Neil Kamal Ganju, Ph.D.
My research spans the multiple disciplines that converge in estuarine systems. Research projects include numerical model development, field observations of hydrodynamics and water quality, wetland and coastal vulnerability assessments, geomorphic change, and eutrophication. For more details, visit http://woodshole.er.usgs.gov/project-pages/estuaries/
I studied civil engineering at the University of Michigan (BSCE), the University of Florida (MSCE), and the University of California-Davis (Ph.D.). In 2001, I began working for the USGS at the California Water Science Center, on the San Francisco Bay Sediment Transport Project with Dr. David Schoellhamer. In 2008 I moved to the Woods Hole Coastal and Marine Science Center and began multiple projects throughout the northeast US. The Estuarine Processes, Hazards, and Ecosystems project, started in 2015, details the past and ongoing studies we are involved with.
Science and Products
Hurricane Sandy Response- Linking the Delmarva Peninsula's Geologic Framework to Coastal Vulnerability
The Delmarva Peninsula is a 220-kilometer-long headland, spit, and barrier island complex that was significantly affected by Hurricane Sandy. In order to better constrain controls on coastal vulnerability and evolution, the region’s sediment sources, transport pathways and sediment sinks must be identified. This project defines the geologic framework of the Delmarva coastal system through...
Estuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling. Both the spatial and temporal scales of these mechanisms are important, and therefore require modern instrumentation and state-of-the-art hydrodynamic models. These projects are led from the U.S....
Numerical models are used by scientists, engineers, coastal managers, and the public to understand and predict processes in the coastal ocean. This project supports the development and application of open-source coastal models and has several objectives: 1) improve the code of numerical sediment-transport models by implementing new or improved algorithms; 2) obtain measurements of coastal...
Quantification of storm-induced bathymetric change in a back-barrier estuary
Geomorphology is a fundamental control on ecological and economic function of estuaries. However, relative to open coasts, there has been little quantification of storm-induced bathymetric change in back-barrier estuaries. Vessel-based and airborne bathymetric mapping can cover large areas quickly, but change detection is difficult because...Ganju, Neil K.; Suttles, Steven E.; Beudin, Alexis; Nowacki, Daniel J. ; Miselis, Jennifer L.; Andrews, Brian D.
Quantifying the residence time and flushing characteristics of a shallow, back-barrier estuary: Application of hydrodynamic and particle tracking models
Estuarine residence time is a major driver of eutrophication and water quality. Barnegat Bay-Little Egg Harbor (BB-LEH), New Jersey, is a lagoonal back-barrier estuary that is subject to anthropogenic pressures including nutrient loading, eutrophication, and subsequent declines in water quality. A combination of hydrodynamic and particle tracking...Defne, Zafer; Ganju, Neil K.
Sediment transport-based metrics of wetland stability
Despite the importance of sediment availability on wetland stability, vulnerability assessments seldom consider spatiotemporal variability of sediment transport. Models predict that the maximum rate of sea level rise a marsh can survive is proportional to suspended sediment concentration (SSC) and accretion. In contrast, we find that SSC and...Ganju, Neil K.; Kirwan, Matthew L.; Dickhudt, Patrick J.; Guntenspergen, Glenn R.; Cahoon, Donald R.; Kroeger, Kevin D.
Physical and biogeochemical controls on light attenuation in a eutrophic, back-barrier estuary
Light attenuation is a critical parameter governing the ecological function of shallow estuaries. In these systems primary production is often dominated by benthic macroalgae and seagrass; thus light penetration to the bed is of primary importance. We quantified light attenuation in three seagrass meadows in Barnegat Bay, New Jersey, a shallow...Ganju, Neil K.; Miselis, Jennifer L.; Aretxabaleta, Alfredo L.
Modeling future scenarios of light attenuation and potential seagrass success in a eutrophic estuary
Estuarine eutrophication has led to numerous ecological changes, including loss of seagrass beds. One potential cause of these losses is a reduction in light availability due to increased attenuation by phytoplankton. Future sea level rise will also tend to reduce light penetration and modify seagrass habitat. In the present study, we integrate a...del Barrio, Pilar; Ganju, Neil K.; Aretxabaleta, Alfredo L.; Hayn, Melanie; García, Andrés; Howarth, Robert W.
Metabolism of a nitrogen-enriched coastal marine lagoon during the summertime
We measured metabolism rates in a shallow, nitrogen-enriched coastal marine ecosystem on Cape Cod (MA, USA) during seven summers using an open-water diel oxygen method. We compared two basins, one directly receiving most of the nitrogen (N) load (“Snug Harbor”) and another further removed from the N load and better flushed (“Outer Harbor”). Both...Howarth, Robert W.; Hayn, Melanie; Marino, Roxanne M.; Ganju, Neil; Foreman, Kenneth H.; McGlathery, Karen; Giblin, Anne E.; Berg, Peter; Walker, Jeffrey D.
Water level response in back-barrier bays unchanged following Hurricane Sandy
On 28–30 October 2012, Hurricane Sandy caused severe flooding along portions of the northeast coast of the United States and cut new inlets across barrier islands in New Jersey and New York. About 30% of the 20 highest daily maximum water levels observed between 2007 and 2013 in Barnegat and Great South Bay occurred in 5 months following Hurricane...Aretxabaleta, Alfredo L.; Butman, Bradford; Ganju, Neil K.
Exchange of nitrogen and phosphorus between a shallow lagoon and coastal waters
West Falmouth Harbor, a shallow lagoon on Cape Cod, has experienced a threefold increase in nitrogen load since the mid- to late 1990s due to input from a groundwater plume contaminated by a municipal wastewater treatment plant. We measured the exchange of nitrogen and phosphorus between the harbor and the coastal waters of Buzzards Bay over...Hayn, Melanie; Howarth, Robert W.; Ganju, Neil K.; Berg, Peter; Foreman, Kenneth H.; Giblin, Anne E.; McGlathery, Karen
Inferring tidal wetland stability from channel sediment fluxes: observations and a conceptual model
Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment...Ganju, Neil K.; Nidzieko, Nicholas J.; Kirwan, Matthew L.
Comparison of sediment supply to San Francisco Bay from watersheds draining the Bay Area and the Central Valley of California
Quantifying suspended sediment loads is important for managing the world's estuaries in the context of navigation, pollutant transport, wetland restoration, and coastal erosion. To address these needs, a comprehensive analysis was completed on sediment supply to San Francisco Bay from fluvial sources. Suspended sediment, optical backscatter,...McKee, L.J.; Lewicki, M.; Schoellhamer, D.H.; Ganju, N.K.
Tidal and groundwater fluxes to a shallow, microtidal estuary: Constraining inputs through field observations and hydrodynamic modeling
Increased nutrient loading to estuaries has led to eutrophication, degraded water quality, and ecological transformations. Quantifying nutrient loads in systems with significant groundwater input can be difficult due to the challenge of measuring groundwater fluxes. We quantified tidal and freshwater fluxes over an 8-week period at the entrance of...Ganju, Neil K.; Hayn, Melanie; Chen, Shih-Nan; Howarth, Robert W.; Dickhudt, Patrick J.; Aretxabaleta, Alfredo L.; Marino, Roxanne
Methyl mercury dynamics in a tidal wetland quantified using in situ optical measurements
We assessed monomethylmercury (MeHg) dynamics in a tidal wetland over three seasons using a novel method that employs a combination of in situ optical measurements as concentration proxies. MeHg concentrations measured over a single spring tide were extended to a concentration time series using in situ optical measurements. Tidal fluxes were...Bergamaschi, B.A.; Fleck, J.A.; Downing, B.D.; Boss, E.; Pellerin, B.; Ganju, N.K.; Schoellhamer, D.H.; Byington, A.A.; Heim, W.A.; Stephenson, M.; Fujii, R.