Captiva Water Quality Assessment Project Update Supported by TDC s Beach & Shoreline Program through the Captiva Community Panel

Transcription

1 Captiva Water Quality Assessment Project Update Supported by TDC s Beach & Shoreline Program through the Captiva Community Panel Mark Thompson & Loren Coen Marine Laboratory, Sanibel-Captiva Conservation Foundation January 12, 2010

2 This Presentation Update: 1 st Year s Data, Assessment and Findings Update: Scope and progress on 2 nd year

3 Data Assessment Includes data from several concurrent projects undertaken by SCCF and other agencies: Bayous Preservation Association WQ Monitoring FL Department of Health Beach Data Blind Pass Opening Project : FL Sea Grant J.N. Ding Darling NWR WQ Monitoring CHNEP Scallop Project Additional sources to be added to the final analysis: Lee County City of Sanibel SCCF s RECON data SFWMD data

4 TDC 1 st Year Monitoring Sites Began Oct 2008 Total of 22 Sites

5 Added Bayous Preservation Association WQ Data Total of 26 Sites

6 Added DOH Beach Data Total of 30 Sites

7 Added Blind Pass Opening Project Data Total of 94 Sites

8 Added Scallop Spat Project Data Total of 100 Sites

9 Added Wildlife Refuge WQ Project Data Total of 110 Sites

10 Added TDC 2 nd Year Data Total of 170 Sites

11 Data Analysis For initial analyses, data assessed by division of sites: Captiva Island Sanibel Island National Wildlife Refuge Estuary (PIS) vs. Beach (Gulf) Assessed Dry vs. Wet Season Assessed Events: Rain vs. No Rain

12 Captiva Sites Division of Sites Beach Sites Captiva Sites Sanibel Sites Estuary Sites Ding Darling Wildlife Refuge Sites Sanibel Sites

13 Summary of Results by Water Quality Parameter

14 Parameters Evaluated in This Study Field Measurements Dissolved Oxygen (DO), Temperature, ph, Turbidity, Salinity, Wind, Tide, Light (PAR), possibly Radon, Rainfall Laboratory Analyses Enterococci bacteria, Fecal Coliform bacteria, Chlorophyll h ll a, Total Nitrogen, Ammonia, Nitrate/Nitrite, t Total Phosphorus, CDOM, Optical Brighteners, Bacterial DNA typing for identification Focusing on a few parameters only today

15 Enterococci Bacteria Indicator of Fecal Contamination in Water Imperfect: May be human or other animal source. Possible Disease Agent = Beach Closures Florida DEP WQ Criteria Cannot exceed 104 col./100 ml any sample Cannot exceed 35 col./100 ml average

16 Samples Since October 2008 Captiva Beach Stations Enterococci Bacteria Sanibel Beach Stations Enterococci Bacteria 95% 92% n= 187 Samples 4% 1% n= 123 Samples 1% 7% No Beach Closures During Period

17 In Perspective Captiva Beach Stations Enterococci Bacteria Florida Beach Stations Overall Enterococci Bacteria 95% 76% 20% n= 187 Samples 4% 1% USA Beach Stations ti Overall Enterococci Bacteria n= 15,912 Samples 4% NRDC % 31% 7% n= Many Samples NRDC 2009

18 Captiva Estuary Stations Enterococci Bacteria Sanibel Estuary Stations Enterococci Bacteria 71% 75% 14% 14% n= 120 Samples 15% n= 92 Samples 11% Wildlife Refuge Stations Enterococci Bacteria 97% n= 34 Samples 3%

19 Aver rage Enter rococci (c col/100ml ) Enterococci Bacteria Concentrations in Water After Rainfall Events Compared to Concentrations With No Rainfall Within 48 hrs. Statistically Significant Greater Bacteria Concentration in Water After Rainfall Events for both TDC and DOH Studies TDC Study Rainfall TDC No Rain DOH Rain DOH No Rain

20 Areas of Concern Mean Enterococci Concentrations

21 Chlorophyll-a Measures the amount of algae present in water column Indicator of nutrient enrichment and eutrophication (Seagrass loss and Fish Kills) Florida DEP WQ Criteria: : < 7 µg/l : >7 µg/l Impaired: >11 µg/l (annual average)

22 Captiva Estuary Stations Chlorophyll-a 82% 62% Sanibel Estuary Stations Chlorophyll-a 13% n= 156 6% 12% n= % 73% Wildlife Refuge Stations All Florida Estuary Stations Chlorophyll-a h ll Chlorophyll-a 80% 15% n= 74 12% 10% n= thousands 10% Hand

23 Captiva Coastal Stations Chlorophyll-a 92% Sanibel Coastal Stations Chlorophyll-a 93% 2% 6% n= 51 0% 7% n= 14 All Florida Coastal Stations Chlorophyll-a 87% 8% n= thousands 5% Hand

24 10 9 Seasonal Variation in Chlorophyl-a: All Data 8.29 Ave erage Ch hlorophy yll-a (ug/ /l) Significantly Higher Chl-a Values in Wet Season 3.89 n=244 n = Wet Season Dry Season

25 Mean Chlorophyll Concentrations Areas of Concern

26 Total Nitrogen Often the limiting nutrient in estuaries: Adding nitrogen can cause algal l blooms Decreases water clarity Decreases dissolved oxygen Decreases seagrass health Water Quality Criteria Currently being developed by State and EPA Guidelines: (< 70 th percentile all Florida): 093mg/l 0.93 (< 90 th percentile all Florida): mg/l : (> 90 th percentile for all Florida): 1.20 mg/l

27 97% Captiva Estuary Stations Total Nitrogen Sanibel Estuary Stations Total Nitrogen 72% 13% n= 105 Samples 0% 3% n= 160 Samples 15% Wildlife Refuge Stations Total Nitrogen All Florida WQ Stations Total Nitrogen 91% 70% 20% 6% 3% n= 32 Samples n= many 10%

28 1 Seasonal Variation in Total Nitrogen Estuary Stations Averag ge TN (m mg/l) n = n = 144 Significantly Higher TN Values in Wet Season 0 Wet Season Dry Season

29 Areas of Concern Mean TN Concentrations

30 Average Total Nitrogen Concentrations 1 Before and After Blind Pass Opening Averag ge TN (m mg/l) n = n = 31 Significantly Lower TN Values After Opening 0 Before Opening After Opening

31 Ammonia Nitrogen Several forms of nitrogen: ammonia, organic, nitrate, and nitrite, each is biologically convertible to one of the other forms High concentrations in surface waters good indicator of contamination from WWTP, septic tanks or fertilizer run-off Used quickly by algae in water column Water Quality Criteria: (70 th percentile Florida): < 0.05 mg/l : mg/l (90 th percentile Florida): > mg/l

32 Captiva Estuary Stations Ammonia Nitrogen 63% 52% Sanibel Estuary Stations Ammonia Nitrogen 25% 24% 56% n= 114 Samples 13% Wildlife Refuge Stations Ammonia Nitrogen n= 99 Samples 70% 23% All Florida Estuary Stations Ammonia Nitrogen 36% 20% n= 39 Samples 8% n= many 10%

33 Rain Event vs. Dry Period: Ammonia 0.1 Average e NH3 (m mg/l) Significantly Higher NH3 Values After Rain 0 n = 81 Rain Event n = 111 Dry Period

34 Areas with multiple occurrences of high ammonia concentrations Areas of Concern

35 Total Phosphorus Sometimes the limiting nutrient in estuaries (add TP and same problems as TN) Water Quality Criteria : mg/l or less : mg/l : 0.23 mg/l or greater

36 Captiva Estuary Stations Total Phosphorus Sanibel Estuary Stations Total Phosphorus 96% 99% n= 115 Samples 1% 3% n= 163 Samples 0%1% 97% Wildlife Refuge Stations Total Phosphorus 70% All Florida Stations Total Phosphorus 20% 0% 3% n= 33 Samples 10% n= many

37 Rain Event vs. Dry Period: TP Avera age TP (m mg/l) Significantly Higher TP Values After Rain Events 0 n = 119 Rain Event n = 108 Dry Period

38 Summary of Findings: Year 1 Bacteria levels at Captiva s Beaches: As good or better than levels from Sanibel Better than average for all Florida beaches Better than average levels for all US beaches No advisories since August 2008 (Only 1 in 2008)! Higher bacteria concentrations in water after rainfall events Some areas of concern (higher than average levels) on Some areas of concern (higher than average levels) on estuary side which may be able to affect beaches (part of year two focus)

39 Summary of Findings to Date Nutrient Enrichment Captiva Waters: Beach/estuary- as low or lower than Sanibel, Ding Darling NWR Refuge and Florida sites for chlorophyll-a, TN, and TP A few areas of concern near golf courses, stormwater outfalls on estuary (PIS) side Ammonia levels after rain events may indicate possible local surface water or groundwater mechanism of transport to gulf side (Year Two focus)

40 Nutrients and Bacteria Preliminary Summary: Areas of Possible Concern Nutrients and Bacteria a Nutrients and Bacteria Nutrients and Bacteria Nutrients

41 Year Two Progress to Date Using Enterolert system to better characterize problem bacteria areas. Using DNA techniques to determine human/nonhuman sources of fbacteria. Using concentrated sampling around problem areas to characterize bacteria and nutrient levels.

42 Intensive Enterococci Sampling After December 09 Rain Events

43 Wind NE South Seas Tidal Current Transect Sampled 48 Hours After 0.8 Rain Event Tidal Current Tween Waters Tidal Current Tidal Current Sanctuary

44 Year Two Proposed Intensive site surveys to characterize areas of concern Source evaluation Land use evaluation Potentially ti evaluate possible transport t mechanisms for bacteria to beaches: Thru-inlet transport evaluation Groundwater transport evaluation

45 SCCF Clam Bayou Habitat Restoration Efforts Bag Shell Restore habitat Improve water quality Have fun See you there on these dates Jan 28 th Thursday Generally Tuesdays in February Bagging at Bowman s Beach

46 Questions?