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Stony Brook University -
School of Marine and Atmospheric Sciences
Joseph D. Warren
My current research includes these projects:


 The effect of zooplankton populations on the behavior of marine mammals.

In conjunction with collaborators at Penn State and the Provincetown Center for Coastal Studies, we are measuring the distribution and abundance of zooplankton populations in Cape Cod Bay and Stellwagen Bank National Marine Sanctuary. Our net tow, acoustic backscatter, and hydrographic data will be combined with data from scientists who are monitoring the behavior of right and humpback whales in these waters. We are examining what role do zooplankton prey play in determining marine mammal behavior.

Assessment of underwater noise and animal vocalizations in local waters.

We are constructing small, portable underwater recorders to assess the temporal and spatial variability of underwater sound, both from anthropogenic sources and marine organsisms.
EuphausiidModeling the Target Strength of Bering Sea Euphausiids

The walleye pollock fishery is the largest United States fishery (in terms of landings) and is annually studied by the NMFS Alaska Fisheries Science Center MACE program through regular cruises in the Bering Sea. To assess the stock of pollock, the fishery scientists use a combination of acoustic echosounder surveys and net trawls. We are working with them to develop an improved model of the scattering characteristics of the zooplankton of the Bering Sea, in particular the euphausiids. Aggregations of these animals scatter sound and can be confused with the scattering from pollock schools. We collected and measured a variety of Bering Sea zooplankton and are developing mathematical models that describe their acoustic scattering so that the fishery scientists can better identify scatterers as pollock or other biological organisms.
RV Yuzhmo The Nearshore Antarctic Krill Ecosystem

Using a variety of platforms (large research vessel, small boat, and instrumented buoys), my co-PI David Demer (SWFSC, NOAA) and I are trying to understand the biological and physical factors that create regions of high krill productivity in the nearshore waters off of Livingston Island, Antarctica. These areas serve as the main foraging grounds for resident penguin and fur seal populations and understanding the spatial and temporal variability of the krill distribution is important to understand how the ecosystem functions. Additionally, I'm working with other scientists who study krill predators in this area to understand how the distribution of prey (krill) is related to predator foraging range and behavior. This project is supported by the National Science Foundation and NOAA.
Flanders Kettle Hole Pond SCERP and Long Island South Shore Estuary System
 
Understanding the local waters of Long Island in terms of the biological and physical oceanography is important for a variety of reasons, including shellfish and finfish stocks, anthropogenic influences, effect of development, and management of recreational areas. Studies have been undertaken by several researchers investigating many different aspects of the local estuarine environment. Our group has investigated the influence that the ocean inlets along the south shore of Long Island have on the temperature and salinity distributions within the bays. Both tidal and wind-driven circulation are the primary factors controlling the levels of salinity and temperature within the bays which are critical factors affecting shellfish habitat, recruitment, and growth. This project is supported by New York Sea Grant and the SCERP foundation.
ADCP at work
Acoustic Scattering from Submerged Aquatic Vegetation (SAV)

Preliminary studies indicate that some types of SAV can scatter a significant amount of acoustic energy, and at times can even register "false bottoms" on a depth-finder. We are investigating whether acoustics can be used to map SAV populations, what the scattering mechanisms are for different types of SAV, whether acoustics can be used to non-invasively study the growth and health of SAV, and the implications for SAV scattering as a factor for "noise" in sonar systems such as mine-detection. Initial funding for this work was provided by UNH CICEET program.

Some of my past research areas include:

    Surveys of zooplankton populations in the Ligurian Sea to assist in assessments of marine mammal distributions

    Use of multifrequency acoustics to distinguish between biological and physical sources of scattering

    Surveys of zooplankton populations in the Gulf of Maine

    Study and validation of mathematical scattering models for different types of zooplankton




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