"Due to climate change, the mussel nurseries in the Ebro delta are emptied sooner and earlier because the water in the months of July and August is already too hot for the breeding of this bivalve, but, on the other hand, it is ideal for cultivation of algae, which are large capturers of carbon dioxide (CO₂),” explains Ignasi Gairín, researcher at the La Ràpita center of the Institute of Agroalimentaris Research and Technology (IRTA). From this center in the Montsià region, Gairín works to produce macroalgae commercially. “In 2023 and in collaboration with the FAO, we successfully carried out cultivation tests, and this year the objective is to start scaling production,” adds the expert.
Seaweed is common in Eastern cuisine and, due to its popularity, it is beginning to make a place for itself on the tables of Western countries. “They are a rich source of nutrients and have become increasingly popular in European gastronomy due to their unique flavor and health benefits,” says Aida Serra, collaborating professor in Health Sciences Studies at the Open University of Catalonia (UOC). Furthermore, their production “requires few resources, especially water and soil, so they have a low environmental footprint compared to the production of meat or other products of animal origin,” points out the UOC expert.
According to data from the European Union, world production of seaweed has gone from 0.56 million tons in 1950 to 35.82 million tons in 2019. In Europe, the most popular – according to the UOC – are nori, wakame, sea spaghetti, dulse, kelp, Chlorella and spirulina (the latter is actually a cyanobacteria, but colloquially known as a microalgae).
From IRTA, the groups of species under investigation are those of the Ulva and Gracilaria genera because they are marine macroalgae, unlike, for example, the Chlorella and Spirulina genera, which are freshwater. “Macroalgae are rich in proteins and, being marine, they do not conflict with the use of fresh water, an increasingly scarce resource, especially in Catalonia, unlike the sea,” argues Ignasi Gairín. In addition to the nurseries in the Ebre delta area, the expert explains that the Gulf of Roses is another ideal area for growing algae.
Aida Serra highlights that, in addition to capturing CO₂, “algae produce oxygen, which improves the balance of atmospheric gases and oxygenates the water, both fresh and salty, and benefits the species that live in that habitat.” According to the UOC, it is estimated that laminar algae that grow up to half a meter each day in underwater forests can capture 120 kilograms of CO₂ per ton. Likewise, they are capable of filtering wastewater from excess inorganic nutrients.
From a commercial point of view, algae have many more outlets than human consumption. “They can be used in the composition of feed for animal consumption and also have applications in the pharmaceutical and cosmetic industries. “They are a huge economic and environmental opportunity!” says Gairín.
The promotion of initiatives around the sustainable cultivation of algae is one of the lines of work included in the Maritime Strategy of Catalonia 2018-2030, whose purpose is to vindicate the condition of Catalonia as a maritime country, as well as the relevance of the sustainable blue economy as an economic engine.
