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Florida Coastal Office Seagrass San Carlos Bay 11/19/13 Melynda Brown- Charlotte Harbor Aquatic Preserves What is Seagrass •Vascular •Photosynthetic •Occurs in tropical and temperate waters •Species adapted to variety of environmental conditions •Indicator Species 7/21/2015 2 Benefits of Seagrass • Improves water quality and stabilizes sediment • Nutrient and carbon cyclinghigher than rainforests • Provides shelter, nursery and food source for 90% of commercial and recreational important fisheries 7/21/2015 3 Value of Seagrass • ~2.2 million acres of seagrass in Florida waters, Provide ecological services worth over 40 billion each year (Carlson and Yarbro, 2009). = $20,000 per acre of seagrass • A recent study for Pine Island Sound/SWFL (Beever 2012) found that continuous seagrass Total Economic Value was $93,829/ acre. 7/21/2015 4 Common SWFL Species Halodule wrightii (Shoal grass) Thalassia testudinum (Turtle grass) Syringodium filiforme (Manatee grass) 7/21/2015 5 Seagrass Monitoring Charlotte Harbor AP: -Began in 1999 -50 transects -Annually; Aug-Oct. 7/21/2015 6 Seagrass Monitoring DEP South District EAR: -3 River transects began in 2001 -3 CHAP transects since 2008 -Quarterly: Feb, May, August and November 7/21/2015 7 Stressors to Seagrass • Boat traffic- waves and propscars • High flow- erosion/sedimentation • Tidal exposure • Temperature o o optimal 20-30 C (68-86 F) Zieman 1982 7/21/2015 8 Stressors to Seagrass • Light availability: depends on color, turbidity, chlorophyll levels 7/21/2015 9 Effects of stressors • High Nutrient Loading: increase in algae blooms decrease in seagrass abundance SCCF 7/21/2015 10 Nutrient Loading and Seagrass Production 7/21/2015 11 Stressors to Seagrass Salinity Levels- varies by species Dense T. testudinum S. fliforme Decreased light High salinity Decreased light Sparse T. testudinum 7/21/2015 From Greenawalt et. al. 2004 H. wrightii 12 Seagrass Abundance by Region 7/21/2015 13 Mean Abundance in San Carlos Bay vs. Annual S-79 Flow • NEW GRAPH!! 7/21/2015 14 Site Specific Data 7/21/2015 15 Low salinities: decreased seagrass abundances and species shifts Hurricane Wilma/ highest flows 7/21/2015 16 SC03 Density 3,600 Hurricane Wilma/ highest flows 7/21/2015 17 Conclusions & Next Steps • Goal: abundant and diverse seagrass beds • High flow can cause variable salinities in estuaries, leads to decrease in abundance or species shifts and loss • Salinity driven or other contributing factors? • Combine all water quality and seagrass data for bigger picture view of affects 7/21/2015 18 Thank You Charlotte Harbor Aquatic Preserves 12301 Burnt Store Rd Punta Gorda, FL 33955 7/21/2015 19