MONTHLY NEWSLETTER

October 2025

Do you remember these classic horror movies— the Creature from the Black Lagoon, Swamp Thing and The Legend of Boggy Creek? What do swamps, bogs and marshes all have in common besides being settings for scary movies? They are all types of wetlands and, far from being scary, they are essential to our health and the well being of our planet.



As we begin wading into wetlands, we better make sure to have some tall boots on; things can get complicated and confusing fast. Wetland classifications and definitions vary depending on the source. In fact, the Federal government uses one designation for wetlands, while the state of California has another.

In California, wetlands are designated by three properties:

1. Hydrology: The area where plants can root and grow is filled with water (saturated).
2. Hydric Soils: The saturated soil causes anaerobic conditions (no oxygen).
3. Hydrophytic Vegetation: The vegetation in the area is dominated by plants that grow either partly or totally submerged in water (aka hydrophytes) or the area is lacking vegetation. (CA Water Boards)

Federal wetlands management is overseen and regulated by the US Army Corps of Engineers and also by the Environmental Protection Agency and the US Department of Agriculture. Federal wetlands lost some protections and their designation became more confusing in 2023. The Supreme Court ruled that a wetland, to gain federal protections under the Clean Water Act as “waters of the United States,” must bear a “continuous surface connection” to perennial navigable waters. 

Our local and regional conservation plans do not include coverage for wetland impacts—they still require a separate permitting process through state and federal agencies

Adding another layer, the CA Coastal Commission plays a role in protecting wetlands too. Their jurisdiction extends 3 miles out to sea and varying distance inland. Impacts in those areas require Coastal Development Permits from the Commision. All jurisdictions along the coast are required to update their Local Coastal Programs to address Sea Level Rise by 2035. 

Flowering SD button celery. Photo credit Pacific SW Region USFWS.

Large vernal pool at the south end of the Poinsettia Station Vernal Pool Preserve. San Diego button celery is visible growing throughout.

Photo credit: Scott McMillan

With fewer federal protections, this could open up wetlands to more development and more pollution. At stake in California are seasonal streams, ponds and vernal pools, which are only saturated with water part of the time. This would exclude them from wetlands designation under the Supreme Court ruling since they are not continuous. In California, an estimated 80% of all linear miles of streams and rivers are ephemeral or intermittent. And already at risk vernal pools (read more April 2025) would lose vital protections. California will ensure that these waters of the state will continue to be protected even if protections for federal waters are narrowed by administrative actions or the courts.

Although it is estimated that wetlands only make up 4-6% of earth’s land surface, they are among the world’s most productive and biologically diverse environments—rivaling rainforests.

The outsized role of wetlands in maintaining healthy ecosystems is often compared to the job our kidneys do for our bodies; filtering and remove pollutants. Wetlands do this by slowing down water as it travels through the watershed. This allows suspended materials in the water to settle out so pollutants are trapped before reaching the ocean. Some of the pollutants are absorbed within soil layers and some taken up by plants. Soils and plants are able to break down many of the pollutants over time using their biological processes.

Imagine wetlands acting as the kidneys in your body and helping to purify our environment. Illustration credit University of Florida.

The graphic below from the National Oceanic and Atmospheric Administration describes the value of Coastal Welland Habitat.

California has lost more than 90% of its historical wetlands and today, many of the remaining wetlands are threatened.

Wetlands continue to be drained for agriculture, dewatered from groundwater withdrawals, filled for development, or disturbed by changes to the watershed such as dams or water diversions. Pollution and invasive species have also contributed to wetland loss. Climate change poses a significant threat, as many wetlands today are dependent on artificial water delivery systems or high groundwater levels, and may be impacted by changing climatic conditions. Further, wetlands along the coast face flooding from potential sea level rise. (Source)

Sea level rise is also causing saltwater to move inland, which is then mixing with the fresh groundwater and other freshwater systems (such as marshes) along the coast. This impacts humans and wildlife that are dependent on freshwater. This process is known as saltwater intrusion. Please read more about saltwater intrusion and its threats to the freshwater supply: USGS

Wetlands are essential habitat for waterfowl, shorebirds and other wetland-dependent species.

California's wetlands provide stopover, wintering, and breeding habitat for vast numbers of waterfowl along the Pacific Flyway—the bird-migration corridor extending from the southern tip of South America to Alaska. 

Below, snow geese stopping off along the flyway at the Sacramento National Wildlife Refuge Photo credit: Jenn Bowles, Water Education Foundation.

Above: Light-footed Ridgway's rail at Buena Vista Lagoon.

Photo by Jane Mygatt

Below: Whelan Lake, a freshwater marsh in Oceanside. At right, Canadian Geese stopping by the lake. Photo credits: Whelan Lake Bird Sanctuary.

Because of their critical role, wetland habitats have the highest level of environmental protection.

A potential project impacting wetlands is first obligated to eliminate impacts and, if that is not possible, mitigation is used. Land use mitigation refers to purposeful actions taken to lessen the adverse impacts of human activities on the land and to the environment. The CA Coastal Commission has generally accepted that permanent impacts to wetlands are mitigated at a 4:1 ratio. This means that four acres of mitigation would be required for every one acre of impact on the wetland. In contrast sensitive Coastal Sage Scrub habitat is generally mitigated at a 2:1 ratio. 

Wetlands Delineation: How do you find the boundaries of a wetland area?

Wetlands can be deceiving as some wetlands are only wet on a seasonal basic. Some may only hold water for 6 weeks of the year, but they are still classified as wetlands.

If a suspected wetland is present on a site, the Environmental Impact Report has to include a formal wetland delineation. This is a procedure to find the boundary between a wetland and upland; the approximate extent and location of wetland on the site of interest.

For example, the marked up image above indicates the upland, wetland, and stream. The red line marks the boundary between a wetland and an upland. The blue line marks the boundary between a stream and the wetlands on either side of the stream’s banks. Photo credit: Princeton Hydro. And if you have ever wondered what your day would be like as an environmental scientist doing a wetlands delineation, you will enjoy checking out Princeton Hydro's: A Day in the Life: Performing a Wetland Delineation!

Five major wetland types are generally recognized-- but that's complicated too!

Below are the five general types of wetlands but there also various ways they can be classified.

• marine: coastal wetlands including coastal lagoons, rocky shores, and coral reefs
• estuarine: including deltas, tidal marshes, and mangrove swamps
• lacustrine: wetlands associated with lakes, reservoirs, and large ponds 
• riverine: wetlands along rivers and streams
• palustrine (meaning marshy):marshes, swamps and bogs, fens

If you would like to dive into the classification and definitions of wetlands, the US Geological Survey gives a nice historical perspective: LINK

Below: San Elijo Lagoon, a primarily shallow-water estuary (photo by Rennett Stowe)

On September 20th, El Salto Falls (aka Quarry Creek) was one of around 100 sites around San Diego County that was part of the I Love a Clean San Diego's Coastal Cleanup Day. Once again, Preserve Calavera sponsored the site along with the San Diego Habitat Conservancy (SDHC).

Mel Vernon, Tribal Captain, San Luis Band of Mission Indians, was at the site and spoke to volunteers about its history and significance for the Luiseño people.

El Salto Falls has been identified by the Luiseño people as a sacred site for tribal religious ceremonies and its significance in their cultural history. It is also home to endangered, threatened and sensitive animal and plant species—including the least Bell's vireo, a small song bird placed on the endangered species list back in 1986 due to its loss of habitat.

Least Bell's Vireo photo by Wendy Miller

Above, Mel Vernon (far left) with site captains Vince Rivas (blue shirt) and Diane Nygaard (at right holding sign).

Volunteers signing in Saturday morning before the clean up. The fence that was erected in 2023 is visible near the top left of the photo below the tree. (photo by E. Bartlett)

BY THE NUMBERS:

44 volunteers

403 pounds of trash

200 pounds of recycling material

40 pounds of scrap metal

15 shopping carts

And volunteers helped remove invasive weeds along the creek; targeting castor bean and Virginia creeper.

Below left, Vince Rivas (SDHC Conservation Habitat Manager) tagging invasive castor bean for removal. At right Justin Gamble (City of Oceanside, Sustainability Program Administrator) deftly wielding a machete to remove the castor bean plant.

As we were wrapping up the clean up, we noticed a great egret perching atop a willow tree along the creek. Cleaning up the creek is not just for the humans but for all of the wildlife that calls El Salto Falls home. The planet belongs to all creatures great and small so let's work at keeping it clean. Photo by GT Wharton.

Your Halloween Decorations Can Entangle Real Bats

Bat themes are all around us during the Halloween season, but no one wants to accidentally injure a live bat. 

Please don’t use fake cobwebs outdoors for Halloween décor. It can entangle bats and birds and all kinds of other small victims, such as this Mexican Long-tongued bat. He was rescued and released, lucky to be unharmed by his ordeal. (photo credit Dick Wilkins)

You can read more about bats in our August 2024 Newsletter.

Pickleweed: a salt marsh plant

Pacific Pickleweed (Salicornia pacifica) is a low growing succulent that is native to California. The name pickleweed comes from the pickle-like appearance of its stems, along with its salty taste. Its special adaptions allow it to thrive in high salt areas. Pickleweed grows prolifically along salt marshes and beaches along the coast. If you visit the Buena Vista Lagoon Nature Center and walk along the trail, pickleweed abounds. It is an important food source and shelter for many creatures.

Pickleweed species are found in salt marshes and along coastal regions worldwide.

How is pickleweed able to live in salt water?

When salt water is taken up by the plant, the salt is removed and stored as a concentrated brine solution in vacuoles at the ends of its stalk segments. A vacuole is a large storage compartment within the cell that is able to keep the harmful salt separated from the rest of the cell. In late summer and early fall, the stem tips begin turning red as a result of salt accumulation. Chlorophyll in the stems, the pigment for photosynthesis, gives the plant its green color. Chlorophyll begins to degrade in the tips where the salt is stored. The red color results from another pigment called anthocyanin which is produced when the cells begin to break down as the vacuoles become overfilled with salt. The red stem tips eventually fall off— which does the job of removing the salt from the plant.

Pickleweed above is predominantly green with some reddish-pink coloring at some stem tips.

Below large portions of the stems are a deep red color from the pigment anthocyanin.