Chlorophyll Criteria Development for Chesapeake Bay

1. Chlorophyll Criteria Developmentfor Chesapeake Bay Chlorophyll Criteria Team Workshop November 2, 2005 Larry Haas & Michael Williams VIMS / UMCES / CBPO

2. Rich Batiuk’s Objectives • Chlorophyll a concentrations must have direct, quantitative connection with water quality parameter or ecological impairment • Criteria must be derived using methods that enable specific use in different segments; must reflect seasonality by different salinity zone • Recommended data analyses by Larry Haas • Conduct analyses similar to Sin et al. (1999 – Estuaries); i.e., seasonal variations of Chl-a conc.

4. Chlorophyll a Concentrations in VA Tidal Tributaries James Rappahannock York

7. growing season

12. Comments • Chlorophyll a concentrations in the TF, OH, MH, and PH regions of the Bay have distinct seasonal patterns that generally track those observed by Sin et al. 1999 (Estuaries) in different salinity zones of the York River • TF zone – max Chl-a conc. occurred in June and July; commonly < 25 mg L-1 • OH zone – max Chl-a conc. occurred in May, followed by other peaks in July and Sept.; commonly < 30 mg L-1 • MH zone – winter-spring blooms followed by smaller summer blooms; commonly < 15 mg L-1 • PH zone – smaller winter-spring blooms and no apparent summer blooms; commonly < 10 mg L-1