Office of Research and DevelopmentNational Health and Environmental Effects

Research Laboratory

Office of Research and DevelopmentNational Health and Environmental Effects

Research LaboratoryGulf of Mexico Hypoxia Monitoring &

ModelingGulf of Mexico Hypoxia Monitoring &

Modeling

Water Quality Issues in the Gulf of Mexico

Reduce coastal nutrient loads Reduce hypoxia in northern

Gulf Improve water quality Restore wetlands Preserve habitats

Sources: Gulf Alliance, draft reportNCCR2, 2005Hypoxia Action Plan, 2001

Office of Wetlands, Oceans& WatershedsMS River/Gulf of MexicoWatershed Nutrient Task Force

Office of Science & TechnologyNational Nutrient Criteria

2001 Hypoxia Action called for reassessment in 5 years – assess progress towards goals and revise if needed

SAB will conduct assessment of Gulf hypoxia science (beginning in 2006) - SAB will require information update (GED lead for Hypoxia Science Symposium)

MS River Basin and Gulf receiving water focus for EcoProtection MYP revision

Nutrient criteria recommendations for freshwater systems by ecoregion released in 2001 - States are working to revise FW criteria

OST required to release estuarine nutrient criteria recommendations by 2007

OST required to release nutrient criteria recommendations for wetlands and coastal marine waters by ???

Office of Water Needs

Gulf Hypoxia Monitoring and Modeling

MED Field StationGrosse Ile, MichiganRussell G. Kreis Jr.

Gulf Ecology DivisionGulf Breeze, FloridaRichard M. Greene

Gulf of Mexico Program OfficeStennis, Mississippi

Western Ecology DivisionNewport, OregonPeter M. Eldridge

Office of WaterWashington DC

Gulf Hypoxia Monitoring and ModelingGulf Hypoxia Monitoring and ModelingGoal:Develop consensus modeling framework targeting Gulf hypoxia

o to reduce uncertainty and enhance credibility of model estimates of nutrient load reductions required to meet Action Plan goals

o provide defensible options to guide restoration and decision-making

Goal:Develop consensus modeling framework targeting Gulf hypoxia

o to reduce uncertainty and enhance credibility of model estimates of nutrient load reductions required to meet Action Plan goals

o provide defensible options to guide restoration and decision-making

CENR National HypoxiaAssessment Report (1999)

CENR National HypoxiaAssessment Report (1999)

o Primary obstacle to reducing model uncertainties … is lack of a sufficiently comprehensive database

o Existing database not designed to quantify load-response relationships – new monitoring approaches needed

o Comprehensive monitoring programs alone will not be sufficient for developing, calibrating and validating quantitative WQ models – relevant and targeted research needed

o Future modeling should include linkages of WQ/Eutro and hydrodynamics, expansion of spatial domain, and refinement of temporal and spatial resolution – new integrated, multimedia modeling constructs needed

ORD ObjectivesORD Objectives

• Establish an integrated multimedia, mathematical modeling framework that incorporates monitoring, condition assessment, diagnosis, and research

• Support the framework with a statistically-based, seasonal field monitoring design and targeted research

• Integrate physical, chemical, biological components with external and internal nutrient loads

• Establish stressor-response relationships for nutrient loads & concentrations, Chl a, and DO

• Develop predictive capability to forecast the benefits of risk reduction options and the time to realize the benefits

• Examine stressor-response relationships using forecasting to provide bases for biologically-based, nutrient criteria for ambient nutrients, Chl a, and DO

• Provide managers with defensible methods, tools, and options to aid and guide the environmental decision-making process

ORD Gulf Hypoxia Modeling Framework

SurfaceWaveModel

HydrodynamicModel

AtmosphericTransport

Model

ComputationalTransport

SedimentTransport &

Diagenesis Model

WaterQualityModel

EutrophicationModel

MassBalance

Wave direction,height, period

DepositionFluxes

Advective/DispersiveTransport

DissolvedOxygen Model

(water/sediment)

Meteorological data

ConstituentMass

loadings

Framework ModelsFramework Models

Atmospheric

Hydrodynamic/Meteorological

Sediment transport, fate, and diagenesis

Water Quality/Eutrophication/Dissolved Oxygen

Model Components

ORD/NERL

USN, NRL

ORD/NHEERL

ORD/NHEERL

CMAQ, CTM, MM5

IAS NCOM

IPX-MT andCE-QUAL-ICM hybrid

WASP andCE-QUAL-ICM hybrid

Partners

U.S. EPA-ORD/NERL

Conceptual Relationship Between Maximum Hypoxic Zone Size and

Load Reduction

Establish a defensible nutrient loading target necessary to reduce the areal extent of hypoxic bottom waters in the Gulf

Develop eco-forecasting capabilities to evaluate nutrient management strategies and timelines to achieve results

2000 2005 2010 2015

Hyp

oxi

c A

rea

(10

3 k

m2)

0

10

20

30No Change-20% by 2015 -50% by 2015

Hypoxia Recovery Scenarios Under Gradual Nutrient Reductions and

Hydrologic Variability

Gulf Hypoxia Monitoring SurveysGulf Hypoxia Monitoring SurveysCharacterize the spatial and temporal variability in oceanographic state and process variables, including resolution of the seaward and down-plume boundary conditions of the model domain

Quantify key processes influencing hypoxia to improve predictive models

Develop geo-referenced database to support model development

Gulf Hypoxia Monitoring SurveysGulf Hypoxia Monitoring SurveysSurveys Completed

Dec 2–15 2002March 17–31 2003June 9–23 2003Nov 5–19 2003April 2–7 2004March 21-31 2005Sept 26 – Oct 9, 2005

Station Sampling SummaryCTD CTD+Water Benthic17 19 029 36 626 25 728 42 9 0 22 424 42 10

-94.5 -94 -93.5 -93 -92.5 -92 -91.5 -91 -90.5 -90 -89.5 -89 -88.527.5

28

28.5

29

29.5

30

30.5

Map shows transect stationsand depth contours

Dissolved Inorganic –nitrate, nitrite, phosphate, ammonium, silicate

X

Particulate C, N, P X XTotal Dissolved N, PTotal N, P

X

Dissolved organic carbon XTotal Suspended solids XBiogenic silica XChlorophyll a X XPAR, secchi depth, attenuation X

Dissolved oxygen XT, S, turbidity, transmissivity XPhytoplankton taxonomy XGrain size, benthic taxonomy XTotal organic matter/organic C XBulk density, porosity, % water X

Primary productivity (14C & FRRF) X

Bacterial productivity (3H-Leucine)

X

Respiration rates XSediment oxygen demand XSulfate reduction rates XBenthic nutrient flux X

Parameter Water SedimentGulf Hypoxia Monitoring Data – discrete waters samples collected at minimum of 2 and maximum of 6 depths depending on water column structure and depth

93° W 92° W 91° W 90° W

28° N

29° N

30° N

0

2

4

6

8

10

kg/m3

June 9 – 19, 2003

Water column stratificationand Hypoxic Region

93° W 92° W 91° W 90° W

28° N

29° N

30° N

0

1

2

3

4

5

6

7

8

9

10

µg/L

June 9 – 19, 2003

Surface Chlorophyll aand Hypoxic Region

93° W 92° W 91° W 90° W 89° W

28° N

29° N

30° N

Bottom Dissolved Oxygen (mg/l)LA Shelf / Gulf of Mexico -- 3/22 - 3/31/2005

9 3 9 2 9 1 9 0 8 9

2 8

2 9

3 0

R e l a t i v e C h l o r o p h y l l - a F l u o r e s c e n c eL A S h e l f / G u l f o f M e x i c o - - 3 / 2 2 - 3 / 3 1 / 2 0 0 5

- 8

- 4

0

4

8

1 2

1 6

2 0

+ + + + + S h i p T r a c k

Resolving Seaward Boundary Conditions

Resolving Seaward Boundary Conditions

Salinity distributions along transect D showing oceanic conditions seaward

Dep

th (

m)

0 2 0 4 0 6 0 8 0 1 0 01 4 0

1 2 0

1 0 0

8 0

6 0

4 0

2 0

0

June 2003

Transect Distance (km)0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0

1 4 0

1 2 0

1 0 0

8 0

6 0

4 0

2 0

0

March 2003

-9 0.5 -9 0.4 -9 0.3 -9 0.2 -9 0.1 -90 -8 9.9 -8 9.8 -8 9.7 -8 9.6 -8 9.5 -8 9.4 -8 9.3 -8 9.2 -8 9.1 -89

29

2 9.2

2 9.4

Time

09:00:00 11:00:00 13:00:00 15:00:00

Sal

inity

0

5

10

15

20

25

30

PO

43

- ( M

)

0.0

0.5

1.0

1.5

2.0

Salinity

0 5 10 15 20 25

PO

43- ( M

)0

1

Continuous Surface Mapping Array MS River to Continuous Surface Mapping Array MS River to FourchonFourchon

Surface salinity and PO43-

Cruise trackStart

Stop

Mixing zone

Not baseline corrected

Project TimelinesProject Timelines

FY ‘02 FY ‘03 FY ‘07FY ‘06FY ‘05FY ‘04

Planning

Field Monitoring

Sample/Data Analysis

Database Development

Model Development& Application APM APM APM

Cruise WQ DbaseReport Trends

FY ‘08