My
current research includes these projects:
 | Modeling 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. |
 |
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.
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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.
|
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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.
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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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