Bangladesh is considered one of the most suitable countriesin the world for freshwater fish production because of its deltaicnature with favorable resources and agro-ecological conditions.The country is blessed with numerous water bodies includingrivers, beel (natural depressions), flood plains, lakes, ponds, ox-bowlakes, etc., which contain 260 different species of fish (Rahman,1989). However, the growth of inland capture fisheries productionhas been limited by a variety of factors including habitat loss as aresult of agricultural intensification, urbanization, environmentaldegradation, pollution, and overexploitation of resources (Beltonet al., 2011). For example, in 2001–2002, inland capture fisheries contributed 36.42% of total fish production whereas in 2012–2013,it was 28.19% (DoF, 2014). In contrast, fish supply from aquaculturehas increased rapidly in Bangladesh over the last two decades. Thistrend is similar to that in many other Asian countries, includingChina, India, Philippines, Thailand, Vietnam and Indonesia, whereaquaculture is an increasingly important source of animal proteinand contributes to the food security of millions (Ahmed and Lorica,2002; Belton et al., 2011).Currently, fish production plays an important role in the peo-ple’s daily diet, contributing 60% of national animal protein supply,representing a crucial source of micro-nutrients (DoF, 2014). More-over, it plays an important role in the economy of Bangladesh,contributing to generating livelihoods opportunities and to earningforeign currency (Haque et al., 2014). According to recent statis-tics, fish accounts for 4.37% of gross domestic product and 2.01%of export earnings (DoF, 2014). Fish are produced in a varietyof production systems, but ponds are by far the most important, accounting for more than 78% of total production in 2012–2013.
Regionally, pond aquaculture production has developed tremendously
in the north-central and south-east regions of Bangladesh,
most notably in Mymensingh and Jessore districts (DoF, 2014). This
is mainly due to access to advanced aquaculture technologies and
markets, and availability of fish seed, fish feed and other necessary
production inputs.
Like other areas of Bangladesh, rural households in Barisal
region have perennial ponds which were mainly excavated originally
as borrow pits in order to raise the level of homesteads to
avoid flooding (Rahman et al., 1992). Traditionally these sorts of
ponds were used as trap ponds for fish, with limited stocking of carp
fry, and were mainly used for subsistence consumption (Rahman
et al., 1992). However, trap pond production has reduced over the
years and the abundance of wild fish has declined. In this context,
aquaculture has increasingly compensated for the gap between fish
supply and demand in Barisal region (Fig. 1).
Barisal district is a part of the south-central region of
Bangladesh, located on the northern shore of the Bay of Bengal,
which was developed by the alluvial flow of the Kirtankhola
River (Fig. 2). Although Barisal is just 112 km away from the capital
city of Dhaka, due to the large number of rivers between these
locations, Barisal remains far away from mainstream development.
The livelihoods of a considerable proportion of rural people depend
entirely on fishing in inland open water bodies (mainly rivers and
canals) and the sea, and poverty levels are particularly high. The
EU funded ANEP (Agriculture and Nutrition Extension Project) was
implemented in Barisal district from 2012 to 2014 in order to help
increase fish production and improve household nutrition, following
an integrated aquaculture-agriculture approach. WorldFish
implemented the aquaculture component of ANEP in collaboration
with other partners. Pond dykes in Barisal are commonly used for
planting trees which provide cooking fuel, fruits, and timber for
sale. Trees on the pond dyke create shadow, which reduces sunlight
penetration to the edges of the pond and the dykes. Moreover,
these kinds of ponds are often deep and irregular in shape, making
it is difficult to harvest carp from deeper ponds during the peak
monsoon season (June–September). All of these aspects negatively
impact potential for fish and vegetable production. However, the
sunlight exposed areas of the pond water have the potential for
growing vegetables. Considering this potential, an action research
component of the project trialled an IFCAS (integrating floating
cage aquageoponics system), alongside an improved carp polyculture
system. IFCAS was designed to complement this project
intervention by ensuring an early and regular supply of fish (tilapia) and vegetables to farming households for home consumption. The
improved carp polyculture in the pond was expected to increase
pond production, nutritional benefits and income at the end of the
season when the pond is harvested completely.