What is a wetland?
A wetland is an area of land where water floods or saturates the soil, either permanently or seasonally! Wetlands are generally categorized into two types of systems: coastal or tidal wetlands and inland and non-tidal wetlands. Our beautiful Bolsa Chica reserve is considered a coastal wetland due to its proximity to the ocean and the presence of saltwater.
Due to varying features, wetlands can have many names, including marsh, bog, swamp, bayou, and more. Our Bolsa Chica wetlands are categorized as salt marsh due to the year-round saltwater that enters through Anaheim Bay and a coastal inlet. Our wetlands also have an estuarine component to them. This is from the presence of freshwater that flows in from the Wintersburg Flood Control Channel, creating “brackish” conditions (salt and freshwater combination).
The Bolsa Chica Wetlands, located south of Point Conception, was once an extensive saltwater marsh. However, due to various reasons, they have now shrunk in size and are considered one of the few remaining saltwater marshes in the area, as confirmed by CDFW. The daily fluctuations in tidal water levels in the marsh directly impact the salinity levels, creating an ideal habitat for a diverse range of wildlife. This dynamic ecosystem is home to various species of plants and animals that have adapted to thrive in the changing conditions of the marsh.
While Bolsa Chica does not have rocky tidepools, many familiar creatures can be found in the bays and basins of the region. The salt marshes still experience changing tides daily: twice as water ebbs out and twice as water flows back in. As water flows out of the wetlands, many intertidal animals are exposed. This hidden community thrives through filter-feeding organic particles in the water, grazing on algae, and preying on one another.
Barnacles, mussels, crabs, snails, hermit crabs, shore crabs, and limpets live higher up in the basin and are exposed to sunlight for many hours of the day.
Photo by Keith Vale
In deeper water, ochre sea stars, bat stars, and turban snails are present and use adaptations to cling to nearby rocks.
Gliding along the seafloor, you might see deeper water vertebrates such as small sharks, rays, and guitarfish.
Photo by Gary Skipper
As the condition and motion of the wetlands change, migratory shorebirds and waterfowl take a rest and find homes in the salt marsh. In the fall and winter, birds fly into the salt marsh to refuel and make pit stops on their way to warmer weather. During the spring and summer months, many birds make their nests within the wetlands and raise their young within native vegetation.
The Bolsa Chica wetlands are an important ecological site for migrating birds in western North America. These wetlands play a critical role in supporting the survival and breeding of several bird species, making them an essential part of the local ecosystem.
Photo by Carrie Knoll
Salt marshes like the Bolsa Chica estuary provide shelter, food, and nursery grounds for a variety of fish. Adult fish typically lay their eggs on the marsh floor, growing and drifting with the current. As offspring grow, they become free-swimming fish occupying different marsh depths.
Benthic fish: Benthic fish are those that live and eat primarily on the bottom floor of a body of water. These types of fish have diverse body structures that have developed to serve certain niches. For example, the round rays have a flattened body that allows them to glide closely over bottom sediments to better search for prey.
Photo by Rebecca Pry
Nektonic fish: Nekton fish are those that can swim independently of currents. These types of fish range greatly in size and can act as indicators of ecosystem health! Many species are capable of transferring organic material from intertidal and subtidal habitats in a salt marsh, so their presence is a good sign of a healthy environment.
Wetland ecosystems overall provide a multitude of benefits to the environment. In fact, wetlands are one of the most productive ecosystems in the world, along with rainforests and coral reefs! Here are some ecosystem services the Bolsa Chica salt marshes provide to wildlife and humans:
Fishing Industry
- Wetlands support more than 75% of commercial and recreational fish populations by providing food, refuge, and nursery habitat. Thus, our salt marshes help sustain a global industry worth billions of dollars.
Runoff Support and Erosion Control
- Wetlands protect coastal towns by absorbing the influx of water during storm surges and by slowing the effects of runoff. In addition to mitigating the effects of storms, salt marshes serve as a protective barrier for shorelines by absorbing wave activity and capturing sediments to prevent erosion. As storms become more frequent and intense, salt marshes are more important than ever to be protected.
Nutrient and Pollutant Control
- Salt marshes are also beneficial for their ability to filter polluted runoff and excess nutrients, therefore protecting the water quality of coastal bays, sounds, and estuaries. This ability helps give ocean communities clean water, allowing oyster reefs and seagrass beds to thrive.
- In addition to pollutant control, salt marshes are also known for their ability to absorb and retain carbon, which is an important factor in mitigating the effects of climate change. Through the process of carbon sequestration, these wetlands act as a natural buffer, absorbing carbon dioxide from the atmosphere and storing it in the soil. This helps regulate the Earth’s climate and provides a valuable service to our planet. Therefore, it is crucial that we continue to protect and preserve these important ecosystems.
