1. Spatially coherent intermittent stratification and hypoxia in disparate sub-regions of an estuary. Jamie Vaudrey & Jim Kremer Department of Marine Sciences, University of Connecticut Dan Codiga Graduate School of Oceanography, University of Rhode Island courtesy of R.L. Wilke Funded by the NOAA Coastal Hypoxia Research Program (CHRP), 2005

2. Field and Lab Work Supported By… Kaitlyn Shaw (UCONN) – Profiler and Sonde maintenance and deployment, assistance with data processing Gary Grenier, Dennis Arbige, Bob Dziomba (UCONN) – technical and mechanical support for the profilers Dr. Candace Oviatt’s Lab group (URI) – boat rides to the field sites, maintained the deep water buoys ~ Edwin Requintina Sr., Heather Stoffel, Taylor Crockford, Leslie Smith

3. Autonomous Profiler - Grover 1 profile every 3 hours deployment = 2 to 3 weeks samples every 8 seconds ~ 12cm intervals max depth = 5m

4. Bullock Reach Field’s Point Warwick Neck Rumstick Neck Northern Narragansett Bay, RI

5. 2007, Rumstick Neck

7. Similar patterns seen at the stations… Dissolved Oxygen, July 2006

8. Similar patterns seen at the stations… Density, July 2006

9. Similar patterns seen at the stations… Dissolved Oxygen, August 2006

10. Similar patterns seen at the stations… Density, August 2006

11. Hypoxia linked to stratification, but… Is tidal stage (spring/neap) an adequate predictor of stratification?

12. Bottom DO vs. the Neap Tide Prediction

13. July August Sept.

15. Conclusions NNB shows a certain synchronicity to stratification / hypoxic events for the stations surveyed. Bottom water hypoxia is linked with stratification. There is a high probability that the water will be stratified during and just following a neap tide. However, hypoxia (and stratification) also occur at other stages of the monthly tidal cycle.

16. Rumstick July 2006

17. Warwick July 2006

18. Bullock Reach Aug 2006

19. Warwick Neck Aug 2006

20. Rumstick Neck Aug 2006

21. Warwick Neck Sept 2006

22. Rumstick Neck Sept 2006

23. Field’s Point Sept 2006