The History of Mission Bay Wetlands

Learn about Mission Bay’s history from the prehistoric to the modern era, and how ReWild is working to restore its natural areas.

Mission Bay is home to expansive salt marshes along San Diego’s coast. Once occupied by the Kumeyaay people, this area underwent rapid economic development in the 20th century that drastically altered the landscape. Future plans spurred by ReWild Mission Bay hope to restore Mission Bay’s wetlands to their former health and reestablish the valuable ecosystem services they provide. 

Natural History of Mission Bay

The San Diego coastline is dominated by salt marshes and vast estuarine complexes. These wetlands provide vital ecosystem services for San Diegans and the wildlife that inhabits the area. The saltwater marshes are fed by freshwater inland wetlands, which provide nutrients to the vast array of vegetation species that make up the marshes. These plants are home to a variety of animal species, primarily birds and fish, most of which rely on the health and functionality of these wetlands to survive.

Kendall frost marsh - history of mission bay

The landscape we know as Mission Bay formed approximately 10,000 years ago. Most of the area was underwater at that time, but as waves deposited sand from the south, Mission Bay slowly rose out of the water and formed the salt marshes we see today.

Inhabitance of the Kumeyaay People

From the time the San Diego coastline began forming, Kumeyaay communities dotted the coast, valleys, and mountains of California and Baja. Also known as the Tipai-Ipai, the Kumeyaay Nation extends east from coastal San Diego across the Laguna Mountains toward the Salton Sea, southeast to Mexicali, and as far south as Ensenada Bay. The cultural traditions and religious ceremonies of the Kumeyaay are shaped by the land, with innovative uses of native plants and water preservation that ensured their communities’ survival.

Kumeyaay people - history of mission bay

Although the Kumeyaay peoples have been displaced, confined to reservations, and isolated by borders, they continue to protect their homelands around the California coasts. In the 1990s, the Kumeyaay established an independent environmental protection agency that uses a combination of traditional Kumeyaay practices and modern technology as a means of environmental restoration and management. In doing so, they’ve utilized effective and inexpensive means of erosion and flood control that have improved the health of their wetlands, which improved the ecological health and resilience of adjoining areas. ReWild’s goal of restoring Mission Bay is a vital part of revitalizing historic Native land.

Read more about the Kumeyaay people here: Restoring a People to Mission Bay

Development in the 20th Century

development in kendall frost marsh - history mission bay

From the 1940s to 1960s, Mission Bay experienced a rapid increase in economic growth and development. San Diego city leaders eradicated the wetlands as part of its modification of Mission Bay into the self-proclaimed “largest aquatic park in the nation,” bringing increased tourism with the opening of Sea World in 1964 and Campland in 1969. These attractions not only brought residents from around the city to enjoy the bay, but tourists from around the U.S., giving the city a considerable financial and population boom which it continues to enjoy today.

However, because the landscape that these attractions were built on was primarily coastal marshes, construction required heavy alterations of the land. To prevent structures from sinking into the mucky silt ground, crews had to dredge the soft sand and silt to make way for more stable material that would be suitable for lasting infrastructure.

Read more about development in Mission Bay here: How Development Has Impacted the Northeast Corner of Mission Bay

While these modifications made the economic boom from the attractions possible, they severely altered the landscape in a way that had a detrimental effect on the health and functionality of the wetlands. The mucky silt that was removed and constructed over was a valuable tool in preventing flooding and erosion, as the absorbent silt and vegetation would accumulate seawater that would otherwise spill over onto the land. However, with construction overtaking the natural landscape and blocking the flow of fresh water and nutrients into the bay, the surrounding area is at risk of overflow, especially as sea levels rise.

Read more about how Mission Bay helps San Diego adapt to climate change here: Sea Level Rise in San Diego: How Mission Bay’s Wetlands Help Us Adapt

Future Plans for Historic Land

wetland restoration work - history of mission bay

As the impacts of climate change are felt and sea levels are forecast to rise along the coast, and prompted by the determination of the 1994 Mission Bay Park master plan to make clean water a priority, city leaders have become aware of the growing need to restore the native wetlands of northeast Mission Bay.

Created in 2014 as a project of the San Diego Audubon Society, ReWild Mission Bay formally proposed three separate options for wetland restoration in 2018, with each plan offering increasingly extensive restoration scopes including greater public access, education and research centers, and over 200 acres of habitat restoration that would significantly improve Mission Bay’s ability to counteract sea-level rise. While all three options offer expansive wetland restoration, ReWild continues to promote its “Wildest” alternative as the most comprehensive and economically feasible option for the city, which would create 227 acres of new wetland, 4,800 feet of public-access trails, and best prepare San Diego for climate change and sea level rise over the coming century.

While the city has not yet agreed to any of these options, it announced its own “De Anza Natural” plan in 2022 to provide a balance between environmental restoration and economic development. Experts with ReWild Mission Bay see this plan as a positive step forward to Mission Bay’s ecological health, but argue it will not be adequate to functionally restore the green infrastructure of Mission Bay.

ReWild is currently pushing the city to commit to its preferred Wildest plan to best equip Mission Bay with the ecosystem services needed to adapt to climate change. 

Learn how you can take action here. Or, learn more about the history of ReWild Mission Bay.

Photos courtesy of Roy Little, Isabelle Kay, and others.