Development of Regional Objectives for Southern California Coastal Wetlands using
Landscape-level Metrics
Restore America’s Estuaries
December 13, 2016
Jeremy Lowe, San Francisco Estuary Institute
Upper Newport
1. Gaviota Coast
2. Ventura Coast
3. Santa Monica Bay
4. San Pedro Bay
5. San Diego Coast
Point ConceptionCounty Line (Santa Barbara/Ventura)
Santa Monica Mountains
Palos Verdes
Tijuana
San Onofre Mountains
1. Bight-wide objectives
2. Sub-regional objectives
3. Management recommendations
Southern California Bight
Habitat Losses
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Bight GaviotaCoast
VenturaCoast
SantaMonica Bay
San PedroBay
San DiegoCoast
Marine
Non-wetland
Non-tidal wetland
Different estuarine wetland
No change
Structure of Objectives
• Total Estuarine Area
• Habitat Distribution
• System Coherence
• Archetype Distribution
• Wetland Size
• Transition Zones
• Physical and Hydrologic Processes
Bolsa Chica
Historical Present
Total Estuarine Area
Tijuana
Present Future
Expand overall estuarine area toward historical levels, constrained by development with 0.6m sea level rise.
Total Estuarine Area
Tijuana
Total Estuarine Area
0
50
100
150
200
250
300
350
400
Historical Present UndevelopedExtent
Are
a (h
a)
Tidal Marsh
Intertidal Flat
Subtidal
Future: SLR 0.6m
Total Estuarine Area
Realize a total of 8300 ha by
maintaining the existing 4200 ha and
restoring an additional 4100 ha.
27%, 2270 ha
19%, 1570 ha
54%, 4480 ha
Area = 8320 ha
Subregion Restore
Gaviota Coast 280 ha
Ventura Coast 1660 ha
Santa Monica Bay 170 ha
San Pedro Bay 1160 ha
San Diego Coast* 810 ha
Bight 4100 ha
Habitat Distribution
Approximate the historic distribution of habitat types and provide redundancy of habitat types across systems in the region.
Ballona Santa Ana
Habitat Distribution
Subregion % Tidal flats % Marsh
Gaviota Coast 29% 50%
Ventura Coast 22% 63%
Santa Monica Bay 19% 71%
San Pedro Bay 26% 69%
San Diego Coast 35% 59%
Historically, estuarine wetlands were composed of 63% marsh, 29% flats and 8% subtidal in the Bight Region. Habitat distribution in the subregions should be made up of the following proportions:
Realize distribution of archetypes comparable to historical conditions in their appropriate locations within the subregion.
Bataquitos Lagoon Tijuana
Mission Bay
Bell Canyon Malibu
Archetype Distribution
Example - Maintain and enhance at least 10 small creeks in the subregion.
Example - Maintain 6 lagoon or estuary systems in the Gaviota region.
Gaviota Coast Gaviota State Park
System Coherence
Historic Santa Ana River Mouth System Current fragments include Santa Ana River, Santa Ana River Wetlands and Talbert Marsh
Maintain coherence of existing systems.Reconnect currently fragmented systems and to their watersheds.
Wetland Size
0
10
20
30
40
50
60
0-20 ha 20-50 ha 50-100 ha 100-200 ha 200-300 ha 300-400 ha 400-500 ha 500-750 ha 750-1000 ha 1000+ ha
Historic Present 2050 Undeveloped Constrained
Ensure adequate patch size distribution of systems
Transition Zones
Elevation Public ownership
Enhance connectivity with upland habitats and maintain existing transition areas.
San Dieguito San Dieguito
Physical and Hydrologic Processes
• Support internal structure and habitats in other objectives.
• Include structural elements that were present historically.
• Objectives are related, and cannot be accomplished in isolation.
1. Restore tidal prism and residence time
2. Reduce coastal jetties
3. Manage water and sediment inflow
Upper Newport
Summary of objectives
1. Total estuarine area is based on future projections.
2. Habitat distribution is based upon historical mapping.
3. Maintain archetype distribution in subregions.
4. Reconnect fragmented systems guided by historical archetype.
5. Increase system sizes generally.
6. Maintain existing and restore additional transition zones.
7. Maintain and enhance physical and biological processes.
Thank you
Carpinteria