Can Seaweed Help Save the Planet?

            The Marion Natural History Museum’s focus on timely science and matters pertaining to the natural world was once again brought to the fore when the museum hosted Scott Lindell of the Woods Hole Oceanographic Institution on September 30. Lindell is a researcher whose primary interests are in finding ways to make the oceans a viable source for foods and fuel for the masses.

            Lindell presented significant evidence of the importance of exploring new food sources for both animals and humans as pressure from rising CO2 levels are now an everyday reality.

            A cornerstone of the researcher’s talk was just how the production and consumption of cattle and hogs negatively impact Earth’s delicate balance. At the very top of the list are beef cattle and hogs, reigning supreme in the need and use of land, fresh water, and feed. And then there are the gas emissions that add to the complexity of the problem. Livestock alone release a whooping 7.1 gigatons of CO2, or 15-percent of all animal emissions into the atmosphere annually.

            Seaweed produces none.

            From that platform, Lindell went on to discuss research activities he and others are exploring in an effort to come up with seaweed production and marketing strategies that are not only viable, but sustainable.

            The importance of this work also touched on the need to find new food source as human populations continue to grow, outstripping standard farming and food production methods. Lindell said projections now stand at well over 10 billion people living on Earth by 2050, roughly 3 billion more than today’s estimated population. The question is: How will the planet support the people?

            The production of seaweeds for foods is currently very small, Lindell pointed out, with U.S. consumption negligible versus Asian nations that consume 90-percent of seaweeds as a traditional food source. Marketing seaweed as food will be part of the answer, he said.

            Lindell shared that the U.S. government is pumping dollars into finding and funding seaweed farming techniques that can help with food demands from hungry animals of the four and two-legged varieties. Lindell said that presently the U.S. Department of Energy is supporting 18 projects with $50 million invested thus far. The projection for seaweed production for 2021 was 1 million pounds, not nearly enough for full-scale usage by man and beast.

            Lindell discussed some of the methods currently used to propagate seaweed beds as well as explaining the lifecycle of seaweeds.

            Each strand of kelp is called a “blade,” which can reach many tens of feet in length. The plant itself is a rather amazing life form, requiring both male and female spores (which start life as unisex cells) in order to produce the blades. These cells are called “gametophyte.” Once these have combined to create juvenile “sporophyte,” they are sprayed onto seed strings wound around cylinders and placed into the ocean farms.

            Lindell said the process of finding the best spores for propagation evolves over several growing seasons. The entire process has 10 steps, as he noted. Those are: spawn spores from blades, separate individual male and female spores, vegetatively culture, cross-select best males and females, apply baby blades to farm, plant, maintain farm from November to May, harvest and evaluate cross breeds, conduct genetic analyses, and select spores for the next generation.

            It is through this continuance crossbreeding process that the best kelp plants are produced.

            Another aspect of Lindell’s research is the concept of “sinking seaweed to capture or sequester CO2.” Here’s how that works. After the kelp spores are cultivated and sprayed onto the strings, those strings are eventually attached to ropes that are sunk to as much as 1,000 meters deep. They decay over time, not returning to the surface where they could rejoin the carbon cycle.

            There are questions as to the viability of sequestering carbon through kelp on a scale large enough to make an impact, but as Heather Smith of Sierra Magazine wrote in her June 20, 2021 article, “Seaweed farming has promise. In addition to sequestering carbon, it can provide habitat for fish and mitigate local effects of ocean acidification …[yet] the most effective way to sequester carbon is to not release it in the first place.”

            One question Lindell received from the audience was, what can we as individuals do to help mitigate the problem with CO2 and promote more aquaculture activities? Lindell responded that one of the biggest hurdles to farming at sea is going through a permitting process that can be cumbersome, expensive, and time-consuming. He suggested talking to and working with local licensing agencies, making them aware of the need to explore this type of food production and to find new ways to get licensing approved.

            Lindell said that in Maine and other commercial fishing areas, kelp farming can help support working waterfronts by creating jobs and sustaining boat owners when and where fish stocks may be depleting. He also suggested that anyone who hasn’t yet eaten a recipe that contains seaweed should try it. It might not be an acquired taste after all.

            To learn more about this and other research taking place at Woods Hole Oceanography Institution, visit For more information on upcoming presentations offered by the Marion Natural History Museum, visit

By Marilou Newell

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