Watershed Partners’ Draft Recommended Refined Designated Uses Chesapeake Bay and its Tidal Rivers

1. Watershed Partners’ Draft Recommended Refined Designated Uses Chesapeake Bay and its Tidal Rivers Alan Pollock, Chair Chesapeake Bay Program Water Quality Technical Workgroup August 21, 2000

2. Where We Are • Secured agreement with EPA HQ on details of refined designated uses in May • WQ Standards Coordinators Team representation has ensured input from all seven watershed jurisdictions, EPA HQ/Regions 2 and 3 • Have gotten preliminary review/input from wide cross section of Bay scientific community

3. Migratory Spawning/Nursery • “Protect the propagation and growth of balanced, indigenous populations of ecologically, recreationally and commercially important anadromous and semi-anadromous fish species inhabiting spawning and nursery grounds.” • Boundary Delineation: upper extent of tidally influenced waters to the lower reach of existing spawning and nursery habitats defined by composite of all targeted fish species

4. Migratory Spawning/Nursery • Example target species: adult spawning, egg, larval, and juvenile life stages of striped bass, American shad, hickory shad, alewife, blueback herring, white perch, and yellow perch • Seasonal consideration: combined spawning periods extend from mid-February to early June; nursery habitat utilized principally from late April through mid-summer

5. Shallow Waters • “Protect the propagation and growth of balanced, indigenous populations of ecologically, recreationally and commercially important fish, shellfish and underwater grasses inhabiting shallow waters.” • Boundary Delineation: intertidal zone down to a depth of 2 meters

6. Shallow Waters • Example target species: largemouth bass, pickerel, speckled sea trout (juvenile), blue crabs • Seasonal consideration: all year round for fish and shellfish species; April to November for underwater Bay grasses

7. Open Waters • “Protect the propagation and growth of balanced, indigenous populations of ecologically, recreationally, and commercially important fish and shellfish that depend upon open water habitats.” • Boundary Delineation: water column extending out from shallow waters across the tidal tributaries and Bay mainstem down to the calculated depth of the pycnocline or 10 meters

8. Open Waters • Example target species: menhaden, Bay anchovy, striped bass, aquatic reef communities • Seasonal consideration: year round as these water must support a mix of eggs, larval, juvenile, and adult life stages of a wide array of different species beyond the above list of target species

9. Deep Waters • “Protect the propagation of balanced, indigenous populations of ecologically, recreationally, and commercially important fish and shellfish that depend upon deep water habitats.” • Boundary Delineation: water column extending from the calculated depth of the pycnocline or 10 meters down to depths delineated as deep channel habitat (where seasonal anoxia/hypoxia routinely sets in)

10. Deep Waters • Example target species: blue crab, oyster, softshell clam, hard clam, spot, croaker, flounder, catfish • Seasonal consideration: these habitats support different arrays of species throughout the year with different habitat requirements; critical timeframe is mid-May through early October when the water is warmer and low dissolved oxygen conditions are naturally more prevalent

11. Deep Channels • “Protect the propagation of balanced, indigenous populations of ecologically, recreationally, and commercially important fish and shellfish that depend upon deep channel habitats.” • Boundary Delineation: very deep water column located principally in lower river channels and the upper and middle mainstem Bay channels at depths where seasonal anoxia/hypoxia routinely sets in

12. Deep Channels • Example target species: blue crabs, migrating adult striped bass • Seasonal consideration: these habitats are important to both bottom forging blue crabs and larger fish species seeking refuge in these deeper, warmer waters (e.g., striped bass) during the cooler months of the year

13. Scientific Community Feedback • CBPO staff met with/”interviewed” 16 Bay scientists during the month of June • Cross section of expertise, backgrounds, institutions • Focus was on criteria, but sought input on uses • Solid, strong support for refined designated uses • Stratification of uses by depth critical for DO criteria • Need to factor in consideration of salinity and different physical factors (e.g., flushing rates) into regional application of criteria applied to the same designated use

14. Issues to be Resolved • Defining the boundaries for the designated uses and, thereby, the appropriate criteria values for ensuring protection of critical Bay habitats • Use Bay model scenario output and monitoring data to help define the designated use boundaries through estimation of what Bay water quality we can expect factoring in natural conditions and permanent alterations

15. Schedule • October: proposed designated use language and mapped out boundaries submitted to WQ Technical Workgroup for review • November: draft documentation detailing the technical basis of the proposed designated uses submitted to the WQ Technical Workgroup for review • December: proposed designated uses w/technical documentation submitted to WQ Steering Comm.