A New Initiative to Save an Ecosystem in Crisis: Saline Lake Connections

By SFBBO Director of Regional Strategies Dr. Nathan Van Schmidt

​SFBBO is refocusing three of its longstanding community science-driven Waterbirds programs—our phalarope surveys and our California Gull walkthroughs—as well as our gull abatement research under a new umbrella: Saline Lake Connections. This is in recognition of the significant momentum behind the pressing need to understand the unique saline lake ecosystem and their connections to San Francisco Bay in order to preserve both.

​When SFBBO was founded in 1981, a central goal of the organization was to study how waterbird species were using the salt ponds of South San Francisco Bay. Those founding researchers had no idea that these salt ponds would become the site of the largest restoration effort on the U.S. Pacific Coast, the South Bay Salt Pond Restoration Project. But they did immediately see the value of the hypersaline ecosystem for many waterbirds, including specialist species that normally only occurring in saline lakes like Mono Lake and the Great Salt Lake. These include Wilson’s and Red-necked Phalaropes, California and Bonaparte’s Gulls, and Eared Grebes. California Gulls breed locally, while the others participate in a hemispheric migratory network that connects saline lakes from Canada to Argentina.

That system of saline lakes is in crisis. Nearly all of these ecosystems in an extremely fragile due to decades of unsustainable water diversions. As a result, some like Lake Abert are drying out and functionally collapsing as an ecosystem when hit by drought. The salt ponds of San Francisco Bay may act as refuge in such years, though the influxes of avian refugees can significantly impact our own ecosystems.
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As a result of this crisis, Dr. Nathan Van Schmidt, SFBBO’s Director of Regional Strategies, joined other leading phalarope researchers in signing scientific petition to list the Wilson’s Phalarope as threatened under the Endangered Species Act. This was driven in part by documented 98% declines of this species locally. This winter, this action produced results: the federal government has officially agreed that a review of the species status was warranted and begun the review process. Agency heads and scientists across the Western U.S. are now forming a Core Workgroup to help conserve and manage populations of this unique shorebird.

To guide these conservation efforts, Dr. Van Schmidt just completed the first-ever rangewide model of phalarope migratory dynamics. Because the two species can be difficult to identify at a distance, estimating their relative population required developing a complex novel statistical model of their joint abundance and identification rates, which may in the future help improve population estimates for many other tricky species like yellowlegs. The model, which is still in peer review, uncovered more clearly than ever before what phalarope researchers had feared: the 2022 drought that brought Great Salt Lake to the brink of collapse corresponded with a huge decline in the global population of Wilson’s Phalarope. Future work aims to integrate information from partner researchers in South America, who Nathan met with in the 2024 International Workgroup meeting in Argentina, to create a full global model.

Great Salt Lake isn’t the only saline lake in trouble. Chronic low water levels persist at Mono Lake despite it being the only North American saline lake with a legal mandate to retain enough water for its ecosystem to function, which was set by the State Water Board in 1994. A new modelling report has confirmed that the ongoing lack of recovery is primarily due to unsustainable water diversions to Los Angeles. These conditions led to record-low breeding success and population declines of California Gulls in recent years, and a historic explosive growth of California Gulls displaced from Mono Lake to the Bay Area, which in turn has increased predation on sensitive breeding species like Snowy Plovers. This creates a thorny conservation challenge: if California Gulls are declining elsewhere, should they be re-listed by the state as a Species of Conservation Concern even if they are problematic for other sensitive waterbirds in San Francisco? We are keeping a close tabs on this situation with our gull abatement monitoring, which last year we expanded from just South Bay to also cover Suisun Marsh in North Bay and via a partnership with Scott Stevens lab in San Jose State University to band and GPS-track gulls to see where they are foraging. We are also watching how populations of California Gulls may be changing in response to the dire conditions at Mono Lake with our walkthrough community science surveys, which are taking place in early May.

Last month, Nathan wrote a letter to the State Water Board detailing these concerning trends and commenting on the results new model. As a result of these comments and those of our partner researchers in the Mono Lake Committee and Oikonos, the State Water Board is convening a public workshop on bird populations in early June and invited Nathan to present SFBBO’s findings at it. This hearing is expected to be one key step in reassessing whether Mono Lake’s water diversions are to be adjusted to meet sustainability needs for this critical ecosystem, potentially by the end of next year.

Given the complex connections we are seeing between what is happening here and across the intermountain West, and the significant management effort now underway to figure out how to save these unique ecosystems, SFBBO is rethinking how we are managing these long-term monitoring projects. Our new Saline Lakes Connections approach emphasizes the need to build on the foundation of our phalarope, gull walkthrough, and gull abatement projects with several new initiatives:

1) Work directly with managers, agencies, and other researchers across the Great Basin to provide technical expertise in how to manage phalarope and other saline specialist waterbird populations;

1) Partner with other researchers to extend our field research efforts beyond the confines of South San Francisco Bay, including developing new monitoring efforts at saline lakes across the West;

3) Integrate models of water supply and demand into our understanding of saline lake dynamics (as Nathan has done for California’s Central Coast) to better understand and predict how human water use drives the declines and recovery of waterbird populations.

These ambitious efforts will take time to come to fruition, but SFBBO is committed to tackling the challenge of conserving these unique and underappreciated ecosystems.