Fresh Faces in Mission Bay: Building a Lasting Sanctuary

While wetlands captivate us with their visible beauty, it’s their unseen role in supporting marine life that truly makes them invaluable. Many species of fish are reliant on coastal habitats such as marshes during their juvenile stages, and wetlands provide protection for these tiny inhabitants as they grow. Not only is it a sanctuary for juvenile fish, but this year the Mission Bay marsh has become a sanctuary for thousands of Elegant Terns, who are nesting this year on the adjacent crescent-shaped West Ski Island. Given the crucial role wetlands play in supporting both populations above and below the surface, every day we postpone ReWilding is a missed opportunity to strengthen our economy and these delicate ecosystems. 

Juvenile California Halibut and White Seabass are found in nearly every coastal bay and estuary along the California coast. Our staff has partnered with the University of San Diego to seine for fish in Kendall-Frost Marsh all summer, contributing to historical data that demonstrates which species utilize the wetland for sanctuary. With substantial work being done to rehabilitate fish populations in San Diego waters, the creation of more wetland areas is essential to provide these recovering species with the nursery grounds they need to thrive. The value of these efforts is not just ecological but also economic: researchers at the University of California, San Diego show on Wetlands Worth that a restored wetland in Mission Bay could contribute up to $440,000 annually to commercial fishing of just these two species. Moreover, these thriving fish populations support diverse seabird communities, like the one at W. Ski Island, creating a rich ecosystem that benefits everyone.

Mission Bay has proven to be a beneficial nesting site for 16,000 Elegant Terns and hundreds of other Larid species this year, to the delight of local birders and neighbors. Seabirds, as a top predator, are indicators of marine ecosystem health and fish populations, but are also the most imperiled₁. Nearly 30% of them are threatened with extinction, and face many environmental disturbances and pressures including habitat loss, egging, and invasive species that can force them to find new breeding grounds, like they’ve done here in San Diego₂. These reasons underscore why this population is so unique for us to witness, and why they need protection from greater anthropogenic pressures. 

The population we’re hosting this year are facing some of these human pressures, including recreational boating, fireworks, and encroachment onto the island. We’ve recently witnessed the terns begin to use the sandy spit along Stribley Marsh as sanctuary, and spend time flying between the two sites. San Diego Bird Alliance has been hard at work trying to raise awareness about the current impacts to them, and how we can do better at ensuring a safe nesting season. Striking a balance between recreation and conservation is yet another reason why restored wetlands will be a critical advantage in ensuring the future for all species who call the bay home. 

Imagine squeezing all of San Diego’s diverse wildlife into a space smaller than Seaworld’s parking lot. That’s the reality for Mission Bay’s remaining wetlands—a mere 40 acres, teeming with life. These precious pockets of nature are working overtime, providing critical ecosystem services and sanctuary for countless species. But here’s the catch: these overworked wetlands simply can’t accommodate human recreation right now. But here’s the exciting part: by investing in wetland restoration, we can create a future where both nature and people thrive. More wetlands mean more space for wildlife to flourish and for us to connect with nature.

To learn more about what you can do to help nesting seabirds in Mission Bay, check out our webpage.

Reference to San Diego Bird Alliance, previously San Diego Audubon Society. For more information on the name change, see here.

Resources

1. Velarde, E., E. Ezcurra, M. H. Horn and R. T. Patton. 2015. Warm oceanographic anomalies and fishing pressure drive seabird nesting north. Science Advances 1: e1400210 Google Scholar
2. Gabriella S. Perez, Katharine S. Goodenough, Michael H. Horn, Robert T. Patton, Enrico A. Ruiz, Enriqueta Velarde, and Andres Aguilar “High Connectivity Among Breeding Populations of the Elegant Tern (Thalasseus elegans) in Mexico and Southern California Revealed Through Population Genomic Analysis,” Waterbirds 43(1), 17-27, (19 May 2020). https://doi.org/10.1675/063.043