In response to concerns about the dam's likely impact on fisheries on the Mun River, a fish ladder was incorporated into the scheme to allow fish into the Mun River to spawn. The fish ladder has been "unsuccessful". A report from the World Commission on Dams found that of 265 fish species previously found in the Mun River, at least 50 had disappeared and numbers of others had declined significantly. The fish catch decreased by 60–80%. It is uncertain what proportion of this decrease is attributable to the dam, and what proportion to other factors.