan, an undergraduate student at the University of New England, to identify relevant environmental datasets for Casco Bay that can be used in this project. We have beta-tested an approach for spatial extrapolation of this data and will work to incorporate the temporal component in the coming months.
We do not have results or a discussion to present at this time.
Education & Outreach Activities and Participation Summary
I have been contacted by 6 prospective kelp farmers or researchers for consultations related to this project.
From February 2019 – May 2019 I collected environmental measurements, water samples, and kelp samples from Casco Bay, ME that will be used to inform the modeling activities of this project. This sampling was conducted with kelp farmer Tollef Olson (Ocean’s Balance, LLC). This sampling effort was funded by National Science Foundation award #IIA-1355457 to Maine EPSCoR at the University of Maine but the collected data will be leveraged for this SARE project.
In January 2019, I gave an oral presentation sharing news of this SARE project with aquatic farmers, researchers, students, and governmental representatives at the Northeast Aquaculture Conference and Exposition in Boston, MA. I also engaged in numerous one-on-one discussions about kelp aquaculture and nitrogen dynamics in the Gulf of Maine.
In January 2020 I will share progress on this SARE project with aquatic farmers, researchers, students, and governmental representatives in one-on-one conversations and small-group breakout sessions at the Maine Aquaculture, Research, and Education Forum in Belfast, ME.
In February 2020 I will share project updates via an oral presentation at Aquaculture America in Honolulu, HI.
Grant applications building on this project
In the Spring of 2019 graduate students Gretchen Grebe and Caitlyn Cleaver, and Dr. Carrie Byron, submitted a research pre-proposal to the Maine SeaGrant 2020 -2022 Biennial Call for Proposals that built upon the preliminary findings developed through this SARE project. The proposal was titled “Co-Development of Research on Potential Water Quality Benefits of Kelp Installations along Maine’s Midcoast”. A full proposal was not encouraged but the reviewers’ comments helped to further steer the present project. The pre-proposal may be modified and resubmitted in the future.
Preliminary analysis of our data suggests that nitrogen dynamics may have less of an influence on the success of kelp aquaculture in Casco Bay than we originally thought. We are continuing analysis on the relationship between kelp biomass, nutrient dynamics, and other environmental factors measured at these sites.
Data acquisition has been more challenging than originally anticipated. The geographic and temporal scope of historical nitrogen data for Casco Bay limited the resolution of our preliminary modeling efforts. Weather and field logistics limited the number of sampling days completed in the Spring 2019.