Real-Time NO 3 and PO 4 Sensors for Chesapeake Bay

Real-Time NO 3 and PO 4 Sensors for Chesapeake Bay Lora Harris Jeremy Testa Amanda Moore UMCES Chesapeake Biological Laboratory Mark Trice Rebecca Burrell Kristin Heyer John Zimmerelli Bruce Michael Ben Cole Brian Smith Maryland Department of Natural Resources

Why do we need these sensors? (1) There is a vast amount of nutrient concentration measurements in Chesapeake Bay, but most of these have been measured at a bi-weekly or monthly scales (2) Event-scale dynamics (floods, wind events) are poorly understood (3) Nutrient conditions leading to phytoplankton blooms poorly understood (4) Model simulations made at short time scales that could be better validated

Growing use of in-situ nutrient systems Pellerin et al. 216, JAWRA

The WIZ system Miniaturized wet chemistry Won EPA Nutrient Sensor Challenge Relatively affordable (1-15k; SUNA=3k+) Reagent canister Reagent canister filter Internal electronics pump Internal electronics, colorimetric components

Deploying The WIZ system Solar Panel and Data Logger WIZ (submerged) Waste and rinse water Arundel on the Bay

Deploying The WIZ system Solar Panel and Data Logger WIZ (submerged) Dares Beach

Existing Nitrate Sensor Solar Panel and Data Logger WIZ (submerged) Darlington, MD

Water In site AnalyZer System (WIZ): Real-Time NO3 and PO4 measurements Miniaturized wet chemistry Long-term deployments, but labor-intensive

2. NO 3 mg L 1.5 1. AOB Nutrient Sensor DAB Nutrient Sensor SUNA Sensor.5 Oct Nov Dec Jan 6 PO 4 ug L 4 2 AOB Nutrient Sensor DAB Nutrient Sensor Oct Nov Dec Jan 218-219

Arundel on the Bay Dare's Beach 2. 2. NO 3 mg L 1.5 1. AOB Grab NO 3 mg L 1.5 1. DAB Grab.5.5 Oct Nov Dec Jan Dec 17 Dec 24 Dec 31 6 6 PO 4 ug L 4 AOB Grab PO 4 ug L 4 DAB Grab 2 2 Oct Nov Dec Jan 218-219 Dec 17 Dec 24 Dec 31 218-219

Arundel on the Bay 1.5 RMSE =.2416 6 RMSE = 22.38322 1. 4 WIZ NO 3 mg L WIZ PO 4 ug L.5 2 Original Original Replacement Replacement.5 1. 1.5 LAB NO 3 mg L Arundel 2 4 6 LAB PO 4 ug L

Susquehanna Flow 218 Black = Long Term Mean Yellow = IQR Red = 218

USGS SUNA Nitrate Sensor

1.8 Arundel on the Bay Wiz Sensors 7 Arundel on the Bay 1.6 1.4 1.2 IQR Long-Term Monthly Median (1984-217) 218 WIZ Data NASL Data 6 5 IQR Long-Term Monthly Median (1984-217) 218 WIZ Data Susquehanna NASL Data NO 3 Conc (mg/l) 1.8.6 PO 4 Conc (mg/l) 4 3 2.4.2 1 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb 1.8 Dare's Beach 7 Dare's Beach IQR IQR 1.6 Long-Term Monthly Median (1984-217) 218 WIZ Data 6 Long-Term Monthly Median (1984-217) 218 WIZ Data 1.4 NASL Data 5 1.2 NO 3 Conc (mg/l) 1.8.6 PO 4 Conc (mg/l) 4 3 2.4.2 1 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

Arundel on the Bay Ecological Insights? 6 6 SUS Flow m 3 s 4 2 4 2 SUS Flow m 3 s Oct Nov Dec Jan Arundel on the Bay NO 3 mg L 2. 1.5 1..5 AOB NO3 AOB PO4 6 4 2 PO 4 ug L Oct Nov Dec Jan 1 Chl Salinity WTemp 4 Salinity (ppt) 7.5 5. 2.5 Oct Nov Dec Jan 218-219 3 2 1 Chl (ug/l) / Temp (C

Dares Beach Ecological Insights? 6 6 SUS Flow m 3 s 4 2 4 2 SUS Flow m 3 s Dec 17 Dec 24 Dec 31 Dare's Beach NO 3 mg L 2. 1.5 1..5 DAB NO3 DAB PO4 6 4 2 PO 4 ug L Dec 17 Dec 24 Dec 31 1 Chl Salinity WTemp 4 Salinity (ppt) 7.5 5. 2.5 Dec 17 Dec 24 Dec 31 218-219 3 2 1 Chl (ug/l) / Temp (C

Dares Beach Ecological Insights? 6 6 SUS Flow m 3 s 4 2 4 2 SUS Flow m 3 s Dec 17 Dec 24 Dec 31 Dare's Beach NO 3 mg L 2. 1.5 1..5 DAB NO3 DAB PO4 6 4 2 PO 4 ug L Dec 17 Dec 24 Dec 31 1 Chl Salinity WTemp 4 Salinity (ppt) 7.5 5. 2.5 Dec 17 Dec 24 Dec 31 218-219 3 2 1 Chl (ug/l) / Temp (C

Nitrate Loading Based on SUNA data Daily Load (kg/day) 1,, 5, Jan 218 Apr 218 Jul 218 Oct 218 Jan 2 flo

SUNA shifted 8 days 2. 1.5 NO 3 mg L 1. AOB Nutrient Sensor DAB Nutrient Sensor SUNA Sensor.5 Oct Nov Dec Jan

Arundel on the Bay 3 AOB NO3 Salinity 1 7.5 NO 3 mg L 2 1 5. 2.5 Salinity (ppt) Oct Nov Dec Jan 218-219 Dare's Beach 3 DAB NO3 Salinity 1 7.5 NO 3 mg L 2 1 5. 2.5 Salinity (ppt) Oct Nov Dec Jan 218-219

Maintenance Insights: Costs Chemicals : Data plan : Site Visits Planned Maintenance : Malfunction Response: $445 (for chemicals we didn t have)? / month (for data transmission) 4 based on sampling frequency 9 additional Hours Chemical Prep : 4 hours for initial reagent mixing Maintenance day prep : 3 hours to fill canister and gather equipment/standards Maintenance Day : 1.5 hours travel each way (75 miles) 2 hours on site for cleanup and calibration check Post Maintenance Day : 3 hours to empty/clean used canister and waste bag Malfunction Trouble Shooting : 14 (total) additional to normal maintenance on site Total hours dedicated : 25 for everything involved

25 Number of Missed Samples 2 15 1 5 Maintenance Malfunction Reason for Missed Sample

Ecological Insights: Sensors useful for tracking temporal shifts in response to flow events Documented variability will be useful for understanding estuarine responses on time scale better suited to modeling and continuous sensor data Maintenance is a challenge and calibration data still indicates proceed with some caution Susquehanna inputs impacted main stem of bay on short time scales this summer (~8 days) how does this compare to other years with lower flow? Thank you!