Microalgae rich in omega-3 fatty acids could act as an environment-friendly alternative to fish: Study
Wild salmon numbers have dropped dramatically in the North Atlantic and the Pacific Northwest, since the late 1980s and these concerns have ignited interest in microalgae
Microalgae could act as environmental-friendly factories to produce the nutritious omega-3 fatty acids, suggests a new study. What is more, algae farming could reduce the load on the oceans by giving some respite to fish species such as salmon, mullet, and mackerel. Consuming omega-3 fatty acids offers a host of health benefits, including staving off the cardiovascular, nervous system, and inflammatory conditions. But these nutrients are scarce.
"Fish catch alone cannot meet the global demand for omega-3 fatty acids, which causes great concern and has sparked the search for alternative sources," Susann Schade from Germany's Martin Luther University (MLU) Halle-Wittenberg, told MEA WorldWide (MEAWW).
Further, half of the salmon sold globally are farm-raised. And fish farming harms free fish roaming the oceans. According to the Surfrider Foundation, a non-profit environmental organization, wild salmon numbers have dropped dramatically in the North Atlantic and the Pacific Northwest, since the late 1980s. These concerns have ignited interest in microalgae. "Microalgae have become a focus as an alternative nutrient source, in particular, because some species contain high amounts of these valuable omega-3 fatty acids," explains Schade. She adds that some microalgae contain high amounts of protein, and even more valuable nutrients, such as vitamins and carotenoids. And people have been consuming microalgae for thousands of years. Now, they are sold as supplements or as a component in cereals and pasta.
However, little is known about the precise extent of the environmental impacts of algae produced for human consumption, explains Schade. So, the team investigated the impacts of producing omega-3 fatty acids from microalgae and fish farming. More specifically, they compared the two practices for their role in releasing carbon dioxide, acidifying the waters, and algal bloom -- all of which lead damage the plants and animals. "In our analysis, we found that nutrients from aquaculture fish therefore often cause higher environmental impacts than nutrients from microalgae," Schade notes. Algae cultivation needs less land, and they are not hindered by infertile soils. Fish farming, on the other hand, needs open ponds and large swaths of land. "A last big advantage is that having an alternative, or complement like microalgae as a nutrient source, may help reduce the pressure on aquatic systems," she adds.
"Microalgae should not and cannot completely replace fish as a food source. But if microalgae could be established as common food, it would be another excellent environmentally friendly source of long-chain omega-3 fatty acids," explains Dr Toni Meier, head of the Innovation Office nutriCARD at MLU. The researchers assert that these environmental impacts may not apply across the globe. "A big limitation of microalgae farming is that the outdoor cultivation of microalgae is dependent on the climatic conditions of the location. In a climate like that of our selected location in Germany, cultivation can only take place from April until October. As we remarked in our study, it is crucial to investigate microalgae under different climatic conditions to evaluate their potential as a global nutrient source," Schade says.
The study is published in the Journal of Applied Phycology.