Principal Investigators Physics

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Lagrangian Transport Transformation Experiment
An Interdisciplinary Process Study of the Hudson
River Plume in an Operational Research
Observatory
Principal InvestigatorsPhysics Bob Chant
(Rutgers) Scott Glenn (Rutgers) Bob Houghton
(Lamont) Bernie Gardner (U. Mass) John Wilkin
(Rutgers) Chemistry John Reindfelder
(Rutgers) Bob Chen (U.Mass) Biology Paul
Bissett (FERI) Tom Frazer (U. Florida) Mark
Moline (Cal-Poly) Oscar Schofield (Rutgers) Meng
Zhou (U. Mass)
Phytoplankton, Zooplankton and Metals
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LaTTE Goals
Lagrangian Transport Transformation Experiment

• Quantify
• -the physical response of the freshwater plume
  to local forcing
• -the diapycnal mixing rates.
• -the strength and structure of secondary
  flows in a buoyant plume.
• Characterize the chemical and biological
  processes that further affect the transport,
  transformation and fate of metal contaminants.
• Rates of primary production
• Zooplankton grazing rates
• Transport, transformation and fate of metal
  contaminants

Downwelling
Geyer and Fong
Upwelling
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The Operational Research Observatory
Rutgers University Coastal Ocean Observation
Lab The COOLRoom Operations Center
CODAR Network
Glider Fleet
X-Band
Cable
L-Band
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Ocean Color Images Hudson River Plume
2004
2005
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Phytoplankton biomass was greatest in the plume
near the estuary and declined in the evolving
plume
15.5
7.3
Chlorophyll (ug/L)
1.5
1.6
4.5
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Growth rates of phytoplankton, calculated from
changes in Chl a in dilution experiments, were
similar inside and outside of the plume
0.75
Growth Coefficient (d-1)
Phytoplankton
0.50
0.60
0.74
0.79
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Grazing rates by microzooplankton on
phytoplankton were also similar inside and
outside of the plume, but do not explain the
decline in biomass
0.27
Grazing Coefficient (d-1) Microzooplankton
0.13
0.19
0.14
0.16
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Grazing by mesozooplankton?

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NO.primary production is actually enhanced by
the larger grazers !
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Anthropogenic enrichment of contaminant metals in
plume particles
shelf
Lower Hudson River estuary
Hudson River plume
Pb
Cu
Hudson River CuAl
Hudson River PbAl
Windom, 1990
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Quantifying the enrichment of metals in suspended
particles
? metal ratios in Hudson River suspended
particles from Windom (1990) ? metal ratios in
upper continental crust from Wedepohl (1995)
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Anthropogenic enrichment of contaminant metals in
plume particles
Hudson River plume
Lower Hudson River estuary
Hudson River Cu EF
Hudson River Pb EF
Crust Wedepohl, 1995 River Windom, 1990
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gt20 ?m particulate trace metals and phosphorus -
Ag, Al, Cr, Cu, Fe, P, Pb
salinity
50 ng L-1 (Al, Fe, P ?g L-1 Ag x 10, Al x 5, P x
10)
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Non-conservative mixing of particulate metals in
the plume
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Total suspended particle concentration in the HR
plume
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estuary
plume
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plume
estuary
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Metal enrichment of plume phytoplankton (e.g. Cu)
Ho et al. (2003)
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Non-conservative mixing of particulate iron in
the HR plume
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Depletion of clays and enrichment in biogenic
particles
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SUMMARY
Phytoplankton biomass high in plume relative to
offshore water, but declines as plume evolves
Microzooplankton grazing is not sufficient to
control phytoplankton Mesozooplankton grazing
actually stimulates phytoplankton production in
plume Concentrations of contaminant trace metals
in particles are high in the plume relative to
river or offshore coastal water, but decline non-
conservatively in the evolving plume Relatively
high concentrations of trace metals in the plume
particles reflects a decline in particles of
terriginous origin and an increase in biogenic
particles
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LaTTE 2006 Q What happens to the
phytoplankton generated in the plume ?
A Sedimentation to the benthos ? Q What
are the ecological implications ? A
Hypoxia ? Bioaccumulation of metal contaminants
in the benthic food web ?
More COOL stuff to come...
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LaTTE Goals
Lagrangian Transport Transformation Experiment

• To quantify diapycnal mixing rates as well as
  the strength and structure of secondary flows in
  a buoyant plume and characterize the chemical
  and biological processes that further affect the
  transport, transformation and fate of metal
  contaminants.
• Rates of primary production
• Zooplankton grazing rates
• Transport, transformation and fate of metal
  contaminants

Downwelling
Link these rates and processes to wind forced
changes in the structure of the plume.
Geyer and Fong
Upwelling