E. John Simmonds

Bio: E. John Simmonds is an academic researcher. The author has contributed to research in topics: Fisheries acoustics. The author has an hindex of 1, co-authored 1 publications receiving 784 citations.

Fisheries Acoustics: Theory and Practice

Abstract: Series Foreword Preface Acknowledgements 1 Introduction 2 Underwater Sound 3 Acoustic Instruments 4 Biological Acoustics 5 Observation and Measurement of Fish 6 Target Strength of Fish 7 Plankton and Micronekton Acoustics 8 Survey Design 9 Data Analysis References Species Index Author Index Subject Index

Anthropogenic and natural sources of ambient noise in the ocean

Abstract: Ocean ambient noise results from both anthropogenic and natural sources. Different noise sources are dominant in each of 3 frequency bands: low (10 to 500 Hz), medium (500 Hz to 25 kHz) and high (>25 kHz). The low-frequency band is dominated by anthropogenic sources: pri- marily, commercial shipping and, secondarily, seismic exploration. Shipping and seismic sources con- tribute to ambient noise across ocean basins, since low-frequency sound experiences little attenua- tion, allowing for long-range propagation. Over the past few decades the shipping contribution to ambient noise has increased by as much as 12 dB, coincident with a significant increase in the num- ber and size of vessels comprising the world's commercial shipping fleet. During this time, oil explo- ration and construction activities along continental margins have moved into deeper water, and the long-range propagation of seismic signals has increased. Medium frequency sound cannot propagate over long ranges, owing to greater attenuation, and only local or regional (10s of km distant) sound sources contribute to the ambient noise field. Ambient noise in the mid-frequency band is primarily due to sea-surface agitation: breaking waves, spray, bubble formation and collapse, and rainfall. Var- ious sonars (e.g. military and mapping), as well as small vessels, contribute anthropogenic noise at mid-frequencies. At high frequencies, acoustic attenuation becomes extreme so that all noise sources are confined to an area close to the receiver. Thermal noise, the result of Brownian motion of water molecules near the hydrophone, is the dominant noise source above about 60 kHz.

ViBand: High-Fidelity Bio-Acoustic Sensing Using Commodity Smartwatch Accelerometers

Abstract: Smartwatches and wearables are unique in that they reside on the body, presenting great potential for always-available input and interaction. Their position on the wrist makes them ideal for capturing bio-acoustic signals. We developed a custom smartwatch kernel that boosts the sampling rate of a smartwatch's existing accelerometer to 4 kHz. Using this new source of high-fidelity data, we uncovered a wide range of applications. For example, we can use bio-acoustic data to classify hand gestures such as flicks, claps, scratches, and taps, which combine with on-device motion tracking to create a wide range of expressive input modalities. Bio-acoustic sensing can also detect the vibrations of grasped mechanical or motor-powered objects, enabling passive object recognition that can augment everyday experiences with context-aware functionality. Finally, we can generate structured vibrations using a transducer, and show that data can be transmitted through the human body. Overall, our contributions unlock user interface techniques that previously relied on special-purpose and/or cumbersome instrumentation, making such interactions considerably more feasible for inclusion in future consumer devices.

Spatial Heterogeneity of Methane Ebullition in a Large Tropical Reservoir

Abstract: Tropical reservoirs have been identified as important methane (CH4) sources to the atmosphere, primarily through turbine and downstream degassing. However, the importance of ebullition (gas bubbling) remains unclear. We hypothesized that ebullition is a disproportionately large CH4 source from reservoirs with dendritic littoral zones because of ebullition hot spots occurring where rivers supply allochthonous organic material. We explored this hypothesis in Lake Kariba (Zambia/Zimbabwe; surface area >5000 km2) by surveying ebullition in bays with and without river inputs using an echosounder and traditional surface chambers. The two techniques yielded similar results, and revealed substantially higher fluxes in river deltas (∼103 mg CH4 m–2 d–1) compared to nonriver bays (<100 mg CH4 m–2 d–1). Hydroacoustic measurements resolved at 5 m intervals showed that flux events varied over several orders of magnitude (up to 105 mg CH4 m–2 d–1), and also identified strong differences in ebullition frequency. Both fa...

From behavioural analyses to models of collective motion in fish schools.

Abstract: Fish schooling is a phenomenon of long-lasting interest in ethology and ecology, widely spread across taxa and ecological contexts, and has attracted much interest from statistical physics and theoretical biology as a case of self-organized behaviour. One topic of intense interest is the search of specific behavioural mechanisms at stake at the individual level and from which the school properties emerges. This is fundamental for understanding how selective pressure acting at the individual level promotes adaptive properties of schools and in trying to disambiguate functional properties from non-adaptive epiphenomena. Decades of studies on collective motion by means of individual-based modelling have allowed a qualitative understanding of the self-organization processes leading to collective properties at school level, and provided an insight into the behavioural mechanisms that result in coordinated motion. Here, we emphasize a set of paradigmatic modelling assumptions whose validity remains unclear, both from a behavioural point of view and in terms of quantitative agreement between model outcome and empirical data. We advocate for a specific and biologically oriented re-examination of these assumptions through experimental-based behavioural analysis and modelling.

Environmental DNA as a 'snapshot' of fish distribution: A case study of Japanese jack mackerel in Maizuru Bay, Sea of Japan

Abstract: Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R(2) value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10-150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a 'snapshot' of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.