Restoring Diverse Ecosystem Services for Lake Urmia, Iran: Moving Beyond a Uniform Target Lake Level

Abstract:

There is widespread interest to restore drying saline lakes to improve local economies and ecosystems. At Iran’s large, hypersaline Lake Urmia, managers seek a uniform target lake level of 1274.1 m above sea level to lower salinity below 240 g L^-1 and recover Artemia and flamingos (Phoenicopterus roseus). We define 8 metrics for lake ecosystem services to lower salinity, sustain Artemia and flamingo populations, separate islands from each other and the mainland, reduce lake bed dust, maintain valuable ions, and improve recreational access from resort beaches. We use 40 years of experimental, field, satellite, and model data to relate each metric to lake level. We describe variations through time and uncertainties in ecosystem service provision. We show: 1) lake variations prevent setting a precise target restoration level. 2)The current target will not sufficiently lower salinity nor recover Artemia or flamingos. A higher lake level is needed. 3) Ecosystem services do not converge to a single lake level; trade offs are murky. To procure more ecosystem services, 4) managers can track services and intentionally vary lake level over time within ranges.As lake information improves, managers should revisit and adapt inter-basin transfers, agriculture conservation, and bounds on lake level ranges.