estuary, we have developed a coupled Eulerian-Lagrangian bio-physical model (MIKE powered by DHI Software Suite). Introduction. Florida Gulf Coast ...
Impact of salinity variations on oyster (Crassostrea virginica) larvae settlement in the Caloosahatchee River Estuary in Southwest Florida a Department
B. Dye
a,
J. Richard
The eastern oyster, Crassostrea virginica, forms biogenic reefs which are essential habitats providing numerous ecosystem services within estuaries. Oyster reefs act as natural water filters and serve to increase biodiversity as Wells (1961) listed 300 species that depend either directly or indirectly on oyster reefs. However, oyster reefs have declined over the past decades in many estuarine and coastal ecosystems due to overharvesting, diseases, and deteriorated water quality (Beck et al., 2011). A series of locks and dams within the Caloosahatchee River control the amount of freshwater released into the estuary, in particular the furthest downstream lock and dam, S-79. Florida’s subtropical climate consists of wet (June – Oct.) and dry (Nov. – May) seasonal patterns, which results in vastly higher freshwater releases from S-79 during the wet season as opposed to the dry season. Unstable freshwater releases may be responsible for fluctuating peaks in larval supply as high freshwater releases may coincide with oyster spawning periods, thus resulting in spatio-temporal variable settlement intensity. To investigate the impact of freshwater discharge on the larval settlement in the estuary, we have developed a coupled Eulerian-Lagrangian bio-physical model (MIKE powered by DHI Software Suite).
Run MIKE 21 Hydrodynamic Model
b,
J. B. Mortensen
Workflow
c
NO
Ö
Model Outputs • Currents • Water level variations
MIKE ECO Lab – Agent Based Model • Active particles
Calib rate mod Com el p
Is the model accurate?
YES
Completed Ö
• Model includes: larval development, mortality, sensitivities to temperature and salinity In progress
In progress
MIKE Particle Tracking Model
MIKE ECO LAB – Agent Based Model
Surface Elevation (m)
S-79
• 2-D model • Flexible mesh • Forced by wind, tide, and freshwater inputs
Crassostrea virginica oyster larvae (Univ. of Maryland Horn Point Oyster Hatchery).
Ebb Tide Phase - May 07, 2016 Surface Elevation (m)
Shell Point
Length portrays magnitude of currents
Oysters
Gonad index
Frequency Dry and wet season Monthly
Oysters - spat
Settlement
Monthly
Water Quality Monitoring Sites Monitoring performed by: • Sanibel Captiva Conservation Foundation - River, Estuary, and Coastal Observing Network (RECON) • Matlacha Pass Aquatic Preserve • Estero Bay Aquatic Preserve • South Florida Water Management District – DBHYDRO Parameters measured: Temperature Salinity Discharge
• Evaluate the effects of freshwater releases on oyster larvae: larval mortality and possible flushing events
• Identify oyster reefs as larval sources or sinks
Florida Gulf Coast University Oyster Monitoring Sites 2000 – 2016 Oysters – adult Density per m2
Research Outcomes • Compare and contrast larval transport and settlement under various hydrological regimes (e.g. wet season, 2016 El Niño period)
Caloosahatchee River Estuary (Wan et al., 2013).
Parameters
• Salinity and temperature data from water quality stations spatially and temporally interpolated and included as model input forcing
MIKE 21 Hydrodynamic Model Flood Tide Phase - May 07, 2016
Field Data
www.PosterPresentations.com
E. Milbrandt
leted
Study Site
RESEARCH POSTER PRESENTATION DESIGN © 2015
F. Jose
a,
of Marine and Ecological Sciences, Florida Gulf Coast University; b Sanibel Captiva Conservation Foundation Marine Laboratory; c DHI, Hørsholm, Denmark
Introduction
The Caloosahatchee River Estuary is characterized as a shallow, mixed estuary (Scalatos, 1998; Zheng & Weisberg, 2003) with a mean water depth of 2.6 m and covering a surface area of about 63 km2 (Wan et al., 2013). The estuary begins at the Franklin Lock and Dam (S-79) and continues to Shell Point before entering the Gulf of Mexico (Volety et al., 2010). Sources of freshwater entering the estuary include runoff within the watershed and freshwater releases from Lake Okeechobee into the Caloosahatchee River which ultimately flows into the estuary at the S-79 dam.
a,
Length portrays magnitude of currents
• Simulation period May 1 – June 15 2016 • Avg. discharge from S-79 = 4280 cfs
• Provide insight into optimal locations for the restoration or construction of new oyster reefs
o Wind data collected from NCEP North American Regional Reanalysis (NARR) o Tide data collected from MIKE 21 Toolbox, Tide Prediction of Heights tool o Freshwater data collected from the United States Geological Survey National Water Information System & DBHYDRO
• • • • •
Acknowledgements
MIKE Particle Tracking Model
Passive particles 100 particles ( ) released from four known oyster reef locations ( ) Oyster reefs shown in black Day refers to time after particles release on May 1, 2016 Particle paths indicated by white lines
Day 0
• Discern population connectivity between oyster reefs
This research was funded by The Whitaker Center for STEM Education - Blair Foundation STEM Summer Scholarship Award. A special thank you to Charlotte Harbor Aquatic Preserve, Matlacha Pass Aquatic Preserve, Estero Bay Aquatic Preserve for providing water quality data; South Florida Water Management District for funding the FGCU Oyster Monitoring Survey; Mikkel Anderson for his generous support in the development of the MIKE models; DHI for granting the permission to use their MIKE powered by DHI Software Suite.
Day 20
References Beck, M. W., Brumbaugh, R. D., Airoldi, L., Carranza, A., Coen, L. D., Crawford, C., ... & Lenihan, H. S. (2011). Oyster reefs at risk and recommendations for conservation, restoration, and management. Bioscience, 61(2), 107-116. Scarlatos, P. D. (1988). Caloosahatchee estuary hydrodynamics. Water Resources Division, Resource Planning Department, South Florida Water Management District. Volety, A. K., Tolley, S. G., Loh, A. N., & Abeels, H. (2010). Oyster Monitoring Network for the Caloosahatchee Estuary. Final Report Submitted to the South Florida Water Management District. Wan, Y., Qiu, C., Doering, P., Ashton, M., Sun, D., & Coley, T. (2013). Modeling residence time with a three-dimensional hydrodynamic model: Linkage with chlorophyll a in a subtropical estuary. Ecological modelling, 268, 93-102. Weisberg, R. H., & Zheng, L. (2003). How estuaries work: A Charlotte Harbor example. Journal of Marine Research, 61(5), 635-657. Wells, H. W. (1961). The fauna of oyster beds, with special reference to the salinity factor. Ecological Monographs, 31(3), 239-266.
