Seaweeds in Sustainability: Green Solutions for the Future

Seaweeds, referred to as benthic marine algae, are critical renewable resources in marine and brackish ecosystems. They perform photosynthesis, absorb carbon dioxide, and are of significant relevance for mitigating climate change. However, carbon capture aside, seaweeds form essential components of marine ecosystems, shore stability, and water quality. They also serve as natural fertilizers and biostimulants for sustainable agriculture and present applications in food, biofuels, and so many more for a greener future.

Ecology and Biology of Seaweeds

Seaweeds act like critical primary producers and engineering functions in coastal ecosystems, particularly found in kelp forests as well as in coral reefs. Seaweeds are very sensitive to changes in the environment. The species and region also have variations in growth patterns. Their growth reaches its highest point from June to August and again from November to January. Seaweeds are renewed annually by reproductive bodies. Some seaweed fruit throughout the year while others are seasonal. Seaweed utilization is being studied for sustainability.

Utilization of Seaweeds:

Seaweed use dates to 2700 BC, especially in Japan and China. Today, seaweed is popular worldwide, particularly in South Korea. While most seaweeds are used as food, they also yield useful products such as agar, alginate, and carrageenan, which find application in cosmetics, medicine, and food processing. Seaweeds are used as animal feed, fertilizers, and even in wastewater treatment. Recently, they have been used as an alternative source of biofuel and for carbon sequestration.

Seaweeds are environmentally important and play a role in sustainability in several ways:

On the other hand, Madhya Pradesh experienced the highest loss in green cover, which was 612 square kilometers, followed by Karnataka, Ladakh, and Nagaland, which all had considerable losses. Madhya Pradesh, at 85,724 sq. km of area, still leading in the total green cover, is followed by Arunachal Pradesh at 67,083 sq. km and Maharashtra at 65,383 sq. km of area.

• Seaweed as Manure It takes more time to act, but it has some potash lacking in sandy soils; with a good content of polysaccharides, it helps improve soil structure. Further, it helps in the growth of plants with its rich growth hormones, trace elements, and amino acids. The seaweed-based fertilizer is biodegradable and non-toxic. With its increasing use in the coconut plantations of India, the full benefits are still unknown.

• Seaweed as Animal Feed Seaweeds are rich in essential nutrients and are used as animal feed, especially when it comes to fish farming. Species of Gracilaria and Macrocystis help absorb excess nutrients, which come from the waste of fish, thus improving water quality and benefitting both seaweed and fish. Seaweed meal used on livestock feed provides essential minerals, vitamins, and proteins. Seaweed cultivation in aquaculture improves productivity and environmental sustainability.

• Biomass of Seaweeds for Fuel Since petroleum fuels are unsustainable, biodiesel from algae is an alternative source. Algae have a rapid growth rate, and one acre produces 20,000 to 80,000 liters of oil annually, which is far greater than the palm oil yield. Seawater can be used to cultivate algae on wastelands, and the issue of food vs. fuel is not there. The process of producing biodiesel includes growing algae, extracting oils, and then converting it into biodiesel, which is comparable in quality and stability to conventional biodiesel.

Control of Coastal Eutrophication Nutrient pollution and eutrophication of coastal waters will be controlled through intensive agriculture and industrialization. Seaweeds can absorb surplus nutrients for the recovery of water quality. The cultivation of seaweed helps China to eliminate the large quantity of nitrogen and phosphorus in water. The increase in seaweed farming shortly would decrease nutrient levels in coastal water, which could then be supplied through polyculture by combining aquatic animals. Seaweed farming might help remove 30% of nitrogen and 33% of phosphorus from water systems by 2050.

• Carbon Sequestration The increasing CO2 levels from rapid economic growth are contributing to global warming. Seaweed farming helps mitigate climate change by absorbing and binding more CO2 than land plants. Seaweeds use CO2 in photosynthesis to produce carbohydrates and sequester carbon. In Indonesia, seaweed farming sequesters over 2.6 million tons of carbon annually. Kappaphycus sequesters 12,551 tons of carbon per hectare per cycle, meaning that seaweed farming is a critical tool to reduce atmospheric CO2 and stop global warming.

Conclusion:

Seaweed farming offers a sustainable and eco-friendly solution for combating climate change while enhancing the health of our oceans. The activity reduces ocean acidification, removes nutrients in polluted water, and produces biomass for food and other products. This farming process also employs the coastal communities. Seaweeds are rich in proteins, vitamins, and bioactive compounds that can be used in food, medicine, cosmetics, biofuels, and wastewater treatment.