DIRECTIONAL UNITS have been found at dif-ferent levels in the visual pathways of sev-eral vertebr... more DIRECTIONAL UNITS have been found at dif-ferent levels in the visual pathways of sev-eral vertebrates. In the retina, ganglion cells signal direction-specific movements in the rabbit (l), ground squirrel (26), gray squirrel (4), pigeon (23), pike (40), goldfish (IS), Necturus (39), turtle ...
A tagged whale of the genus Balaenoptera was intermittently tracked by radio for 27.8 hours over ... more A tagged whale of the genus Balaenoptera was intermittently tracked by radio for 27.8 hours over a distance of about 145 kilometers. Data on breathing and movement show that during that time the whale took 58 breaths in 130 minutes and traveled 20 kilometers at more than 9 kilometers per hour. Precise measurements of such parameters and of other features of the life history of great whales, which travel long distances over the high seas, often in groups, are now possible through radio tagging.
This review considers the effect of anthropogenic sound on beaked whales2. Two major conclusions ... more This review considers the effect of anthropogenic sound on beaked whales2. Two major conclusions are presented: (1) gas-bubble disease, induced in supersaturated tissue by a behavioural response to acoustic exposure, is a plausible pathologic mechanism for the morbidity and mortality seen in cetaceans associated with sonar exposure and merits further investigation; and (2) current monitoring and mitigation methods for beaked whales are ineffective for detecting these animals and protecting them from adverse sound exposure. In addition, four major research priorities, needed to address information gaps on the impacts of sound on beaked whales, are identified: (1) controlled exposure experiments to assess beaked whale responses to known sound stimuli; (2) investigation of physiology, anatomy, pathobiology and behaviour of beaked whales; (3) assessment of baseline diving behaviour and physiology of beaked whales; and (4) a retrospective review of beaked whale strandings.
The Journal of the Acoustical Society of America, 1983
The anatomy of the cochlea of six species of odontocetes, or toothed whales (Physeter catadon, Gr... more The anatomy of the cochlea of six species of odontocetes, or toothed whales (Physeter catadon, Grampus griseus, Lagenorhynchus albirostris, Phocoena phocoena, Tursiops truncatus, and Stenella longirostris) was compared using conventional micrography and radiographic techniques including edge enhancement x-ray, CT scan, magnification radiography, and digital subtraction. These species were selected for differences in frequency and patterning of normal and ultrasonic vocalizations in their natural environments. The cochlea were extracted post-mortem and preserved by injection. Whole cochlea were first examined radiographically for species-specific differences in gross morphology and topology, particularly for angular change of the scalae and torsion of membranal and neural components. Specimens were then decalcified and processed for SEM or thin section microscopy. Measurements obtained by both methods are presented and the advantages of the radiographic techniques discussed. The resu...
In dynamic fission–fusion societies, following specific individuals consistently would not be exp... more In dynamic fission–fusion societies, following specific individuals consistently would not be expected in the absence of benefits to followers. Followers in groups may benefit if leaders have greater knowledge about habitats that are available for foraging and how to access these areas efficiently. A small residential population of bottlenose dolphins (Tursiops truncatus) in the Lower Florida Keys (LFK) demonstrates such specific individual leadership, but why others choose to follow is unknown. To determine whether consistent leaders demonstrated greater knowledge of resources and habitat we (1) compared habitat use patterns across areas that varied in prey abundance for groups led by consistent leaders and groups led by individuals that did not consistently lead, (2) compared directness of travel along with number of lead animal switches when traveling for these same two group types and (3) compared home range size and home range complexity between animals that consistently led an...
The risks posed by a range of acoustic scientific instruments were assessed by the construction o... more The risks posed by a range of acoustic scientific instruments were assessed by the construction of matrices of scale and likelihood. We recognized six levels of impact ranging from none or short term, minimal behavioural response (Level 1) to multiple injuries and fatalities and/or compromised populations (Level 6) and six levels of likelihood ranging from “Expected in almost all instances” (Level 1) to “cannot see how it could happen” (Level 6). Typical scientific instruments ranging from acoustic releases to large air gun arrays were assessed. To provide a perspective for the risks of scientific operations, other activities were also ranked. These included large chemical explosions, submarine detection sonars implicated in some mass strandings of cetaceans and normal Antarctic shipping activities. The conclusion reached was that most scientific instruments pose a similar or lower risk than normal shipping operations. High source-level equipment poses some risk to individual animal...
The Journal of the Acoustical Society of America, 2001
William A. Watkins, Woods Hole Oceanographic Institution (WHOI), led the development and refineme... more William A. Watkins, Woods Hole Oceanographic Institution (WHOI), led the development and refinement of the WHOI Radio Whale Tag. The initial tags were developed in the 1960s at WHOI, improved in the 1970s and 1980s by Ocean Applied Research, Inc., and adapted to satellite telemetry in the 1990s by Microwave Telemetry, Inc. Through this entire period, the tag delivery and attachment methods were continually refined. The same delivery and attachment methods were used with acoustic tags, radio tags, combined radio and acoustic tags, and satellite tags. Scientific studies using these tags have been conducted on finback, humpback, Brydes, bowhead, and sperm whales. These field studies have ranged from Venezuela to the Canadian arctic and Alaska, and from the Pacific to the Mediterranean. Every tagging experiment led to new information about the animals, and in most cases the information from radio and acoustic tagged whales showed that the best available data based on surface observation...
: Three abstracts of papers presented at scientific meetings are combined in this report. The tit... more : Three abstracts of papers presented at scientific meetings are combined in this report. The titles of the abstracts are: Social function of phonation in walrus; A recording instrument package designed for use with marine mammals; Effects of CO2 breathing and hypoxia on venous return in the harbor seal (Phoca vitulina concolor).
Humans generate sounds in the ocean intentionally (e.g., sonar) and as a consequence of other act... more Humans generate sounds in the ocean intentionally (e.g., sonar) and as a consequence of other activities (e.g., shipping). These sounds increase the noise level in the acoustic spectrum which one or more species of marine mammals utilize. Different marine mammal species are sensitive to sound at frequencies between 10 Hz and 180 kHz and thus all human-generated sounds have the potential to impact some marine mammals. Any sound that rises to the level of detectability has the potential to alter behavior. Louder sounds can interfere with acoustic communication or detection of relevant acoustic cues from the environment. Still louder sounds can lead to physiological changes such as temporary or permanent threshold shifts in hearing sensitivity with extremely loud sounds at very close range causing acoustic trauma. Continued exposure to noise causes stress reactions in humans and other terrestrial species studied and is likely to cause stress reactions in marine mammals. Determining the significance of any of these effects of human-generated sounds on marine mammal populations is exceedingly difficult.
The resident bottlenose dolphin community at Dolphin Bay in Bocas del Toro sustains the largest d... more The resident bottlenose dolphin community at Dolphin Bay in Bocas del Toro sustains the largest dolphin watching (DW) industry in Panama. Our previous work shows that dolphins significantly respond to DW boat presence by modifying their whistle frequency and duration particularly when engaged in foraging activities. The usual assumption is that the noise associated with the DW boats is responsible for the change in whistle parameters. In this study we evaluate the effect of noise levels on whistles acoustic structure by analyzing recordings obtained in 2007, 2008 and 2012 under various boat interactions. We measured ambient noise levels (RMS values, 100Hz to 48kHz) for each of these recordings and for each whistle within those recordings we measured a number of standard frequency variables and duration. Noise levels increased with boat presence; however, there was also significant variation among years. After adjusting the level of significance for multiple comparisons to α= 0.006, ...
DIRECTIONAL UNITS have been found at dif-ferent levels in the visual pathways of sev-eral vertebr... more DIRECTIONAL UNITS have been found at dif-ferent levels in the visual pathways of sev-eral vertebrates. In the retina, ganglion cells signal direction-specific movements in the rabbit (l), ground squirrel (26), gray squirrel (4), pigeon (23), pike (40), goldfish (IS), Necturus (39), turtle ...
A tagged whale of the genus Balaenoptera was intermittently tracked by radio for 27.8 hours over ... more A tagged whale of the genus Balaenoptera was intermittently tracked by radio for 27.8 hours over a distance of about 145 kilometers. Data on breathing and movement show that during that time the whale took 58 breaths in 130 minutes and traveled 20 kilometers at more than 9 kilometers per hour. Precise measurements of such parameters and of other features of the life history of great whales, which travel long distances over the high seas, often in groups, are now possible through radio tagging.
This review considers the effect of anthropogenic sound on beaked whales2. Two major conclusions ... more This review considers the effect of anthropogenic sound on beaked whales2. Two major conclusions are presented: (1) gas-bubble disease, induced in supersaturated tissue by a behavioural response to acoustic exposure, is a plausible pathologic mechanism for the morbidity and mortality seen in cetaceans associated with sonar exposure and merits further investigation; and (2) current monitoring and mitigation methods for beaked whales are ineffective for detecting these animals and protecting them from adverse sound exposure. In addition, four major research priorities, needed to address information gaps on the impacts of sound on beaked whales, are identified: (1) controlled exposure experiments to assess beaked whale responses to known sound stimuli; (2) investigation of physiology, anatomy, pathobiology and behaviour of beaked whales; (3) assessment of baseline diving behaviour and physiology of beaked whales; and (4) a retrospective review of beaked whale strandings.
The Journal of the Acoustical Society of America, 1983
The anatomy of the cochlea of six species of odontocetes, or toothed whales (Physeter catadon, Gr... more The anatomy of the cochlea of six species of odontocetes, or toothed whales (Physeter catadon, Grampus griseus, Lagenorhynchus albirostris, Phocoena phocoena, Tursiops truncatus, and Stenella longirostris) was compared using conventional micrography and radiographic techniques including edge enhancement x-ray, CT scan, magnification radiography, and digital subtraction. These species were selected for differences in frequency and patterning of normal and ultrasonic vocalizations in their natural environments. The cochlea were extracted post-mortem and preserved by injection. Whole cochlea were first examined radiographically for species-specific differences in gross morphology and topology, particularly for angular change of the scalae and torsion of membranal and neural components. Specimens were then decalcified and processed for SEM or thin section microscopy. Measurements obtained by both methods are presented and the advantages of the radiographic techniques discussed. The resu...
In dynamic fission–fusion societies, following specific individuals consistently would not be exp... more In dynamic fission–fusion societies, following specific individuals consistently would not be expected in the absence of benefits to followers. Followers in groups may benefit if leaders have greater knowledge about habitats that are available for foraging and how to access these areas efficiently. A small residential population of bottlenose dolphins (Tursiops truncatus) in the Lower Florida Keys (LFK) demonstrates such specific individual leadership, but why others choose to follow is unknown. To determine whether consistent leaders demonstrated greater knowledge of resources and habitat we (1) compared habitat use patterns across areas that varied in prey abundance for groups led by consistent leaders and groups led by individuals that did not consistently lead, (2) compared directness of travel along with number of lead animal switches when traveling for these same two group types and (3) compared home range size and home range complexity between animals that consistently led an...
The risks posed by a range of acoustic scientific instruments were assessed by the construction o... more The risks posed by a range of acoustic scientific instruments were assessed by the construction of matrices of scale and likelihood. We recognized six levels of impact ranging from none or short term, minimal behavioural response (Level 1) to multiple injuries and fatalities and/or compromised populations (Level 6) and six levels of likelihood ranging from “Expected in almost all instances” (Level 1) to “cannot see how it could happen” (Level 6). Typical scientific instruments ranging from acoustic releases to large air gun arrays were assessed. To provide a perspective for the risks of scientific operations, other activities were also ranked. These included large chemical explosions, submarine detection sonars implicated in some mass strandings of cetaceans and normal Antarctic shipping activities. The conclusion reached was that most scientific instruments pose a similar or lower risk than normal shipping operations. High source-level equipment poses some risk to individual animal...
The Journal of the Acoustical Society of America, 2001
William A. Watkins, Woods Hole Oceanographic Institution (WHOI), led the development and refineme... more William A. Watkins, Woods Hole Oceanographic Institution (WHOI), led the development and refinement of the WHOI Radio Whale Tag. The initial tags were developed in the 1960s at WHOI, improved in the 1970s and 1980s by Ocean Applied Research, Inc., and adapted to satellite telemetry in the 1990s by Microwave Telemetry, Inc. Through this entire period, the tag delivery and attachment methods were continually refined. The same delivery and attachment methods were used with acoustic tags, radio tags, combined radio and acoustic tags, and satellite tags. Scientific studies using these tags have been conducted on finback, humpback, Brydes, bowhead, and sperm whales. These field studies have ranged from Venezuela to the Canadian arctic and Alaska, and from the Pacific to the Mediterranean. Every tagging experiment led to new information about the animals, and in most cases the information from radio and acoustic tagged whales showed that the best available data based on surface observation...
: Three abstracts of papers presented at scientific meetings are combined in this report. The tit... more : Three abstracts of papers presented at scientific meetings are combined in this report. The titles of the abstracts are: Social function of phonation in walrus; A recording instrument package designed for use with marine mammals; Effects of CO2 breathing and hypoxia on venous return in the harbor seal (Phoca vitulina concolor).
Humans generate sounds in the ocean intentionally (e.g., sonar) and as a consequence of other act... more Humans generate sounds in the ocean intentionally (e.g., sonar) and as a consequence of other activities (e.g., shipping). These sounds increase the noise level in the acoustic spectrum which one or more species of marine mammals utilize. Different marine mammal species are sensitive to sound at frequencies between 10 Hz and 180 kHz and thus all human-generated sounds have the potential to impact some marine mammals. Any sound that rises to the level of detectability has the potential to alter behavior. Louder sounds can interfere with acoustic communication or detection of relevant acoustic cues from the environment. Still louder sounds can lead to physiological changes such as temporary or permanent threshold shifts in hearing sensitivity with extremely loud sounds at very close range causing acoustic trauma. Continued exposure to noise causes stress reactions in humans and other terrestrial species studied and is likely to cause stress reactions in marine mammals. Determining the significance of any of these effects of human-generated sounds on marine mammal populations is exceedingly difficult.
The resident bottlenose dolphin community at Dolphin Bay in Bocas del Toro sustains the largest d... more The resident bottlenose dolphin community at Dolphin Bay in Bocas del Toro sustains the largest dolphin watching (DW) industry in Panama. Our previous work shows that dolphins significantly respond to DW boat presence by modifying their whistle frequency and duration particularly when engaged in foraging activities. The usual assumption is that the noise associated with the DW boats is responsible for the change in whistle parameters. In this study we evaluate the effect of noise levels on whistles acoustic structure by analyzing recordings obtained in 2007, 2008 and 2012 under various boat interactions. We measured ambient noise levels (RMS values, 100Hz to 48kHz) for each of these recordings and for each whistle within those recordings we measured a number of standard frequency variables and duration. Noise levels increased with boat presence; however, there was also significant variation among years. After adjusting the level of significance for multiple comparisons to α= 0.006, ...
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Papers by Douglas Wartzok