Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh...
-
Upload
jaquelin-pardue -
Category
Documents
-
view
214 -
download
0
Transcript of Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh...
![Page 1: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/1.jpg)
Legacy PhosphorusImplications for the Recovery of Lake Okeechobee, Florida, USA
Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James
![Page 2: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/2.jpg)
OutlineGeographic and historical setting
Phosphorus reduction programs
Loading and lake TP responses
Watershed and lake P mass balances
Effects of legacy phosphorus
Implications for management
![Page 3: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/3.jpg)
Lake Okeechobee, FLArea 1,730 km2
Mean Depth 2.7 mMax Depth 5 m
Emergent Wetland
![Page 4: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/4.jpg)
Source: South Florida Water Management District
![Page 5: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/5.jpg)
P control projects since 1960s
Fencing of waterways to prevent animal access
Agricultural best management practices
Dairy buy out programDairy waste management systemsWetland treatment areasVarious other advanced technologies
![Page 6: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/6.jpg)
P loads vary from year to year but no long-termdecline has occurred.
![Page 7: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/7.jpg)
The difference between P input and P outputis declining over time = reduced assimilation.
![Page 8: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/8.jpg)
The concentration of TP in the lake has increasedover time, except in recent drought years.
![Page 9: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/9.jpg)
In shallow shoreline areas that support SAV, fish habitat, and most human uses, water quality and biological conditions are excellent when the lake depth is low, regardless of high P out in the deeper mid-lake region.
![Page 10: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/10.jpg)
Why have the lake and watershed not responded to all the P reduction measures?
Legacy phosphorus in the soils, wetlands and lake sediments – phosphorus that accumulated there over decades when there was high export from agricultural lands, and is now slowly leaching back into the surface water.
![Page 11: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/11.jpg)
![Page 12: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/12.jpg)
![Page 13: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/13.jpg)
![Page 14: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/14.jpg)
Management implicationsP control measures up in the watershed will
not achieve load reduction for decades or longer
More immediate P reduction would require large-scale wetland treatment right at the lake
Lake sedimentary P still will delay recovery
Yet there is an opportunity to achieve good conditions for fish, SAV, and users in near-shore area if lake depths can be kept low, perhaps through large-scale storage of water in the basin
![Page 15: Implications for the Recovery of Lake Okeechobee, Florida, USA Karl Havens, Hans Paerl, K. Ramesh Reddy and R. Thomas James.](https://reader030.fdocuments.in/reader030/viewer/2022032517/56649c865503460f9493dd3d/html5/thumbnails/15.jpg)
Thank you