Ending trial-and-error aquaculture

Locals and tourists flocking to the coast to eat fresh shellfish may not know about costs and risks that aquaculturists encounter getting the seafood to the table.

One of the biggest issues for aquaculture farmers is selecting lease sites without knowing the physics and biology of the estuary environment, which can result in unpredictable productivity.

With more and better information, the industry could become increasingly sustainable, both economically and environmentally. Katie Coupland, a doctoral candidate in oceanography at the University of Maine Darling Marine Center, is working to make that happen.

Coupland’s mentor, assistant professor Damian Brady, describes her work as “beginning the end of trial-and-error aquaculture.”

“In aquaculture, we’re at a point where there isn’t enough information out there to decrease risk, so what we’re pursuing in the SEANET program is bringing new information to this field so we can make better decisions and decrease the risk,” Brady says.

“What’s really innovative about our approach is to take those same tools that we’ve been using for water quality and start applying it to the aquaculture industry, so that we can make viable predictions about a particular marine species and the environment.”

Coupland utilizes buoys, handheld sensors, computer models and biweekly boat trips to gather water samples that can improve understanding of shellfish growth in different areas of the river and understand the potential for climate to impact the aquaculture industry.

She does a lot of work on a computer in her lab, a small building nestled in the pine trees just up the hill from the Darling Marine Center’s boat launch. Coupland also regularly gets out in the field, or rather, in the water. During her river research cruise, she obtains data and water samples in additional locations over a much larger area.

“Just being out there and feeling — physically — the differences in temperature between the upper and lower river is a lot more meaningful than just seeing the numbers being read out from a buoy,” she says. “I love being out there in the field and seeing those differences firsthand and being able to get an idea and that instinctual feeling of how the system is different from the head down to the mouth.”

Coupland came to UMaine after earning an undergraduate degree in environmental science and management and a master’s degree in biological oceanography at the University of Rhode Island.

She enrolled in UMaine’s School of Marine Sciences to take part in the Sustainable Ecological Aquaculture Network (SEANET) project to learn numerical modeling, a skill that’s “applicable and has a direct impact on people outside of academia,” more specifically, the community and shellfish growers.

The Damariscotta River grows more than 50 percent of the oysters in Maine, which Coupland says makes it a great laboratory in which to learn about the economic value of shellfish aquaculture.

Coupland’s developing a water current model to estimate the temperature, salinity and the speed of currents in five estuaries of midcoast Maine. The information will enable her to know more about how changes in temperature and precipitation impact shellfish growth differently across the estuaries.

She’s also developing a water quality model to explore how nutrients and light penetration change based on the physics of the estuaries and how this affects algae and shellfish growth in the Damariscotta River.

To do the research, she uses LOBO (land/ocean biogeochemical observatory) buoys, which measure temperature, salinity and pH (acidity of the water), as well as nutrient and chlorophyll levels and turbidity (cloudiness of the water).

Because the models provide hourly high-resolution estimates of both the physics and the biology of the river, Coupland can examine short- and long-term responses to weather and climate change.

Optimally, her research will yield information about variables in aquaculture, which could bolster economic and environmental sustainability in Maine’s changing climate. All of which could help aquaculture farmers reduce their costs and risks as they work to supply seafood for diners on the Maine coast.

More information is on the SEANET website.

EPSCoR stands for the Experimental Program to Stimulate Competitive Research. It is a federal program directed at states that have historically received smaller portions of federal research and development funding. EPSCoR develops partnerships between its higher education institutions, industry, government, and others to effect lasting improvements in research capacity, innovation, and economic development. For more information see www.umaine.edu/epscor/