Chesapeake Bay Dissolved Oxygen Criteria . 65 
Literature Cited. 67 
IV. Water Clarity Criteria . 81 
Background . 81 
Approach . 82 
The relationships between water quality, light and 
underwater bay grasses . 82 
Determining light requirements. 84 
Strengths and limitations of the criteria derivation procedures. 85 
Water Clarity Criteria Derivation. 90 
Minimum light requirements. 90 
Light-through-water requirements. 95 
Chesapeake Bay Water Clarity Criteria. 96 
r 
Literature Cited. 97 
V. Chlorophyll a Criteria .101 
Background .101 
Scope and magnitude of nutrient enrichment in Chesapeake Bay . . 101 
Chlorophyll a: key indicator of phytoplankton biomass.102 
Chesapeake Bay Chlorophyll a Criteria.104 
Supporting Technical Information and Methodologies.105 
Context for the narrative Chesapeake Bay chlorophyll a criteria ... 105 
Chlorophyll a concentrations characteristic of 
various ecological conditions.107 
Chlorophyll a concentrations characteristic of 
trophic-based conditions .129 
Chlorophyll a concentrations protective against 
water quality impairments.132 
Methodologies for deriving waterbody-specific 
chlorophyll a criteria .134 
Literature Cited.137 
VI. Recommended Implementation Procedures.143 
Defining Criteria Attainment.144 
Dissolved oxygen criteria.144 
Water clarity criteria.144 
Chlorophyll a criteria.147 
Contents 
