As ecosystems transform under climate change and expanding human activities, multidisciplinary in... more As ecosystems transform under climate change and expanding human activities, multidisciplinary integration of empirical research, conceptual frameworks and modelling methods is required to predict, monitor and manage the cascading effects on wildlife populations. For example, exposure to anthropogenic noise can lead to changes in the behaviour and physiology of individual marine mammals, but management is complicated by uncertainties on the long‐term effects at a population level. We build on a decade of diverse efforts to demonstrate the strengths of integrating research on multiple stressors for assessing population‐level effects. Using the case study of blue whales exposed to military sonar in the eastern north Pacific, we model how behavioural responses and environmental effects induced by climate change affect female survival and reproductive success. Environmental changes were predicted to severely affect vital rates, while the current regime of sonar activities was not. Simul...
The 2010 Deepwater Horizon (DWH) oil spill exposed common bottlenose dolphins (Tursiops truncatus... more The 2010 Deepwater Horizon (DWH) oil spill exposed common bottlenose dolphins (Tursiops truncatus) in Barataria Bay (BB), Louisiana to heavy oiling, resulting in increased mortality and leaving surviving dolphins with chronic disease and impaired reproduction. We have monitored BB dolphins since the spill, conducting veterinary assessments and photo-identification studies that now provide a decade long time series to examine temporal trends. We have found that disease conditions persist and have recently worsened in dolphins that were presumably exposed to DWH oil: 0.78 (95% CI 0.49-0.83) of those assessed in 2018 were given a guarded or worse prognosis. Dolphins born after the spill are in better health. To provide an updated status and outlook for the population, we integrated these new data into a population dynamics model, also incorporating results from expert elicitations to quantify the implications of observed health trends for demography. We compared the resulting population trajectory with that predicted under baseline (no spill) conditions. We estimate that the population has declined by 45% (95% confidence interval (CI) 14-74%) relative to baseline and will take 35 years (95% CI 18-67) to recover back to 95% of baseline numbers. The sum of annual differences between impacted and baseline trajectories - i.e., the "lost cetacean years" is 30,993 (95%CI 6,607-94,148). The population is currently at a minimum point in its recovery trajectory and is vulnerable to emerging threats, including planned ecosystem restoration efforts that are likely to be detrimental to the dolphins' survival. Our modeling framework demonstrates an approach for integrating different sources and types of data, highlights the utility of expert elicitation for indeterminable input parameters, and emphasizes the importance of considering and monitoring long-term health of slow-living species subject to environmental disasters. This article is protected by copyright. All rights reserved.
The assessment of behavioural disturbance in cetacean species (e.g. resulting from exposure to an... more The assessment of behavioural disturbance in cetacean species (e.g. resulting from exposure to anthropogenic sources such as military sonar, seismic surveys, or pile driving) is important for effective conservation and management. Disturbance effects can be informed by Behavioural Response Studies (BRSs), involving either controlled exposure experiments (CEEs) where noise exposure conditions are presented deliberately to meet experimental objectives or in opportunistic contexts where ongoing activities are monitored in a strategic manner. In either context, animal‐borne sensors or in situ observations can provide information on individual exposure and disturbance responses. The past 15 years of research have greatly expanded our understanding of behavioural responses to noise, including hundreds of experiments in nearly a dozen cetacean species. Many papers note limited sample sizes, required knowledge of baseline behaviour prior to exposure and the importance of contextual factors modulating behavioural responses, all of which in combination can lead to sampling biases, even for well‐designed research programs. It is critical to understand these biases to robustly identify responses. This ensures outcomes of BRSs help inform predictions of how anthropogenic disturbance impacts individuals and populations. Our approach leverages concepts from the animal behaviour literature focused on helping to avoid sampling bias by considering what shapes an animal's response. These factors include social, experience, genetic and natural changes in responsiveness. We developed and applied a modified version of this framework to synthesise current knowledge on cetacean response in the context of effects observed across marine and terrestrial taxa. This new ‘Sampling, Exposure, Receptor’ framework (SERF) identifies 43 modulating factors, highlights potential biases, and assesses how these vary across selected focal species. In contrast to studies that identified variation in ‘Exposure’ factors as a key concern, our analysis indicated that factors relating to ‘Sampling’ (e.g. deploying tags on less evasive individuals, which biases selection of subjects), and ‘Receptor’ (e.g. health status or coping style) have the greatest potential for weakening the desired broad representativeness of BRSs. Our assessment also highlights how potential biases could be addressed with existing datasets or future developments.
Advances in Experimental Medicine and Biology, 2016
There are many developments for offshore renewable energy around the United Kingdom whose install... more There are many developments for offshore renewable energy around the United Kingdom whose installation typically produces large amounts of far-reaching noise, potentially disturbing many marine mammals. The potential to affect the favorable conservation status of many species means extensive environmental impact assessment requirements for the licensing of such installation activities. Quantification of such complex risk problems is difficult and much of the key information is not readily available. Expert elicitation methods can be employed in such pressing cases. We describe the methodology used in an expert elicitation study conducted in the United Kingdom for combining expert opinions based on statistical distributions and copula-like methods.
Understanding the population health status of long‐lived and slow‐reproducing species is critical... more Understanding the population health status of long‐lived and slow‐reproducing species is critical for their management. However, it can take decades with traditional monitoring techniques to detect population‐level changes in demographic parameters. Early detection of the effects of environmental and anthropogenic stressors on vital rates would aid in forecasting changes in population dynamics and therefore inform management efforts. Changes in vital rates strongly correlate with deviations in population growth, highlighting the need for novel approaches that can provide early warning signs of population decline (e.g., changes in age structure). We tested a novel and frequentist approach, using Unoccupied Aerial System (UAS) photogrammetry, to assess the population age structure of small delphinids. First, we measured the precision and accuracy of UAS photogrammetry in estimating total body length (TL) of trained bottlenose dolphins (Tursiops truncatus). Using a log‐transformed line...
There is an increasing concern that anthropogenic underwater noise may have a negative impact on ... more There is an increasing concern that anthropogenic underwater noise may have a negative impact on marine life. Governmental authorities are introducing regulations to address this problem. The European Commission, for instance, has adopted the Marine Strategy Framework Directive requiring EU Member States to achieve or maintain Good Environmental Status, regarding underwater noise amongst other forms of pollution. A task group (the technical sub-group on underwater noise) has formulated indicators for underwater noise pollution, resulting in an advice to monitor low frequency sound in particular frequency bands (sound pressure level in the third-octave bands centred at 63 Hz and 125 Hz). Model generated sound maps were identified as a monitoring tool to complement measurements. Recently, the SONIC (Suppression Of underwater Noise Induced by Cavitation) project was awarded within the European Seventh Framework Program to develop tools to investigate and mitigate the effects of underwater noise generated by shipping activities. In this paper, we will present the SONIC approach to generate shipping sound maps. The sound map generation tool uses Automatic Identification System (AIS) as well as biological distribution data to generate maps representative of the sound exposure that marine mammals and fish would experience. This tool uses a fast acoustic model developed specifically for this purpose that was compared to normal modes and parabolic equation models. Results of the models compared with reference models are presented in this paper.
As ecosystems transform under climate change and expanding human activities, multidisciplinary in... more As ecosystems transform under climate change and expanding human activities, multidisciplinary integration of empirical research, conceptual frameworks and modelling methods is required to predict, monitor and manage the cascading effects on wildlife populations. For example, exposure to anthropogenic noise can lead to changes in the behaviour and physiology of individual marine mammals, but management is complicated by uncertainties on the long‐term effects at a population level. We build on a decade of diverse efforts to demonstrate the strengths of integrating research on multiple stressors for assessing population‐level effects. Using the case study of blue whales exposed to military sonar in the eastern north Pacific, we model how behavioural responses and environmental effects induced by climate change affect female survival and reproductive success. Environmental changes were predicted to severely affect vital rates, while the current regime of sonar activities was not. Simul...
The 2010 Deepwater Horizon (DWH) oil spill exposed common bottlenose dolphins (Tursiops truncatus... more The 2010 Deepwater Horizon (DWH) oil spill exposed common bottlenose dolphins (Tursiops truncatus) in Barataria Bay (BB), Louisiana to heavy oiling, resulting in increased mortality and leaving surviving dolphins with chronic disease and impaired reproduction. We have monitored BB dolphins since the spill, conducting veterinary assessments and photo-identification studies that now provide a decade long time series to examine temporal trends. We have found that disease conditions persist and have recently worsened in dolphins that were presumably exposed to DWH oil: 0.78 (95% CI 0.49-0.83) of those assessed in 2018 were given a guarded or worse prognosis. Dolphins born after the spill are in better health. To provide an updated status and outlook for the population, we integrated these new data into a population dynamics model, also incorporating results from expert elicitations to quantify the implications of observed health trends for demography. We compared the resulting population trajectory with that predicted under baseline (no spill) conditions. We estimate that the population has declined by 45% (95% confidence interval (CI) 14-74%) relative to baseline and will take 35 years (95% CI 18-67) to recover back to 95% of baseline numbers. The sum of annual differences between impacted and baseline trajectories - i.e., the "lost cetacean years" is 30,993 (95%CI 6,607-94,148). The population is currently at a minimum point in its recovery trajectory and is vulnerable to emerging threats, including planned ecosystem restoration efforts that are likely to be detrimental to the dolphins' survival. Our modeling framework demonstrates an approach for integrating different sources and types of data, highlights the utility of expert elicitation for indeterminable input parameters, and emphasizes the importance of considering and monitoring long-term health of slow-living species subject to environmental disasters. This article is protected by copyright. All rights reserved.
The assessment of behavioural disturbance in cetacean species (e.g. resulting from exposure to an... more The assessment of behavioural disturbance in cetacean species (e.g. resulting from exposure to anthropogenic sources such as military sonar, seismic surveys, or pile driving) is important for effective conservation and management. Disturbance effects can be informed by Behavioural Response Studies (BRSs), involving either controlled exposure experiments (CEEs) where noise exposure conditions are presented deliberately to meet experimental objectives or in opportunistic contexts where ongoing activities are monitored in a strategic manner. In either context, animal‐borne sensors or in situ observations can provide information on individual exposure and disturbance responses. The past 15 years of research have greatly expanded our understanding of behavioural responses to noise, including hundreds of experiments in nearly a dozen cetacean species. Many papers note limited sample sizes, required knowledge of baseline behaviour prior to exposure and the importance of contextual factors modulating behavioural responses, all of which in combination can lead to sampling biases, even for well‐designed research programs. It is critical to understand these biases to robustly identify responses. This ensures outcomes of BRSs help inform predictions of how anthropogenic disturbance impacts individuals and populations. Our approach leverages concepts from the animal behaviour literature focused on helping to avoid sampling bias by considering what shapes an animal's response. These factors include social, experience, genetic and natural changes in responsiveness. We developed and applied a modified version of this framework to synthesise current knowledge on cetacean response in the context of effects observed across marine and terrestrial taxa. This new ‘Sampling, Exposure, Receptor’ framework (SERF) identifies 43 modulating factors, highlights potential biases, and assesses how these vary across selected focal species. In contrast to studies that identified variation in ‘Exposure’ factors as a key concern, our analysis indicated that factors relating to ‘Sampling’ (e.g. deploying tags on less evasive individuals, which biases selection of subjects), and ‘Receptor’ (e.g. health status or coping style) have the greatest potential for weakening the desired broad representativeness of BRSs. Our assessment also highlights how potential biases could be addressed with existing datasets or future developments.
Advances in Experimental Medicine and Biology, 2016
There are many developments for offshore renewable energy around the United Kingdom whose install... more There are many developments for offshore renewable energy around the United Kingdom whose installation typically produces large amounts of far-reaching noise, potentially disturbing many marine mammals. The potential to affect the favorable conservation status of many species means extensive environmental impact assessment requirements for the licensing of such installation activities. Quantification of such complex risk problems is difficult and much of the key information is not readily available. Expert elicitation methods can be employed in such pressing cases. We describe the methodology used in an expert elicitation study conducted in the United Kingdom for combining expert opinions based on statistical distributions and copula-like methods.
Understanding the population health status of long‐lived and slow‐reproducing species is critical... more Understanding the population health status of long‐lived and slow‐reproducing species is critical for their management. However, it can take decades with traditional monitoring techniques to detect population‐level changes in demographic parameters. Early detection of the effects of environmental and anthropogenic stressors on vital rates would aid in forecasting changes in population dynamics and therefore inform management efforts. Changes in vital rates strongly correlate with deviations in population growth, highlighting the need for novel approaches that can provide early warning signs of population decline (e.g., changes in age structure). We tested a novel and frequentist approach, using Unoccupied Aerial System (UAS) photogrammetry, to assess the population age structure of small delphinids. First, we measured the precision and accuracy of UAS photogrammetry in estimating total body length (TL) of trained bottlenose dolphins (Tursiops truncatus). Using a log‐transformed line...
There is an increasing concern that anthropogenic underwater noise may have a negative impact on ... more There is an increasing concern that anthropogenic underwater noise may have a negative impact on marine life. Governmental authorities are introducing regulations to address this problem. The European Commission, for instance, has adopted the Marine Strategy Framework Directive requiring EU Member States to achieve or maintain Good Environmental Status, regarding underwater noise amongst other forms of pollution. A task group (the technical sub-group on underwater noise) has formulated indicators for underwater noise pollution, resulting in an advice to monitor low frequency sound in particular frequency bands (sound pressure level in the third-octave bands centred at 63 Hz and 125 Hz). Model generated sound maps were identified as a monitoring tool to complement measurements. Recently, the SONIC (Suppression Of underwater Noise Induced by Cavitation) project was awarded within the European Seventh Framework Program to develop tools to investigate and mitigate the effects of underwater noise generated by shipping activities. In this paper, we will present the SONIC approach to generate shipping sound maps. The sound map generation tool uses Automatic Identification System (AIS) as well as biological distribution data to generate maps representative of the sound exposure that marine mammals and fish would experience. This tool uses a fast acoustic model developed specifically for this purpose that was compared to normal modes and parabolic equation models. Results of the models compared with reference models are presented in this paper.
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