Oyster growers can now prove and track how well their farms benefit the local water supply thanks to a new tool from NOAA’s Connecticut-based Milford Lab.
The Aquaculture Nutrient Removal Calculator, which provides growers with a science-based estimate of how much nitrogen their farms remove from local waterways, will help farmers to demonstrate what scientists call the ecological services (nitrogen reduction capability) of their farms. The team behind the project, which included scientists from the Northeast Fisheries Science Center and the National Centers for Coastal Ocean Science, hopes that this will help farmers with the aquaculture permitting process.
“We hope this tool will provide growers and managers with an easy-to-use way to generate defensible values and context for the ecosystem services provided by a proposed or existing farm,” NOAA Marine Ecologist Chris Schillaci said.
“We’ve heard from both regulators and industry members that they need a simple, intuitive way to calculate the environmental benefits shellfish aquaculture provides,” Research Ecologist and project lead Julie Rose said. “We're excited to share our tool, which synthesizes data collected by excellent scientists from around the region, to create a robust prediction of nitrogen removal that industry members and regulators can have confidence in.”
The team said it hopes that the calculator will help quantify the well-documented benefits bivalves offer to water supplies. Lawn fertilizers, agricultural runoff, and other human activities are often responsible for excess nutrients in the water supplies of coastal communities; these nutrients can allow algae to grow out of control, causing a host of other problems, like low oxygen levels in the water, fish kills, and dead zones.
Bivalves like oysters filter feed on algae, cleansing coastal waters in the process. Oyster growers have long touted the ecological benefits of their work, but have not been able to track their farms’ individual contributions to water cleanliness till now.
To get an estimate of their farm’s contribution to nitrogen removal, shellfish growers input some basic information about their farm, including the number of oysters they are harvesting, the average size of harvested oysters, the location of the farm, the culture method that they are using, the period of harvest, and the oysters’ ploidy (whether they have two or three sets of chromosomes).
With this information, the tool will produce a report, complete with supporting citations which can be used in both federal reviews and state-level permitting processes. The tool’s results can also help shellfish growers educate their communities about the benefits of shellfish farming.
The project will continue to grow as NOAA seeks feedback from the shellfish aquaculture community on the tool, and as the research team incorporates new data as it becomes available. Future expansions to the project’s scope include incorporating data on phosphorus removal and expanding its scope into the Gulf of Mexico.
