Periphyton-based aquaculture: Cost-free fish cultivation

Md Yeamim Aftad | Published: March 08, 2019 21:25:03 | Updated: March 11, 2019 21:02:26

The global population is increasing and with it, the demand for food is also growing. Comparatively in high demand are the high protein foods. This demand cannot be covered by livestock production and with the total fish catch from wild fishing grounds. The worst hit by the increase in global population are the developing and least developed countries. Some food experts claim that aquaculture production is the answer to the growing demand for high protein food. Also known as aquafarming, aquaculture is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other organisms.

Feed is one of the most important criteria for aqua farming. In aquaculture, 60 per cent of the production cost is incurred as feed. The majority of fish farmers in the world especially in Africa and Asia are poor and so, they are unable to buy expensive inputs to farm made and commercial feeds. An improved technique of fish culture based on the natural production could be a solution for poorer countries like Bangladesh. In this regard, periphyton-based fish culture may offer a new direction.

Periphytons are aquatic organisms like certain algae that live while attached to submerged plant stems and leaves as well as other substrates. Periphytons play significant roles in providing food for fish and other fauna in natural and controlled environment. The effects of periphyton, grown on bamboo substrates, on growth and production of Indian major carp, rohu, Labeo rohita (Hamilton), were studied in 10 ponds during July to October 1995 at the Bangladesh Agricultural University, Mymensingh. Five ponds were provided with bamboo substrates (treatment I) and the rest without bamboo substrates (treatment II). It was revealed that there was no discernible difference in the water quality parameters between treatments. A large number of plankton (30 genera) showed periphytic nature and colonised on the bamboo substrates. The growth and production of fish was significantly (p<0.05) higher in the ponds with bamboo substrates as compared to the ponds without substrates. The net production of rohu in treatment I was about 1.7 times higher than that of treatment II. Fish production was as much as 1,899 kg/ha over a culture period of four months in the periphyton-based production system.

It was shown that by enhancing periphyton growth, fish production in traditional pond systems in South Asia increases substantially. The application of this process does not require fertilisers or feeds. As substrate bamboo, branches of trees can also be used. It is also possible in rice fields, where the straw of rice plant works as substrate. This makes the technique useful for resource poor farmers. In order to dissipate information about this process, mass awareness needs to be generated in rural areas. Greater fish production can help not just the financial conditions of fish breeders, fishermen and fish traders, but also support the economy at meeting its demand for high protein food items.

Md Yeamim Aftad is a student at the Department of Fisheries & Marine Science, Noakhali Science & Technology University.


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