Shallow Water Monitoring – We’re In It for the Long Haul

1. Shallow Water Monitoring – We’re In It for the Long Haul Breakout Session - Synopsis Monitoring and Analysis Subcommittee Workshop October 25, 2006

2. Shallow Water MonitoringBreakout Session – Discussion Issues • Primary goal of SWM Program is to assess new water quality criteria BUT, there are many other critical uses as well • Use in Bay Health Indicators • Measure progress towards criteria attainment, not just attainment (need for sentinel stations, long-term trends, SWM program will not end after 2014/2015) • Evaluate SAV habitat criteria and potential SAV restoration sites • Assess episodic events • Assess effectiveness of nutrient reduction strategies • Understand estuarine ecosystems and processes

3. Shallow Water Monitoring Issues • Schedule for segment assessments • Segment prioritization • Water clarity segment assessment – calibrating turbidity to Kd, CFD analysis approach • Dissolved oxygen – temporal standardization and instantaneous criteria assessment • Chlorophyll a assessment – calibrating fluorescence to chlorophyll a

4. SWM Issues • Agreed on SWM segment assessment schedule and segment prioritization schedule • Of remaining SWM issues for water clarity, DO and chlorophyll assessments, water clarity is the most critical

5. Water Clarity Assessment – Primary Goal for implementing SWM Program • Develop consistent Baywide methodology • Kd vs. turbidity – evaluate data at low end of Kd scale (Kd = 1.0); values at higher end of scale are in non compliance • Evaluate CFD approaches, different application depths • Water clarity acreage goal – function of segment size and historical SAV acreage goal – results can be misleading • CBP staff (John Wolf) evaluating various analysis approaches using 2003-2005 MD and VA data

6. Chlorophyll a / Fluorescence Measurement Issues • Lower priority – continue to evaluate baywide chlorophyll criteria • CDOM impacts on chlorophyll – evident in upper York River tributaries • Evaluate YSI CDOM sensors • MD measures background fluorescnece

7. Develop a kd model • Using linear regression, USGS found that turbidity was the best single variable predictor of kd at 5 of 10 sites (r2 from 0.23 to 0.62) • Turbidity was significant, but not best at one site • Other than turbidity, TP, DOC, salinity, TN, DIN, and TVS were found to good predictors of kd • VA found that in general, turbidity was the best predictor of kd in their systems

8. Develop a post-calibration chlorophyll model • Match extractive and YSI 6600 chlorophyll • Outlier prediction model to remove data • Test for significant differences (adjust all data, or only for significant differences?) • Geographical differences • Background fluorescence adjustment • Photo-inhibition (diel study conducted on the Patuxent estuary)

9. Dissolved Oxygen Issues • Currently using fixed monitoring data to assess DO instantaneous minimum • Continuous monitoring results are needed for instantaneous DO criteria, and to help develop logistic regression and spectral analysis models for short term DO duration criteria • Evaluate existing continuous monitoring sites – 2006; preliminary results indicate that approx. 25% con. Mon. sites pass in DO criteria; this is similar to 30 day DO criteria • 2007 - set up MD and VA con. mon. research funds to implement and evaluate spatially intensive con. mon.

11. Virginia – 2006 Tidal Monitoring Sites