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Elkhorn Slough Water quality Programs Trends and Concerns. ESNERR WQ Monitoring Program-Volunteer Sites Sample Monthly 1989 – Present Params by Probe (DO,Temp,Sal,pH,Turb, Chl) & Nutrients (Nitrate, Phosphate Ammoinium).
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Elkhorn Slough Water quality Programs Trends and Concerns
ESNERR WQ Monitoring Program-Volunteer SitesSample Monthly 1989 – PresentParams by Probe (DO,Temp,Sal,pH,Turb, Chl) & Nutrients (Nitrate, Phosphate Ammoinium)
ESNERR WQ Monitoring Program-NERR SitesSample every 15 mins; 1995 (AP & SM) – PresentParams by probe (Depth, DO,Temp,Sal,pH,Turb) & Monthly Nutrients (Nitrate, Phosphate Ammoinium)
Azevedo Pond below 5 mg/L almost year round, hypoxic <2.3 mg/L summer and fall
Nitrate concentrations mg NOx/L Comparison of means of all available data by Reserve and Station, 2006–2011 OWC takes the prize highest average nitrate NERR range .02 – 2.7 mg/L
Nitrate concentrations mg NOx/L Comparison of means of all available data by Reserve and Station, 2006–2011 Salinas River Sites Average 22 mg/L 10X higher than Highest NERR site in Country
Chl by tidal exchange in the Estuary Low Moderate High Hyper
EUTROPHICATION: anoxic sediment A much narrower layer at the top of the mud is well oxygenated at muted vs. full tidal sites
EUTROPHICATION: dissolved oxygen Greater variation with less tidal exchange b b b b a a
Nitrate 900 800 700 600 µM 500 400 300 200 100 0 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98
How different are the NERR sites? Comparison of means of all available data by Reserve and Station, 2002 – 2006/7 OWC WEL DEL PDB HUD CBM WKB APA SFB TJR SOS CBV JAC GRB http://nerrs.noaa.gov ELK KAC NOC WQB NIW ACE NAR GND SAP GTM RKB JOB 0.001 0.01 0.1 1 10 mg NOx L-1
Annual Hypoxia from two NERR stations Azevedo Pond South Marsh AVIRIS photo, John Ryan, MBARI
Tidal range vs % time hypoxic Figure 5. Maximum tidal exchange v. % time hypoxic
How different are the NERR sites? WEL WKB CBM OWC DEL WQB ACE MAR CBV TJR ELK APA SAP NIW SFB GND GRB PDB NOC HUD RKB GTM JAC SOS JOB KAC NAR 0.1 1.0 10 100 mg Chl a L-1 Comparison of means of all available data by Reserve and Station, 2002 – 2006/7 http://nerrs.noaa.gov