Seaweed, the wonder aquatic plant

For the fitness-freak/diet conscious eaters, this aquatic-plant provides nutrient-rich-low-fat-low-calorie-high fibre super food and dietary supplements. For those suffering from various lifestyle diseases or metabolic ailments, bioactive molecules (nutraceuticals) derived from the plant can offer relief and health benefits. For the environment conscious, edible, biodegradable natural biopolymer sachets derived from this plant can be a substitute for toxic, polluting plastics.

During the pandemic, hand sanitizers were also made from this plant. All thanks to this all-in-one magical aquatic herb – seaweed or macro algae and its multifarious applications.

After Prime Minister Narendra Modi emphasised on developing the blue economy in coastal states and asked stakeholders to re-focus on seaweed farming and research, the latter has been carried out in full swing in the pandemic years. Seaweeds (macro algae) have been put to multifarious uses, especially, in the food, agro and pharma sectors. Government marine scientists from top research institutes – namely the Central Marine Fisheries Research Institute (CMFRI) and Central Institute of Fisheries Technology (CIFT) under the aegis of Indian Council of Agricultural Research (ICAR) have come up with diversified and interesting natural, seaweed-based products and culture, which are primarily produced along the coasts of Tamil Nadu, Andhra Pradesh, Kerala and Gujarat.

India, with a total coastline of 7,517 km across its states and islands, has around 844 species of seaweeds. Seaweeds are broadly classified in three groups - Rhodophyta (red algae), Phaeophyta (brown algae) and Chlorophyta (green algae).

The Challenges

In India, most of the commercial scale seaweed cultivation takes place in Tamil Nadu and partly in Gujarat. Traditionally the raft method is used where bamboo raft-like structures containing shelves, which are prone to breakage and drifting off in case of a rough sea and cyclone. To counter it, scientists have devised an innovative HDP (high density polyethylene) Tubenet and grid-mooring method.

Explaining it, principal scientist of ICAR-CMFRI, Visakhapatnam Regional Centre, Subhadeep Ghosh, says, “In the last one year, we have developed an innovative method of protecting the seaweeds. The seaweed seedling (a species of red algae kappaphycus alvarezii) is cultivated in the HDP net, which is folded like a tube.  Around 25 HDP rafts are interlinked using polypropylene ropes and anchored using stainless steel chains and reinforced cement concrete (RCC) blocks at four corners to prevent them from drifting away during high currents and turbulent conditions. In one year, six cycles of seaweeds (45 days each) have been cultivated. There has been a fivefold increase of biomass through vegetative propagation since it was stocked. We have also applied for a patent for this method.”

Super-food

Diversifying the utilization of seaweed, scientists have also developed varieties of value-added food products and dietary supplements enriched with seaweed nutrients. This nutrient-rich, high-fibre super food is low in calories and fat, rich in antioxidants and polyunsaturated fatty acid (good fat), high in protein, iodine, calcium, copper, iron and vitamins (especially Vitamin K). It is being used to make nutra-drink and fucoidan dietary supplements, dietary fibre fortified-fish sausages, seaweed yoghurt, cookies, seaweed-enriched noodles and pasta.