Devil’s Bargain? Hydropower vs Food Trade-offs in the Mekong River Basin
The 60 million people living in the Mekong River basin get most of their animal protein and many important nutrients from wild-caught fish from the river. The knock-on effects of hydropower dam construction on wild fish catch and food supplies in the basin is the focus of the research described here.
The governments of Cambodia, Laos, Thailand and Vietnam are contemplating the construction of more than 88 hydropower dams in the lower Mekong River basin by 2030. These governments commissioned a strategic environmental assessment in 2010 through their Mekong River Commission (ICEM, 2010). The Assessment found that there would be a loss of between 550,000 to 880,000 tons of the wild fish catch due to the dams preventing the migration and breeding of a substantial minority of the fish species found in the river system. This loss would be ameliorated by only 10% in terms of the amount of sedentary fish that would find new habitat in reservoirs. The Assessment concluded that fish ladders would be largely ineffective in the case of the Mekong, based on experience of dams on other tropical rivers, the huge volume of migratory fish in the Mekong River and the problems in managing fish passages.
The Assessment’s conclusion that the dams would dramatically decrease the fish populations and catch is far from new. Yet the governments concerned have continued to advance dam construction regardless of this projected loss of biodiversity and food. My colleagues at the Australian National University and WWF and I decided to see what the loss of this fishery would mean to food supplies in the countries concerned, as their governments have traditionally emphasized the importance of food security through domestic production.
We considered the value of the wild fish catch in terms of both calories and protein. I focus on protein here as calories could be replaced more readily from a number of sources. There are only five options for dealing with the loss of fish protein. It would be morally untenable for governments not to articulate policies for ensuring that their people have access to nutritious food, so this is not really an option. Second, the lower Mekong Nations could import food to replace lost fish, but they have policies that favor self-sufficiency in supply. Third, there could be an increase in aquaculture production or diversion to local consumption of half of Vietnam’s aquaculture production exports or a third of Thailand’s marine fish exports. Fourth, these nations could raise more protein-rich crops like soy or peanuts. The trade-offs involved in these last two options are explored in our forthcoming research, but suffice it to say that the numbers involved make them hard choices. For example, to replace protein from fish, people would need to eat two and a half times that mass of rice, and to replace the key amino acid, lysine, six times the mass of rice is required.
In our view the fifth option is most likely, namely that the loss of protein from fish would be replaced by scaling up production of the livestock that people already grow and consume in the region. We have modelled the additional pasture land and water resources required to produce this livestock using national statistics (Orr et al., 2012). Our projections are based on data from the Mekong governments provided to the United Nations Food and Agriculture Organization and via the Mekong River Commission’s Assessment. These are conservative projections for a number of reasons. The Assessment data only considers the barrier effect of dams on fish but not other impacts, such as changing flow patterns that are likely to further reduce fish population. Our calculations do not consider the likely increased demand for protein-rich foods in the region due to growing populations and increasing wealth. A further assumption in our calculations is that scavenging livestock, such as pigs and poultry, need no additional dedicated land to scale up production, as opposed to grazing livestock.
We found that under the scenario of 88 dams by 2030, water use in production of grazing livestock to replace lost fish protein would need to increase by 6–17% and the area of pasture land by 19–63%. In this water-rich region, increased use may not be a problem, although there could be opportunity costs in not using the water for other purposes, including in fisheries or agriculture. The land use change of 7,080 km2 to 24,188 km2 is an area equivalent to a small nation like Brunei or East Timor and would come from converting forests and woodland to pasture. More recent work suggests that this land area may be an underestimate due to the difference in nutrition between consumption of whole wild fish versus fish filets used in FAO statistics. Laos and Cambodia would be particularly impacted due to their extensive consumption of freshwater fish and limited alternative protein sources.
This scenario raises questions as to whether rural poor dependent on subsistence fishing could physically or economically access alternative protein sources. Laos, Cambodia and Vietnam have 2.9 million people who are regarded as vulnerable to a 10% increase in food prices. Diet and health could undergo a forced change with the loss of fish as a fundamental source of nutrition.
This research suggests that basic food security could be disrupted by hydropower dam development. Basin stakeholders should be engaged in strategies to manage these impacts. While national governments may have rights to decide to build dams, that right comes with the moral obligation to consider all reasonable alternatives and an obligation to consider all reasonable means to mitigate the impacts of such developments. Articulating credible policies for food security is a fundamental obligation of governments.
The author is a senior lecturer at the Fenner School of Environment and Society, The Australian National University.
