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Chesapeake Bay Hypoxia:History and Management Response
Rich BatiukAssociate Director for Science
Chesapeake Bay Program OfficeU.S. Environmental Protection
Agency
Rob MagnienNOAA Center for Sponsored
Coastal Ocean Research
1949-1950
1957-1950
1960-1963
1967-1968
1972 1978-1980
June 1984-December 20031952
Chesapeake Bay Summer Anoxic/Hypoxic Volumes and Winter-Spring Flow: 1949-2003
Source: www.chesapeakebay.net
Source: Hagy et al. 2004
Calculated Summer
Anoxic/Hypoxic Volumes and
Model Predictions: 1950-
2001
Summer dissolved oxygen profiles in Chesapeake Bay:
Four years with near average January–May
SusquehannaRiver flow
Source: Hagy et al. 2004
Extent of Anoxic Conditions
January
February
March
April
May
Early June
Late June
Early July
Late July
Early August
Late August
September
October
November
December
A Year in Chesapeake Bay Dissolved Oxygen: 2004
2006 Summer Chesapeake Bay Dissolved Oxygen
0.00
0.50
1.00
1.50
2.00
2.50
3.00
30,0
00,0
00
40,0
00,0
00
50,0
00,0
00
60,0
00,0
00
70,0
00,0
00
80,0
00,0
00
90,0
00,0
00
100,
000,
000
Algal Index
Anoxi
c V
olu
me,
km
3
_
2002
1993
2005
2006 Chesapeake Bay Mainstem Anoxic Volume Forecast
Red zone indicates forecast area
Forecast Volume
Observed Volume
95% Confidence Interval
Source: www.chesapeakebay.net/bayforecastspring2006.htm
Algal index = spring Susq. TN, TP + N. Bay PS TN, TP
Impaired Water
Over 90% of the Bay and its tidal rivers are impaired due to low dissolved oxygen levels and poor water clarity, all related to nutrient and sediment pollution.
Source: U.S. EPA
Partners Commitment to Restored Bay Water Quality
“By 2010, correct the nutrient‑ and sediment‑related problems in the Chesapeake Bay and its tidal tributaries...”
Step 1: What is the water quality of a restored Bay?
Step 2: How much pollution do we need to reduce?
Step 3: What actions do we need to take to reduce pollution?
Source: Chesapeake Executive Council 2000
What Do We Want to Achieve?
Water quality that supports abundant fish,
crabs, oysters and underwater grasses in
the Bay and its rivers. Source: Chesapeake Executive Council 2000
Water Quality in a Restored Bay
• Fewer algae blooms and better fish food.• Clearer water and more underwater Bay grasses.• More oxygen and improved habitat for more fish,
crabs and oysters.
Source: U.S. EPA 2003a
A. Cross Section of Chesapeake Bay or Tidal Tributary
B. Oblique View of the “Chesapeake Bay” and its Tidal Tributaries
Shallow-WaterBay Grass Use Open-Water
Fish and Shellfish UseDeep-Water
Seasonal Fish andShellfish Use
Deep-ChannelSeasonal Refuge Use
Open-WaterHabitat
Migratory FishSpawning andNursery Use
Refined Designated Uses forthe Bay and Tidal Tributary Waters
Shallow-WaterBay Grass Use
Deep-WaterSeasonal Fish and
Shellfish Use Deep-Channel Seasonal Refuge Use
Source: U.S. EPA 2003b
Bay Dissolved Oxygen Criteria
Minimum Amount of Oxygen (mg/L) Needed to Survive by Species
Migratory Fish Spawning & Nursery
Areas
Hard Clams: 5
Striped Bass: 5-6
Worms: 1
Shallow and Open Water Areas
Deep Water
Deep Channel
6
5
3
2
1
4
0
Crabs: 3
Spot: 2
White Perch: 5
American Shad: 5
Yellow Perch: 5
Alewife: 3.6
Bay Anchovy: 3
Source: U.S. EPA 2003a
Chesapeake Bay Dissolved Oxygen CriteriaDesignated 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-1 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 mg liter-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-1 Survival of open-water juvenile and adult fish.
Instantaneous minimum > 1.7 mg liter-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 mg liter-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 (>29C), dissolved oxygen concentrations above an instantaneous minimum of 4.3 mg liter -1 will protect survival of this listed sturgeon species.
Dissolved Oxygen Criteria TeamRichard Batiuk, U.S. EPA Chesapeake Bay Program Office; Denise Breitburg, Academy ofNatural Sciences; Arthur Butt, Virginia Department of Environmental Quality; Thomas Cronin,U.S. Geological Survey; Ifeyinwa Davis, U.S. EPA Office of Water; Robert Diaz, VirginiaInstitute of Marine Science; Frederick Hoffman, Virginia Department of Environmental Quality;Steve Jordan, Maryland Department of Natural Resources; James Keating, U.S. EPA Office ofWater; Marcia Olson, NOAA Chesapeake Bay Office; James Pletl, Hampton Roads SanitationDistrict; David Secor, University of Maryland Chesapeake Biological Laboratory; Glen Thursby,U.S. EPA Office of Research and Development; and Erik Winchester, U.S. EPA Office ofResearch and Development.
Scientists from across the country, well-recognized for their work in the area of low dissolvedoxygen effects on individual species up to ecosystem trophic dynamics, contributed their time,expertise, publications and preliminary data and findings to support the derivation of ChesapeakeBay-specific criteria: Steve Brandt, NOAA Great Lakes Environmental Research Laboratory;Walter Boynton, University of Maryland Chesapeake Biological Laboratory; Ed Chesney,Louisiana Universities Marine Consortium; Larry Crowder, Duke University Marine Laboratory;Peter deFur, Virginia Commonwealth University; Ed Houde, University of Maryland ChesapeakeBiological Laboratory; Julie Keister, Oregon State University; Nancy Marcus, Florida StateUniversity; John Miller, North Carolina State University; Ken Paynter, University of Maryland;Sherry Poucher, SAIC; Nancy Rabalais, Louisiana Universities Marine Consortium; Jim Rice,North Carolina State University; Mike Roman, University of Maryland Horn Point Laboratory; Linda Schaffner, Virginia Institute of Marine Science; Dave Simpson, Connecticut Departmentof Environmental Protection; and Tim Target, University of Delaware.
Scientific Basis for Decisions was Documented by the Partners
Bay Criteria, Uses Adopted in State WQS
Regulations• DE (2004), MD (2005),
VA 2005/2006), DC (2006)
• Standards adopted in terms of designated use by CBP segment
• WQ criteria, uses, attainment assessment methods essentially fully consistent across jurisdictions
Chesapeake Bay Program Models
Chesapeake Bay Watershed Model
Chesapeake Bay Airshed Model
Chesapeake Bay Water Quality Model
SAV/Light Model
Hydrodynamic Model
Sediment Transport Model
Benthic Infauna Model
Zooplankton Model
Oyster Filter Feeders Model
Sediment Process Model
Phytoplankton Model
Chesapeake Bay ProgramCurrent Modeling Structure
Airshed Model Watershed Model Estuary Model
Nutrient Loadings vs. Dissolved Oxygen Criteria Attainment
% Dissolved OxygenCriteria Attainment
Millions of pounds per year
nitrogen phosphorus
337
285
175
26.5 19.1 12.8
Nutrient pollution
loads have differing
impacts on the Bay water
quality, depending on
where they come from.
WatershedStates
Responsibility
Allocating Responsibility for Reducing Nutrients and Sediments
By 9 major river basins
...then by 20 major tributary basins by
jurisdiction
…then by 44 state-defined tributary
strategy subbasins
WatershedPartners
Responsibility
WatershedStates
Responsibility
Nitrogen Allocation Phosphorus Allocation Upland Sediment Allocation Basin/Jurisdiction (million pounds/year) (million pounds/year) (million tons/year)
SUSQUEHANNA PA 67.58 1.90 0.793 NY 12.58 0.59 0.131 MD 0.83 0.03 0.037
SUSQUEHANNA Total 80.99 2.52 0.962 EASTERN SHORE - MD
MD 10.89 0.81 0.116 DE 2.88 0.30 0.042 PA 0.27 0.03 0.004 VA 0.06 0.01 0.001
EASTERN SHORE - MD Total 14.10 1.14 0.163 WESTERN SHORE
MD 11.27 0.84 0.100 PA 0.02 0.00 0.001
WESTERN SHORE Total 11.29 0.84 0.100 PATUXENT
MD 2.46 0.21 0.095 PATUXENT Total 2.46 0.21 0.095
POTOMAC VA 12.84 1.40 0.617 MD 11.81 1.04 0.364 WV 4.71 0.36 0.311 PA 4.02 0.33 0.197 DC 2.40 0.34 0.006
POTOMAC Total 35.78 3.48 1.494 RAPPAHANNOCK
VA 5.24 0.62 0.288 RAPPAHANNOCK Total 5.24 0.62 0.288
YORK VA 5.70 0.48 0.103
YORK Total 5.70 0.48 0.103 JAMES
VA 26.40 3.41 0.925 WV 0.03 0.01 0.010
JAMES Total 26.43 3.42 0.935 EASTERN SHORE - VA
VA 1.16 0.08 0.008 EASTERN SHORE - VA Total 1.16 0.08 0.008
SUBTOTAL 183 12.8 4.15 CLEAR SKIES REDUCTION -8
BASIN-WIDE TOTAL 175 12.8 4.15
Nutrient and Sediment Cap Load Allocations
-Science-based
-Equitable
- Based on pollution contribution to Bay/river water quality
-Adopted by the six watershed states’ Governors, the DC Mayor and EPA Adminstrator in 2003
• Unprecedented multi-state permitting agreement
• Annual load limits vs. monthly conc. limits
• Watershed-based permitting
• Addresses complex compliance schedule issues
• Addresses monitoring requirements and reporting schedules
Basinwide Permitting Approach
Nitrate and ammonia deposition from improved Daily Nitrate and Ammonium
Concentration Models using 35 monitoring stations over 18 simulation
years.Adjustments to deposition from
Models-3/Community Multi-scale Air Quality (CMAQ) Modeling System
Phase 5 Watershed ModelYear-to-year changes in land use and BMPs; 899 segments; 24 land uses; 296 calibration stations; 21
simulation years; sophisticated calibration procedures; calibration demonstrably better in quality and
scale
Chesapeake Bay Estuary Model Detailed sediment input; Wave model for resuspension, Full
sediment transport; Filter feeder simulation; Simulation of Potomac algal blooms; 54,000
model cells; 18 simulation years
The Forthcoming Next Generation of Bay Models
Less Than Third of the Bay Has Enough Oxygen
Rich Batiuk
Associate Director for Science
U.S. Environmental Protection Agency Chesapeake Bay Program
Office
410-267-5731
www.chesapeakebay.net