**5. The need to monitoring hypersaline lagoons dynamics to predict waterbird presence**

The food web of these lagoons is simple and sensitive to environmental conditions such as salinity changes caused by water or brine diversion. The main ecosystem components are bacteria, microalgae, and different zooplankters (Ostracoda, Copepoda, Branchiopoda); among the latter the brine shrimp *Artemia* plays a key ecological role in the ecosystem grazing on bacteria and phytoplankton (such as the halotolerant unicellular green algae *Dunaliella*) and hence modulate their biomass. Studies in the Mediterranean [67], Crimean lakes in Ukraine [17], and Dubai [63] have evidenced the *Artemia* role to predicting waterbirds presence. Besides, *Artemia* is an intermediate host for avian helminth parasites, particularly cestodes and nematodes [68–70], also providing useful information on waterbird abundance and diversity in hypersaline ecosystems. In turn, *Artemia* abundance is controlled by copepods and amphipods species that are common at lower salinities but can also tolerate high salinities, particularly copepods [71, 72].

Waterbirds inhabiting hypersaline wetlands, particularly flamingos, disperse *Artemia* by carrying cysts in their feathers or in the digestive tube which are released to the environments with their feces [52, 53]. This service provided by flamingos would favor the colonization of new suitable habitats and would explain *Artemia* distribution to some extent [73]. The knowledge on the halophilic biodiversity of hypersaline lagoons is, therefore, a first step toward understanding why local and long migratory waterbirds use them as a source of energy and as breeding sites. Lagoons in Salar de Atacama are essential habitats for flamingos and shorebirds [74–76], some of them with conservation problems according to the IUCN Red List of Endangered Species. The Chilean flamingo and the Puna flamingo are both near threatened; meanwhile, the Andean flamingo is recognized as a vulnerable species. Lagoons from Salar de Atacama (particularly Puilar) represent the most important breeding site in the world for the Andean flamingo (**Figure 5**). In addition, these lagoons are important for migrating interhemispheric species such as Baird's sandpiper *Calidris bairdii* and Wilson's phalarope *Steganopus tricolor*, among others, despite there is no quantitative data for these species in the area. Charadriiformes and Anseriformes such as the Andean gull *Larus serranus*, and the Andean Goose *Chloephaga melanoptera* (Anatidae) are also present in the Salar.

Patagonian saline lagoons also hold a great diversity of waterbirds, including flamingos, swans, grebes, and shorebirds [77]. Among the most abundant birds in

#### **Figure 5.**

*Saline lagoons in northern Chile (Salar de Atacama) provide waterbird habitat, a relevant noneconomic service. (A) Flamingos. (B) Nests. (C) Nestlings. (D) Salar de Atacama is the epicenter of the world's largest lithium exploitation from brine pumped from beneath the Salar. The challenge ahead is how will both services coexist in a scenario of soaring lithium demand, and hence brine diversion, to support electromobility.*

Amarga lagoon are the Black-necked swan *Cygnus melancoryphus*, Coscoroba swan *Coscoroba coscoroba*, upland goose *Chloephaga picta*, white-tufted grebe *Rollandia rolland*, and silvery grebe *Podiceps occipitalis* and several species of dabbling ducks. Cisnes lagoon is used mainly as feeding places by sandpipers and plovers (Charadriiformes) such as the White-rumped sandpiper *Calidris fuscicollis*, the Baird's sandpiper, Two-banded plover *Charadrius falklandicus*, Rufous-chested plover *Charadrius modestus*, and the Magellanic plover *Pluvianellus socialis*, a species near threatened at a global scale. Both lagoons include representatives of Anseriformes, such as the shelducks (Tadorninae) *Chloephaga rubidiceps* and *C. picta* and dabbling ducks (Anatinae) such as *Speculanas specularis* (near threatened), *Anas georgica*, *Lophonetta specularioides*, *Tachyeres patachonicus*, and *Mareca sibilatrix* [78]. Among Phoenicopteridae, the Chilean flamingo is abundant in Patagonian saline lagoons, being one of the main *Artemia* predators, and such abundance is likely to explain the abundance of flamingo parasites recorded in the *Artemia* population from Los Cisnes lagoon [28].
