Linking Flow Regime, Floodplain Lake Connectivity and Fish Catch in a Large River-Floodplain System, the Volga–Akhtuba Floodplain (Russian Federation)

• DOI: 10.1007/s10021-011-9457-3
• Publication Date: 2011-06-03T06:01:30Z
• Authors: K. E. van de Wolf...; H. Middelkoop; E. Addink; H. V. Winter; L. A. J. Nagelkerke
• Keywords: Flood stage

River-floodplain systems are amongst the most productive—but often severely impacted—aquatic worldwide. We explored ecological response of fish to flow regime in a large river-floodplain system by studying relationships between (1) discharge and inundated floodplain area, with focus on spatial temporal patterns lake connectivity, (2) flood volume fisheries catch. Our results demonstrate non-linear relationship inundation considerable hysteresis due differences drainage rate. Inundation extent was mostly determined volume, not peak discharge. found that more isolated lakes (that is, shorter connection duration river) located at higher local elevation larger hydrological distance from main rivers: geographical river appears poor predictor isolation. Although year-to-year catches were significantly volumes floodplain, they river, suggesting mechanisms increase catch, such as increased access or somatic growth, stimulated flooding but river. Fish species profit belong different feeding guilds, all trophic levels may benefit flooding. indications functioning floodplains is limited its temporary availability habitat. Refugia can be present within itself, which should considered management rivers their floodplain.