Water Quality and the Chesapeake Bay David O’Brien NOAA Fisheries Service Gloucester Point, VA.
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Transcript of Water Quality and the Chesapeake Bay David O’Brien NOAA Fisheries Service Gloucester Point, VA.
Water Quality
and the
Chesapeake Bay
David O’BrienNOAA Fisheries Service
Gloucester Point, VA
Chesapeake Bay
The nation’s largest estuary
Nation’s most biologically diverse estuary;
>3600 species of plants and animals
Over 17 million people live in the watershed
Chesapeake Bay watershedVirginia
Maryland
Pennsylvania
New York
Delaware
West Virginia
Dist. Columbia
What Is a Watershed?
Adapted from NEMO
Water-vapor transport
Ocean
Infiltration
Increased runoff
Decreased
Less groundwaterflow
Lower water table
Evaporation
Evaporation
Less vegetation, thus less Less vegetation, thus less evapotranspiration!!evapotranspiration!!
Increased pollutionIncreased pollution
The Water Cycle
Development: Increased Development: Increased impervious surfaceimpervious surface
Ches Bay Population Growth2010 - 17.2 million
Threats to the Chesapeake Bay
NUTRIENTS
SEDIMENTS
TOXIC CHEMICALS
HABITAT LOSS
OVERFISHING
Chesapeake Bay:
How is it Doing???
Habitat
Conversion
Watershed development
% impervious surface
Water Quality Problems
Algae blooms and sediment cloud the water and block sunlight, causing underwater bay grasses to die.
When the algae die and decompose, they use up oxygen needed by other plants and animals living in the Bay's waters.
Algae blooms and depleted oxygen levels are caused by excessive nutrients
Poor water clarity is caused by algae blooms and suspended sediments
Impaired WatersEPA 303(d) list
Portions of the Chesapeake Bay and its tidal rivers are listed under the Clean Water Act as “impaired waters” largely because of low dissolved oxygen levels and other problems related to nutrient pollution.
This “listing” requires the development of a clean-up plan for the Bay by 2011.
Impaired Water
Note: Representation of 303(d) listed waters for nutrient and/or sediment water quality impairments for illustrative purposes only. For exact 303(d) listings contact EPA (http://www.epa.gov/owow/tmdl/).
Unimpaired Water
Nutrient and/or Sediment Impaired
Harmful Algal Bloom (HAB) Harmful Algal Bloom (HAB) HRBTHRBT
y
HAB Lafayette RiverHAB Lafayette River
Healthy vs. Unhealthy Water Quality
Sunlight Sunlight
HealthyHabitat
UnhealthyHabitat
BalancedAlgae Growth
Minimal nutrient and sediment
inputs
Excessive nutrient and sediment inputs
HealthyBay Grasses Reduced
Bay Grasses
Algae Die-off
Algae Decomposition
No Oxygen
No Benthic Community
Benthic Community
HealthyOyster Reef
AdequateOxygen
Algal Bloom
Barren Oyster Reef
Chesapeake Bay DO 2006-2009
Sources of Pollutants to the Bay
Nonpt. Sources
•Run-off from farmland•Run-off from lawns and
paved areas
Point Sources
•Industry•Wastewater Treatment Plants
Nature of Contaminant Inputs
Point SourceInputs with well defined point of dischargeDischarge is usually continuous
Nonpoint SourceOrigin of discharge is diffuseDischarge may be transient in time
Runoff from croplandEffluent from septic systemsHighway de-icing salts
Leakage from landfills and storage tanksWastewater treatment facilitiesIndustrial inputs
Sediment
Nutrients
Toxic Substances
Pathogens
Non-pointNon-point Source PollutantsSource Pollutants
Hurricane Irene sediment plumeSept. 14, 2011
Nutrient and Sediment Load Reduction Goals
The 2010 pollutant reduction goals are:
Nitrogen - Reduce annual loads to no more than 175 million pounds.
Phosphorus - Reduce annual loads to no more than 12.8 million pounds.
Land-based Sediment - Reduce annual loads to no more than 4.15 million tons.
0
5
10
15
20
25
30
1985 2000 2002*
Pho
spho
rus
Load
(m
illion
lbs/
yr)
2010PhosphorusGoal
0
50
100
150
200
250
300
350
400
1985 2000 2002*
Nitr
ogen
Loa
d (m
illion
lbs/
yr) 2010
NitrogenGoal
0
1
2
3
4
5
6
7
1985 2000 2002*
Sed
imen
t Loa
d (m
illion
tons
/yr) 2010
SedimentGoal
Nitrogen Loading
Phosphorus Loading
Chesapeake Bay Water Quality Goals 2009
Water Clarity
Dissolved Oxygen (DO)
Wetland restoration
Chesapeake Bay Fish / Shellfish Goals 2009
Rockfish Population Stable
Rockfish have rebounded to levels not seen since the 1950’s, but concerns remain over disease, sufficient sources of food and availability of spawning habitat.
0
5
10
15
20
25
30
35
40
4519
8219
8319
8419
8519
8619
8719
8819
8919
9019
9119
9219
9319
9419
9519
9619
9719
9819
9920
0020
0120
0220
03
SS
B (
fem
ales
ag
es 4
+yrs
, mill
ion
s o
f lb
s)
Fishing moratoria:MD & DE: 1985-1990
VA: 1989-1990
Baywide Female Spawning Stock Biomass
Striped Bass
0
5
10
15
20
25
30
35
40
53 58 63 68 73 78 83 88 93 98 2003
Com
mer
cial
Lan
ding
s (m
illio
n lb
s)
Oysters at Historic Lows
VA
MD
Oyster populations in the Chesapeake are at historic lows due to disease, intense harvest pressure and poor water quality.
Oyster stocks
Oyster restoration efforts
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
1968
1971
1974
1977
1980
1983
1986
1989
1992
1995
1998
2001
2004
Sp
aw
nin
g F
em
ale
Ind
ex
Blue Crabs At RiskMature Female Blue Crabs
Average
Blue Crab populations have stabilized at below-average levels.
Improved water quality and habitat restoration efforts along with proper management of the crab harvest are needed to restore the Bay’s blue crab populations.
Blue Crab
Largest crab fishery in the world
$80 million dockside value in Ches Bay
$360 million value to national economy
Blue Crab stock
SAV 2007-2009 goals
Bay Grasses Show Annual Variation
Underwater bay grasses are slowly improving, but further reductions in the pollutants flowing into the Bay are needed to help them flourish.Annual variations in bay grasses show the sensitivity of the Bay ecosystem.
0
20
40
60
80
100
120
140
160
18019
7819
7919
8019
8119
8219
8319
8419
8519
8619
8719
8819
8919
9019
9119
9219
9319
9419
9519
9619
9719
9819
9920
0020
0120
0220
0320
04
Acr
es o
f Bay
Gra
sses
(th
ousa
nds) Restoration Goal (185,000 acres by 2010)
*Note – Hatched area of bar includes estimated additional acreage. No Baywide surveys 1979-83 and 1988 Source: Chesapeake Bay Program.
SAV aerial coverage
PRE-1930’S 1960’S PRESENT
Clam Dredge Scarring in Chincoteague Bay
SAV Restoration - Planting
Special thanks to:
Dr. Bob Orth, VIMS SAV Program
Chesapeake Bay Program
Chesapeake Bay Foundation
NOAA Chesapeake Bay Office
Thanks for your interest!!!