TIJUANA RIVER NATIONAL ESTUARINE RESEARCH RESERVE

August 16, 2005 — The Tijuana River National Estuarine Research Reserve lies in the extreme southwest corner of the continental United States. The TRNERR is owned and managed cooperatively by multiple local, state and federal agencies, with funding provided by NOAA. The primary land managers are California State Parks and the United States Fish and Wildlife Service. Support for reserve operations are also provided by the Southwest Wetlands Interpretive Association, a non-profit focused on restoration, education and research.

The 2,500-acre reserve is situated in a unique and dynamic location that presents many challenges and opportunities. The TRNERR lies between the major metropolitan areas of Tijuana; Baja Calif.; Mexico and San Diego, Calif., and the southern boundary of the reserve is the U.S. — Mexico border. The Tijuana River itself flows through the Mexican towns of Tecate and Tijuana before entering the United States approximately 3 miles east of the Pacific Ocean. Almost three-quarters of its watershed lies within Mexico.

The reserve’s landscape is dominated by coastal salt marshes, dunes, riparian corridors, upland transition zones and coastal mesas. Overall, the system is relatively intact compared to other southern California estuaries, as it is not cut by roads and railways. However, like other estuaries in the region, it has been dramatically impacted by human activities. Major problems include exotic species, sewage pollution, filling of marshes and sedimentation.

Stewardship and Conservation
The marsh loss due to historical filling and sedimentation, brought about largely by the settlement and denudation of the Tijuana hillsides adjacent to the reserve, have
led to a marked loss in the volume of water that circulates into and out of the system with the rising and falling tides. To remedy this loss, an ambitious plan was developed to restore the historic circulation of the system by excavating filled marshes to depths where they are under the influence of tidal action.

The Tijuana Estuary Tidal Restoration Program has identified 200 acres in the reserve with restoration potential. In addition to the restoration of tidal circulation and habitat, a primary goal of TETRP is to beneficially use any excavated material. Specifically, the TRNERR would like to use this sediment to nourish eroding barrier beaches at the reserve. TETRP is being implemented in modules as an adaptive restoration plan, with lessons learned from each phase applied to future efforts. There have been two phases to date, and the third is in a design and feasibility analysis.

The invasion of exotic species is another serious threat to the integrity of estuarine ecosystems. In the Tijuana River Valley, several ecosystem-altering invaders are becoming much more abundant. These include tamarisk (or salt cedar), the giant reed Arundo donax, and castor bean (which is toxic). To address these invasions, the TRNERR has initiated an invasives control program, which should slow the invasion and facilitate the recovery of native species (i.e., spiny bulrush and pickleweed) in this sensitive and threatened ecosystem.

Research and Monitoring
The international scope of the Tijuana River watershed, the diversity of habitats, and the range of human and physical problems facing the reserve make it an area rich for study in both the life and social sciences. The TRNERR's research and monitoring programs are guided by national plans (such the NERR Strategic Plan) that identify goals, priorities and implementation strategies for all the NERRs, as well as research needs specific to the TRNERR. This approach, when used in combination with TRNERR education and outreach programs, helps ensure the availability of scientific information that has long-term, system-wide consistency and utility for managers and members of the public to use in protecting or improving natural processes in their estuaries.

The monitoring program at the TRNERR consists of both continuous and periodic measurements of various oceanographic parameters, conducted as part of NERR System Wide Monitoring Program (also known as SWMP). This is coupled with additional monitoring of wetland vegetation, fish, invertebrates and birds. The primary research questions being addressed at the reserve relate to our two most pressing conservation issues: invasive species and restoration — both of which feed into the TRNERR stewardship and restoration efforts (described earlier). These research and monitoring efforts have already assisted in converting invasive tall thickets of tamarisk back into its original low lying succulent plains. Likewise, once-buried salt marshes have become wetlands again, and the study of this process is yielding important insights into restoration science.

Education
The goal of the TRNERR education program is to use the environment to engage students through “real world” learning experiences and provide quality environmental education, while focusing on the estuarine habitat. Specifically, it aims to provide college level educational opportunities to high school students and a unique arts program to explore the interpretive themes of the estuary. Multi-cultural programs, including education about native American history and the use of the region, are also provided.

The Tijuana Estuary offers free visits to elementary, middle and high school groups and other youth groups (ecology clubs, service groups, etc.). School visits to the Tijuana Estuary are theme-based and meet California state education standards. For example, the "Tijuana Estuary Explorers" (targeting 3rd, 4th and 5th graders) is an in-class and field trip program that incorporates reading, writing and science into four comprehensive activities about the Tijuana Estuary and its watershed. The “Marsh Awareness with Resources for Slough Habitats” (also known as MARSH) is an educational program for grades 1 to 6, designed to introduce students to basic wetland and upland ecology and cultural history. The TRNERR staff also recently completed an inter-disciplinary “Tijuana Estuary High School Teachers' Guide” that contains a curriculum designed to educate students about the valuable TRNERR natural and cultural resources — making it the only field-based estuary science high school program in the county.

Coastal Training Program
Faced with rapid growth and enormous development pressures, natural and human environments are in a constant struggle to coexist in the San Diego-Tijuana coastal region. To address these needs, the mission of the TRNERR Coastal Training Program is to provide accurate science-based information and training for those individuals and organizations whose daily decisions affect the health of this coastal region. The TRNERR also aims to improve coastal resource management on both sides of the U.S.-Mexico border through a progressive program of partnerships, collaboration and high quality "cutting-edge" information exchange.

Relevant Web Sites
NOAA Oceans and Coasts Service

National Estuarine Research Reserve System

Tijuana River Reserve, California

NOAA SEEKS REMEDY FOR INVASIVE TREE SPECIES THREAT
TO CALIFORNIA SALT WATER MARSH

Media Contact:
Glenda Powell , NOAA Ocean Service, (301) 713-3066 ext. 191 or Ben Sherman, NOAA Ocean Service, (301) 713-3066 ext. 178