Tank cultivation of edible seaweeds: an overview of the Indian perspective for opportunities and challenges

Marine macroalgae (seaweeds) have been attracting the attention of both consumers and researchers in recent days because of their enormous nutritional and biotechnological properties. Seaweeds are autotrophic plants that are edible in Asia, especially in Indonesia, Philippines, China, and Korea, and recently in Europe, the USA, and Australia. The high rate of lipids, proteins, and fiber-content of seaweeds is an advantageous one. Their bioactive molecules play a major role in the pharmaceutical, nutraceutical, and cosmetics industries. The daily usage of seaweed has been increasing day by day, but their wild harvest rate does not meet their requirements. Hence, on-shore seaweed cultivation was initiated several decades ago in some Asian countries, and subsequently such culture-methods have been followed in some other countries (to encourage seaweed cultivation and its associated products). On-shore cultivation would provide a large algal-quantity at a specific time interval, but when it comes to edible purposes, on-shore cultivation fails to provide contamination free, and nutritionally rich seaweeds. Therefore, the land-based tank cultivation-practise could provide an opportunity to cultivate seaweed (without contamination) and also to make it possible to enhance their nutritional compounds under laboratory conditions initially. Natural calamities may not affect the cultivation of seaweed in tanks. It would ensure the continuous supply of raw material to consumers and industries. This review discusses the world scenario of edible seaweed production especially the green seaweeds, as to why land-based seaweed cultivation is essential, the advantages of tank cultivation, how to select the seaweeds for tank cultivation, the methods of plantlet preparation and the indoor and the outdoor cultivation in tanks, basic applications of tank cultivated seaweeds; and the challenges during tank cultivation.