On July 2 this past summer, U.S. Senator Jeff Merkley (D-OR) and U.S. Senator Mitt Romney (R-UT) introduced the Saline Lake Ecosystems in the Great Basin States Program Act of 2020. Nevada Senators Rosen and Cortez-Masto, also have joined as co-sponsors. The legislation recognizes the ecological and economic benefits of saline (salt) lakes in the American West. This legislation will establish a program within the U.S. Geological Survey (USGS) to assess, monitor, and benefit the hydrology of saline lakes in the Great Basin and the migratory birds and other wildlife, that depend on them.
As our human communities grow, so does agriculture and urban development, and the corresponding need for freshwater. The ever growing demand of freshwater, combined with frequent drought conditions and climatic changes, has led to terminal saline lakes with water levels declining. This is especially true in the Great Basin of the American West, which includes Utah, Nevada, and small portions of Idaho, California, and Oregon. The communities near saline lakes rely on the lakes for their businesses, livelihoods, and quality of life. Less water leads to increased concern for public health, the economy, and environment**
Left: Sandpipers roosting and foraging at the Great Salt Lake (Utah). Right: Constructed islands and wetlands at Owens Lakes (CA). Photo: Ray Ramirez.
For wildlife, including shorebirds, these changes in saline lakes are also devastating. Contrary to what you might think, salt lakes are a highly-productive system that supports the life cycles of thousands of species, among which are dozens of species of shorebirds. Due to their great importance for shorebird communities, many saline lakes such as Great Salt Lake (Utah, United States), Mono Lake (California, United States) and Laguna Mar Chiquita (Argentina) have been designated as sites in the Western Hemisphere Shorebird Reserve Network (WHSRN).
But what makes these sites so attractive for some birds? Terminal saline lakes are able to efficiently accumulate and recycle nutrients that sustain many flora and fauna. However, living in a hypersaline environment is a physiological challenge to which not all living things are adapted. Fish, for example, cannot survive in lakes with extremely high salinity. In the absence of these predators, the few species of invertebrates that inhabit these environments reach high levels of abundance and are exclusively available as prey to birds. But the abundance of invertebrates is not the only factor, the seasonality of their life cycles is also of vital importance. Thousands of shorebirds descend on the salt lakes, which serve as migratory stopover sites, at the exact moment when the invertebrates are at their maximum abundance.
Wilson’s Phalarope (Phalaropus tricolor). Photo: Maina Handmaker
Wilson’s Phalarope (Phalaropus tricolor) is one of the bird species that is best adapted to hypersaline environments. Imagine for a moment that you are a little phalarope at the end of the reproductive season. You are exhausted after the great investment of energy you have undertaken during the last few weeks, molting your feathers to a colorful dress, performing courtship and building a nest, laying eggs and taking care of your chicks. The time has arrived for you to begin your migration south, but ahead of you lies a journey of thousands of kilometers to South America. There will be days and days of uninterrupted flight. To be successful you will need to store all the energy you can in your little body. As if that wasn’t enough, you don’t need your breeding plumage anymore and you have to molt your feathers again! All of this needs to be done in a couple of weeks, but how?
Fortunately, as a phalarope, you can count on the resources offered by the salt lakes of the western United States for help. The few species of invertebrates that inhabit these environments (mainly crustaceans of the genus Artemia and dipterans of the genus Ephydra) reach high levels of abundance, and are an abundant food source that is rich in lipids and proteins. Feeding on them allows you to rapidly raise your body weight, so that it may almost double in just a couple of weeks.
This situation is not an accident but is the result of an ecological equilibrium that is directly related to the salinity of the water. Changes in the water levels entering into these lakes can drastically alter the invertebrate prey communities of a site, with direct consequences for species higher up the food chain.
This legislation will support comprehensive monitoring and assessment of saline lake ecosystems to understand changes and promote coordinated management across the Great Basin.
A large flock of Wilson’s Phalaropes swimming and foraging at Mono Lake. Photo: Marie Read.
“Saline lakes contribute significantly to local communities and their economies, as well as habitat for millions of birds,” said Marcelle Shoop, Audubon’s Saline Lakes Program Director. “While there have been efforts to study and protect these saline lakes at a local level, this effort also will support birds across the flyway, while benefitting communities locally. Improving our scientific understanding of the hydrology and habitats of these unique natural resources can inform coordinated approaches to management and conservation across the Great Basin.”
If you imagine yourself as the phalarope again, traveling through the arid western part of the United States, you must have these saline refuges available every year. A long term monitoring and assessment plan with the USGS will support the protection of the habitat that phalaropes need.
For more information visit Audubon’s press release on the legislation or contact Marcelle Shoop, Director of Audubon’s Saline Lakes Program.
Cover photo: Moonset at Rock Hill. Photo: USFWS
