ALEKSANDRA RODYCZ1, HEINRICH RECK1, JENS KAHLE2
1Ecology Center Kiel, University Kiel, Germany
2WAB Trading International GmbH, Germany
Shrimp aquaculture is practised since old times in Bangladesh. Extensive shrimp and fish polyculture in exchange with paddy culture and salt pans was and is still the main agri-aquacultural activity. However in the recent years chemical fertilisers and pesticides are displacing cow dung or compost, in the context of culture intensification. This can have a negative impact on the pond ecosystem and on biodiversity.
The Organic Shrimp Project (OSP) was established in 2007 in the southwestern part (Khulna division) of Bangladesh. The production of Naturland organic certified shrimps for western markets, while supporting the local farmers, are some of the goals of the project. Participating farms are managed extensively, socially, ecologically and economically sustainable, according to Naturland standards.
The objective of this study was to understand the ecosystem of these ponds and to compare the biodiversity in shrimp ponds with different management practices (organic with conventional) as well as rice paddies, as an alternative ``aquatic'' culture in the research area.
Biodiversity is chosen as an indicator for the evaluation of these ecosystems, since it is a key issue in the sustainable aquaculture vicinity. Chosen categories were benthos, pelagic fauna and flora, plankton and dike coverage. All results were summed up in the context of ecosystem services. The more ecosystem services are provided by the system itself, the less it relies on adjacent ecosystems, like in this case of the Sundarban Mangrove Forest.
The study revealed more species with higher abundance in the organic shrimp ponds then the conventionally managed and the paddies throughout. A positive impact on biodiversity by the organic management practices was concluded.
Keywords: Aquaculture, Benthos, biodiversity, ecosystem services, organic shrimp production