The sustainable development of aquaculture faces significant challenges, including a shortage of high-quality feeds and concerns about the safety and quality of aquatic products.
A scientific review published by researchers from the Shenzhen Institute of Advanced Technology at Shenzhen University explores the potential of microalgae as an essential component of aquaculture feeds to address these issues.
Nutritional Value of Microalgae
Microalgae are microscopic photosynthetic organisms abundant in aquatic ecosystems. They are highly regarded in aquaculture for their exceptional nutritional value.
Microalgae serve as a vital food source for various aquatic species, including larval bivalves, shrimp, and fish, owing to their high nutritional content and suitable cell size. Bivalves, in particular, rely on microalgae throughout their entire life cycle.
Additionally, microalgae are indispensable as food sources and nutritional supplements for secondary live prey, such as rotifers, Artemia, and copepods. These microorganisms contain significant amounts of proteins and lipids, making them a promising alternative to traditional fish meal and fish oil in aquaculture feed formulations.
Bioactive Substances in Microalgae
In addition to their macronutrients, microalgae are rich in bioactive substances, including ω-3 polyunsaturated fatty acids, carotenoids, vitamins, and β-glucans. These compounds have the potential to serve as powerful feed additives, enhancing the growth rate, skin coloration, antioxidant capacity, immunity, and survival rate of aquatic animals.
The scientific review focuses on the positive effects of carotenoids, vitamins, and β-glucans from microalgae in balanced aquaculture feeds.
Overcoming Challenges in Microalgae Production
One of the main obstacles to fully harnessing the potential of microalgae in aquaculture has been the high production cost. Establishing economically efficient microalgae cultivation technology is a prerequisite for the large-scale application of microalgae in aquaculture.
Fortunately, recent advancements in microalgae cultivation techniques, particularly in the field of fermentation technology, have substantially improved production efficiency and reduced costs. This progress paves the way to make microalgae a more accessible and sustainable ingredient in aquaculture feeds.
Currently, there are three main types of microalgae cultivation: photoautotrophy, heterotrophy, and mixotrophy.
The Way Forward: Opportunities and Challenges
Looking ahead, the integration of microalgae into aquaculture holds significant promise for advancing sustainability. Opportunities include increased access to cost-effective, high-quality food sources, reduced pressure on wild fish populations, and improved nutritional profiles of farmed seafood.
However, challenges persist. Scaling up microalgae production to meet the demands of the aquaculture industry while maintaining sustainability is a complex task. Careful consideration of environmental impacts, regulation, and the economics of large-scale microalgae production is essential.
The review also includes a SWOT analysis (Strengths, Weaknesses, Opportunities, and Threats) of microalgae as a source of food and feed additives to promote sustainable aquaculture.
The use of microalgae as an ingredient in aquaculture feeds represents a revolutionary approach to addressing the pressing challenges of achieving desired sustainability in aquaculture. These tiny organisms offer a rich source of nutrition for a wide range of aquatic species and have the potential to revolutionize the industry.
By leveraging technological advancements in microalgae production, we can unlock their potential to support sustainable aquaculture. As we move forward, it is crucial to strike a balance between the opportunities presented by microalgae and the challenges associated with their integration.
Incorporating this knowledge into aquaculture practices can pave the way toward a more sustainable and nutritious future for both aquatic ecosystems and our diets.
The study was funded by the National Natural Science Foundation of China and the China Postdoctoral Science Foundation.
Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology
Shenzhen 518055, China.
Reference (open access)
Ma, M, Hu, Q. Microalgae as feed sources and feed additives for sustainable aquaculture: Prospects and challenges. Rev Aquac. 2023; 1-18. doi:10.1111/raq.12869