Integrated Reconnaissance of the Physical and Biogeochemical
Characteristics of Jamaica Bay: Initial Activity Phase
Researchers at The Earth Institute of Columbia
University have carried out an integrated, coordinated pilot reconnaissance
of the physical, chemical, geological, and biological systems
within Jamaica Bay, entitled "Integrated Reconnaissance
of the Physical and Biogeochemical Characteristics of Jamaica
Bay". We believe that such an integrated approach is
necessary to fully understand the complex inter-relationship of
the wetland ecosystem. This effort was jointly funded by the US
National Park Service/Gateway National Recreational Area and The
Earth Institute of Columbia University.
The program focused on obtaining a synergistic
view of the varied elements of Jamaica Bay by carrying out coordinated
research in four areas: submarine sediment morphology, sediment
and soil sampling, circulation and mixing, and chemical analysis
of the Bay waters.
Results of the research can be summarized by
the following key points:
Jamaica Bay is an energetic system:
- • There is significant transport of
coarse sediment in the channels; Grassy Bay is a sediment sink.
- • The Jamaica Bay system is stratified,
at least during summer; inflow to the Bay via Rockaway Inlet
is likewise stratified.
- • Stratification is highly time dependent;
tidal influences have a profound impact on vertical structure
throughout the Bay.
- • Flushing times vary for different
portions of the Bay; estimates using two independent methods
yield a flushing time on the order of 1 week for the upper 5
meters of Grassy Bay.
- • Multiple sources of freshwater contribute
to the Bay—Hudson plume, sewage treatment outfalls, and
surface runoff.
- • Nitrogenous nutrients remain abundant
throughout the summer, and we noted periods of suboxic conditions
at the sediment-water interface in Grassy Bay.
- • During hyper-eutrophic conditions
the phytoplankton appear to be limited by the availability of
carbon dioxide.
Jamaica Bay is an evolving system:
- • In JoCo Marsh, the present Spartina
patens marsh began forming 2000 years ago as a shallow pool
atop sand.
- • Marsh pollen and seed stratigraphy
show the impact of human development in the region.
- • Recent loss of salt marshes has been
rapid; the high rate is difficult to explain.
This pilot reconnaissance study has raised
a host of questions worthy of further investigation:
- • What is the sediment/energy budget
of the system? Is marsh loss associated with a net change in
sediment budget within Jamaica Bay and sediment transport between
the surrounding lowlands and coastal ocean?
- • How do two-layer flow & vertical
mixing vary throughout the Bay over tidal cycles?
- • What are the seasonal variations of
stratification? residence times? freshwater sources?
- • How significant are storm events on
sediment movement, water properties & mixing times?
- • Will the observed trend toward greater
Bay production over the last two decades induce more frequent
and extensive sub-oxic conditions?
- • Can isotopic data be useful to gauge
the amount of excess nutrients in the Bay?
- • Do mainland marshes share the same
history as the island marshes? What is the age and development
of the marsh at Old Mill Creek (site 5)?
- • What accounts for the high rate of
salt marsh loss?
Participants
- Arnold L. Gordon, Coordinator
of the Columbia Jamaica Bay Program
- Robin Bell, Suzanne Carbotte
and Roger Flood - Geophysical Mapping of Submarine Environments
- Ellen Hartig, Alexander Kolker
and Vivien Gornitz - Investigations into Recent Salt Marsh
Losses in Jamaica Bay
- Dorothy Peteet and Louisa
Lieberman - Paleoenvironmental History of Jamaica Bay Marshes
- Arnold Gordon, Robert Houghton
and Bruce Huber - Temperature, Salinity and Currents in Jamaica
Bay; Dye Tracer Experiments in Jamaica Bay
- James Rubenstone - Stable
Isotope Evidence for Water Mass Mixing in Jamaica Bay
- Renee Takesue and Alexander
van Geen - Patterns of Nutrient Enrichment and Depletion in
Jamaica Bay
- Chris Langdon - Trophic
Status of Jamaica Bay: Spatial and Temporal Patterns
- Ray Sambrotto - Nitrogenous
Nutrients and Plankton Production in Jamaica Bay