Around Sundarbans, a biosphere reserve in eastern India, more and more farmland is being converted to brackish water aquaculture – despite the risk of adverse impacts on the environment and local livelihoods.
“The emergence and rapid expansion of brackish water aquaculture in Sundarbans threatens to have long-term consequences such as biodiversity loss and socioeconomic impacts,” said Tim Daw, a researcher at the Stockholm Resilience Center, who is one of the authors behind a study recently published in Ambio appeared.
What drives this land change has previously been a matter of debate. The Ambio study cites economic profitability as the main reason for the switch.
But environmental reasons also play a role, as agricultural productivity has fallen due to salinity, frequent hurricanes, floods and a decreasing availability of freshwater for irrigation.
The core of the study are interviews with 67 aquaculture farmers in the region.
“Profits primarily go to groups of outside investors and do not significantly improve the well-being of the local community,” said Max Troell, another researcher at the center and author of the study.
bycatch and biodiversity loss
According to the researchers, the shrimp are exported and a large part of the financial gains are accumulated outside of the communities. In addition, local food security is threatened by shrinking arable land available for staple crop production.
In addition, they are concerned about the adverse effects on the environment, pointing out that this can lead to soil salination and land degradation, which can then no longer be converted into arable land. In addition, more intensive aquaculture systems require chemicals such as fertilizers that can leach and damage local ecosystems.
Even traditional systems rely largely on collecting wild-caught young shrimp, which are then kept in ponds until they are fully grown. This leads to too much bycatch and risks depleting the region’s biodiversity, they argue.
A way forward?
Since neither traditional nor modern intensive aquaculture systems bring sustainability to the region, the authors propose a middle ground that can bring more income to farmers but does not come with the adverse effects of intensive farming.
These improved traditional systems, already practiced by some of the farmers who participated in the study, stock seasonal ponds with purchased, non-wild caught shrimp seeds.
In addition, the researchers make the following suggestions to support sustainability in the region:
- Strictly enforce laws prohibiting further illegal conversion of farmland into aquaculture.
- Create alternative livelihoods for the people, including many women, who currently rely on collecting wild juvenile shrimp.
- Strengthening of current agriculture through rainwater harvesting.
- Promote the conservation and expansion of mangrove forests.
The full study can be accessed here.