40-years of Lake Urmia restoration research: Review, synthesis and next steps.

Public concern over environmental issues such as ecosystem degradation is high. However, restoring coupled human-natural systems requires integration across many science, technology, engineering, management, and governance topics that are presently fragmented. Here, we synthesized 544 peer-reviewed articles published through September 2020 on the desiccation and nascent recovery of Lake Urmia in northwest Iran.

It Takes Two to Tango: When and Where Dual Nutrient (N & P) Reductions Are Needed to Protect Lakes and Downstream Ecosystems.

Preventing harmful algal blooms (HABs) is needed to protect lakes and downstream ecosystems. Traditionally, reducing phosphorus (P) inputs was the prescribed solution for lakes, based on the assumption that P universally limits HAB formation. Reduction of P inputs has decreased HABs in many lakes, but was not successful in others.

Rationale for control of anthropogenic nitrogen and phosphorus to reduce eutrophication of inland waters.

Concentrations of phosphorus and nitrogen in surface waters are being regulated in the United States and European Union. Human activity has raised the concentrations of these nutrients, leading to eutrophication of inland waters, which causes nuisance growth of algae and other aquatic plants. Control of phosphorus often has had the highest priority because of its presumed leading role in limiting development of aquatic plant biomass.

Biostrome communities and mercury and selenium bioaccumulation in the Great Salt Lake (Utah, USA).

The Great Salt Lake has a salinity near 150 g/L and is habitat for over 200 species of migratory birds. The diet of many of these birds is dependent on the food web of carbonaceous biostromes (stromatolites) that cover 260 km(2) of the lake's littoral zone. We investigated the biostrome community to understand their production processes and to assess whether they are a potential vector for bioconcentration of high mercury and selenium levels in the lake.

Amoebae and Legionella pneumophila in saline environments.

Amoeboid protists that harbor bacterial pathogens are of significant interest as potential reservoirs of disease-causing organisms in the environment, but little is known about them in marine and other saline environments. We enriched amoeba cultures from sediments from four sites in the New England estuarine system of Mt. Hope Bay, Massachusetts and from sediments from six sites in the Great Salt Lake, Utah.

Food-web modification by an invertebrate predator in the Great Salt Lake (USA).

During unusually wet years the salinity of the Great Salt Lake (Utah) decreased from above 100 g/L to 50 g/L. This allowed the predaceous insect Trichocorixa verticalis to invade the pelagic region of the lake and reach a mean summer density of 52/m. Concurrent changes in the pelagic ecosystem were: a decrease in the dry biomass of the previously dominant filter-feeding brine shrimp Artemia franciscana from 720 to 2 mg/m, the invasion of three other zooplankton taxa, a 10 × decrease in community filtration rate, a 20 × increase in chlorophyll a concentration, a 4 × decrease in water clarity and perhaps a decrease in soluble nutrients.