Fish Movement through a Wetland Floodgate in the Lower Mekong Basin

Off-channel wetlands are important feeding, breeding and nursery habitats for fish in the Lower Mekong Basin. The construction of weirs and floodgates to protect wetland croping from river flooding has created barriers to fish passage and isolated productive fish habitats from the Mekong River. Although fish ladders can be used to re-establish floodplain access for wetland fish, recent research suggests that substantial numbers of fish may be injured or killed as they pass back downstream through some floodgate types as a wetland drains. To assist in the design of 'fish-friendly' floodgate designs research is underway to better understand which species and life stages of fish are passing downstream through wetland floodgates. Preliminary data are presented from Pak Peung Wetland floodgate in Laos PDR.