In the quiet, sandy bottoms of the ocean, a simple-looking creature is working hard to clean the sea floor, the sea cucumber. While they may not look impressive, sea cucumbers play a crucial role in the marine environment and are also a source of livelihood for many coastal farmers today.
Sea cucumbers have been traditionally harvested for food and medicine in East Asia, especially in China, where they are known as a delicacy and a health booster. With wild populations declining due to overfishing, aquaculture of sea cucumbers has emerged as a profitable and sustainable alternative. In India, farming sea cucumbers, especially the species Holothuria scabra (commonly called sandfish), is now picking up pace in coastal regions like Tamil Nadu, Lakshadweep, and the Andaman & Nicobar Islands.
What Are Sea Cucumbers?
Sea cucumbers are marine animals that look like soft, fat worms or cucumbers with leathery skin. They belong to the phylum Echinodermata, which also includes starfish and sea urchins. Despite their odd appearance, they are not vegetables. These creatures slowly crawl on the seabed and feed on decaying organic matter, algae, and micro-organisms in the sand. In doing so, they clean and recycle the ocean floor, just like earthworms clean and fertilise soil on land.
They are also known to have medicinal properties and are rich in nutrients like collagen, making them popular in traditional Chinese medicine and wellness industries.
Why Farmers Should Consider Sea Cucumber Farming
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High Market Value: Dried sea cucumbers (called beche-de-mer) fetch high prices in international markets up to Rs. 10,000–20,000 per kg depending on the quality.
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Low Feeding Cost: They feed on natural organic matter in the sediment, so there is no need for expensive feed.
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Eco-Friendly: Sea cucumbers improve the quality of sea bottom and help in nutrient recycling.
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Additional Livelihood: Coastal fishers and farmers can earn extra income with minimal investment.
Ideal Species for Farming
The most preferred species for farming in India is Holothuria scabra, commonly known as the sandfish. It grows fast, adapts well to culture conditions, and has high demand in export markets.
Suitable Environment and Site Selection
Sea cucumber farming can be done in:
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Shallow sea areas with sandy or muddy bottoms
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Brackishwater ponds
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Polyculture systems with shrimp or finfish
The ideal water temperature ranges from 26°C to 30°C, and the salinity should be between 28–35 ppt. The bottom soil should be soft, sandy or muddy with rich organic matter, as this serves as their primary food source.
Hatchery and Seed Supply
Farming starts with seed collection from hatcheries. CMFRI and other research institutions in India have developed hatchery protocols to produce juvenile sea cucumbers. The hatchery-produced seeds are usually 2-4 cm in length and are ready to be stocked in the pond or sea pens.
Farmers should procure healthy, disease-free seeds from registered hatcheries. About 2,000–3,000 seeds can be stocked per hectare depending on the availability of natural food and soil quality.
Pond or Sea Pen Preparation
If farming in ponds:
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Drain and clean the pond properly before stocking.
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Apply lime if needed to adjust pH.
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Fill with filtered seawater.
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Ensure organic content is adequate (sometimes cow dung or rice bran is added before stocking to enrich the sediment).
If using sea pens or net enclosures, set them up in calm coastal areas where water flow is gentle. Nets should be secured to prevent predators like crabs and fishes from entering.
Feeding and Management
Sea cucumbers graze on the organic matter in the sediment. No additional feed is necessary, though in some cases, fermented rice bran or seaweed powder is sprinkled over the pond bottom to boost nutrition.
Pond maintenance includes:
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Checking water quality and temperature regularly
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Preventing predators like crabs
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Avoiding overcrowding
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Ensuring sediment has enough organic matter for feeding
Growth and Harvest
Sea cucumbers usually take 6 to 8 months to grow to a marketable size of 300–400 grams. During this time, they can double or triple in size depending on the water quality and food availability.
Harvesting is done by hand-picking, preferably during low tide. After harvesting, they are washed, boiled, dried, and processed for export. The drying process is very important to maintain the quality and price of the final product.
Challenges and Opportunities
Though sea cucumber farming is promising, it requires training and initial support in seed supply and pond management. With growing interest from government agencies like CMFRI and support under the Blue Revolution, more coastal farmers are receiving training and assistance.
Illegal harvest and overexploitation of wild sea cucumbers are banned in India, making hatchery-based farming the only legal and sustainable route. With rising global demand, farmers have an opportunity to earn significantly while preserving marine biodiversity.
Sea cucumbers may not be the most glamorous creatures in the ocean, but their role in marine ecosystems and their market value make them a rising star in aquaculture. For coastal farmers looking to diversify income and adopt eco-friendly practices, sea cucumber farming is a low-risk, high-reward opportunity.
With minimal investment, proper guidance, and patience, farmers can turn sandy bottoms into valuable assets quietly growing wealth beneath the waves.
