Abstract

Changes in fisheries in the Xe Bangfai River (Lao PDR) were assessed thanks to a fish catch monitoring program implemented for a ten-year period. Household fish catches were collected before and after the start of hydro-power operations of the Nam Theun 2 project in 2010. Data underlined a succession of three periods that consisted in (i) a long term pre-project decline in the fish catch, (ii) a second period defined as an immediate project related decline in the catch to finally reach (iii) the third period where changes in the catches are better influenced by climatic conditions or likely caused by other factors like the increase in commercial fishing, cumulative effects of increased development and water management in the Xe Bangfai and wider Mekong basin. Followed indicators underlined a decline in the household catch in the mainstream river of 19% (vs. 40-60% predicted), no impact on species composition and little variation in income with an increase of this last indicator since the operation. Finally, it is encouraging to note that catch trends post-operation are not merely pointing at a continuing decline. This shows ecological resilience and that fisheries still are a viable livelihood and continues to offer access to high value protein for riparian households.

Keywords: Fish catches; Hydropower project; Downstream river; Riparian household; Impact assessment