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Proceedings ArticleDOI

From acoustic scattering models of zooplankton to acoustic surveys of large regions

05 Jun 1998-pp 2-2
TL;DR: The bioacoustics research group at the Woods Hole Oceanographic Institution is actively conducting field surveys, laboratory acoustic scattering experiments, and theoretical modeling of acoustic scattering as discussed by the authors, which has been used to map portions of Georges Bank near Cape Cod, MA, US.
Abstract: The bioacoustics research group at the Woods Hole Oceanographic Institution is actively conducting field surveys, laboratory acoustic scattering experiments, and theoretical modeling of acoustic scattering. While the focus of the research has been on zooplankton, we have also investigated the scattering by internal waves and suspended sediment. The field surveys are taking advantage of the newly developed towed instrument, BIOMAPER-II, that contains a suite of acoustical (43 kHz to 1 MHz), optical, and environmental sensors. The system has been used to map portions of Georges Bank near Cape Cod, MA, US. Our laboratory contains a wide range of acoustic transducers (24 kHz to 1.4 MHz, some of which are broadband) that are used to measure the acoustic backscattering as a function of acoustic frequency and animal orientation. The system has been used to measure the acoustic scattering properties of live tethered animals, either at sea on the deck of a ship with freshly caught animals or on land with live animals that have been maintained. The laboratory data have provided a basis for the development of physics-based acoustic scattering models of the zooplankton which have been used to interpret the field surveys. The models take into account the material properties of the animals, size, shape, and orientation, as well as acoustic frequency. Broadband echo classification methods have been developed based on the models and data. Finally, two new systems are under development: one is used to measure target strength of individuals in situ and the other is to be used to measure sound speed of the animals in situ.
Citations
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Journal ArticleDOI
TL;DR: In this article, a passive acoustic recorder and three-frequency echosounder system were integrated into a biophysical mooring on the central eastern Bering Sea continental shelf.

29 citations


Cites background from "From acoustic scattering models of ..."

  • ...The resonant scatterer type represents an organism with a gas-inclusion such as a swim-bladdered fish or siphonophore which has a strong resonant peak in the scattering spectra (Stanton, 1998)....

    [...]

Journal ArticleDOI
25 Jun 2015-PLOS ONE
TL;DR: The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given changing climate scenarios.
Abstract: Variability of hydrographic conditions and primary and secondary productivity between cold and warm climatic regimes in the Bering Sea has been the subject of much study in recent years, while interannual variability within a single regime and across multiple trophic levels has been less well-documented. Measurements from an instrumented mooring on the southeastern shelf of the Bering Sea were analyzed for the spring-to-summer transitions within the cold regime years of 2009–2012 to investigate the interannual variability of hydrographic conditions, primary producer biomass, and acoustically-derived secondary producer and consumer abundance and community structure. Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column. Primary producer biomass was more tightly coupled to hydrographic conditions in 2012 than in 2009 or 2011, and shallow and mid-column phytoplankton blooms tended to occur independent of one another. There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year. Phytoplankton blooms stimulated different populations of secondary producers in each year, and summer consumer populations appeared to determine dominant populations in the subsequent spring. Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years. The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given changing climate scenarios.

12 citations


Cites background from "From acoustic scattering models of ..."

  • ...The resonant scatterer type represents an organism with a gas-inclusion such as a swim-bladdered fish or siphonophore which has a strong resonant peak in the scattering spectra [37]....

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Book ChapterDOI
01 Jan 2002
TL;DR: In this article, the authors present selected results from a program designed to address the origin of variability in high-frequency acoustic backscattering in the water column and identify the model parameters with the highest degree of uncertainty.
Abstract: High-frequency acoustic backscattering in the water column is highly variable in both space and time. We present selected results from a program designed to address the origin of this variability. There are many naturally occurring processes in the water column, of both physical and biological origin, that give rise to acoustic backscattering. The naturally occurring spatial and temporal variability of these physical and biological processes contribute significantly to variability in acoustic backscatter. In addition, there is uncertainty associated with identifying and obtaining high-resolution information of the physical and biological parameters that contribute to volume scattering. Uncertainty in predicting volume scattering also arises from possible inaccuracies of the scattering models, as well as variability due to speckle. Emphasis is given here to identifying the model parameters with the highest degree of uncertainty.

9 citations


Cites methods from "From acoustic scattering models of ..."

  • ...This program has involved significant model development, laboratory measurements, and field measurements [1]....

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ReportDOI
30 Sep 2013
TL;DR: In this article, the long-term goal of a collaborative research effort is to enhance the understanding of how variability in physical, biological, and acoustic signals impact marine mammal habitat use.
Abstract: : The long-term goal of this collaborative research effort is to enhance the understanding of how variability in physical, biological, and acoustic signals impact marine mammal habitat use. This is especially critical in areas like the Bering Sea where global climate change can lead to rapid changes of the entire ecosystem. The Arctic is projected to experience ice-free summers within 30 years (Wang & Overland, 2009). This will have significant impacts for the natural ecosystem dynamics and human use associated with transportation, fishing, military activity, and energy exploration. Baseline measurements will play an important role in mitigation efforts and environmental assessments as military activity increases in the region. A major component of this research is to use passive ambient sound to identify the physical environment present, and then to use this information to interpret the biological data collected.

5 citations


Cites background from "From acoustic scattering models of ..."

  • ...The resonant scatterer type represents an organism with a gas-inclusion such as a swim-bladdered fish or siphonophore which has a strong resonant peak in the scattering spectra (Stanton, 1998)....

    [...]

Journal ArticleDOI
16 Aug 2018-PLOS ONE
TL;DR: It is shown, using simulation of sampling, that gliders can resolve acoustic targets at greater resolutions than ships, due to their diving pattern, but that survey accuracy is strongly dependent on the speed of the target.
Abstract: Underwater gliders are autonomous robots that follow a slow, see-saw path and may be deployed for months on end. Gliders have a dramatically lower payload capacity than research vessels and are thus limited to more simple instrumentation. They have the advantage, however, of being deployable for long periods of time without the high running costs of a ship. Recent years have seen development of the use of gliders to undertake acoustic surveys of biomass in the pelagic environment, highlighting their potential to fill future survey gaps. Here it is shown, using simulation of sampling, that gliders can resolve acoustic targets at greater resolutions than ships, due to their diving pattern, but that survey accuracy is strongly dependent on the speed of the target.

3 citations