Kerri Seger | University of California, San Diego (original) (raw)
Papers by Kerri Seger
The Journal of the Acoustical Society of America, Dec 1, 2016
Automated and manual acoustic localizations of migrating bowhead whales were used to estimate sou... more Automated and manual acoustic localizations of migrating bowhead whales were used to estimate source level and calling depth distributions of their frequency-modulated-modulated calls over seven years between 2008 and 2014. Whale positions were initially triangulated using directional autonomous seafloor acoustic recorders, deployed between 25 and 55 m water depth near Kaktovik, Alaska, during the fall westward migration. Calling depths were estimated by minimizing the "discrepancy" between source level estimates from at least three recorders detecting the same call. Applying a detailed waveguide propagation model to the data yielded broadband source levels of 161 ± 9 dB re 1 μPa(2) s at 1 m (SEL) for calls received between 20 and 170 Hz. Applying a simpler 15 log10(R) power-law propagation model yielded SEL source levels of 158 ± 10 dB. The most probable calling depths lay between 22 and 30 m: optimal depths for long-range acoustic signal transmission in this particular e...
Oceanography
Sound travels further through water than light and is one reason why many marine animals use soun... more Sound travels further through water than light and is one reason why many marine animals use sound to communicate and gain information about their surroundings. Scientists collect recordings of these underwater sounds to gain information on species' habitat use, abundance, distribution, density, and behavior. In waters where visibility is severely limited or access is difficult or cost-intensive, passive acoustic monitoring is a particularly important technique for obtaining such biological information over space and time. The "soundscape" of an ecosystem is defined as the characterization of all the acoustic sources present in a certain place (Wilford et al., 2021). A soundscape includes three fundamental sound source types (Figure 1): (1) anthropophony, or sounds associated with human activity; (2) biophony, or sounds produced by animals; and (3) geophony, or sounds generated by physical events such as waves, earthquakes, or rain (Pijanowski et al., 2011). Studying soundscapes can provide biological information for a specific habitat, which could then be linked to ecosystem health status and other bioindicators. This information can be used to monitor the habitat over time, allowing for rapid detection of habitat degradation, such as in response to human-driven events.
Author(s): Seger, Kerri Dawn | Advisor(s): Thode, Aaron M | Abstract: The past two centuries have... more Author(s): Seger, Kerri Dawn | Advisor(s): Thode, Aaron M | Abstract: The past two centuries have seen an increased exploitation of marine habitats by humans, so a growing appreciation of the role ambient noise plays in cetacean studies has resulted. To achieve a broad acoustical view of understudied areas (namely Mexican waters), this dissertation tackles three overarching principles: (1) parameterizing current baseline ambient acoustic environments for subsequent comparisons, (2) determining whether the sounds that animals introduce into their environments can provide employable information for population estimation purposes, and (3) cataloguing and characterizing the sounds whales use to communicate so they can later be compared across time, geography, and ambient noise levels. Only when we have a handle on the relative contributions of anthropogenic, physical / geological, and biological sounds in a whales habitat can we begin to understand how each source may elicit and / or ch...
Overview: The rapid warming of the Arctic and melting of Arctic sea and land ice will have ramifi... more Overview: The rapid warming of the Arctic and melting of Arctic sea and land ice will have ramifications around the globe. Shipping routes through an ice-free Northwest Passage in combination with modifications to ocean circulation and regional climate patterns linked to Arctic ice melt will affect trade, fisheries, tourism, coastal ecology, air and water quality, animal migration, and demographics not only in the Arctic but also in lower latitude coastal regions such as New England. With profound changes on the horizon, this is a critical opportunity for New England to prepare for uncertain yet inevitable economic and environmental impacts of Arctic change. In order to detect and respond to the challenges that New England will face as the nation’s eastern gateway to the Arctic, it will be necessary to modify traditional observational networks and models. This workshop pairs two of NSF’s 10 Big Ideas: Navigating the New Arctic and Growing Convergence Research at NSF. During this eve...
Will be presented at the 21st International Bioacoustics Congress in Pavia Italy in September of ... more Will be presented at the 21st International Bioacoustics Congress in Pavia Italy in September of 2007, then pulished in the proceedings from the congress.
Climate change affects the distributions of marine mammals1, and some temperate water species are... more Climate change affects the distributions of marine mammals1, and some temperate water species are spreading northward into the Arctic Ocean2, 3. Tracking expanding species is crucial to conservation efforts and using automatic detectors and classifiers to track the locations of their vocalizations could help. Risso’s (Gg) and Pacific white-sided (Lo) dolphins were documented spreading poleward2 and make very similar sounds, making it difficult for both human analysts and classification algorithms to tell them apart. Variational Mode Decomposition (VMD) has provided both an easier visualization tool4 for human analysts and offers promising capabilities in separating call types of similar spectral and temporal properties. Here we show a new visualization tool and feature extraction technique using VMD that achieves 81.3% accuracy, even when using audio files with faint signals and high background noise levels and without context clues. Because not all dolphins whistle5–7, being able t...
In passive acoustic monitoring, source localization using multipath propagation can be challengin... more In passive acoustic monitoring, source localization using multipath propagation can be challenging whenever the source-receiver configuration leads to overlapping multipath arrival patterns. We propose a single-hydrophone model-based method with matched-impulse response (IR) processing that exploits unresolved multipath arrival patterns to locate the source in 3D, making the best use of the bathymetric information as well as the time differences of groups of arrivals. When only groups of paths are resolved, the identity of the paths constituting the groups remains unknown, preventing the use of classical localization methods. To overcome this critical limitation, we apply an approach based on the characterization of groups of paths to estimate the source location.
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
Frontiers in Marine Science
Soundscapes with minimal anthropogenic noise sources are key for the survival and effective commu... more Soundscapes with minimal anthropogenic noise sources are key for the survival and effective communication of marine mammals. The Gulf of Tribugá is part of the breeding ground for humpback whale Stock G. Currently, no large-scale infrastructure exists on the Gulf's coastline, making it an area with high biodiversity and little anthropogenic noise. Whale-watching is one of the few human activities that contributes to the soundscape. By Morro Mico, on the southern limit of the Utría Natural National Park, an Ecological Acoustic Recorder (EAR, Oceanwide Science Institute) was deployed in the Gulf to record samples of acoustic activity from October to November 2018. It recorded for 10-min intervals with 20-min lapses for a duty cycle of 33.3%. One of the common peak frequencies of humpback whale song units from these recordings was used as input to an acoustic propagation model using the parabolic equation to simulate the communication space of a humpback whale when zero, one, and t...
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
As Arctic seas rapidly change with increased ocean temperatures and decreased sea ice extent, tra... more As Arctic seas rapidly change with increased ocean temperatures and decreased sea ice extent, traditional marine mammal distributions may be altered, and non-traditional Arctic species may shift poleward. Extant and seasonal continental shelf odontocete species in the Arctic Ocean include sperm whales, killer whales, beluga whales, delphinids, harbour porpoises, and Dall’s porpoises. Until recently, recording constraints limited higher sampling rates, preventing detection of many of these high frequency-producing species in the Arctic seas. Using one of the first long-term data sets to record clicks, buzzes, and whistles, multiple species have been detected and classified to explore shifting distributions in the Arctic Corridor. The data were then paired with environmental variables for generalized linear and additive modeling. Pacific white-sided dolphins were detected for a few years during minimal ice coverage. Dall’s porpoises and Risso’s dolphins may have been acoustically detected in areas farther n...
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
To monitor potential changes in the humpback whale (Megaptera novaeangliae) singing cycle, typica... more To monitor potential changes in the humpback whale (Megaptera novaeangliae) singing cycle, typical singing intensities, and acoustic behaviors requires a baseline understanding of singing activity in the context of an acoustic environment that is minimally disturbed. The Gulf of Tribuga in the Colombian Pacific (the breeding ground for Stock G) was named a Hope Spot in June 2019 as a local conservation campaign against the Colombian government’s plans to build an international port here. To document this minimally disturbed acoustic ecosystem, data were recorded at Morro Mico from October to November 2018. An Ecological Acoustic Recorder (EAR) collected data on a 33.3% duty cycle at a 15 kHz sampling rate. Power spectral densities were explored across several bands up to 6250 Hz and were used to rank sound source influence and to detect diel and lunar cycles. Spectrograms in Raven Pro 1.5 were used to manually classify sounds into six groups: dolphins, humpback whales, fish, wind and rain, snapping shrimp, and boats. These sound source time series combined with power spectral density and humpback whale song intensity cycles now serves as the first year of a baseline study in preparation to document the effects of a pending major construction project.To monitor potential changes in the humpback whale (Megaptera novaeangliae) singing cycle, typical singing intensities, and acoustic behaviors requires a baseline understanding of singing activity in the context of an acoustic environment that is minimally disturbed. The Gulf of Tribuga in the Colombian Pacific (the breeding ground for Stock G) was named a Hope Spot in June 2019 as a local conservation campaign against the Colombian government’s plans to build an international port here. To document this minimally disturbed acoustic ecosystem, data were recorded at Morro Mico from October to November 2018. An Ecological Acoustic Recorder (EAR) collected data on a 33.3% duty cycle at a 15 kHz sampling rate. Power spectral densities were explored across several bands up to 6250 Hz and were used to rank sound source influence and to detect diel and lunar cycles. Spectrograms in Raven Pro 1.5 were used to manually classify sounds into six groups: dolphins, humpback whales, fish, wind and rain, snapping shrimp...
The Journal of the Acoustical Society of America
The Gulf of Tribuga in the Colombian Pacific is still relatively undisturbed. No road access betw... more The Gulf of Tribuga in the Colombian Pacific is still relatively undisturbed. No road access between villages nor from major urban areas exists. Small boats and walking beaches at low tide serve as the main transportation conduits. In this breeding ground for humpback whale Stock G, small-scale artisanal and shrimp fisheries and whale-watching activities support the livelihood of local communities but may already interfere with biological communication systems. Once a proposed international port is built anthropogenic pressure is expected to increase. Baseline information is key to understand the Gulf's current acoustic state and to document the best approximation of its practically pristine state. An ecological Acoustic Recorder (EAR, Oceanwide Science Institute) was deployed between the largest town (about 2000 residents) and the southern boundary of the Utria National Park marine reserve from October to December, 2018. Also, opportunistic over-the-side recordings from July to September, 2018, provided point surveys at a greater spatial resolution during peak humpback whale breeding season. Results include the first acoustic catalogue of the area and a preliminary understanding of important bandwidths for future monitoring and current contributions of small vessels to the soundscape.The Gulf of Tribuga in the Colombian Pacific is still relatively undisturbed. No road access between villages nor from major urban areas exists. Small boats and walking beaches at low tide serve as the main transportation conduits. In this breeding ground for humpback whale Stock G, small-scale artisanal and shrimp fisheries and whale-watching activities support the livelihood of local communities but may already interfere with biological communication systems. Once a proposed international port is built anthropogenic pressure is expected to increase. Baseline information is key to understand the Gulf's current acoustic state and to document the best approximation of its practically pristine state. An ecological Acoustic Recorder (EAR, Oceanwide Science Institute) was deployed between the largest town (about 2000 residents) and the southern boundary of the Utria National Park marine reserve from October to December, 2018. Also, opportunistic over-the-side recordings from July to September, 2018, provided ...
The Journal of the Acoustical Society of America, Dec 1, 2016
Automated and manual acoustic localizations of migrating bowhead whales were used to estimate sou... more Automated and manual acoustic localizations of migrating bowhead whales were used to estimate source level and calling depth distributions of their frequency-modulated-modulated calls over seven years between 2008 and 2014. Whale positions were initially triangulated using directional autonomous seafloor acoustic recorders, deployed between 25 and 55 m water depth near Kaktovik, Alaska, during the fall westward migration. Calling depths were estimated by minimizing the "discrepancy" between source level estimates from at least three recorders detecting the same call. Applying a detailed waveguide propagation model to the data yielded broadband source levels of 161 ± 9 dB re 1 μPa(2) s at 1 m (SEL) for calls received between 20 and 170 Hz. Applying a simpler 15 log10(R) power-law propagation model yielded SEL source levels of 158 ± 10 dB. The most probable calling depths lay between 22 and 30 m: optimal depths for long-range acoustic signal transmission in this particular e...
Oceanography
Sound travels further through water than light and is one reason why many marine animals use soun... more Sound travels further through water than light and is one reason why many marine animals use sound to communicate and gain information about their surroundings. Scientists collect recordings of these underwater sounds to gain information on species' habitat use, abundance, distribution, density, and behavior. In waters where visibility is severely limited or access is difficult or cost-intensive, passive acoustic monitoring is a particularly important technique for obtaining such biological information over space and time. The "soundscape" of an ecosystem is defined as the characterization of all the acoustic sources present in a certain place (Wilford et al., 2021). A soundscape includes three fundamental sound source types (Figure 1): (1) anthropophony, or sounds associated with human activity; (2) biophony, or sounds produced by animals; and (3) geophony, or sounds generated by physical events such as waves, earthquakes, or rain (Pijanowski et al., 2011). Studying soundscapes can provide biological information for a specific habitat, which could then be linked to ecosystem health status and other bioindicators. This information can be used to monitor the habitat over time, allowing for rapid detection of habitat degradation, such as in response to human-driven events.
Author(s): Seger, Kerri Dawn | Advisor(s): Thode, Aaron M | Abstract: The past two centuries have... more Author(s): Seger, Kerri Dawn | Advisor(s): Thode, Aaron M | Abstract: The past two centuries have seen an increased exploitation of marine habitats by humans, so a growing appreciation of the role ambient noise plays in cetacean studies has resulted. To achieve a broad acoustical view of understudied areas (namely Mexican waters), this dissertation tackles three overarching principles: (1) parameterizing current baseline ambient acoustic environments for subsequent comparisons, (2) determining whether the sounds that animals introduce into their environments can provide employable information for population estimation purposes, and (3) cataloguing and characterizing the sounds whales use to communicate so they can later be compared across time, geography, and ambient noise levels. Only when we have a handle on the relative contributions of anthropogenic, physical / geological, and biological sounds in a whales habitat can we begin to understand how each source may elicit and / or ch...
Overview: The rapid warming of the Arctic and melting of Arctic sea and land ice will have ramifi... more Overview: The rapid warming of the Arctic and melting of Arctic sea and land ice will have ramifications around the globe. Shipping routes through an ice-free Northwest Passage in combination with modifications to ocean circulation and regional climate patterns linked to Arctic ice melt will affect trade, fisheries, tourism, coastal ecology, air and water quality, animal migration, and demographics not only in the Arctic but also in lower latitude coastal regions such as New England. With profound changes on the horizon, this is a critical opportunity for New England to prepare for uncertain yet inevitable economic and environmental impacts of Arctic change. In order to detect and respond to the challenges that New England will face as the nation’s eastern gateway to the Arctic, it will be necessary to modify traditional observational networks and models. This workshop pairs two of NSF’s 10 Big Ideas: Navigating the New Arctic and Growing Convergence Research at NSF. During this eve...
Will be presented at the 21st International Bioacoustics Congress in Pavia Italy in September of ... more Will be presented at the 21st International Bioacoustics Congress in Pavia Italy in September of 2007, then pulished in the proceedings from the congress.
Climate change affects the distributions of marine mammals1, and some temperate water species are... more Climate change affects the distributions of marine mammals1, and some temperate water species are spreading northward into the Arctic Ocean2, 3. Tracking expanding species is crucial to conservation efforts and using automatic detectors and classifiers to track the locations of their vocalizations could help. Risso’s (Gg) and Pacific white-sided (Lo) dolphins were documented spreading poleward2 and make very similar sounds, making it difficult for both human analysts and classification algorithms to tell them apart. Variational Mode Decomposition (VMD) has provided both an easier visualization tool4 for human analysts and offers promising capabilities in separating call types of similar spectral and temporal properties. Here we show a new visualization tool and feature extraction technique using VMD that achieves 81.3% accuracy, even when using audio files with faint signals and high background noise levels and without context clues. Because not all dolphins whistle5–7, being able t...
In passive acoustic monitoring, source localization using multipath propagation can be challengin... more In passive acoustic monitoring, source localization using multipath propagation can be challenging whenever the source-receiver configuration leads to overlapping multipath arrival patterns. We propose a single-hydrophone model-based method with matched-impulse response (IR) processing that exploits unresolved multipath arrival patterns to locate the source in 3D, making the best use of the bathymetric information as well as the time differences of groups of arrivals. When only groups of paths are resolved, the identity of the paths constituting the groups remains unknown, preventing the use of classical localization methods. To overcome this critical limitation, we apply an approach based on the characterization of groups of paths to estimate the source location.
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
Frontiers in Marine Science
Soundscapes with minimal anthropogenic noise sources are key for the survival and effective commu... more Soundscapes with minimal anthropogenic noise sources are key for the survival and effective communication of marine mammals. The Gulf of Tribugá is part of the breeding ground for humpback whale Stock G. Currently, no large-scale infrastructure exists on the Gulf's coastline, making it an area with high biodiversity and little anthropogenic noise. Whale-watching is one of the few human activities that contributes to the soundscape. By Morro Mico, on the southern limit of the Utría Natural National Park, an Ecological Acoustic Recorder (EAR, Oceanwide Science Institute) was deployed in the Gulf to record samples of acoustic activity from October to November 2018. It recorded for 10-min intervals with 20-min lapses for a duty cycle of 33.3%. One of the common peak frequencies of humpback whale song units from these recordings was used as input to an acoustic propagation model using the parabolic equation to simulate the communication space of a humpback whale when zero, one, and t...
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
As Arctic seas rapidly change with increased ocean temperatures and decreased sea ice extent, tra... more As Arctic seas rapidly change with increased ocean temperatures and decreased sea ice extent, traditional marine mammal distributions may be altered, and non-traditional Arctic species may shift poleward. Extant and seasonal continental shelf odontocete species in the Arctic Ocean include sperm whales, killer whales, beluga whales, delphinids, harbour porpoises, and Dall’s porpoises. Until recently, recording constraints limited higher sampling rates, preventing detection of many of these high frequency-producing species in the Arctic seas. Using one of the first long-term data sets to record clicks, buzzes, and whistles, multiple species have been detected and classified to explore shifting distributions in the Arctic Corridor. The data were then paired with environmental variables for generalized linear and additive modeling. Pacific white-sided dolphins were detected for a few years during minimal ice coverage. Dall’s porpoises and Risso’s dolphins may have been acoustically detected in areas farther n...
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
To monitor potential changes in the humpback whale (Megaptera novaeangliae) singing cycle, typica... more To monitor potential changes in the humpback whale (Megaptera novaeangliae) singing cycle, typical singing intensities, and acoustic behaviors requires a baseline understanding of singing activity in the context of an acoustic environment that is minimally disturbed. The Gulf of Tribuga in the Colombian Pacific (the breeding ground for Stock G) was named a Hope Spot in June 2019 as a local conservation campaign against the Colombian government’s plans to build an international port here. To document this minimally disturbed acoustic ecosystem, data were recorded at Morro Mico from October to November 2018. An Ecological Acoustic Recorder (EAR) collected data on a 33.3% duty cycle at a 15 kHz sampling rate. Power spectral densities were explored across several bands up to 6250 Hz and were used to rank sound source influence and to detect diel and lunar cycles. Spectrograms in Raven Pro 1.5 were used to manually classify sounds into six groups: dolphins, humpback whales, fish, wind and rain, snapping shrimp, and boats. These sound source time series combined with power spectral density and humpback whale song intensity cycles now serves as the first year of a baseline study in preparation to document the effects of a pending major construction project.To monitor potential changes in the humpback whale (Megaptera novaeangliae) singing cycle, typical singing intensities, and acoustic behaviors requires a baseline understanding of singing activity in the context of an acoustic environment that is minimally disturbed. The Gulf of Tribuga in the Colombian Pacific (the breeding ground for Stock G) was named a Hope Spot in June 2019 as a local conservation campaign against the Colombian government’s plans to build an international port here. To document this minimally disturbed acoustic ecosystem, data were recorded at Morro Mico from October to November 2018. An Ecological Acoustic Recorder (EAR) collected data on a 33.3% duty cycle at a 15 kHz sampling rate. Power spectral densities were explored across several bands up to 6250 Hz and were used to rank sound source influence and to detect diel and lunar cycles. Spectrograms in Raven Pro 1.5 were used to manually classify sounds into six groups: dolphins, humpback whales, fish, wind and rain, snapping shrimp...
The Journal of the Acoustical Society of America
The Gulf of Tribuga in the Colombian Pacific is still relatively undisturbed. No road access betw... more The Gulf of Tribuga in the Colombian Pacific is still relatively undisturbed. No road access between villages nor from major urban areas exists. Small boats and walking beaches at low tide serve as the main transportation conduits. In this breeding ground for humpback whale Stock G, small-scale artisanal and shrimp fisheries and whale-watching activities support the livelihood of local communities but may already interfere with biological communication systems. Once a proposed international port is built anthropogenic pressure is expected to increase. Baseline information is key to understand the Gulf's current acoustic state and to document the best approximation of its practically pristine state. An ecological Acoustic Recorder (EAR, Oceanwide Science Institute) was deployed between the largest town (about 2000 residents) and the southern boundary of the Utria National Park marine reserve from October to December, 2018. Also, opportunistic over-the-side recordings from July to September, 2018, provided point surveys at a greater spatial resolution during peak humpback whale breeding season. Results include the first acoustic catalogue of the area and a preliminary understanding of important bandwidths for future monitoring and current contributions of small vessels to the soundscape.The Gulf of Tribuga in the Colombian Pacific is still relatively undisturbed. No road access between villages nor from major urban areas exists. Small boats and walking beaches at low tide serve as the main transportation conduits. In this breeding ground for humpback whale Stock G, small-scale artisanal and shrimp fisheries and whale-watching activities support the livelihood of local communities but may already interfere with biological communication systems. Once a proposed international port is built anthropogenic pressure is expected to increase. Baseline information is key to understand the Gulf's current acoustic state and to document the best approximation of its practically pristine state. An ecological Acoustic Recorder (EAR, Oceanwide Science Institute) was deployed between the largest town (about 2000 residents) and the southern boundary of the Utria National Park marine reserve from October to December, 2018. Also, opportunistic over-the-side recordings from July to September, 2018, provided ...