1. ROMS Modeling for Marine Protected Area (MPA) Connectivity Satoshi Mitarai, Dave Siegel, James Watson (UCSB) Charles Dong & Jim McWilliams (UCLA) A biocomplexity project “Flow, Fish & Fishing” Coastal Environmental Quality Initiative (CEQI)

2. Marine Protected Areas (MPAs) To be implemented in Southern California Bight in 2009 BiomassDiversitySizeDensity Percent change 446% 166% 21%28% 30 cm45 cm60 cm = 100,000 young Science of marine reserve (2007)

3. Quantification of “Coastal Connectivity” Key info in designing a network of MPAs = connectivity of nearshore sites via advection of water parcels Rocky reefs in Southern California Bight Rocky reefs by Michael Robinson Larval transport by coastal circulations Advected 100’s km over months Rocky reefs Good MPA candidate Good MPA candidate

4. Natural mortalityHarvesting Population Dynamics Model Requires coastal connectivity info # of adults at x in year n+1 # of recruits to x from everywhere # of survivors at x in year n =+ # of larvae produced at y Fraction of water parcels transported to x Recruitment success (%) xy Coastal connectivity

5. Goal of This Study Quantify coastal connectivity in the SCB Using ROMS simulations validated with observations [ C ] Dong, Idica & McWilliams, Progress in Oceanography (in revision) Simulated sea surface temperature (Southern California Bight)

6. Lagrangian PDF methods Describe expected dispersal patterns from a single site Delineate nearshore waters into 135 sites Cover most of rocky reefs Release many particles from each site From each site, around 100 particles are released every 12 hours from Jan. 1996 – Dec. 2002

7. Sample Trajectories From Single Site Chaotic dominated by mesoscale eddy motions Red dots: locations after 30 days

8. Expected Location (Lagrangian PDF) Nearly isotropic from this particular site [ km ] -2 (averaged for 1996 – 2002)

9. Lagrangian PDFs From Different Sites Heterogeneous reflecting distinctive circulation patterns (advection time = 30 days, averaged for 1996 – 2002) [ km ] -2

10. Seasonal Variability in Lagrangian PDFs Reflect seasonal variability in circulations (advection time = 30 days, averaged for 1996 – 2002) WinterSpringSummerAutumn Strong equatorward wind Reduced current in SB Channel

11. Interannual Variability in Lagrangian PDFs Reflect El Niño & La Niña transitions (advection time = 30 days, averaged for all seasons) 1996199719981999 El Niño La Niña

12. Quantifying Coastal Connectivity Connectivity can be deduced from Lagrangian PDFs Spawning: Apr – Nov Planktonic: 25 – 33 days Kelp bass Lagrangian PDF for kelp bass from site #43 Mainland to Islands Islands to Mainland

13. Connectivity for Different Species Different due to different life histories Spawning: Jan – May Planktonic: 60 – 180 days Spawning: year around Planktonic: 3 – 12 days

14. Potential Larval Source Locations Useful for MPA implementation Where are larval sources? Summation Averaged for kelp bass, blue rockfish, lingcod, cabezon, canary rockfish & red sea urchin Santa Barbara x Santa Cruz Island San Miguel Island Santa Barbara Island San Nicholas Island x Oceanside San Miguel Island Anacapa Island San Clemente Island Santa Catalina Island Poor sources...

15. Summary Quantified connectivity in SCB using ROMS simulations Lagrangian PDF method is employed Connectivity is deduced from Lagrangian PDFs Potential larval sources are suggested Some ongoing MPAs on Northern Islands are not really…. Mitarai, Siegel, Watson, Dong & McWilliams, JGR - Oceans (in review)

16. Questions How can we tell if the simulated connectivity is accurate? Accurate enough for what? To predict nearshore marine population dynamics Distinctive biogeographic regions Can we reproduce this? Courtesy – Pete Raimondi

17. Two Species Abundance (CRANE Data) Q: can we reproduce this, given the simulated connectivity? Kelp bassKelp rockfish (Paralabrax clathratus) (Sebastes atrovirens) Coexist Kelp bass dominates Coexist dominates CRANE survey (2004)

18. A Thought Experiment Two species population dynamics Given the simulated connectivity matrices Initialization (randomly seeded) Species #2 Species #1 Spawning: Summer Larval duration: 1 month Life time: 20 years #1. Kelp bass type #2. Kelp rockfish type Spawning: Winter Larval duration: 2 months Life time: 20 years

19. Population Dynamics Model Let’s integrate the model, given the simulated connectivity # of adults at x in year n+1 # of recruits to x from everywhere # of survivors at x in year n =+ x y Natural mortality Coastal connectivity Harvesting

20. Population Composition Shows reasonable agreement with CRANE data Regardless of the initial condition 100 % species #1 100 % species #2 75 % species #1 75 % species #2 50-50 Kelp rockfish (#2) Kelp bass (#1) F1 / F2 = 1.1 (when they coexist) After reaches equilibrium Kelp bass dominates Coexist

21. Future Direction Integrate the framework into SCCOOS Forecast dispersal, connectivity & population dynamics Data assimilation? Clarify connectivity through boundaries With Central Coast, across the international border Important to address species invasion Lagrangian validation Examine dispersal patterns against drifters & HF radar (A part of Carter’s talk)

22. Thank you!