Polyculture

In Bangladesh, homestead pond aquaculture currently comprises a polyculture of large fish species but provides an ideal environment to integrate a range of small fish species. Small fish consumed whole, with bones, head and eyes, are rich in micronutrients and are an integral part of diets, particularly for the poor. Results from three large projects demonstrate that the small fish, mola (Amblypharyngodon mola) contributes significantly to the micronutrients produced from all fish, in homestead ponds, in one production cycle.

Production of the mola carplet (Amblypharyngodon mola), a small vitamin A rich fish, has the potential to reduce human malnutrition in Bangladesh. However, although efforts have been made to promote mola culture, the factors affecting its production are poorly understood. Therefore, this study was undertaken to identify factors contributing to mola productivity in polyculture systems. The study indicates that application of appropriate inputs could be considered to maximize production of mola in future projects attempting to promote its culture.

Small indigenous species (SIS) of fish such as the mola carplet (Amblypharyngodon mola) are rich in nutrients, often containing high levels of zinc, iron, and vitamin A. Despite scientific and government efforts, culture of SIS for improved nutrition is not yet widespread. This paper investigates the contribution of the mola carplet, commonly referred to in Bangladesh as ‘‘mola’’ to household fish consumption, and the factors influencing productivity and income from carp–mola polyculture in southwest Bangladesh.

Due to inadequate technical knowledge and training in advanced methods of gradually growing tilapia culture, framers are not getting expected yield. From the very beginning of the CSISA-BD project, WoldFish Center has taken initiative to introduce advanced methods in tilapia culture. To do this, the shortage of skilled trainers and training materials, has, particularly, been realized. Presently, a number of manuals on tilapia culture from Department of Fisheries, Bangladesh Fisheries Research Institute, WorldFish Center and different GOs and NGOs are available.

In rural areas of Bangladesh, the vast majority of households own only small or large shaded homestead ponds located next to their dwellings and the pond dikes are covered with large timber trees, a situation where it is quite difficult to produce fish and vegetables on the dikes. Incorporation of appropriate technologies however, can successfully utilize homestead ponds for commercial fish farming that can meet growing protein and nutritional demand.

The Southwestern coastal zone of Bangladesh is agro-based and one of the world’s most populous, poverty-stricken and food-insecure regions, with high vulnerability to climate change. Shrimp aquaculture rapidly expanded in this tidal floodplain but shrimp is highly susceptible to disease, has less contribution in local consumption, and its profitability depends on international market prices, leading the demand for improving the farming system.

Small fish are a common food and an integral part of the everyday carbohydraterich diets of many population groups in poor countries. These populations also suffer from undernutrition, including micronutrient deficiencies – the hidden hunger. Small fish species, as well as the little oil, vegetables and spices with which they are cooked enhance diet diversity. Small fish are a rich source of animal protein, essential fatty acids, vitamins and minerals.

The fisheries sector in Cambodia contributes 8%–12% to national GDP and 25% - 30% to agricultural GDP, with an estimated 4.5 million people involved in fishing and associated trades. Fish and other aquatic animals are important food sources, contributing an estimated national average of 60% - 70% of total animal protein intake. Of the 2013 total fish production, 550,000 metric tons were harvested from freshwater habitats, of which rice field fisheries and small-scale family fisheries contributed approximately 20%.

Two sustainable, low-cost pond polyculture technologies have been developed to culture carps and mola in ponds, and culture carps and mola in ponds connected to rice fields. These technologies can increase total fish production from ponds. Farmers depend on carps as an income source, and mola is rich in micronutrients that can help to meet the nutritional requirements of the rural poor, particularly women and young children.

This article gives an account of the beneficial effect of rearing sea water acclimated tilapia with oyster culture.