Coastal Bangladesh

As part of an ESPA Consortium project in the Bangladesh coastal zone we have collated around 50 time-series of social, ecological, environmental and economic data from official records stretching back to ~1950.  The figure shows that since the 1980s, increasing GDP and per capita income mirror rising levels of food and inland fish production. As a result, the size of population below the poverty line has reduced by ~10% over the past 20 years. In contrast, non-food ecosystem services such as water availability, water quality and land stability have deteriorated – at least by comparison with conditions in the 1960s. There is clear evidence for climate change from the early 1980s in terms of later monsoons and higher temperatures.  The extent to which the growing levels of food production and ecological deterioration are directly linked is difficult to judge, though conversion of rice fields to shrimp farms is almost certainly a factor in increasing soil and surface water salinity. The state of the Sundarbans mangrove forest is difficult to assess on the present data. The area of mangrove forest and production of timber forest products seem relatively stable, but declining tree density and volume suggests growing exploitation or fragmentation.  Preliminary analysis of published accounts suggests that there are multiple drivers of these shifts that range from global climate change and new agricultural methods to specific infrastructural developments(e.g. polders), like the Farakka barrage, and local policy driven actions (e.g. commercial shrimp farming). Widespread trends in indicators of ecosystem services and human wellbeing point to non-stationary dynamics and slowly changing variables.  As a result, theoretical arguments may be made for declining resilience in agriculture and aquaculture with increased probability of positive feedbacks driving threshold changes/tipping points.  There is already evidence that water availability, shrimp farming and maintenance of biodiversity passed thresholds in the 1980s.  There is also evidence that high magnitude events, like large cyclones, that can potentially trigger threshold events are becoming more frequent. 

Figure: Co-evolutionary dynamics of the Bangladesh coastal zone socio-ecological system showing normalized time-series for a range of ecosystem services, environmental drivers and socio-economic indicators (Hossain et al. in review).