A strong, salty sea breeze blows past large blue tanks on the coast of Yerseke near the Royal Netherlands Institute for Marine Research (NIOZ). Marine biologist Klaas Timmermans is experimenting with growing sustainable fish and shellfish in these tanks. “Here, grab it, it doesn’t bite,” says the marine biologist, lifting the lid of a tank and taking out something shiny.
It is not a fish, but a smooth, brown strand of seaweed about one meter long. It feels like a plastic shopping bag. “This is brown seaweed, Saccharina latissima, it contains a lot of sugar and more protein than milk. Brown algae contains about 10 percent protein, cow’s milk about 3.5.”
Seaweed is becoming an important protein source for humans, if it’s up to him. Timmermans: “Now we consume seaweed sparingly. For example, E number 406, agar-agar, is used in some brands of chocolate milk and in some toothpaste to create a gel-like texture. And most people know seaweed from sushi.”
But seaweed can play a bigger role in our diet, says Timmermans: “Only 1 percent of our food comes from oceans, while around 70 percent of the earth is covered by oceans. And we don’t eat the food that comes from the sea efficiently. The healthy fatty acids in tuna, for example, come indirectly from algae. To grow one kilogram of tuna, approximately ten thousand kilograms of algae are needed. The lower you eat in the food chain, the less food is lost. Plus, I don’t need pesticides here, and I didn’t have to cut a jungle for this.”
Like a potato farmer
Since 2012, Timmermans and colleagues have been researching the reproduction of seaweed, among other things, to see how they can grow young seaweed plants with the right properties. “Just as a potato farmer wants seed potatoes with certain characteristics, a seaweed farmer wants to grow seaweed with, for example, as much protein as possible.”
Seaweed reproduction is complex, explains the biologist: “They do not reproduce with flowers and seeds. More like ferns. Mature seaweed may decide to form spores in the leaf. These are microscopic, round cells and are found in the bright spots in seaweed.”
He points to light spots in the dark brown stripe, a few centimeters in diameter. Spores grow into male or female gametes. These are called gametophytes and can live individually in the water for a while. After a while, a gametophyte fertilizes a female cell and new seaweed is created. It then grows through photosynthesis, just like plants.”
The darker the sea lettuce, the more protein
Klaas Timmermans Marine biologist
By breeding, collecting algae of different genetic origin, Timmermans and his colleagues try to get algae with ‘better’ properties. Until now, this only works with brown algae and green algae. Not yet with red algae.
Inside the tanks, Timmermans and his colleagues check the amount of turbulence, nitrogen, light and temperature to investigate under which conditions different species grow best.
How will seaweed farmers grow seaweed outside such tanks, at sea? Timmermans: “On a line under water. The practicality is that tang has no fear of commitment. Small, newly born seaweed plants attach themselves to everything, even a thread that a seaweed farmer can stretch out into the sea. We can grow small plants here in the laboratory, and they can grow up to two meters in seawater.”
Thick cell walls
But it sounds easier than it is. Before seaweed can be marketed on a large scale, marine biologists still have a number of problems to solve. The first is that proteins are difficult to obtain from seaweed. The marine biologist opens another tank and fishes a green line from it. “In sea lettuce, Ulva lactuca, contains not less than 10 to 15 percent protein. This one is a nice dark green. The darker the sea lettuce, the more protein.” Only: seaweed has thick cell walls. This makes it difficult to extract protein from seaweed. “We are investigating whether we can do this with enzymes from marine fungi. We believe that these enzymes dissolve the cell walls and can release dissolved proteins.”
The marine biologist enters the NIOZ building. “No field boots behind this point,” says the door. In his office room, he has an endless view of a smooth Oosterschelde. “Today it looks calm, but an ocean is not a friendly environment. That’s the other problem. There are high waves that have already washed away countless seaweed farming experiments. Who wouldn’t want to be a sailor?” he says sarcastically. There are several seaweed farms in the Oosterschelde, but these are located in a small, sheltered location away from too many waves. An area like the Oosterschelde is too small for large-scale seaweed cultivation.
Another problem is that seaweed rots quickly. “You can keep a potato for weeks, but I start to smell kelp leaves after just one day. We don’t yet know how to solve this in an affordable, sustainable way.”
On the wall of his office hangs a photo of King Willem-Alexander and Timmermans with a brown seaweed by a seaweed tank. Timmermans: “He thought it was wonderful. More and more attention is being paid to seaweed as a food. I think it will be another five to ten years before seaweed comes to market on a large scale.”
Is there seaweed on our table like spinach? “No,” says Timmermans. “Seaweed has a very intense taste. I rather expect us to take seaweed mainly as a protein supplement. I regularly use it as a flavor enhancer when I cook. It is.”