Seaweed is increasingly seen as a solution to nutritional deficiency in population. However seaweed cultivation has not taken off in India.
- Seaweeds are photosynthetic algae.
- They are primitive plants and roots, stems and leaves are absent in seaweed.
- They are macrophytic algae which mean they live in water or moist land surfaces.
- They grow in the shallow waters in the tidal zone.
- Seaweeds exhibit highest photosynthesis efficiency due to moist conditions. As a result they contribute to about 50% of all photosynthesis in the world.
Types of seaweed
- Based on the pigments present in seaweed they are of 3 types:
- Brown algae
- Red algae
- Green algae
- Red and Green seaweeds are found in subtropical and tropical waters.
- Brown seaweeds are common in cooler, temperate waters.
- Asia is prominent in seaweed cultivation with China, Korea and Japan contributing to 80%
- Seaweeds are used as food, renewable source of energy, pharmaceuticals, cosmetics, textiles, fertilizers
Benefits of Seaweed
- Edible Seaweeds are low-calorie and nutrient-dense food items.
- They are rich in vitamins A and C.
- They are a good source of minerals such as Ca, Mg, Zn, Se and Fe.
- They also have a high level of vegetable proteins and omega 3 and 6 fatty acids.
- Since Seaweeds live in water they do not require irrigation.
- They do not require pesticides, fertilizers.
- Categorised under vegan diet, they are easily acceptable.
Seaweed Cultivation: Global Scenario
- China tops the list of countries in seaweed cultivation.
- Other leaders in seaweed cultivation include North Korea, South Korea, Japan, Philippines, Chile, Norway, Indonesia, USA and India.
- Seaweed is the staple food in many parts of South East Asia including Philippines, Malaysia, Vietnam, Indonesia, China, Korea and Japan.
In brief: Seaweed Cultivation: Potential in India
- About 844 seaweed species are reported from India which has a coast line of 7,500 km.
- Tamil Nadu, Gujarat coasts, Lakshadweep and Andaman and Nicobar islands are abundant in seaweed.
- Rich seaweed beds are also found around Mumbai, Ratnagiri, Goa, Karwar, Varkala, Vizhinjam and Pulicat inTamil Nadu and Chilka in Orissa.
- Gulf of Mannar is home to more than 240 seaweed varieties out of which at least 185 are edible ones.
Challenges to seaweed harvesting in India
- Lack of livelihood security due to low wages and during bad weather
- Risky as they have to be collected from depths of more than 25 to 30 feet to collect seaweed.
- Over-exploitation: While India has rich source of seaweed varieties we have focused only on harvesting not cultivation thus leading to over-exploitation.
- Lack of awareness about health benefits act as hindrance to nutrition transition among population.
- In the aftermath of 2004 tsunami, the volume of harvest has fallen.
Commonly known seaweed products (important for prelims)
- Made of red algae
- Used as food additive as a thickener, emulsifier etc.
- They are used to absorb glucose and thus used in weight loss diets.
- Made of brown algae
- Form non-toxic gels and are often used in pharmaceuticals, cosmetics, processed food etc.
- Made of brow algae
- Used in gelation in ice creams