St. Johns River Water Management District
Chuck Jacoby Supervising Environmental Scientist, Estuaries Section, St. Johns River Water Management District Program Scientist, Indian River Lagoon National Estuary Program St. Johns River Water Management District Lagoon is:
• Sensitive New Smyrna Beach • Long (156 miles) Mosquito Lagoon • Shallow • Wind & tide driven Banana River • Not a river (no flow) • Segmented (flushing 2 wks–3 mos) Indian River • Diverse – ecology – challenges
West Palm Beach St. Johns River Water Management District 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 St. Johns River Water Management District Seagrasses 80,000
70,000
60,000
50,000
40,000
30,000
Seagrass area (acres) 20,000
10,000
0
(Historic Mapping years coverage)
Drought & Vero WWTP discharge ⇓ Mini- drought TS Fay flushing ‘04 hurricanes Drought & surge & flushing IRFWCD discharge ⇓ St. Johns River Water Management District Algal blooms St. Johns River Water Management District Seagrasses 80,000
70,000
60,000
50,000
40,000
30,000
Seagrass area (acres) 20,000
10,000
0
(Historic coverage) Mapping years
Loss of ~30,000 acres ~45% of the acres mapped in 2009 St. Johns River Water Management District Seagrasses 80,000
70,000
60,000
50,000
40,000
30,000
Seagrass area (acres) 20,000
10,000
0
(Historic Mapping years coverage)
Some recovery in 2013 ~12% gain from 2011 – not uniform St. Johns River Water Management District
What happened? St. Johns River Water Management District 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. 1977. 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) St. Johns River Water Management District St. Johns River Water Management District
Eutrophication progression scheme Increased nutrient delivery
Enhanced growth phytoplankton & macroalgae
Increased shading & benthic respiration
Adapted from C.M. Duarte (1995) Seagrass loss St. Johns River Water Management District
What will we do? St. Johns River Water Management District Indian River Lagoon Protection Initiative St. Johns River Water Management District Indian River Lagoon Algal Blooms Investigation
South Mosquito Lagoon Project location = Titusville 2011 superbloom area North Indian Timeframe = River Lagoon Banana 4 years River Lagoon North IRL Eau Gallie Red hatching Banana seagrass loss River Lagoon 2009–2011 St. Johns River Water Management District 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 St. Johns River Water Management District Sand Team • Sediment survey • Groundwater model • Internal nutrient budget (flux)
nearshore seepage nearshore West face seepage East face Lagoon
strong recirculation terrestrial Intracoastal recirculation terrestrial advection diffusion recirculation submarine Waterway diffusion submarine groundwater strong groundwater discharge advection discharge muck weak advection
weak advection St. Johns River Water Management District Green Team
• Seagrass transplanting • Drift algae mapping • Drift algae tolerance – temperature – salinity – Figure 1. Map of donor and recipient sites in light this study. • Nutrient content & release – drift algae – seagrasses St. Johns River Water Management District Orange Team
• Enhanced sampling – fisheries independent monitoring – macrozooplankton – infauna – epifauna • Grazing – macrozooplankton – infauna – epifauna St. Johns River Water Management District 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 St. Johns River Water Management District
Thank you for your time