Falling in Love With Wetlands

Falling in Love With Wetlands

Home to some of the state’s most unique and fascinating flora, California’s wetlands are critically important – and under threat again.

Spring/Summer 2024 · By Kristen Pope

As a child, Carol Witham would hop on her bicycle in San Bernardino and pedal until she reached a nearby wetland, where she and other neighborhood kids would while away the hours building forts, catching frogs, searching for any number of other critters, and fashioning creations out of cattails.

“Every kid should grow up down the street from a wetland that they can go play in with frogs and water fleas and you name it, mud, and all of that other stuff,” Witham says. “I think that is one of the all-time most enjoyable childhood memories I have. It was an incredible outdoor adventure place for me. I think it really engages children in particular with nature, because children aren’t afraid of creepy crawlies, of worms or dirt, so their appreciation of nature skyrockets when they can go out and actually play with the nature. It really, really changed my appreciation for the outdoors.”

Dredging up History

Over the last century, wetlands have been drained, filled, diked, or otherwise altered in ways that prevent them from fulfilling their natural ecosystem functions. Many have been displaced by agriculture and development. These areas, which tend to be flat and expansive, entice farmers to grow crops and developers to build neighborhoods. Today, just 2.9 million acres of California wetlands remain.

“We have siphoned water from the ground and lowered our groundwater levels so that they’re no longer within the reach of roots of plants that used to thrive off of that source of water,” CNPS Vegetation Ecologist Jennifer Buck-Diaz says. “There are many alterations that have already occurred and that continue to occur, and our growing human population stretches thin an already finite resource.”

This isn’t a problem unique to the Golden State. All over the country, wetlands are under attack. Recently, the U.S. Fish and Wildlife Service released a report prepared for Congress called “Status and Trends of Wetlands in the Conterminous United States 2009 to 2019” that says wetland loss has increased more than 50% in recent years. The report notes that in 2019 wetlands covered less than 6% of the land in the Lower 48, approximately half of the historic acreage.

These losses aren’t news, however, says coastal plant ecologist Peter Baye. They were in fact the basis for the original Clean Water Act protection of wetlands in the 1970s. What’s newly concerning is that a 2023 U.S. Supreme Court decision (Sackett v. Environmental Protection Agency) significantly narrows the protections of the Clean Water Act. The ruling largely leaves wetland protection up to individual states, and it may take states years to bridge the legislative and operational gaps created by the ruling.

“Until California can map out a strategy, many wetlands are literally abandoned,” says CNPS Board Vice President and consulting biologist Vince Scheidt.

California has had a state administrative policy since 1993 to ensure “no net loss” and instead a “long-term gain” of wetlands. However, despite this policy, the state has continued to lose wetlands. This year, in response to the weakening of federal wetland protections, Assemblymember Laura Friedman (D-Burbank) introduced Assembly Bill 2875 to make the state wetlands policy a law. By putting this administrative policy into statute this year, California would signal its focus on protection and restoration of wetlands even as the federal government is stepping back.

Once maligned, now known to be vital

Wetlands are irreplaceable for the biodiversity they support and the many services they provide. Sometimes called the “Earth’s kidneys,” many serve as massive water filters, removing sediment, excess nutrients, and even pollution before waters pass through to lakes, rivers, or other bodies of water. When extreme storms hit California, they store and slow floodwaters, which can reduce damage to property and even save lives.

These unique ecosystems are also a crucial and often overlooked source for carbon sequestration that helps with groundwater recharge. Wetlands allow water to gradually seep into the earth and replenish underground water stores that have often been depleted by wells and agricultural uses. During extreme droughts, these areas can also serve as refuges for plants and wildlife that would normally live in drier areas.

As Witham noted in her childhood memories, wetlands are also just a nice place to spend time. According to the U.S. Fish and Wildlife Service, recreational activities create billions of dollars in economic benefits in wetland areas, where people enjoy hiking, canoeing, fishing, and hunting. Birding is also a popular activity since around half of bird species in North America use wetlands either for nesting or to find food.

 Wetlands are irreplaceable for the biodiversity they support and the many services they provide.

Unfortunately, people didn’t always recognize the many benefits wetlands provide. Though Indigenous California Tribes successfully lived with and managed wetland environments for millennia, people moving into the region opted to permanently alter the land.

“In the past, wetlands were seen as a nuisance,” says Scheidt. “They were in the way of land development, and they provided no value. They were seen as being just festering, mosquito-laden centers for disease essentially. They weren’t recognized for what they were, so they were treated with contempt.”

Converting wetlands into other things—like tracts of housing—can also backfire, especially when human-built areas are located in former floodplains and are subject to inundation by storms and extreme weather.

“We have taken so much of the landscape that was naturally prone to flooding—and good at attenuating floods, trapping sediments, and sequestering nutrients and carbon—and we put it into agriculture and low, flat developments that didn’t require grading,” says Baye. “With changes in climate and sea level rise, a lot of those areas are hydrologically pushing back into what they naturally were, and we’re noticing that many of those conversions weren’t particularly sustainable.”

Home to a Dazzling Array of Life

A huge number of animals and plants call wetlands home; many find wetlands to be the perfect place for breeding and raising their young. “Water is life—And everything needs water to survive,” Buck-Diaz says. “So wetlands provide that for every living being, whether it’s a plant or a human or an animal.”

Endangered and Threatened species are especially reliant on the ecosystem services of wetlands. More than one-third of these federally protected species live only in these habitats, and half use wetlands in some way.

Resident species as varied as wood ducks, oysters, Dungeness crabs, and cattails rely on the ecosystem services of wetlands, as do the migratory waterfowl and shorebirds of the entire Pacific Flyway. Wetlands are also home to unique creatures like the California clam shrimp, which has 14 pairs of appendages and a strange way of swimming. When it wants to, it can even close up its shell and float to the bottom of the pool, where it is a filter feeder.

In the Lower 48 states, nearly one-third of plant species live in wetlands. Hydrophytes are water-loving plants found in wetland areas, including familiar marsh plants like duckweed, cattails, horsetails, bulrushes, and many sedges.

More than 40 wetlands around the U.S. have been designated as Ramsar sites, recognized as “Wetlands of International Importance” for their rare and unique characteristics and/or because they are very important for biodiversity. Seven of these sites are in California, including the Tijuana River National Estuarine Research Reserve to the south, as well as half a dozen sites around Northern and Central California, from the San Joaquin River Basin to Elkhorn Slough, San Francisco Bay Estuary, Bolinas Lagoon, Tomales Bay, and the Laguna de Santa Rosa Wetland Complex.

The Laguna de Santa Rosa Wetland Complex in Sonoma County is home to rare endemic plants like Sonoma sunshine (Blennosperma bakeri), and a wealth of wetland types, including marshes, ponds, riparian forests and grasslands, and vernal pools.

For many months of each year, vernal pools are dry, and they can vary in size from being small enough to fit in your living room to more than 90 acres in size (like Olcott Lake). You might walk by one without even noticing it’s there. But when winter rains start to fall, the drops gather and accumulate in the vernal pool indentations in the ground, which have impenetrable clay layers underneath that the water cannot soak through. As the water accumulates, a world of life opens up.

California’s vernal pools provide habitat for more than 200 plant species, and half of these species only grow in vernal pools.

In spring, a dazzling display of “fairy rings” can form around the pools, with rings of flowers in varying shades as dozens—or more—species of plants bloom at once. During the short spring season, these rings can change colors as older blooms fade away and new ones rapidly grow and burst open. The pools are also home to a curious array of lifeforms, like fairy shrimp, tadpole shrimp, and the California tiger salamander. With only a few months of water in vernal pools, the species that use them must speed through their life cycle, being sure to breed and lay eggs before the pond dries out under the summer sun. Amphibians must have their larvae go through metamorphosis and turn into a juvenile that can survive in terrestrial habitat before the water disappears. When the vernal pool dries up, the eggs (also known as cysts) and plant seeds that are left behind dry out in the sun, waiting for winter rains to return and rehydrate them to create yet another burst of life as the cycle continues.

California’s vernal pools provide habitat for more than 200 plant species, and half of these species only grow in vernal pools. One example is Sacramento Orcutt grass, which is an endangered plant that lives in the deepest part of vernal pools, where the water remains the longest. It is only found in a small area in eastern Sacramento County.

Vernal pools are sensitive to disturbance and Witham can tell the proximity to the roadway of each pool based on the responses to disturbances that she observes. She says pools near roadways typically hold water for a longer period of time since the impermeable road surfaces nearby will often funnel water into the pools earlier. She also says the hydrocarbons from runoff change the nutrient cycling and composition of aquatic organisms and plants. Vernal pools near roadways also tend to be weedier due to both more sources of weeds nearby and the increased nutrient load in the runoff water.

“I can tell you how close a vernal pool is to a road based on the amount of algal growth and opportunistic species versus endemic species and things like that,” Witham says. “A lot of that has to do with atmospheric nitrogen deposition and then additional nutrient deposition from roadways.”

One of the places where people can see vernal pools is in Jepson Prairie in Solano County. The prairie is home to Olcott Lake, a 93-acre vernal pool, and harbors a wide array of life, including 400 species, 15 of which are rare and endangered plants, and five of which are rare and endangered animals. Jepson Prairie is home to California Tiger Salamanders, Pacific Chorus Frogs, Conservancy Fairy Shrimp, Vernal Pool Tadpole Shrimp, and Delta Green Ground Beetles, a federally listed threatened species endemic to Jepson Prairie and nearby.

Addressing ongoing threats

Even with all its wonders, Jepson Prairie’s vernal pools and other wetland habitats are in danger from aggressive development proposals and reduced environmental regulations. In Solano County, wetlands advocates are concerned about the East Solano Plan, which would be located near Jepson Prairie and could one day house up to 400,000 people—if the project is approved.

Flora readers can take meaningful action to protect wetlands in a number of ways, including by participating in public comment periods for proposed projects, reaching out to elected officials about proposals, and helping to educate others as a docent and guide for wetlands walks. The first step is knowing what’s going on.

“People should pay attention to what’s around them, and always be cognizant of what land use changes are being proposed within their area,” Witham says.

“Encourage whatever land use authority—whether it be the city, the county, or the state—to do thorough and appropriate biological baselines of these areas in order to determine what may or may not be lost, and to make public the environmental impacts of a project so the public can then make recommendations and suggestions to improve the project to reduce environmental impact.”

Being aware of local issues and taking the time to cast a ballot in every election is also crucial. “It’s more political than anything else, so [people] just have to vote,” Scheidt says.

Local groups—including CNPS’s 36 chapters around the state and in Baja California, Mexico—can also offer many ways to get involved with local projects to benefit wetlands, from a trash clean-up day to opportunities to learn more and educate the public about the value of protecting wetlands. Last year, for example, the CNPS San Diego Chapter cleared 16 tons of trash from the 10-acre Arjons vernal pool site.

“Find out if there are local wetlands nearby and whether or not there’s a docent group that leads public tours of those wetlands,” Witham says. “That is a great way to get involved… the more we can educate people about the value of these resources, the more they cherish them, and the more people will speak out when there are proposals to eliminate important wetlands.”

It’s important to get involved because when we lose wetlands, we lose a lot, from climate benefits to wildlife. “Once you take that away, you really can’t put it back,” says Witham. “Whatever you end up putting back never functions as thoroughly or as well as the natural ecosystem.”

Examples of Wetlands

Wetlands go by many names. The National Oceanic and Atmospheric Administration (NOAA) classifies five types of wetlands: marine, estuarine, riverine, lacustrine (lakes), and palustrine (marshes). More commonly, people call these marshes, swamps, fens, vernal pools, and mangroves. They also vary in terms of soil, water chemistry, vegetation, climate, topography, and other characteristics. Around 95% of U.S. wetlands are freshwater, with the remaining saltwater or brackish, a mix of fresh and saltwater. While they vary widely, they share one commonality: all are saturated with water, at least part of the time. Some are seasonal or ephemeral in nature, making them especially vulnerable to development.

1. Marshes

Rich in nutrients, marshes host abundant life, including plants that have adapted to saturated soil conditions. These areas, which help reduce erosion and protect areas from storms, are inundated with water frequently and sometimes constantly. Marshes can contain fresh or salt water or be “brackish” (somewhere in between the two). They also contribute water to streams—which is especially helpful during droughts—and can also hold floodwater to reduce damage, as well as filter pollutants and sediments. Nontidal marshes are generally freshwater and can contain plants like cattails and bulrushes. Tidal marshes are influenced by ocean tides; though, they may have salty, fresh, or brackish water. The brackish Suisun Marsh is the largest wetland complex in the Pacific states.

2. Swamps

Swamps are wooded wetlands, mostly freshwater or slightly brackish, forested with shrub vegetation. Swamps have very wet soils during much of the year and often contain standing water. Trees and shrubs are prevalent in swamps, and many in California occur along the poorly drained edges of lakes and rivers, including portions of riparian zones with soggy soils that are flooded or saturated most of the spring and summer. Most in Central California have been drained or cleared for agriculture, but swamps still occur in parts of the Sacramento-San Joaquin Delta and North Coast.

3. Vernal Pools

Vernal Pools are a type of seasonal wetland that can be characterized as a non-tidal marsh. An impermeable layer of clay or bedrock underneath this depression allows precipitation to pool in these indentations. Water lasts in them for varying periods of time, based on the amount of initial water and environmental conditions, but they dry out periodically, often annually. An array of dazzling flora and fauna use these unique wetlands as habitat, and during spring, many erupt with rings of wildflowers. They occur in varied kinds of basins and valleys in California, and in many different geologic and soil settings that frame their high biological diversity.

4. Fens

Fens also contain peat, though they receive runoff and other sources of nutrients, so they have higher levels of nutrients and lower acidity than bogs. They often are found in areas with short growing seasons and low temperatures, and these areas are home to sedges, rushes, grasses, and an array of wildflowers. Fens provide ecosystem services such as stemming flooding and boosting water quality. They occur in montane and northern coastal settings in California. Some wonderful, visitor-accessible examples of ancient fens include Inglenook Fen and Sand.

5. Outliers

California also includes wetlands that fail to fit neatly into NOAA classification, such as California desert playa, dry lakebeds that flood intermittently. One example is Rosamond Lake in the Mojave Desert outside of Lancaster.