Biogeochemical Cycles: Integration Across the Land- Estuary-Continental Shelf-Ocean Continuum Sybil P. Seitzinger Rutgers University Institute of Marine and Coastal Sciences New Brunswick, NJ

Major Topics Global models of nutrient export from land to coastal oceans Fate of N along the river – estuary – shelf continuum - denitrification Effect of nutrient sources and sinks on coastal ocean primary production - 3-D hydrodynamic plankton model DOM – opening the Black Box

Human Impacts at Global Scales Global models of nutrient export from land to coastal oceans

N Forms: DIN – ammonia, nitrate DON – Black Box PN Watershed Sources of Nutrients to Coastal Ecosystems

Approach Measured N Export by Range of Rivers Model Predict N Export f(N Inputs to Watersheds) + Spatially Explicit Global Data Bases Spatial Pattern N Export Globally

Model Calculation of NO 3 Export by Global Rivers NO 3 Export = f ( Human Sewage, Fertilizer Use, Atmos. Dep. ) from Caraco & Cole, 1999 [0.4 x Water Runoff 0.8 ] x [Fert Use + Atmos. Dep.] ) ( NO 3 Export = 0.7 x Human x 1.85 kg N Population person -1 yr -1 x Fraction urban +

Bouwman et al Fertilizer 1990 kg N km -2 y -1

NOy 1990 NO y Atmospheric Deposition kg N km -2 y -1 Dentener and Crutzen, Gridded Data bases for: Global population (U.N.) Water runoff Watershed delineation

Seitzinger & Kroeze, Global Biogeochemical Cycles 12:93-133, 1998 Model vs. Measured

Model Predicted DIN Export by Rivers kg N km -2 watershed y -1 Seitzinger & Kroeze, 1998

DIN Export by Rivers Tg N y -1 N. Hemisphere 87% 18.2 S. Hemisphere 13% 2.6 Equator Seitzinger & Kroeze, 1998

Global Total Tg = g DIN, World Regions Tg N y-1 Seitzinger & Kroeze, U.S.

Tg = g Source Apportionment of DIN Export Seitzinger & Kroeze, 1998 Precipitation Fertilizer Sewage Fertilizer Sewage Precipitation USA

Imagining the Future

Business-as-Usual Scenario Inputs, 1990 & 2050 to Global Watersheds Kroeze & Seitzinger, 1998

Bouwman et al Bouwman et al. pers. comm Fertilizer, 1990 & 2050 kg N km-2 y-1

Dentener and Crutzen, 1994 Dentener, pers. comm Atmospheric Deposition NOy kg N km-2 y-1

1990 and 2050 DIN Export by Rivers for World Regions Kroeze & Seitzinger, 1998

Research Needs Other forms (particulate, dissolved organic) Other elements (P, C, Si…….) Time varying (seasonal, daily….) Finer spatial resolution input data including hydrology Enhanced global databases Process-based models

Global NEWS Nutrient Export from Watersheds UNESCO-IOC Workgroup Other forms (particulate, dissolved organic) Other elements (P, C, Si…….) Time varying (seasonal, daily….) Finer spatial resolution input data including hydrology Enhanced global databases Process-based models – NASA IDS

Average SRP Yield by Watershed (kg P/km 2 /yr) Harrison, Seitzinger & Caraco, in prep.

Major Topics Global models of nutrient export from land to coastal oceans Fate of N along the river – estuary – shelf continuum - denitrification Effect of nutrient sources and sinks on coastal ocean primary production - 3-D hydrodynamic plankton model DOM – opening the Black Box

Denitrification NO 3/2 N 2 O N 2

RiversEstuariesContinental Shelf Oceanic Denitrification of terrestrial N sources

From Seitzinger & Giblin Connecting the Ocean Margin to Estuaries and Oceans North Atlantic 72-97

From Seitzinger & Giblin Connecting the Ocean Margin to Estuaries and Oceans North Atlantic N, mol N/y River N SourcesSinks Atmos. Dep. Denitrification

From Seitzinger & Giblin Connecting the Ocean Margin to Estuaries and Oceans North Atlantic N, mol N/y River N SourcesSinks Atmos. Dep. Denitrification Onwelling

Terrestrial Rivers Estuaries Ocean Margins Oceanic Integrating Landscapes to Waterscapes Denitrification – Global View

Dynamic Biogeochemical/Hydrodynamic Model of the MAB K. Fennel et al. in prep.; ASLO 2004 N Based Plankton Model Fasham et al Sediment Denitrification Seitzinger & Giblin 1996

Dynamic Biogeochemical/Hydrodynamic Model of the MAB K. Fennel et al. in prep.; ASLO 2004 N Based Plankton Model Fasham et al Sediment Denitrification Seitzinger & Giblin 1996 River N Inputs Across Shelf Transport

Time for the Movie !

Rundenitrification riverine nutrients/PON Ano Byesno Cyes 2-yr simulations, starting from same initial condition in January 1994 after a 1-yr spinup

A227 gC /m2 /y B184 gC /m2 /y 20% reduction from A C200 gC /m2 /y 10% increase from B K. Fennel et al. unpubl. ASLO 2004 Denitrification River Nutrients Annual Primary Production

A227 gC /m2 /y B184 gC /m2 /y 20% reduction from A C200 gC /m2 /y 10% increase from B K. Fennel et al. in prep. ASLO 2004 Denitrification River Nutrients Denitrification River Nutrients Annual Primary Production

A227 gC /m2 /y B184 gC /m2 /y 20% reduction from A C200 gC /m2 /y 10% increase from B Katja Fennel – Denitrification River Nutrients Denitrification River Nutrients Denitrification River Nutrients

Research Needs 3-D hydrodynamic/biogeochemical models global estuaries and shelf (C,N,P, …..) Enhanced observation systems for coastal ecosystems (remote sensing, in situ) Nutrient-plankton-sediment dynamics Higher trophic levels

Advanced Analytical Capabilities

Major Topics Global models of nutrient export from land to coastal oceans Fate of N along the river – estuary – shelf continuum - denitrification Effect of nutrient sources and sinks on coastal ocean primary production - 3-D hydrodynamic plankton model DOM – opening the Black Box

DOM Compounds DOM 100’s to 1000’s of different DOM compounds

Resource Utilization by Microbial Communities: Is it Chaos? DOM B B B B B B B B B B B B 100’s to 1000’s different DOM compounds 100’s+ different species of bacteria chemical composition, sources, and bioavailability of DOM are not well known

Electrospray Ionization Mass Spectrometry – ESI-MS Molecular Level Analysis Instrument Soft ionization, no fragmentation Mass range = Direct injection of sample (20 µl) Positive and negative ionization modes (Rutgers LC/APESI-MS/CLND facility Agilent 1100) Data mass to charge ratio (m/z), abundance basic/acidic properties (+/- mode) of functional groups m/z Ion Abundance

ESI-Mass Spectra of Streams L and M Stream LStream M m/z Ion Abundance Seitzinger et al. accepted L&O 1435 “compounds” 1751 “compounds”

Both Stream L and M Only Stream L Only Stream M Similarity in DOM Composition in 2 Streams Stream LStream M m/z Ion Abundance Seitzinger et al. accepted L&O 1435 “compounds”1751 “compounds”

Bioavailability of DOM in Streams Spring-collected stream water Inoculated with freshwater bacteria local pond Incubated in the dark for 12 days Bacterial analysis: Bulk analysis: Molecular level analysis: 3 H leucine incorp DOC ESI-MS Time series samples (days 0, 2, 6, 12)

Bulk Measures of Bioavailability Bacterial Production DOC Utilization 51% Stream L 43% Stream M similar in both streams

Patterns of Change in Abundance of Individual “Compounds” - m/z m/z 191 m/z 179 m/z 335

Bioavailability Experiment: Molecular Level Results Stream M

DOM B B B B B B B B B B B B Resource Utilization by Microbial Communities- Is it Chaos? B B B B B B B B B B B B DOM

High Degree of Similarity in Utilization of m/z’s between Replicate Flasks Experiment Day Stream L m/z 265 Flask 1 2

High Degree of Similarity in Utilization of m/z’s between Replicate Flasks Seitzinger et al. accepted L&O

Comparison Between Flasks and Between Streams of m/z that Decreased Between flasks same stream (L) Between streams (L and M)

Future Directions Identification of specific compounds Comparison of DOM chemical composition in time and space - within and across aquatic (fw & marine) systems Effects of biological and physical complexity on patterns of DOM utilization Development of ecological theories of resource utilization by microbial communities Identification of compound-specific effects on aquatic organisms (e.g., HABs)

blank Population (persons km -2 ) Lerner et al. 1988; updated to 1990 by Bouwman Lerner et al. 1988; Bouwman, 1990; United Nations, 1996

Totals (Tg) Model Predicted DIN Export by Rivers Doubles by the Year 2050 DIN export doubles in 2050 Kroeze & Seitzinger, 1998

RiversEstuariesContinental Shelf Oceanic N2N2 N2N2 N2N2

North Atlantic Modified from Seitzinger & Giblin 1996

Terrestrial Rivers Estuaries Ocean Margins Oceanic Integrating Landscapes to Waterscapes Check these blue numbers!!!

Terrestrial Rivers Estuaries Ocean Margins Oceanic Integrating Landscapes to Waterscapes

RiversEstuariesContinental Shelf Oceanic

Terrestrial Rivers Estuaries Ocean Margins Oceanic Integrating Landscapes to Waterscapes Denitrification – Global View