Need to link river management with estuarine wetland conservation: A case study in the Yellow River Delta, China

Estuarine wetlands are valuable ecosystems of coastal zones. Traditionally, wetlands are preserved by establishing nature reserves within them. However, the driving forces of estuarine wetland degradation change at different temporal and spatial scales, rendering it necessary to evaluate the entire river-delta-wetland system. We analyzed the links between management of the Yellow River (YR) and estuarine wetland conservation in the Yellow River Delta (YRD). We measured changes in river runoff and sediment discharge from 1950, and spatial changes in the tail channels from 1855. Changes in the wetland areas of the entire delta, the natural reserves, and the river buffer areas were calculated. Finally, the effects of ecological water supplementation of the YR, mandated in 2008 by the Chinese government to protect estuarine wetlands, were also analyzed. The results indicated that not only the reductions in river runoff and sediment discharge, but also shifts in the tail channels, influenced estuarine wetlands. In addition, ecological water supplementation from the YR have improved wetland health. We suggest that increasing the connectivity between old and new rivers is important to improve the integrity of estuarine wetland ecosystems. Linking river management to estuarine wetland conservation would aid in the planning and improvement of the wetland network in the delta.