Chuck Jacoby Supervising Environmental Scientist, Estuaries Section, St. Johns River Water Management District Program Scientist, Indian River Lagoon

Transcription

1 Chuck Jacoby Supervising Environmental Scientist, Estuaries Section, Program Scientist, Indian River Lagoon National Estuary Program

2 Lagoon is: Sensitive Long (156 miles) Shallow Wind & tide driven Not a river (no flow) Segmented (flushing 2 wks 3 mos) Diverse ecology challenges New Smyrna Beach Mosquito Lagoon Banana River Indian River West Palm Beach

3 Nutrient impairment Total Maximum Daily Load (TMDL) = safe load Loads + Margin of Safety > TMDL reductions Adaptive approach to uncertainty monitor (seagrass = a key indicator) evaluate progress adapt as needed Summarize in Basin Management Action Plans

4 80,000 70,000 Seagrasses Seagrass area (acres) 60,000 50,000 40,000 30,000 20,000 10,000 0 (Historic coverage) Mapping years Drought & Vero WWTP discharge Minidrought 04 hurricanes surge & flushing TS Fay flushing Drought & IRFWCD discharge

5 Algal blooms

6 80,000 70,000 Seagrasses Seagrass area (acres) 60,000 50,000 40,000 30,000 20,000 10,000 0 (Historic coverage) Mapping years Loss of ~30,000 acres ~45% of the acres mapped in 2009

7 80,000 70,000 Seagrasses Seagrass area (acres) 60,000 50,000 40,000 30,000 20,000 10,000 0 (Historic coverage) Mapping years Some recovery in 2013 ~12% gain from 2011 not uniform

8 What happened?

9 Caveats All models are wrong; some models are useful. (attributed to George Box) Ecosystems are not only more complex than we think, they are more complex than we can think. (Egler, Frank The nature of vegetation: its management and mismanagement. Aton Forest Publishers, Norfolk, Connecticut) It s tough to make predictions, especially about the future. (Yogi Berra)

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11 Increased nutrient delivery Eutrophication progression scheme Enhanced growth phytoplankton & macroalgae Increased shading & benthic respiration Adapted from C.M. Duarte (1995) Seagrass loss

12 What will we do?

13 Indian River Lagoon Protection Initiative

14 Indian River Lagoon Algal Blooms Investigation Titusville North Indian River Lagoon Eau Gallie South Mosquito Lagoon Banana River Lagoon Project location = 2011 superbloom area Timeframe = 4 years Red hatching seagrass loss North IRL Banana River Lagoon

15 Blue Team Enhanced sampling event sampling of inputs atmospheric deposition sensors for continuous data bacterioplankton phytoplankton microzooplankton Updated & enhanced models Nutrition for bloom species Grazing by microzooplankton

16 Sand Team Sediment survey Groundwater model Internal nutrient budget (flux) West nearshore seepage face Lagoon nearshore seepage face East terrestrial submarine groundwater discharge strong advection recirculation diffusion Intracoastal Waterway recirculation diffusion muck recirculation weak advection strong advection terrestrial submarine groundwater discharge weak advection

17 Figure 1. Map of donor and recipient sites in this study. Green Team Seagrass transplanting Drift algae mapping Drift algae tolerance temperature salinity light Nutrient content & release drift algae seagrasses

18 Orange Team Enhanced sampling fisheries independent monitoring macrozooplankton infauna epifauna Grazing macrozooplankton infauna epifauna

19 Goals Understand the lagoon s nutrient inventory & cycling processes that regulate blooms Evaluate & recommend strategies ameliorate blooms o magnitude o duration o frequency facilitate seagrass growth & expansion enhance diverse trophic structure

20 Thank you for your time