34 
Table IV-1. Chesapeake Bay dissolved oxygen criteria. 
Designated 
Use 
Criteria 
Concentration/Duration 
Protection Provided 
Temporal 
Application 
Migratory 
fish 
spawning 
and 
nursery use 
7-day mean > 6 mg liter 1 
(tidal habitats with 0 -0.5 ppt 
salinity) 
Survival/growth of larval/juvenile tidal- 
fresh resident fish; protective of 
threatened/endangered species 
February 1 
May 31 
Instantaneous minimum > 5 
mg liter' 
Survival and growth of larval/juvenile 
migratory fish; protective of 
threatened/endangered species 
Open-water fish and shellfish designated-use criteria apply 
June 1 - 
January 31 
Shallow- 
water Bay 
grass use 
Open-water fish and shellfish designated-use criteria apply 
Year-round 
Open-water 
fish and 
shellfish use 
30-day mean > 5.5 mg liter 1 
(tidal habitats with 0-0.5 ppt 
salinity) 
Growth of tidal-fresh juvenile and adult 
fish; protective of threatened/ 
endangered species 
Year-round 
30-day mean > 5 mg liter' 1 
(tidal habitats with > 0.5 ppt 
salinity) 
Growth of larval, juvenile and adult fish 
and shellfish; protective of threatened/ 
endangered species 
7-day mean > 4 mg liter 1 
Survival of open-water fish larvae 
Instantaneous minimum > 3.2 
mgliter' 1 
Survival of threatened/endangered 
sturgeon species 1 
Deep-water 
seasonal fish 
and shellfish 
use 
30-day mean > 3 mg liter' 1 
Survival and recruitment of bay 
anchovy eggs and larvae 
June 1 - 
September 30 
1-day mean > 2.3 mg-liter ' 
Survival of open-water juvenile and 
adult fish 
Instantaneous minimum > 1.7 
mgliter' 1 
Survival of bay anchovy eggs and larvae 
Open-water fish and shellfish designated-use criteria apply 
October 1 - 
May 31 
Deep- 
channel 
seasonal 
refuge use 
Instantaneous minimum > 1 
mgliter 1 
Survival of bottom-dwelling worms and 
clams 
June 1 
September 30 
Open-water fish and shellfish designated-use criteria apply 
October 1 
May 31 
1 At temperatures considered stressful to shortnose sturgeon (> 29EC), dissolved oxygen concentrations above an 
instantaneous minimum of 4.3 mgliter 1 will protect survival of this listed sturgeon species. 
chapter iv • 
Refinements to the Chesapeake Bay Dissolved Oxygen Criteria Assessment Procedures 
