Archives for February 2011

Volunteer Water Quality Monitoring

Volunteers are needed to collect water quality samples and take basic water chemistry measurements one Saturday per month. This program is in partnership with San Diego Coastkeeper, Surfrider San Diego and the Tijuana River National Estuarine Research Reserve. More information can be found on the San Diego Coastkeeper website.

Thank You Think Blue!

Funding from Think Blue San Diego made the TRNERR website redesign possible.

San Diego Plant Atlas

The San Diego Plant Atlas is now even easier to use.  This is a great resource that is underused.  To find every single plant that has been collected in the Reserve, go to the plant atlas website.

  1. Once at the website go to the toolbar on top to Reference.
  2. On the dropdown menu click on Collected in Your Area.  Google Earth will activate and take you to San Diego County with little flowers indicating each grid in the atlas.
  3. Click on the two most southwesterly set of flowers at the bottom left of the map.  You want grid V-10 and W-10.

You can also see every plant that has ever been collected by:

  1. Going to the dropdown menu that says Database Search.
  2. In the dropdown menu click on either search a map polygon or search a map rectangle.
  3. Once you define an area, follow the prompts and a list will be displayed showing every single plant that has ever been collected by anybody in that area.

Voucher specimens collected are now in the museum herbarium at the San Diego Natural History Museum.

Learn More:

Introduction to TRNERR Plant Communities

As much as 70% of the Tijuana River National Estuarine Research Reserve is made up of wetland area. This Reserve contains a variety of unique habitats, including dune, salt panne, salt marsh, mudflat, brackish pond, riparian, coastal sage scrub, and vernal pool. Unique characteristics distinguish one habitat from another. Changes in elevation of a few inches, the presence or absence of salt water or soil type are variables that determine which plants or animals can live in each distinct habitat. Each habitat maintains its own world of inter-dependant life forms.

In an attempt to protect native vegetation and disappearing habitat, Reserve and Refuge staff along with volunteers constantly battle non-native plants while continuing to plant native ones. These native plants provide vital habitat, nesting area and food for native animals, which is desperately needed in Southern California where over 90% of its coastal wetland habitat has been lost to development.

Many people are unaware that plants can be on the endangered species list too. In 1977, the first plant species were listed as endangered – San Clemente Island Indian paintbrush, San Clemente Island larkspur, San Clemente Island broom and San Clemente Island bush-mallow. The Tijuana Estuary is home for one endangered plant called the Salt Marsh Bird’s Beak (Cordylanthus maritimus). It is an annual that grows in the upper marsh and the Tijuana Estuary is one of only 10 locations where the Salt Marsh Bird’s Beak is found. Salt Marsh Bird’s Beak (below) uses Shoregrass (Monanthochloe littoralis) as a host plant.


Plants of the Tijuana River NERR can be divided into sections according to habitat:

  • Salt Marsh
  • Upland
  • Cacti and Succulents
  • Beaches and Dunes
  • Riparian

The plants are listed by their common name, in English and Spanish, and their scientific name.

For more information on the Endangered Species Listing Program or to view the Federal Register of endangered species visit:

Non-Native Plants

  • Why are invasive non-native plants so problamatic?
  • Monthly Community Stewardship Events
  • Native Plant Propagation
  • Invasive plant removal
  • Sources and contacts for native plants and seeds

Learn More:

TRNERR Mammals

The most commonly seen mammal at the Reserve is undoubtedly the desert cottontail (not to be confused with the brush rabbit). They can be seen around the visitor center, darting across the trails, or lying in the shade in the coastal sage scrub. Visitors who hike to the rivermouth via the 5th and Iris St. trail should keep an eye out for Black-tailed Jackrabbits, which are much lankier and larger than their cousins.

Desert Cottontail (Sylvilagus audubonii)

In general, mammals are much harder to spot than reptiles and birds due to their nocturnal (active during the night) or crepuscular (active during dawn and dusk) nature. Other mammal sightings within the Reserve include Long-tailed Weasels, California Ground Squirrels, California Voles, Deer Mice, Coyotes, and even Gray Foxes. Striped Skunks, Opossums, and a few species of bats are known to be around at night.


Learn More:

How does pollution affect the estuary?

Sewage pollution undoubtedly impacts the estuary and river. However, despite this pollution, the salt marsh remains one of the best examples of a healthy, functioning marsh in southern California. The Tijuana Estuary is an intact system with extensive marsh vegetation and is open to tidal flushing (which increases nutrient and oxygen flow). This helps alleviate the pollution problem.

The salt marsh is a very resilient ecosystem (it actually filters out much of the sewage) and remains fairly stable. In fact, excessive fresh water released on both sides of the border can be more problematic, as it throws the estuary’s ecosystem out of balance. Sediment and trash represent a serious threat as they can smother and damage wetland habitat.

  • Is there a lot of pollution in the area?
  • What is being done about pollution in the Tijuana River watershed?
  • What is being done about pollution in the Tijuana River watershed?

    The Reserve’s Watershed Program works in Mexico on issues that directly impact the Reserve.  More information coming soon…

    The Reserve works closely with the Tijuana River Valley Recovery Team, as well as local non-profits and agencies that raise awareness about pollution in the Tijuana River Valley.  For information on clean-up events, contact our Volunteer Coordinator at (619) 576-3613 ext. 330, volunteer(at)


    Find out more: