Poster: 2683 Session: 032 SIMULATING MESOPHOTIC TO SHALLOW REEFS CONNECTIVITY CONSIDERING THREE-DIMENSION HABITATS Ana C. Vaz a,*, Claire B. Parisa, Daniel Holsteinb, M. Josefina Olascoaga a

aUniversity of Miami, Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway, Miami, FL 33149-1098, USA bUniverstiy of the Virgin Islands USA *[email protected], [email protected], [email protected]

Abstract 3. CONNECTIVITY RESULTS Pulley Ridge (PR) is a mesophotic reef habitat in the Gulf of Mexico, home to a diverse fauna. Recent studies indicated the fundamental role mesophotic reef habitats play in PROBABILISTIC CONNECTIVITY 5 YEARS COMBINED increasing the resilience of the more vulnerable shallow water reefs, particularly by the CONNECTIVITY ANOMALIES export of fish and coral larvae, which aid the replenishment of disturbed populations. 3D Seascape 2D Seascape FROM 2D TO 3D SEASCAPES

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m Here we investigate the connections among PR and Florida Keys’ (FK) populations, by Pulley

60 Ridge 80

simulating the dispersal of the bicolor damselfish, Stegastes partitus. To address the Probability connections (log scale) of Lower Keys

complexities of simulating larval transport between shallow waters and mesophotic connections Anomalies of m habitats, we developed a module in the open source Connectivity Modeling System to • S. partitus 40 West represent 3-dimension discreet habitats. Particles with specific larval traits virtual larvae Keys were released from the PR and FK, dispersed by flow fields from HYCOM, and tracked released until their settlement onto the reef. Our results indicate that larvae spawned at PR are at Pulley Ridge Upper Keys exported to the shallower habitats of the FK, potentially aiding the recovery of its are shown to populations. Results also indicate that our novel method is successful in representing Middle complex vertical connections in realistic 3-dimension habitats. successfully Keys m settle in the Lower Keys 20 Dry Tortugas Spawning Reefs 2. MOTIVATION AND QUESTIONS and the Florida West Keys at all Keys depths

! Keys Keys Keys West Keys Keys Keys Keys Keys West Keys West Keys Keys West Keys Keys Keys Keys Keys West Ridge Ridge Pulley Lower Pulley Upper Lower Lower Upper

• 2D Seascape Lower Lower Upper Middle Middle Middle 20 m 40 m 60- 20 m 20 m 40 m 60- overestimate 80m 80m settlement at Settlement reefs Settlement reefs Settlement reefs Fig. 5 Probabilistic connectivity Fig. 6 Probabilistic connectivity Fig. 7. Connectivity Difference 2D/3D most shallow (2004-2008) 3D seascape as illustrated (2004-2008) 2D seascape (reefs found connectivity. Connections in red(blue) are depth ranges on Fig. 4 (1675 releases) from 0-20m) overestimated (sub-estimated) in the 2D case

DAILY PROBABILISTIC CONNECTIVITY ! Time series of export from Pulley Ridge show that major connections from PR are recurrent •However, sporadic Fig 1: Study Area: Pulley Ridge is the deepest known mesophotic reef and the Florida Keys are oceanographic events (e.g. the only reef Archipelago in the Continental U.S. (http://oceanexplorer.noaa.gov/) boxes on Fig. 8) can block larval export from PR, and should be Fig. 2: and found on Pulley Ridge. Fig. 3: Red grouper Epinephelus morio. Photo Photo Credit: Mike Echevarria (http:// Credit: University of North Carolina at Wilmington further investigated oceanexplorer.noaa.gov/ ) (http://oceanexplorer.noaa.gov) Fig. 8. Daily proportion of larvae successfully exported According to the “deep refugia” hypothesis [1], mesophotic reefs could increase the from Pulley Ridge (from 2004 to 2008). Red boxes: periods of low/inexistent larval export resilience of coral reefs by contributing to shallow reef recruitment. ! Is Pulley Ridge connected to the Dry Tortugas and the Florida Keys, and is it a source of larvae for shallow reefs? ! 4. LAGRANGIAN COHERENT STRUCTURE RESULTS This knowledge has critical scientific and conservation implications, helping to identify spatial connections and to re-assess the boundaries of the Florida Keys •Hyperbolic LCS are the most attracting or repelling material fluid National Marine Sanctuary: should they be extended to protect Pulley Ridge? ! lines, e.g. [4] 3. METHODS •Attracting LCSs are useful for identifying physical processes 3. METHODS ‣ use the Connectivity Modelling System [2] to simulate larval trajectories and deep- affecting larval dispersal: they act as attractors of particles, to-shallow and shallow-to-deep connectivity of the bicolor damselfish (Stegates and as barriers to transport in the cross LCS direction [3], partitus) found in both ecosystems [5] • implement a new 3D habitat module •LCSs could be an useful tool to determine the relative ‣ compute Lagrangian Coherent Structures to identify the physical processes that influence larval connectivity between Pulley Ridge and the Florida Keys [3] position of Loop and Florida currents in relation to Pulley Ridge and the Florida Keys. The position of the LC may create what depth SEASCAPE! transient connection and/or dispersal barrier (Fig. 9) to settle⁇ Novel 3-D MODULE ! - allows vertical Fig. 9. LCSs obtained from Finite Time Lyapunov Exponents (showed by the discretization of background). Pulley Ridge is represented in magenta, while particle dispersal from pulley is represented in blue. connectivity ! - User-defined depth strata, production 5. CONCLUSIONS AND FUTURE WORK and settlement nodes • 3D seascape is necessary to •Pulley Ridge may receive larval subsidies •Next steps: investigate sporadic and quantify population connectivity from other areas not considered here vertical dispersal pathways; use an between mesophotic and shallow (self-recruitment ~30%) improved high resolution ocean OCEANOGRAPHY MODULE BIOLOGY MODULE! coral reefs •S. partitus connectivity temporal circulation models for Pulley Ridge Stegastes partitus! GoM-HYCOM 1/25 degree • modeling indicates that Pulley Ridge variability may be explained by the FKEYS-HYCOM 1/100 degree [4] Lunar-cyclic & daily frequency spawning from Jan. to Nov.! exports larvae to shallow coral reefs position of the Loop and Florida 32 vertical layers PLD 25-32 d! (Refugia Hypothesis) Currents relative to Pulley Ridge 2004-2008 mortality 0.2/day! Ontogenetic Vertical Migration [5] REFERENCES [1] Bongaerts P., Ridway T, Sampayo EM, Hoegh-Guldberg O. 2010. Assessing the ‘deep reef refugia’ hypothesis: focus on reefs [2] Paris CB, Helgers J, Sebille EV, Sririvasan A. 2013. Connectivity Modeling System (CMS): A multi-scale tool for the tracking of biotic and abiotic variability in the ocean. Environ. Model. & Soft., 42:47-54. [3] Olascoaga JM. 2010. Isolation on the West Florida Shelf with implications for red tides and pollutant dispersal in the Gulf of Mexico. Nonlin. Proc. Geophys., 17, 685-696 [4] Kourafalou VH, Kang H. 2012. Florida Current meandering and evolution of cyclonic eddies along the Florida Keys Reef Tract: are they inter-connected? J. Geophys. Res. 117, C05028 [5] Paris CB, Cowen RK . 2004. Direct evidence of a biophysical retention mechanism for coral fish larvae. Limn. and Ocean., 49:1964–1979. [6] Haller R, Beron-Vera F. 2012. Geodesic theory of transport barriers in two dimensional flows. Physica D 241, 168. [7] Vaz AC, Richards KJ, Jia Y, Paris CB. 2013. Mesoscale flow variability and its impact on connectivity for the island of Hawaii. Geophys. Res. Lett., 40(2), 332-337.

LAGRANGIAN TRAJECTORIES CONNECTIVITY MATRIX ACKNOWLEDGEMENTS This research is supported the National Oceanic and Atmospheric Administration (NOAA) Center for Sponsored Coastal Ocean Research Fig. 4: Schematic of the Connectivity Modeling System (CMS [2]) modules and under award NA11NOS4780045 to the University of Miami. The authors thank the contributions of John Reed and Dennis Hanisak parameterization used in this study (FAU) for the reef polygons and Villy Kourafalou and Heesook Kang for the FKEYs-HYCOM.