A kelp farm is coming to Nantucket Sound as part of a scientific study to explore growing seaweed for a biofuel and food.
A lead scientist on the study, Scott R. Lindell at the Woods Hole Oceanographic Institution, said that they will start with planting a half-acre of sugar kelp this fall in the sound and expand to a full acre by fall of 2019.
The project is funded by the US Department of Energy to develop a farm model that could be scaled up to hundreds of acres, Dr. Lindell said.
“The initiative is to develop tools for fostering large-scale marine seaweed farming,” he said.
Another part of the local study is determining how to monitor the farm remotely using an autonomous underwater vehicle. That is where Erin Fischell, a robotics researcher at WHOI, comes in.
She will be modifying a Remus 100 AUV with a sonar system and a suite of sensors to take measurements and watch over the kelp farm with a “Kelp Cam” 360-degree camera attached. For example the robot could monitor how fast the kelp grows, nutrient flow, water qualities and equipment.
“The robot will be able to sense and respond to the environment,” Dr. Fischell said. “I hope it will be useful to people like Scott with this infrastructure.”
This automated farmer will offer a solution to managing acreage six to 10 miles offshore and monitoring it underwater, cutting down on the cost of manpower.
Dr. Lindell’s part of the project also includes working with geneticists at Cornell University to develop hardy strains of the seaweed more tolerant to warmer water temperatures. A strong strain would also grow quickly and contain more sugar. A two-step hydrolysis and then fermentation process convert kelp to bio-ethanol.
“We need to grow a lot of seaweed to make a dent in biofuel,” Dr. Lindell said.
Calculations show that offshore farm acreage would have to be on the order of the size of the state of Iowa to be able to replace biofuel produced by corn, which is 10 percent of the transportation fuel used. Corn has its disadvantage. Production takes up arable land that could be used to grow food, uses fresh water, and requires fertilizers and fossil fuel energy.
“It’s not carbon-neutral,” Dr. Lindell said.
Dr. Lindell described seaweed as photosynthetically more efficient than corn. It can grow in lower temperatures and in lower light. The seaweed season runs from November to April in this area.
Also the United States has a lot of space to grow kelp, with more than 95,000 miles of coastline. From land to two hundred nautical miles offshore is designated as the United States Exclusive Economic zone, he said.
Kelp farms may also make ecological sense. In recent years, kelp forests have been in decline, Dr. Lindell said. They provide a habitat for a number of species. Animals living around the farm will also be monitored by the AUV at the study site.
The total funding awarded to the WHOI researchers is $5,767,446 for a three- to four-year project.
The Woods Hole study is part of a larger study called MARINER (Macroalgae Research Inspiring Novel Energy Resources) funded by the Department of Energy. There are 18 MARINER projects nationwide covering both coasts and the Gulf of Mexico. Dr. Lindell said that he expects to be communicating with scientists in these other projects during the study.
The time is right, the two local scientists said.
“The technology is at a point that we can do it,” Dr. Fischell said. “We’re at a point where we can imagine things coming together in the next five years.”
Other countries such as China and Europe are also developing seaweed farm infrastructure and technology.
“They are well ahead of us,” Dr. Lindell said. “But this [project] could leapfrog us ahead.”