Jeremy Goldbogen
Associate Professor of Oceans and, by courtesy, of Biology
Academic Appointments
Honors & Awards
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Terman Fellowship, Stanford University (2017-2020)
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Young Investigator Award, Office of Naval Research (2016-2020)
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Hoagland Award for Teaching Innovation, Vice Provost for Undergraduate Education, Humanities and Sciences Dean's Office, Stanford University (2015)
Professional Education
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BSc, University of Texas at Austin, Zoology (2002)
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MSc, Scripps Institution of Oceanography, University of California - San Diego, Marine Biology (2005)
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PhD, University of British Columbia, Zoology (2010)
2024-25 Courses
- Bio-logging and Bio-telemetry
OCEANS 14H (Spr) - Environmental Change and Marine Biodiversity
OCEANS 125H, OCEANS 225H (Spr) -
Independent Studies (6)
- Directed Instruction or Reading
OCEANS 198H (Aut, Win, Spr) - Out-of-Department Undergraduate Research
BIO 199X (Aut, Win, Spr) - Research
OCEANS 300 (Aut, Win, Spr) - Teaching Practicum in Biology
BIO 290 (Aut, Win, Spr) - Teaching Practicum in Biology
OCEANS 290H (Win, Spr) - Undergraduate Research
OCEANS 199H (Aut, Win, Spr)
- Directed Instruction or Reading
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Prior Year Courses
2023-24 Courses
- Bio-logging and Bio-telemetry
OCEANS 14H (Spr) - Environmental Change and Marine Biodiversity
OCEANS 125H, OCEANS 225H (Spr) - Get to Know Your Oceans
OCEANS 300A (Aut)
2022-23 Courses
- Environmental Change and Marine Biodiversity
BIO 125, BIOHOPK 125H, BIOHOPK 225H, OCEANS 125, OCEANS 225 (Spr) - Topics in Comparative and Environmental Physiology
BIOHOPK 234H (Spr)
2021-22 Courses
- Topics in Comparative and Environmental Physiology
BIOHOPK 234H (Sum)
- Bio-logging and Bio-telemetry
Stanford Advisees
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Postdoctoral Faculty Sponsor
Ashley Blawas, David Cade -
Doctoral Dissertation Advisor (AC)
Hannah Clayton, James Fahlbusch -
Doctoral (Program)
James Fahlbusch
All Publications
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Submesoscale coupling of krill and whales revealed by aggregative Lagrangian coherent structures.
Proceedings. Biological sciences
2024; 291 (2017): 20232461
Abstract
In the marine environment, dynamic physical processes shape biological productivity and predator-prey interactions across multiple scales. Identifying pathways of physical-biological coupling is fundamental to understand the functioning of marine ecosystems yet it is challenging because the interactions are difficult to measure. We examined submesoscale (less than 100 km) surface current features using remote sensing techniques alongside ship-based surveys of krill and baleen whale distributions in the California Current System. We found that aggregative surface current features, represented by Lagrangian coherent structures (LCS) integrated over temporal scales between 2 and 10 days, were associated with increased (a) krill density (up to 2.6 times more dense), (b) baleen whale presence (up to 8.3 times more likely) and (c) subsurface seawater density (at depths up to 10 m). The link between physical oceanography, krill density and krill-predator distributions suggests that LCS are important features that drive the flux of energy and nutrients across trophic levels. Our results may help inform dynamic management strategies aimed at reducing large whales ship strikes and help assess the potential impacts of environmental change on this critical ecosystem.
View details for DOI 10.1098/rspb.2023.2461
View details for PubMedID 38378145
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Cheap gulp foraging of a giga-predator enables efficient exploitation of sparse prey.
Science advances
2023; 9 (25): eade3889
Abstract
The giant rorqual whales are believed to have a massive food turnover driven by a high-intake lunge feeding style aptly described as the world's largest biomechanical action. This high-drag feeding behavior is thought to limit dive times and constrain rorquals to target only the densest prey patches, making them vulnerable to disturbance and habitat change. Using biologging tags to estimate energy expenditure as a function of feeding rates on 23 humpback whales, we show that lunge feeding is energetically cheap. Such inexpensive foraging means that rorquals are flexible in the quality of prey patches they exploit and therefore more resilient to environmental fluctuations and disturbance. As a consequence, the food turnover and hence the ecological role of these marine giants have likely been overestimated.
View details for DOI 10.1126/sciadv.ade3889
View details for PubMedID 37352356
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Minke whale feeding rate limitations suggest constraints on the minimum body size for engulfment filtration feeding.
Nature ecology & evolution
2023
Abstract
Bulk filter feeding has enabled gigantism throughout evolutionary history. The largest animals, extant rorqual whales, utilize intermittent engulfment filtration feeding (lunge feeding), which increases in efficiency with body size, enabling their gigantism. The smallest extant rorquals (7-10 m minke whales), however, still exhibit short-term foraging efficiencies several times greater than smaller non-filter-feeding cetaceans, raising the question of why smaller animals do not utilize this foraging modality. We collected 437 h of bio-logging data from 23 Antarctic minke whales (Balaenoptera bonaerensis) to test the relationship of feeding rates (λf) to body size. Here, we show that while ultra-high nighttime λf (mean ± s.d.: 165 ± 40 lunges h-1; max: 236 lunges h-1; mean depth: 28 ± 46 m) were indistinguishable from predictions from observations of larger species, daytime λf (mean depth: 72 ± 72 m) were only 25-40% of predicted rates. Both λf were near the maxima allowed by calculated biomechanical, physiological and environmental constraints, but these temporal constraints meant that maximum λf was below the expected λf for animals smaller than ~5 m-the length of weaned minke whales. Our findings suggest that minimum size for specific filter-feeding body plans may relate broadly to temporal restrictions on filtration rate and have implications for the evolution of filter feeding.
View details for DOI 10.1038/s41559-023-01993-2
View details for PubMedID 36914772
View details for PubMedCentralID 3731297
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How Whales Dive, Feast, and Fast: The Ecophysiological Drivers and Limits of Foraging in the Evolution of Cetaceans
ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS
2023; 54: 307-325
View details for DOI 10.1146/annurev-ecolsys-102220-025458
View details for Web of Science ID 001094253900015
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Oceanic giants dance to atmospheric rhythms: Ephemeral wind-driven resource tracking by blue whales.
Ecology letters
2022
Abstract
Trophic transfer of energy through marine food webs is strongly influenced by prey aggregation and its exploitation by predators. Rapid aggregation of some marine fish and crustacean forage species during wind-driven coastal upwelling has recently been discovered, motivating the hypothesis that predators of these forage species track the upwelling circulation in which prey aggregation occurs. We examine this hypothesis in the central California Current Ecosystem using integrative observations of upwelling dynamics, forage species' aggregation, and blue whale movement. Directional origins of blue whale calls repeatedly tracked upwelling plume circulation when wind-driven upwelling intensified and aggregation of forage species was heightened. Our findings illustrate a resource tracking strategy by which blue whales may maximize energy gain amid ephemeral foraging opportunities. These findings have implications for the ecology and conservation of diverse predators that are sustained by forage populations whose behaviour is responsive to episodic environmental dynamics.
View details for DOI 10.1111/ele.14116
View details for PubMedID 36197736
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Blue whales increase feeding rates at fine-scale ocean features.
Proceedings. Biological sciences
2022; 289 (1981): 20221180
Abstract
Marine predators face the challenge of reliably finding prey that is patchily distributed in space and time. Predators make movement decisions at multiple spatial and temporal scales, yet we have a limited understanding of how habitat selection at multiple scales translates into foraging performance. In the ocean, there is mounting evidence that submesoscale (i.e. less than 100 km) processes drive the formation of dense prey patches that should hypothetically provide feeding hot spots and increase predator foraging success. Here, we integrated environmental remote-sensing with high-resolution animal-borne biologging data to evaluate submesoscale surface current features in relation to the habitat selection and foraging performance of blue whales in the California Current System. Our study revealed a consistent functional relationship in which blue whales disproportionately foraged within dynamic aggregative submesoscale features at both the regional and feeding site scales across seasons, regions and years. Moreover, we found that blue whale feeding rates increased in areas with stronger aggregative features, suggesting that these features indicate areas of higher prey density. The use of fine-scale, dynamic features by foraging blue whales underscores the need to take these features into account when designating critical habitat and may help inform strategies to mitigate the impacts of human activities for the species.
View details for DOI 10.1098/rspb.2022.1180
View details for PubMedID 35975432
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Baleen whale prey consumption based on high-resolution foraging measurements.
Nature
2021; 599 (7883): 85-90
Abstract
Baleen whales influence their ecosystems through immense prey consumption and nutrient recycling1-3. It is difficult to accurately gauge the magnitude of their current or historic ecosystem role without measuring feeding rates and prey consumed. To date, prey consumption of the largest species has been estimated using metabolic models3-9 based on extrapolations that lack empirical validation. Here, we used tags deployed on seven baleen whale (Mysticeti) species (n=321 tag deployments) in conjunction with acoustic measurements of prey density to calculate prey consumption at daily to annual scales from the Atlantic, Pacific, and Southern Oceans. Our results suggest that previous studies3-9 have underestimated baleen whale prey consumption by threefold or more in some ecosystems. In the Southern Ocean alone, we calculate that pre-whaling populations of mysticetes annually consumed 430million tonnes of Antarctic krill (Euphausia superba), twice the current estimated total biomass of E. superba10, and more than twice the global catch of marine fisheries today11. Larger whale populations may have supported higher productivity in large marine regions through enhanced nutrient recycling: our findings suggest mysticetes recycled 1.2*104tonnesironyr-1 in the Southern Ocean before whaling compared to 1.2*103tonnesironyr-1 recycled by whales today. The recovery of baleen whales and their nutrient recycling services2,3,7 could augment productivity and restore ecosystem function lost during 20th century whaling12,13.
View details for DOI 10.1038/s41586-021-03991-5
View details for PubMedID 34732868
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Animal-Borne Metrics Enable Acoustic Detection of Blue Whale Migration.
Current biology : CB
2020
Abstract
Linking individual and population scales is fundamental to many concepts in ecology [1], including migration [2, 3]. This behavior is a critical [4] yet increasingly threatened [5] part of the life history of diverse organisms. Research on migratory behavior is constrained by observational scale [2], limiting ecological understanding and precise management of migratory populations in expansive, inaccessible marine ecosystems [6]. This knowledge gap is magnified for dispersed oceanic predators such as endangered blue whales (Balaenoptera musculus). As capital breeders, blue whales migrate vast distances annually between foraging and breeding grounds, and their population fitness depends on synchrony of migration with phenology of prey populations [7, 8]. Despite previous studies of individual-level blue whale vocal behavior via bio-logging [9, 10] and population-level acoustic presence via passive acoustic monitoring [11], detection of the life history transition from foraging to migration remains challenging. Here, we integrate direct high-resolution measures of individual behavior and continuous broad-scale acoustic monitoring of regional song production (Figure1A) to identify an acoustic signature of the transition from foraging to migration in the Northeast Pacific population. We find that foraging blue whales sing primarily at night, whereas migratory whales sing primarily during the day. The ability to acoustically detect population-level transitions in behavior provides a tool to more comprehensively study the life history, fitness, and plasticity of population behavior in a dispersed, capital breeding population. Real-time detection of this behavioral signal can also inform dynamic management efforts [12] to mitigate anthropogenic threats to this endangered population [13, 14]).
View details for DOI 10.1016/j.cub.2020.08.105
View details for PubMedID 33007246
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Energetic and physical limitations on the breaching performance of large whales.
eLife
2020; 9
Abstract
The considerable power needed for large whales to leap out of the water may represent the single most expensive burst maneuver found in nature. However, the mechanics and energetic costs associated with the breaching behaviors of large whales remain poorly understood. In this study we deployed whale-borne tags to measure the kinematics of breaching to test the hypothesis that these spectacular aerial displays are metabolically expensive. We found that breaching whales use variable underwater trajectories, and that high-emergence breaches are faster and require more energy than predatory lunges. The most expensive breaches approach the upper limits of vertebrate muscle performance, and the energetic cost of breaching is high enough that repeated breaching events may serve as honest signaling of body condition. Furthermore, the confluence of muscle contractile properties, hydrodynamics, and the high speeds required likely impose an upper limit to the body size and effectiveness of breaching whales.
View details for DOI 10.7554/eLife.51760
View details for PubMedID 32159511
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Why whales are big but not bigger: Physiological drivers and ecological limits in the age of ocean giants.
Science (New York, N.Y.)
2019; 366 (6471): 1367–72
Abstract
The largest animals are marine filter feeders, but the underlying mechanism of their large size remains unexplained. We measured feeding performance and prey quality to demonstrate how whale gigantism is driven by the interplay of prey abundance and harvesting mechanisms that increase prey capture rates and energy intake. The foraging efficiency of toothed whales that feed on single prey is constrained by the abundance of large prey, whereas filter-feeding baleen whales seasonally exploit vast swarms of small prey at high efficiencies. Given temporally and spatially aggregated prey, filter feeding provides an evolutionary pathway to extremes in body size that are not available to lineages that must feed on one prey at a time. Maximum size in filter feeders is likely constrained by prey availability across space and time.
View details for DOI 10.1126/science.aax9044
View details for PubMedID 31831666
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Extreme bradycardia and tachycardia in the world's largest animal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2019; 116 (50): 25329–32
Abstract
The biology of the blue whale has long fascinated physiologists because of the animal's extreme size. Despite high energetic demands from a large body, low mass-specific metabolic rates are likely powered by low heart rates. Diving bradycardia should slow blood oxygen depletion and enhance dive time available for foraging at depth. However, blue whales exhibit a high-cost feeding mechanism, lunge feeding, whereby large volumes of prey-laden water are intermittently engulfed and filtered during dives. This paradox of such a large, slowly beating heart and the high cost of lunge feeding represents a unique test of our understanding of cardiac function, hemodynamics, and physiological limits to body size. Here, we used an electrocardiogram (ECG)-depth recorder tag to measure blue whale heart rates during foraging dives as deep as 184 m and as long as 16.5 min. Heart rates during dives were typically 4 to 8 beats min-1 (bpm) and as low as 2 bpm, while after-dive surface heart rates were 25 to 37 bpm, near the estimated maximum heart rate possible. Despite extreme bradycardia, we recorded a 2.5-fold increase above diving heart rate minima during the powered ascent phase of feeding lunges followed by a gradual decrease of heart rate during the prolonged glide as engulfed water is filtered. These heart rate dynamics explain the unique hemodynamic design in rorqual whales consisting of a large-diameter, highly compliant, elastic aortic arch that allows the aorta to accommodate blood ejected by the heart and maintain blood flow during the long and variable pauses between heartbeats.
View details for DOI 10.1073/pnas.1914273116
View details for Web of Science ID 000502577500056
View details for PubMedID 31767746
View details for PubMedCentralID PMC6911174
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Memory and resource tracking drive blue whale migrations
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2019; 116 (12): 5582–87
View details for DOI 10.1073/pnas.1819031116
View details for Web of Science ID 000461679000061
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Predator-informed looming stimulus experiments reveal how large filter feeding whales capture highly maneuverable forage fish.
Proceedings of the National Academy of Sciences of the United States of America
2019
Abstract
The unique engulfment filtration strategy of microphagous rorqual whales has evolved relatively recently (<5 Ma) and exploits extreme predator/prey size ratios to overcome the maneuverability advantages of swarms of small prey, such as krill. Forage fish, in contrast, have been engaged in evolutionary arms races with their predators for more than 100 million years and have performance capabilities that suggest they should easily evade whale-sized predators, yet they are regularly hunted by some species of rorqual whales. To explore this phenomenon, we determined, in a laboratory setting, when individual anchovies initiated escape from virtually approaching whales, then used these results along with in situ humpback whale attack data to model how predator speed and engulfment timing affected capture rates. Anchovies were found to respond to approaching visual looming stimuli at expansion rates that give ample chance to escape from a sea lion-sized predator, but humpback whales could capture as much as 30-60% of a school at once because the increase in their apparent (visual) size does not cross their prey's response threshold until after rapid jaw expansion. Humpback whales are, thus, incentivized to delay engulfment until they are very close to a prey school, even if this results in higher hydrodynamic drag. This potential exaptation of a microphagous filter feeding strategy for fish foraging enables humpback whales to achieve 7× the energetic efficiency (per lunge) of krill foraging, allowing for flexible foraging strategies that may underlie their ecological success in fluctuating oceanic conditions.
View details for DOI 10.1073/pnas.1911099116
View details for PubMedID 31871184
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Physiological constraints on marine mammal body size
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2018; 115 (16): 3995–97
View details for PubMedID 29618615
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Context-dependent lateralized feeding strategies in blue whales
CURRENT BIOLOGY
2017; 27 (22): R1206–R1208
Abstract
Lateralized behaviors benefit individuals by increasing task efficiency in foraging and anti-predator behaviors [1-4]. The conventional lateralization paradigm suggests individuals are left or right lateralized, although the direction of this laterality can vary for different tasks (e.g. foraging or predator inspection/avoidance). By fitting tri-axial movement sensors to blue whales (Balaenoptera musculus), and by recording the direction and size of their rolls during lunge feeding events, we show how these animals differ from such a paradigm. The strength and direction of individuals' lateralization were related to where and how the whales were feeding in the water column. Smaller rolls (≤180°) predominantly occurred at depth (>70 m), with whales being more likely to rotate clockwise around their longest axis (right lateralized). Larger rolls (>180°), conversely, occurred more often at shallower depths (<70 m) and were more likely to be performed anti-clockwise (left lateralized). More acrobatic rolls are typically used to target small, less dense krill patches near the water's surface [5,6], and we posit that the specialization of lateralized feeding strategies may enhance foraging efficiency in environments with heterogeneous prey distributions.
View details for PubMedID 29161554
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A hydrodynamically active flipper-stroke in humpback whales
CURRENT BIOLOGY
2017; 27 (13): R636–R637
Abstract
A central paradigm of aquatic locomotion is that cetaceans use fluke strokes to power their swimming while relying on lift and torque generated by the flippers to perform maneuvers such as rolls, pitch changes and turns [1]. Compared to other cetaceans, humpback whales (Megaptera novaeangliae) have disproportionately large flippers with added structural features to aid in hydrodynamic performance [2,3]. Humpbacks use acrobatic lunging maneuvers to attack dense aggregations of krill or small fish, and their large flippers are thought to increase their maneuverability and thus their ability to capture prey. Immediately before opening their mouths, humpbacks will often rapidly move their flippers, and it has been hypothesized that this movement is used to corral prey [4,5] or to generate an upward pitching moment to counteract the torque caused by rapid water engulfment [6]. Here, we demonstrate an additional function for the rapid flipper movement during lunge feeding: the flippers are flapped using a complex, hydrodynamically active stroke to generate lift and increase propulsive thrust. We estimate that humpback flipper-strokes are capable of producing large forward oriented forces, which may be used to enhance lunge feeding performance. This behavior is the first observation of a lift-generating flipper-stroke for propulsion cetaceans and provides an additional function for the uniquely shaped humpback whale flipper.
View details for PubMedID 28697357
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Independent evolution of baleen whale gigantism linked to Plio-Pleistocene ocean dynamics.
Proceedings. Biological sciences
2017; 284 (1855)
Abstract
Vertebrates have evolved to gigantic sizes repeatedly over the past 250 Myr, reaching their extreme in today's baleen whales (Mysticeti). Hypotheses for the evolution of exceptionally large size in mysticetes range from niche partitioning to predator avoidance, but there has been no quantitative examination of body size evolutionary dynamics in this clade and it remains unclear when, why or how gigantism evolved. By fitting phylogenetic macroevolutionary models to a dataset consisting of living and extinct species, we show that mysticetes underwent a clade-wide shift in their mode of body size evolution during the Plio-Pleistocene. This transition, from Brownian motion-like dynamics to a trended random walk towards larger size, is temporally linked to the onset of seasonally intensified upwelling along coastal ecosystems. High prey densities resulting from wind-driven upwelling, rather than abundant resources alone, are the primary determinant of efficient foraging in extant mysticetes and Late Pliocene changes in ocean dynamics may have provided an ecological pathway to gigantism in multiple independent lineages.
View details for DOI 10.1098/rspb.2017.0546
View details for PubMedID 28539520
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How Baleen Whales Feed: The Biomechanics of Engulfment and Filtration.
Annual review of marine science
2017; 9: 367-386
Abstract
Baleen whales are gigantic obligate filter feeders that exploit aggregations of small-bodied prey in littoral, epipelagic, and mesopelagic ecosystems. At the extreme of maximum body size observed among mammals, baleen whales exhibit a unique combination of high overall energetic demands and low mass-specific metabolic rates. As a result, most baleen whale species have evolved filter-feeding mechanisms and foraging strategies that take advantage of seasonally abundant yet patchily and ephemerally distributed prey resources. New methodologies consisting of multi-sensor tags, active acoustic prey mapping, and hydrodynamic modeling have revolutionized our ability to study the physiology and ecology of baleen whale feeding mechanisms. Here, we review the current state of the field by exploring several hypotheses that aim to explain how baleen whales feed. Despite significant advances, major questions remain about the processes that underlie these extreme feeding mechanisms, which enabled the evolution of the largest animals of all time.
View details for DOI 10.1146/annurev-marine-122414-033905
View details for PubMedID 27620830
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Kinematic Diversity in Rorqual Whale Feeding Mechanisms
CURRENT BIOLOGY
2016; 26 (19): 2617-2624
Abstract
Rorqual whales exhibit an extreme lunge filter-feeding strategy characterized by acceleration to high speed and engulfment of a large volume of prey-laden water [1-4]. Although tagging studies have quantified the kinematics of lunge feeding, the timing of engulfment relative to body acceleration has been modeled conflictingly because it could never be directly measured [5-7]. The temporal coordination of these processes has a major impact on the hydrodynamics and energetics of this high-cost feeding strategy [5-9]. If engulfment and body acceleration are temporally distinct, the overall cost of this dynamic feeding event would be minimized. However, greater temporal overlap of these two phases would theoretically result in higher drag and greater energetic costs. To address this discrepancy, we used animal-borne synchronized video and 3D movement sensors to quantify the kinematics of both the skull and body during feeding events. Krill-feeding blue and humpback whales exhibited temporally distinct acceleration and engulfment phases, with humpback whales reaching maximum gape earlier than blue whales. In these whales, engulfment coincided largely with body deceleration; however, humpback whales pursuing more agile fish demonstrated highly variable coordination of skull and body kinematics in the context of complex prey-herding techniques. These data suggest that rorquals modulate the coordination of acceleration and engulfment to optimize foraging efficiency by minimizing locomotor costs and maximizing prey capture. Moreover, this newfound kinematic diversity observed among rorquals indicates that the energetic efficiency of foraging is driven both by the whale's engulfment capacity and the comparative locomotor capabilities of predator and prey. VIDEO ABSTRACT.
View details for DOI 10.1016/j.cub.2016.07.037
View details for Web of Science ID 000385690800022
View details for PubMedID 27666966
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Blue whales (Balaenoptera musculus) optimize foraging efficiency by balancing oxygen use and energy gain as a function of prey density.
Science advances
2015; 1 (9)
Abstract
Terrestrial predators can modulate the energy used for prey capture to maximize efficiency, but diving animals face the conflicting metabolic demands of energy intake and the minimization of oxygen depletion during a breath hold. It is thought that diving predators optimize their foraging success when oxygen use and energy gain act as competing currencies, but this hypothesis has not been rigorously tested because it has been difficult to measure the quality of prey that is targeted by free-ranging animals. We used high-resolution multisensor digital tags attached to foraging blue whales (Balaenoptera musculus) with concurrent acoustic prey measurements to quantify foraging performance across depth and prey density gradients. We parameterized two competing physiological models to estimate energy gain and expenditure based on foraging decisions. Our analyses show that at low prey densities, blue whale feeding rates and energy intake were low to minimize oxygen use, but at higher prey densities feeding frequency increased to maximize energy intake. Contrary to previous paradigms, we demonstrate that blue whales are not indiscriminate grazers but instead switch foraging strategies in response to variation in prey density and depth to maximize energetic efficiency.
View details for DOI 10.1126/sciadv.1500469
View details for PubMedID 26601290
View details for PubMedCentralID PMC4646804
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Stretchy nerves are an essential component of the extreme feeding mechanism of rorqual whales
CURRENT BIOLOGY
2015; 25 (9): R360-R361
Abstract
Rorqual whales (Balaenopteridae) are among the largest vertebrates that have ever lived and include blue (Balaenoptera musculus) and fin (Balaenoptera physalus) whales. Rorquals differ from other baleen whales (Mysticeti) in possessing longitudinal furrows or grooves in the ventral skin that extend from the mouth to the umbilicus. This ventral grooved blubber directly relates to their intermittent lunge feeding strategy, which is unique among vertebrates and was potentially an evolutionary innovation that led to gigantism in this lineage [1]. This strategy involves the rorqual whale rapidly engulfing a huge volume of prey-laden water and then concentrating the prey by more slowly expelling the water through baleen plates (Figure 1A). The volume of water engulfed during a lunge can exceed the volume of the whale itself [2]. During engulfment, the whale accelerates, opens its jaw until it is almost perpendicular to the rostrum, and then the highly compliant floor of the oral cavity is inflated by the incoming water [3]. The floor of the oral cavity expands by inversion of the tongue and ballooning of the adjacent floor of the mouth into the cavum ventrale, an immense fascial pocket between the body wall and overlying blubber layer that reaches as far back as the umbilicus. The ventral grooved blubber in fin whales expands by an estimated 162% in the circumferential direction and 38% longitudinally [4]. In fin whales, multiple lunges can occur during a single dive, and the average time between lunges is just over forty seconds [3]. Here, we show that nerves in the floor of the oral cavity of fin whales are highly extensible.
View details for Web of Science ID 000353999000007
View details for PubMedID 25942546
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Behavioral response of megafauna to boat collision measured via animal-borne camera and IMU
FRONTIERS IN MARINE SCIENCE
2024; 11
View details for DOI 10.3389/fmars.2024.1430961
View details for Web of Science ID 001285275700001
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Whale Baleen To Monitor Per- and Polyfluoroalkyl Substances (PFAS) in Marine Environments
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
2024
View details for DOI 10.1021/acs.estlett.4c00409
View details for Web of Science ID 001255904700001
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Evidence of sociality and group foraging in Antarctic minke whales (<i>Balaenoptera bonaerensis</i>)
BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY
2024; 78 (5)
View details for DOI 10.1007/s00265-024-03481-4
View details for Web of Science ID 001232664100001
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Baleen-Plastic Interactions Reveal High Risk to All Filter-Feeding Whales from Clogging, Ingestion, and Entanglement
OCEANS-SWITZERLAND
2024; 5 (1): 48-70
View details for DOI 10.3390/oceans5010004
View details for Web of Science ID 001192848700001
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Energy densities of key prey species in the California Current Ecosystem
FRONTIERS IN MARINE SCIENCE
2024; 10
View details for DOI 10.3389/fmars.2023.1345525
View details for Web of Science ID 001152427200001
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Spin-leap performance by cetaceans is influenced by moment of inertia.
The Journal of experimental biology
2023
Abstract
Cetaceans are capable of extraordinary locomotor behaviors both in water and air. Whales and dolphins can execute aerial leaps by swimming rapidly to the water surface to achieve an escape velocity. Previous research on spinner dolphins demonstrated the capability of leaping and completing multiple spins around their longitudinal axis with high angular velocities. This prior research suggested the slender body morphology of spinner dolphins together with the shapes and positions of their appendages, allowed for rapid spins in the air. To test if greater moments of inertia reduced spinning performance, videos and biologging data of cetaceans above and below the water surface were obtained. The principal factors affecting the number of aerial spins a cetacean can execute were moment of inertia and use of control surfaces for subsurface corkscrewing. For spinner dolphin, Pacific striped dolphin, bottlenose dolphin, minke whale, and humpback whale, each with swim speeds of 6-7 m s-1, our model predicted that the number of aerial spins executable were 7, 2, 2, 0.76, and 1, respectively, which were consistent with observations. These data implied that the rate of subsurface corkscrewing was limited to 14.0, 6.8, 6.2, 2.2, and 0.75 rad s-1 for spinner dolphins, striped dolphins, bottlenose dolphins, minke whales, and humpback whales, respectively. In our study, the moment of inertia of the cetaceans spanned a 21,000-fold range The greater moments of inertia for the latter four species produced large torques on control surfaces that limited subsurface corkscrewing motion and aerial maneuvers compared to spinner dolphins.
View details for DOI 10.1242/jeb.246433
View details for PubMedID 38149677
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Behavioural responses of fin whales to military mid-frequency active sonar.
Royal Society open science
2023; 10 (12): 231775
Abstract
The effect of active sonars on marine mammal behaviour is a topic of considerable interest and scientific investigation. Some whales, including the largest species (blue whales, Balaenoptera musculus), can be impacted by mid-frequency (1-10 kHz) military sonars. Here we apply complementary experimental methods to provide the first experimentally controlled measurements of behavioural responses to military sonar and similar stimuli for a related endangered species, fin whales (Balaenoptera physalus). Analytical methods include: (i) principal component analysis paired with generalized additive mixed models; (ii) hidden Markov models; and (iii) structured expert elicitation using response severity metrics. These approaches provide complementary perspectives on the nature of potential changes within and across individuals. Behavioural changes were detected in five of 15 whales during controlled exposure experiments using mid-frequency active sonar or pseudorandom noise of similar frequency, duration and source and received level. No changes were detected during six control (no noise) sequences. Overall responses were more limited in occurrence, severity and duration than in blue whales and were less dependent upon contextual aspects of exposure and more contingent upon exposure received level. Quantifying the factors influencing marine mammal responses to sonar is critical in assessing and mitigating future impacts.
View details for DOI 10.1098/rsos.231775
View details for PubMedID 38094262
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Acoustic behavior of gray whales tagged with biologging devices on foraging grounds
FRONTIERS IN MARINE SCIENCE
2023; 10
View details for DOI 10.3389/fmars.2023.1111666
View details for Web of Science ID 001033418500001
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Formation of a fringe: a look inside baleen morphology using a multimodal visual approach.
Journal of morphology
2023
Abstract
Filter-feeding has been present for hundreds of millions of years, independently evolving in aquatic vertebrates' numerous times. Mysticete whales are a group of gigantic, marine filter-feeders that are defined by their fringed baleen and are divided into two groups: balaenids and rorquals. Recent studies have shown that balaenids likely feed using a self-cleaning, cross-flow filtration mechanism where food particles are collected and then swept to the esophagus for swallowing. However, it is unclear how filtering is achieved in the rorquals (Balaenopteridae). Lunging rorqual whales engulf enormous masses of both prey and water; the prey is then separated from the water through baleen plates lining the length of their upper jaw and positioned perpendicular to flow. Rorqual baleen is composed of both major (larger) and minor (smaller) keratin plates containing embedded fringe that extends into the whale's mouth, forming a filtering fringe. We used a multimodal approach, including micro-computed tomography (CT) and scanning electron microscopy (SEM), to visualize and describe the variability in baleen anatomy across five species of rorqual whales, spanning two orders of magnitude in body length. For most morphological measurements, larger whales exhibited hypoallometry relative to body length. CT and SEM revealed that the major and minor plates break away from the mineralized fringes at variable distances from the gums. We proposed a model for estimating the effective pore size to determine whether flow scales with body length across species. We found that pore size is likely not a proxy for prey size but instead, may reflect changes in resistance through the filter that affect fluid flow. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/jmor.21574
View details for PubMedID 36807194
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A three-dimensional, dynamic blue whale model for research and scientific communication
MARINE MAMMAL SCIENCE
2023
View details for DOI 10.1111/mms.13007
View details for Web of Science ID 000934344700001
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Seasonal gain in body condition of foraging humpback whales along the Western Antarctic Peninsula
FRONTIERS IN MARINE SCIENCE
2022; 9
View details for DOI 10.3389/fmars.2022.1036860
View details for Web of Science ID 000894204200001
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Fast and Furious: Energetic Tradeoffs and Scaling of High-Speed Foraging in Rorqual Whales
INTEGRATIVE ORGANISMAL BIOLOGY
2022; 4 (1): obac038
Abstract
Although gigantic body size and obligate filter feeding mechanisms have evolved in multiple vertebrate lineages (mammals and fishes), intermittent ram (lunge) filter feeding is unique to a specific family of baleen whales: rorquals. Lunge feeding is a high cost, high benefit feeding mechanism that requires the integration of unsteady locomotion (i.e., accelerations and maneuvers); the impact of scale on the biomechanics and energetics of this foraging mode continues to be the subject of intense study. The goal of our investigation was to use a combination of multi-sensor tags paired with UAS footage to determine the impact of morphometrics such as body size on kinematic lunging parameters such as fluking timing, maximum lunging speed, and deceleration during the engulfment period for a range of species from minke to blue whales. Our results show that, in the case of krill-feeding lunges and regardless of size, animals exhibit a skewed gradient between powered and fully unpowered engulfment, with fluking generally ending at the point of both the maximum lunging speed and mouth opening. In all cases, the small amounts of propulsive thrust generated by the tail were unable to overcome the high drag forces experienced during engulfment. Assuming this thrust to be minimal, we predicted the minimum speed of lunging across scale. To minimize the energetic cost of lunge feeding, hydrodynamic theory predicts slower lunge feeding speeds regardless of body size, with a lower boundary set by the ability of the prey to avoid capture. We used empirical data to test this theory and instead found that maximum foraging speeds remain constant and high (∼4 m s-1) across body size, even as higher speeds result in lower foraging efficiency. Regardless, we found an increasing relationship between body size and this foraging efficiency, estimated as the ratio of energetic gain from prey to energetic cost. This trend held across timescales ranging from a single lunge to a single day and suggests that larger whales are capturing more prey-and more energy-at a lower cost.
View details for DOI 10.1093/iob/obac038
View details for Web of Science ID 000855481000001
View details for PubMedID 36127894
View details for PubMedCentralID PMC9475666
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Intra-seasonal variation in feeding rates and diel foraging behaviour in a seasonally fasting mammal, the humpback whale.
Royal Society open science
2022; 9 (7): 211674
Abstract
Antarctic humpback whales forage in summer, coincident with the seasonal abundance of their primary prey, the Antarctic krill. During the feeding season, humpback whales accumulate energy stores sufficient to fuel their fasting period lasting over six months. Previous animal movement modelling work (using area-restricted search as a proxy) suggests a hyperphagic period late in the feeding season, similar in timing to some terrestrial fasting mammals. However, no direct measures of seasonal foraging behaviour existed to corroborate this hypothesis. We attached high-resolution, motion-sensing biologging tags to 69 humpback whales along the Western Antarctic Peninsula throughout the feeding season from January to June to determine how foraging effort changes throughout the season. Our results did not support existing hypotheses: we found a significant reduction in foraging presence and feeding rates from the beginning to the end of the feeding season. During the early summer period, feeding occurred during all hours at high rates. As the season progressed, foraging occurred mostly at night and at lower rates. We provide novel information on seasonal changes in foraging of humpback whales and suggest that these animals, contrary to nearly all other animals that seasonally fast, exhibit high feeding rates soon after exiting the fasting period.
View details for DOI 10.1098/rsos.211674
View details for PubMedID 35814912
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An accelerometer-derived ballistocardiogram method for detecting heartrates in free-ranging marine mammals.
The Journal of experimental biology
2022
Abstract
Physio-logging methods, which use animal-borne devices to record physiological variables, are entering a new era driven by advances in sensor development. However, existing datasets collected with traditional bio-loggers, such as accelerometers, still contain untapped eco-physiological information. Here we present a computational method for extracting heartrate from high-resolution accelerometer data using a ballistocardiogram. We validated our method with simultaneous accelerometer-electrocardiogram tag deployments in a controlled setting on a killer whale (Orcinus orca) and demonstrate the predictions correspond with previously observed cardiovascular patterns in a blue whale (Balaenoptera musculus), including the magnitude of apneic bradycardia and increase in heart rate prior to and during ascent. Our ballistocardiogram method may be applied to mine heart rates from previously collected accelerometery and expand our understanding of comparative cardiovascular physiology.
View details for DOI 10.1242/jeb.243872
View details for PubMedID 35502794
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High-speed chases along the seafloor put Bryde's whales at risk of entanglement
CONSERVATION SCIENCE AND PRACTICE
2022
View details for DOI 10.1111/csp2.12646
View details for Web of Science ID 000771347000001
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The limits of convergence in the collective behavior of competing marine taxa.
Ecology and evolution
2022; 12 (3): e8747
Abstract
Collective behaviors in biological systems such as coordinated movements have important ecological and evolutionary consequences. While many studies examine within-species variation in collective behavior, explicit comparisons between functionally similar species from different taxonomic groups are rare. Therefore, a fundamental question remains: how do collective behaviors compare between taxa with morphological and physiological convergence, and how might this relate to functional ecology and niche partitioning? We examined the collective motion of two ecologically similar species from unrelated clades that have competed for pelagic predatory niches for over 500million years-California market squid, Doryteuthis opalescens (Mollusca) and Pacific sardine, Sardinops sagax (Chordata). We (1) found similarities in how groups of individuals from each species collectively aligned, measured by angular deviation, the difference between individual orientation and average group heading. We also (2) show that conspecific attraction, which we approximated using nearest neighbor distance, was greater in sardine than squid. Finally, we (3) found that individuals of each species explicitly matched the orientation of groupmates, but that these matching responses were less rapid in squid than sardine. Based on these results, we hypothesize that information sharing is a comparably important function of social grouping for both taxa. On the other hand, some capabilities, including hydrodynamically conferred energy savings and defense against predators, could stem from taxon-specific biology.
View details for DOI 10.1002/ece3.8747
View details for PubMedID 35356556
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Scaling of maneuvering performance in baleen whales: larger whales outperform expectations.
The Journal of experimental biology
2022; 225 (5)
Abstract
Despite their enormous size, whales make their living as voracious predators. To catch their much smaller, more maneuverable prey, they have developed several unique locomotor strategies that require high energetic input, high mechanical power output and a surprising degree of agility. To better understand how body size affects maneuverability at the largest scale, we used bio-logging data, aerial photogrammetry and a high-throughput approach to quantify the maneuvering performance of seven species of free-swimming baleen whale. We found that as body size increases, absolute maneuvering performance decreases: larger whales use lower accelerations and perform slower pitch-changes, rolls and turns than smaller species. We also found that baleen whales exhibit positive allometry of maneuvering performance: relative to their body size, larger whales use higher accelerations, and perform faster pitch-changes, rolls and certain types of turns than smaller species. However, not all maneuvers were impacted by body size in the same way, and we found that larger whales behaviorally adjust for their decreased agility by using turns that they can perform more effectively. The positive allometry of maneuvering performance suggests that large whales have compensated for their increased body size by evolving more effective control surfaces and by preferentially selecting maneuvers that play to their strengths.
View details for DOI 10.1242/jeb.243224
View details for PubMedID 35234874
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Acoustic signature reveals blue whales tune life-history transitions to oceanographic conditions
FUNCTIONAL ECOLOGY
2022
View details for DOI 10.1111/1365-2435.14013
View details for Web of Science ID 000754877300001
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Evidence for Size-Selective Predation by Antarctic Humpback Whales
FRONTIERS IN MARINE SCIENCE
2022; 9
View details for DOI 10.3389/fmars.2022.747788
View details for Web of Science ID 000759254600001
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Advancing the Interpretation of Shallow Water Marine Soundscapes
FRONTIERS IN MARINE SCIENCE
2021; 08
View details for DOI 10.3389/fmars.2021.719258
View details for Web of Science ID 000708461900001
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Tools for integrating inertial sensor data with video bio-loggers, including estimation of animal orientation, motion, and position
ANIMAL BIOTELEMETRY
2021; 9 (1)
View details for DOI 10.1186/s40317-021-00256-w
View details for Web of Science ID 000692170200002
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Sympatry and resource partitioning between the largest krill consumers around the Antarctic Peninsula
MARINE ECOLOGY PROGRESS SERIES
2021; 669: 1-16
View details for DOI 10.3354/meps13771
View details for Web of Science ID 000672774400001
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Too big to study? The biologging approach to understanding the behavioural energetics of ocean giants.
The Journal of experimental biology
2021; 224 (13)
Abstract
Wild animals are under selective pressure to optimise energy budgets; therefore, quantifying energy expenditure, intake and allocation to specific activities is important if we are to understand how animals survive in their environment. One approach toward estimating energy budgets has involved measuring oxygen consumption rates under controlled conditions and constructing allometric relationships across species. However, studying 'giant' marine vertebrates (e.g. pelagic sharks, whales) in this way is logistically difficult or impossible. An alternative approach involves the use of increasingly sophisticated electronic tags that have allowed recordings of behaviour, internal states and the surrounding environment of marine animals. This Review outlines how we could study the energy expenditure and intake of free-living ocean giants using this 'biologging' technology. There are kinematic, physiological and theoretical approaches for estimating energy expenditure, each of which has merits and limitations. Importantly, tag-derived energy proxies can hardly be validated against oxygen consumption rates for giant species. The proxies are thus qualitative, rather than quantitative, estimates of energy expenditure, and have more limited utilities. Despite this limitation, these proxies allow us to study the energetics of ocean giants in their behavioural context, providing insight into how these animals optimise their energy budgets under natural conditions. We also outline how information on energy intake and foraging behaviour can be gained from tag data. These methods are becoming increasingly important owing to the natural and anthropogenic environmental changes faced by ocean giants that can alter their energy budgets, fitness and, ultimately, population sizes.
View details for DOI 10.1242/jeb.202747
View details for PubMedID 34232316
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Scaling of oscillatory kinematics and Froude efficiency in baleen whales.
The Journal of experimental biology
2021
Abstract
High efficiency lunate-tail swimming with high-aspect-ratio lifting surfaces has evolved in many vertebrate lineages, from fish to cetaceans. Baleen whales (Mysticeti) are the largest swimming animals that exhibit this locomotor strategy and present an ideal study system to examine how morphology and the kinematics of swimming scale to the largest body sizes. We used data from whale-borne inertial sensors coupled with morphometric measurements from aerial drones to calculate the hydrodynamic performance of oscillatory swimming in six baleen whale species ranging in body length from 5-25m (fin whale, Balaenoptera physalus; Bryde's whale, Balaenoptera edeni; sei whale, Balaenoptera borealis; Antarctic minke whales, Balaenoptera bonaerensis; humpback whales, Megaptera novaeangliae; and blue whales, Balaenoptera musculus). We find that mass-specific thrust increases with both swimming speed and body size. Froude efficiency, defined as the ratio of useful power output to the rate of energy input (Sloop, 1978), generally increased with swimming speed but decreased on average with increasing body size. This finding is contrary to previous results in smaller animals where Froude efficiency increased with body size. Although our empirically-parameterized estimates for swimming baleen whale drag was higher than that of a simple gliding model, oscillatory locomotion at this scale exhibits generally high Froude efficiency as in other adept swimmers. Our results quantify the fine-scale kinematics and estimate the hydrodynamics of routine and energetically expensive swimming modes at the largest scale.
View details for DOI 10.1242/jeb.237586
View details for PubMedID 34109418
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Modelling short-term energetic costs of sonar disturbance to cetaceans using high-resolution foraging data
JOURNAL OF APPLIED ECOLOGY
2021
View details for DOI 10.1111/1365-2664.13903
View details for Web of Science ID 000653693000001
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Biomechanically distinct filter-feeding behaviors distinguish sei whales as a functional intermediate and ecologically flexible species
JOURNAL OF EXPERIMENTAL BIOLOGY
2021; 224 (9)
View details for DOI 10.1242/jeb.238873
View details for Web of Science ID 000651507000017
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MARINE MAMMALS: ADAPTATIONS FOR AN AQUATIC LIFE. (Book Review)
QUARTERLY REVIEW OF BIOLOGY
2021; 96 (1): 43–44
View details for Web of Science ID 000617258200018
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Predator‐scale spatial analysis of intra‐patch prey distribution reveals the energetic drivers of rorqual whale super‐group formation
Functional Ecology
2021
View details for DOI 10.1111/1365-2435.13763
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Context-dependent variability in the predicted daily energetic costs of disturbance for blue whales.
Conservation physiology
2021; 9 (1): coaa137
Abstract
Assessing the long-term consequences of sub-lethal anthropogenic disturbance on wildlife populations requires integrating data on fine-scale individual behavior and physiology into spatially and temporally broader, population-level inference. A typical behavioral response to disturbance is the cessation of foraging, which can be translated into a common metric of energetic cost. However, this necessitates detailed empirical information on baseline movements, activity budgets, feeding rates and energy intake, as well as the probability of an individual responding to the disturbance-inducing stressor within different exposure contexts. Here, we integrated data from blue whales (Balaenoptera musculus) experimentally exposed to military active sonar signals with fine-scale measurements of baseline behavior over multiple days or weeks obtained from accelerometry loggers, telemetry tracking and prey sampling. Specifically, we developed daily simulations of movement, feeding behavior and exposure to localized sonar events of increasing duration and intensity and predicted the effects of this disturbance source on the daily energy intake of an individual. Activity budgets and movements were highly variable in space and time and among individuals, resulting in large variability in predicted energetic intake and costs. In half of our simulations, an individual's energy intake was unaffected by the simulated source. However, some individuals lost their entire daily energy intake under brief or weak exposure scenarios. Given this large variation, population-level models will have to assess the consequences of the entire distribution of energetic costs, rather than only consider single summary statistics. The shape of the exposure-response functions also strongly influenced predictions, reinforcing the need for contextually explicit experiments and improved mechanistic understanding of the processes driving behavioral and physiological responses to disturbance. This study presents a robust approach for integrating different types of empirical information to assess the effects of disturbance at spatio-temporal and ecological scales that are relevant to management and conservation.
View details for DOI 10.1093/conphys/coaa137
View details for PubMedID 33505702
View details for PubMedCentralID PMC7816799
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Microplastics and microfibers in surface waters of Monterey Bay National Marine Sanctuary, California.
Marine pollution bulletin
2021; 165: 112148
Abstract
Despite a recent report of high concentrations of microplastics and microfibers in the mesopelagic waters of Monterey Bay National Marine Sanctuary (MBNMS), little is known about these particles in surface waters. From 2017 to 2019, we sampled two nearshore and two offshore locations within MBNMS using a manta trawl and analyzed these samples for microplastics and microfibers. We found an average concentration of 1.32 ± 0.70 (SE) particles per m3. We found the highest concentration of particles closest to shore, and the lowest concentration above the remote Davidson Seamount. Fiber-like debris was more common in offshore, as compared to nearshore, sites. Overall, particles in our samples were primarily buoyant synthetic polymers, including polypropylene and polyethylene. Our results provide baseline data on the degree of microplastic and microfiber pollution in MBNMS surface waters and confirm that this pollution can be found in waters from the surface to at least 1000 m depth.
View details for DOI 10.1016/j.marpolbul.2021.112148
View details for PubMedID 33610108
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Quick guide Blue whales
CURRENT BIOLOGY
2020; 30 (23): R1399–R1400
View details for Web of Science ID 000598853500005
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Remoras pick where they stick on blue whales.
The Journal of experimental biology
2020; 223 (Pt 20)
Abstract
Animal-borne video recordings from blue whales in the open ocean show that remoras preferentially adhere to specific regions on the surface of the whale. Using empirical and computational fluid dynamics analyses, we show that remora attachment was specific to regions of separating flow and wakes caused by surface features on the whale. Adhesion at these locations offers remoras drag reduction of up to 71-84% compared with the freestream. Remoras were observed to move freely along the surface of the whale using skimming and sliding behaviors. Skimming provided drag reduction as high as 50-72% at some locations for some remora sizes, but little to none was available in regions where few to no remoras were observed. Experimental work suggests that the Venturi effect may help remoras stay near the whale while skimming. Understanding the flow environment around a swimming blue whale will inform the placement of biosensor tags to increase attachment time for extended ecological monitoring.
View details for DOI 10.1242/jeb.226654
View details for PubMedID 33115921
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The scale of the whale: using video-tag data to evaluate sea-surface ice concentration from the perspective of individual Antarctic minke whales
ANIMAL BIOTELEMETRY
2020; 8 (1)
View details for DOI 10.1186/s40317-020-00218-8
View details for Web of Science ID 000696406400001
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A perfectly inelastic collision: Bulk prey engulfment by baleen whales and dynamical implications for the world's largest cetaceans
AMERICAN JOURNAL OF PHYSICS
2020; 88 (10): 851–63
View details for DOI 10.1119/10.0001771
View details for Web of Science ID 000571786400010
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From a calf's perspective: humpback whale nursing behavior on two US feeding grounds
PEERJ
2020; 8: e8538
Abstract
Nursing influences growth rate and overall health of mammals; however, the behavior is difficult to study in wild cetaceans because it occurs below the surface and can thus be misidentified from surface observations. Nursing has been observed in humpback whales on the breeding and calving grounds, but the behavior remains unstudied on the feeding grounds. We instrumented three dependent calves (four total deployments) with combined video and 3D-accelerometer data loggers (CATS) on two United States feeding grounds to document nursing events. Two associated mothers were also tagged to determine if behavior diagnostic of nursing was evident in the mother's movement. Animal-borne video was manually analyzed and the average duration of successful nursing events was 23 s (±7 sd, n = 11). Nursing occurred at depths between 4.1-64.4 m (along the seafloor) and in close temporal proximity to foraging events by the mothers, but could not be predicted solely by relative positions of mother and calf. When combining all calf deployments, successful nursing was documented eleven times; totaling only 0.3% of 21.0 hours of video. During nursing events, calves had higher overall dynamic body acceleration (ODBA) and increased fluke-stroke rate (FSR) compared to non-nursing segments (Mixed effect models, ODBA: F1,107 = 13.57756, p = 0.0004, FSR: F1,107 = 32.31018, p < 0.0001). In contrast, mothers had lower ODBA and reduced FSR during nursing events compared to non-nursing segments. These data provide the first characterization of accelerometer data of humpback whale nursing confirmed by animal-borne video tags and the first analysis of nursing events on feeding grounds. This is an important step in understanding the energetic consequences of lactation while foraging.
View details for DOI 10.7717/peerj.8538
View details for Web of Science ID 000517940900003
View details for PubMedID 32181052
View details for PubMedCentralID PMC7060748
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Blue whales.
Current biology : CB
2020; 30 (23): R1399–R1400
Abstract
Jeremy Goldbogen introduces blue whales, the largest animals to ever inhabit earth.
View details for DOI 10.1016/j.cub.2020.10.068
View details for PubMedID 33290699
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The advantages of diving deep: Fin whales quadruple their energy intake when targeting deep krill patches
FUNCTIONAL ECOLOGY
2019
View details for DOI 10.1111/1365-2435.13471
View details for Web of Science ID 000494346300001
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Lunge Feeding in Rorqual Whales.
Physiology (Bethesda, Md.)
2019; 34 (6): 409–18
Abstract
The largest animals are baleen filter feeders that exploit large aggregations of small-bodied plankton. Although this feeding mechanism has evolved multiple times in marine vertebrates, rorqual whales exhibit a distinct lunge filter feeding mode that requires extreme physiological adaptations-most of which remain poorly understood. Here, we review the biomechanics of the lunge feeding mechanism in rorqual whales that underlies their extraordinary foraging performance and gigantic body size.
View details for DOI 10.1152/physiol.00010.2019
View details for PubMedID 31577171
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Differential Vulnerability to Ship Strikes Between Day and Night for Blue, Fin, and Humpback Whales Based on Dive and Movement Data From Medium Duration Archival Tags
FRONTIERS IN MARINE SCIENCE
2019; 6
View details for DOI 10.3389/fmars.2019.00543
View details for Web of Science ID 000485749800001
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Anthropogenic disturbance in a changing environment: modelling lifetime reproductive success to predict the consequences of multiple stressors on a migratory population
OIKOS
2019; 128 (9): 1340–57
View details for DOI 10.1111/oik.06146
View details for Web of Science ID 000483708700011
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Foraging energetics and prey density requirements of western North Atlantic blue whales in the Estuary and Gulf of St. Lawrence, Canada
MARINE ECOLOGY PROGRESS SERIES
2019; 625: 205–23
View details for DOI 10.3354/meps13043
View details for Web of Science ID 000485738600013
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Diving Behavior and Fine-Scale Kinematics of Free-Ranging Risso's Dolphins Foraging in Shallow and Deep-Water Habitats
FRONTIERS IN ECOLOGY AND EVOLUTION
2019; 7
View details for DOI 10.3389/fevo.2019.00053
View details for Web of Science ID 000467400300001
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Behavioral responses of individual blue whales (Balaenoptera musculus) to mid-frequency military sonar.
The Journal of experimental biology
2019; 222 (Pt 5)
Abstract
This study measured the degree of behavioral responses in blue whales (Balaenoptera musculus) to controlled noise exposure off the southern California coast. High-resolution movement and passive acoustic data were obtained from non-invasive archival tags (n=42) whereas surface positions were obtained with visual focal follows. Controlled exposure experiments (CEEs) were used to obtain direct behavioral measurements before, during and after simulated and operational military mid-frequency active sonar (MFAS), pseudorandom noise (PRN) and controls (no noise exposure). For a subset of deep-feeding animals (n=21), active acoustic measurements of prey were obtained and used as contextual covariates in response analyses. To investigate potential behavioral changes within individuals as a function of controlled noise exposure conditions, two parallel analyses of time-series data for selected behavioral parameters (e.g. diving, horizontal movement and feeding) were conducted. This included expert scoring of responses according to a specified behavioral severity rating paradigm and quantitative change-point analyses using Mahalanobis distance statistics. Both methods identified clear changes in some conditions. More than 50% of blue whales in deep-feeding states responded during CEEs, whereas no changes in behavior were identified in shallow-feeding blue whales. Overall, responses were generally brief, of low to moderate severity, and highly dependent on exposure context such as behavioral state, source-to-whale horizontal range and prey availability. Response probability did not follow a simple exposure-response model based on received exposure level. These results, in combination with additional analytical methods to investigate different aspects of potential responses within and among individuals, provide a comprehensive evaluation of how free-ranging blue whales responded to mid-frequency military sonar.
View details for PubMedID 30833464
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Behavioral responses of individual blue whales (Balaenoptera musculus) to mid-frequency military sonar
JOURNAL OF EXPERIMENTAL BIOLOGY
2019; 222 (5)
View details for DOI 10.1242/jeb.190637
View details for Web of Science ID 000461414600007
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Memory and resource tracking drive blue whale migrations.
Proceedings of the National Academy of Sciences of the United States of America
2019
Abstract
In terrestrial systems, the green wave hypothesis posits that migrating animals can enhance foraging opportunities by tracking phenological variation in high-quality forage across space (i.e., "resource waves"). To track resource waves, animals may rely on proximate cues and/or memory of long-term average phenologies. Although there is growing evidence of resource tracking in terrestrial migrants, such drivers remain unevaluated in migratory marine megafauna. Here we present a test of the green wave hypothesis in a marine system. We compare 10 years of blue whale movement data with the timing of the spring phytoplankton bloom resulting in increased prey availability in the California Current Ecosystem, allowing us to investigate resource tracking both contemporaneously (response to proximate cues) and based on climatological conditions (memory) during migrations. Blue whales closely tracked the long-term average phenology of the spring bloom, but did not track contemporaneous green-up. In addition, blue whale foraging locations were characterized by low long-term habitat variability and high long-term productivity compared with contemporaneous measurements. Results indicate that memory of long-term average conditions may have a previously underappreciated role in driving migratory movements of long-lived species in marine systems, and suggest that these animals may struggle to respond to rapid deviations from historical mean environmental conditions. Results further highlight that an ecological theory of migration is conserved across marine and terrestrial systems. Understanding the drivers of animal migration is critical for assessing how environmental changes will affect highly mobile fauna at a global scale.
View details for PubMedID 30804188
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Grouping reduces the metabolic demand of a social squid
Marine Ecology Progress Series
2019; 612: 141-150
View details for DOI 10.3354/meps12880
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Scaling of swimming performance in baleen whales.
The Journal of experimental biology
2019
Abstract
The scale-dependence of locomotor factors have long been studied in comparative biomechanics, but remain poorly understood for animals at the upper extremes of body size. Rorqual baleen whales include the largest animals, but we lack basic kinematic data about their movements and behavior below the ocean surface. Here we combined morphometrics from aerial drone photogrammetry, whale-borne inertial sensing tag data, and hydrodynamic modeling to study the locomotion of five rorqual species. We quantified changes in tail oscillatory frequency and cruising speed for individual whales spanning a threefold variation in body length, corresponding to an order of magnitude variation in estimated body mass. Our results showed that oscillatory frequency decreases with body length (∝ length-0.53) while cruising speed remains roughly invariant (∝ length0.08) at 2 m s-1 We compared these measured results for oscillatory frequency against simplified models of an oscillating cantilever beam (∝ length-1) and an optimized oscillating Strouhal vortex generator (∝ length-1). The difference between our length-scaling exponent and the simplified models suggests that animals are often swimming non-optimally in order to feed or perform other routine behaviors. Cruising speed aligned more closely with an estimate of the optimal speed required to minimize the energetic cost of swimming (∝ length0.07). Our results are among the first to elucidate the relationships between both oscillatory frequency and cruising speed and body size for free-swimming animals at the largest scale.
View details for DOI 10.1242/jeb.204172
View details for PubMedID 31558588
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Filtration area scaling and evolution in mysticetes: trophic niche partitioning and the curious cases of sei and pygmy right whales
BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
2018; 125 (2): 264–79
View details for DOI 10.1093/biolinnean/bly121
View details for Web of Science ID 000450042700005
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Allometric scaling of morphology and engulfment capacity in rorqual whales.
Journal of morphology
2018
Abstract
Body length is one of the most important factors that influence organismal function and ecological niche. Although larger animals tend to have a suite of physiological advantages, such as lower mass-specific metabolic rates and lower costs of transport, they may also experience significant limitations to unsteady locomotor performance or maneuverability because of the relative scaling of control surface areas and body mass. Rorqual whales are the largest of all animals and thus represent a unique study system for understanding how animals function at the extreme of body mass. Rorquals are characterized by an engulfment-filtration foraging strategy facilitated by a complex set of morphological adaptations. We studied the scaling of key morphological structures related to locomotion and feeding in six rorqual species in a comparative framework. Our analyses show that most rorqual species exhibit positive allometry of both the control surfaces and body length, but the large scaling differences between these parameters suggest that larger rorquals will predictably suffer from decreased maneuverability and unsteady locomotor performance. However, we found that the dimensions of the engulfment apparatus also exhibit positive allometry, and thus engulfment capacity was relatively greater in larger rorquals. We posit that the allometric growth in the engulfment apparatus may be an adaptation that ameliorates the detrimental effects of large size on maneuverability. Our analyses also reveal significant differences in the scaling of mass-specific engulfment capacity among rorqual species that may reflect the evolution of unique foraging behaviors and the exploitation of divergent ecological niches.
View details for PubMedID 30194740
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Allometric scaling of morphology and engulfment capacity in rorqual whales
JOURNAL OF MORPHOLOGY
2018; 279 (9): 1256-1268
View details for DOI 10.1002/jmor.20846
View details for Web of Science ID 000454455300004
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A Dynamic State Model of Migratory Behavior and Physiology to Assess the Consequences of Environmental Variation and Anthropogenic Disturbance on Marine Vertebrates
AMERICAN NATURALIST
2018; 191 (2): E40–E56
Abstract
Integrating behavior and physiology is critical to formulating new hypotheses on the evolution of animal life-history strategies. Migratory capital breeders acquire most of the energy they need to sustain migration, gestation, and lactation before parturition. Therefore, when predicting the impact of environmental variation on such species, a mechanistic understanding of the physiology of their migratory behavior is required. Using baleen whales as a model system, we developed a dynamic state variable model that captures the interplay among behavioral decisions, energy, reproductive needs, and the environment. We applied the framework to blue whales (Balaenoptera musculus) in the eastern North Pacific Ocean and explored the effects of environmental and anthropogenic perturbations on female reproductive success. We demonstrate the emergence of migration to track prey resources, enabling us to quantify the trade-offs among capital breeding, body condition, and metabolic expenses. We predict that periodic climatic oscillations affect reproductive success less than unprecedented environmental changes do. The effect of localized, acute anthropogenic impacts depended on whales' behavioral response to the disturbance; chronic, but weaker, disturbances had little effect on reproductive success. Because we link behavior and vital rates by modeling individuals' energetic budgets, we provide a general framework to investigate the ecology of migration and assess the population consequences of disturbance, while identifying critical knowledge gaps.
View details for DOI 10.1086/695135
View details for Web of Science ID 000422944300002
View details for PubMedID 29351020
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Determining forward speed from accelerometer jiggle in aquatic environments.
The Journal of experimental biology
2018; 221 (Pt 2)
Abstract
How fast animals move is critical to understanding their energetic requirements, locomotor capacity and foraging performance, yet current methods for measuring speed via animal-attached devices are not universally applicable. Here, we present and evaluate a new method that relates forward speed to the stochastic motion of biologging devices as tag jiggle, the amplitude of the tag vibrations as measured by high sample rate accelerometers, increases exponentially with increasing speed. We successfully tested this method in a flow tank using two types of biologging devices and in situ on wild cetaceans spanning ∼3 to >20 m in length using two types of suction cup-attached tag and two types of dart-attached tag. This technique provides some advantages over other approaches for determining speed as it is device-orientation independent and relies only on a pressure sensor and a high sample rate accelerometer, sensors that are nearly universal across biologging device types.
View details for PubMedID 29191861
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Determining forward speed from accelerometer jiggle in aquatic environments
JOURNAL OF EXPERIMENTAL BIOLOGY
2018; 221 (2)
View details for DOI 10.1242/jeb.170449
View details for Web of Science ID 000424076300018
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FILTER FEEDING
ENCYCLOPEDIA OF MARINE MAMMALS, 3RD EDITION
2018: 363-368
View details for Web of Science ID 000537008800095
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The evolution of foraging capacity and gigantism in cetaceans
Journal of Experimental Biology
2018; 221
View details for DOI 10.1242/jeb.166033
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Resource partitioning facilitates coexistence in sympatric cetaceans in the California Current
ECOLOGY AND EVOLUTION
2017; 7 (21): 9085–97
Abstract
Resource partitioning is an important process driving habitat use and foraging strategies in sympatric species that potentially compete. Differences in foraging behavior are hypothesized to contribute to species coexistence by facilitating resource partitioning, but little is known on the multiple mechanisms for partitioning that may occur simultaneously. Studies are further limited in the marine environment, where the spatial and temporal distribution of resources is highly dynamic and subsequently difficult to quantify. We investigated potential pathways by which foraging behavior may facilitate resource partitioning in two of the largest co-occurring and closely related species on Earth, blue (Balaenoptera musculus) and humpback (Megaptera novaeangliae) whales. We integrated multiple long-term datasets (line-transect surveys, whale-watching records, net sampling, stable isotope analysis, and remote-sensing of oceanographic parameters) to compare the diet, phenology, and distribution of the two species during their foraging periods in the highly productive waters of Monterey Bay, California, USA within the California Current Ecosystem. Our long-term study reveals that blue and humpback whales likely facilitate sympatry by partitioning their foraging along three axes: trophic, temporal, and spatial. Blue whales were specialists foraging on krill, predictably targeting a seasonal peak in krill abundance, were present in the bay for an average of 4.7 months, and were spatially restricted at the continental shelf break. In contrast, humpback whales were generalists apparently feeding on a mixed diet of krill and fishes depending on relative abundances, were present in the bay for a more extended period (average of 6.6 months), and had a broader spatial distribution at the shelf break and inshore. Ultimately, competition for common resources can lead to behavioral, morphological, and physiological character displacement between sympatric species. Understanding the mechanisms for species coexistence is both fundamental to maintaining biodiverse ecosystems, and provides insight into the evolutionary drivers of morphological differences in closely related species.
View details for PubMedID 29152200
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Comparative Three-Dimensional Morphology of Baleen: Cross-Sectional Profiles and Volume Measurements Using CT Images
ANATOMICAL RECORD-ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY
2017; 300 (11): 1942–52
Abstract
Baleen whales are obligate filter feeders, straining prey-laden seawater through racks of keratinized baleen plates. Despite the importance of baleen to the ecology and natural history of these animals, relatively little work has been done on baleen morphology, particularly with regard to the three-dimensional morphology and structure of baleen. We used computed tomography (CT) scanning to take 3D images of six baleen specimens representing five species, including three complete racks. With these images, we described the three-dimensional shape of the baleen plates using cross-sectional profiles from within the gum tissue to the tip of the plates. We also measured the percentage of each specimen that was composed of either keratinized plate material or was void space between baleen plates, and thus available for seawater flow. Baleen plates have a complex three-dimensional structure with curvature that varies across the anterior-posterior, proximal-distal, and medial-lateral (lingual-labial) axes. These curvatures also vary with location along the baleen rack, and between species. Cross-sectional profiles resemble backwards-facing airfoils, and some specimens display S-shaped, or reflexed, camber. Within a baleen specimen, the intra-baleen void volume correlates with the average bristle diameter for a species, suggesting that essentially, thinner plates (with more space between them for flow) have thinner bristles. Both plate curvature and the relative proportions of plate and void volumes are likely to have implications for the mechanics of mysticete filtration, and future studies are needed to determine the particular functions of these morphological characters. Anat Rec, 300:1942-1952, 2017. © 2017 The Authors The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.
View details for PubMedID 28971628
View details for PubMedCentralID PMC5656919
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Structure and Function in the Lunge Feeding Apparatus: Mechanical Properties of the Fin Whale Mandible
ANATOMICAL RECORD-ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY
2017; 300 (11): 1953–62
Abstract
The mandibles of rorqual whales are highly modified to support loads associated with lunge-feeding, a dynamic filter feeding mechanism that is characterized by rapid changes in gape angle and acceleration. Although these structures are the largest ossified elements in animals and an important part of the rorqual engulfment apparatus, details of internal structure are limited and no direct measurements of mechanical properties exist. Likewise, the forces that are sustained by the mandibles are unknown. Here we report on the structure and mechanical behavior of the mandible of an adult fin whale. A series of transverse sections were cut at locations along the entire length of a 3.6-m left mandible recovered post-mortem from a 16-m fin whale, and CT scanned to make density maps. Cored samples 6-8 mm in diameter were tested in compression to determine the Young's modulus and strength. In addition, wet density, dry density and mineral density were measured. Dense cortical bone occupies only a relatively narrow peripheral layer while much less dense and oil-filled trabecular bone occupies the rest. Mineral density of both types is strongly correlated with dry density and CT Hounsfield units. Compressive strength is strongly correlated with Young's modulus, while strength and stiffness are both correlated with mineral density. It appears that the superficial compact layer is the main load bearing element, and that the mandible is reinforced against dorso-vental flexion that would occur during the peak loads while feeding. Anat Rec, 300:1953-1962, 2017. © 2017 Wiley Periodicals, Inc.
View details for PubMedID 28971624
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Early career researchers: an interview with Jeremy Goldbogen
JOURNAL OF EXPERIMENTAL BIOLOGY
2017; 220 (14): 2489-2491
Abstract
Jeremy Goldbogen is an Assistant Professor at the Hopkins Marine Station, Stanford University, USA, where he studies the integrative biology of vertebrate filter feeders from forage fish to baleen whales. He received his Bachelor's degree in Zoology from the University of Texas, Austin, USA, before moving to the Scripps Institution of Oceanography and then the University of British Columbia for his PhD, which he completed in 2010 in the laboratory of Bob Shadwick. After a short postdoc at Scripps, Goldbogen moved to continue his postdoc training at the Cascadia Research Collective in Olympia, Washington.
View details for DOI 10.1242/jeb.165183
View details for Web of Science ID 000405846700003
View details for PubMedID 28724699
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Avoidance responses of minke whales to 1-4kHz naval sonar.
Marine pollution bulletin
2017
Abstract
Minke whales are difficult to study and little information exists regarding their responses to anthropogenic sound. This study pools data from behavioural response studies off California and Norway. Data are derived from four tagged animals, of which one from each location was exposed to naval sonar signals. Statistical analyses were conducted using Mahalanobis distance to compare overall changes in parameters summarising dive behaviour, avoidance behaviour, and potential energetic costs of disturbance. Our quantitative analysis showed that both animals initiated avoidance behaviour, but responses were not associated with unusual dive behaviour. In one exposed animal the avoidance of the sonar source included a 5-fold increase in horizontal speed away from the source, implying a significant increase in metabolic rate. Despite the different environmental settings and exposure contexts, clear changes in behaviour were observed providing the first insights into the nature of responses to human noise for this wide-ranging species.
View details for DOI 10.1016/j.marpolbul.2017.05.037
View details for PubMedID 28552251
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A MULTIVARIATE MIXED HIDDEN MARKOV MODEL FOR BLUE WHALE BEHAVIOUR AND RESPONSES TO SOUND EXPOSURE
ANNALS OF APPLIED STATISTICS
2017; 11 (1): 362-392
View details for DOI 10.1214/16-AOAS1008
View details for Web of Science ID 000398965400017
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Physical trade-offs shape the evolution of buoyancy control in sharks.
Proceedings. Biological sciences
2017; 284 (1866)
Abstract
Buoyancy control is a fundamental aspect of aquatic life that has major implications for locomotor performance and ecological niche. Unlike terrestrial animals, the densities of aquatic animals are similar to the supporting fluid, thus even small changes in body density may have profound effects on locomotion. Here, we analysed the body composition (lipid versus lean tissue) of 32 shark species to study the evolution of buoyancy. Our comparative phylogenetic analyses indicate that although lean tissue displays minor positive allometry, liver volume exhibits pronounced positive allometry, suggesting that larger sharks evolved bulkier body compositions by adding lipid tissue to lean tissue rather than substituting lean for lipid tissue, particularly in the liver. We revealed a continuum of buoyancy control strategies that ranged from more buoyant sharks with larger livers in deeper ecosystems to relatively denser sharks with small livers in epipelagic habitats. Across this eco-morphological spectrum, our hydrodynamic modelling suggests that neutral buoyancy yields lower drag and more efficient steady swimming, whereas negative buoyancy may be more efficient during accelerated movements. The evolution of buoyancy control in sharks suggests that ecological and physiological factors mediate the selective pressures acting on these traits along two major gradients, body size and habitat depth.
View details for PubMedID 29118132
View details for PubMedCentralID PMC5698638
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Kinematics of ram filter feeding and beat–glide swimming in the northern anchovy Engraulis mordax
Journal of Experimental Biology
2017; 220: 2717-2725
Abstract
In the dense aquatic environment, the most adept swimmers are streamlined to reduce drag and increase the efficiency of locomotion. However, because they open their mouth to wide gape angles to deploy their filtering apparatus, ram filter feeders apparently switch between diametrically opposite swimming modes; highly efficient, streamlined 'beat-glide' swimming, and ram filter feeding, which has been hypothesized to be a high-cost feeding mode because of presumed increased drag. Ram filter feeding forage fish are thought to play an important role in the flux of nutrients and energy in upwelling ecosystems, however the biomechanics and energetics of this feeding mechanism remain poorly understood. We quantified the kinematics of an iconic forage fish, the northern anchovy, Engraulis mordax, during ram filter feeding and non-feeding, mouth-closed beat-glide swimming. Although many kinematic parameters between the two swimming modes were similar, we found that swimming speeds and tailbeat frequencies were significantly lower during ram feeding. Rather than maintain speed with the school, a speed which closely matches theoretical optimum filter feeding speeds was consistently observed. Beat-glide swimming was characterized by high variability in all kinematic parameters, but variance in kinematic parameters was much lower during ram filter feeding. Under this mode, body kinematics are substantially modified, and E. mordax swims more slowly, and with decreased lateral movement along the entire body, but most noticeably in the anterior. Our results suggest that hydrodynamic effects that come with deployment of the filtering anatomy may limit behavioral options during foraging and result in slower swimming speeds during ram filtration.
View details for DOI 10.1242/jeb.158337
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Hydrodynamic properties of fin whale flippers predict maximum rolling performance.
journal of experimental biology
2016; 219: 3315-3320
Abstract
Maneuverability is one of the most important and least understood aspects of animal locomotion. The hydrofoil-like flippers of cetaceans are thought to function as control surfaces that effect maneuvers, but quantitative tests of this hypothesis have been lacking. Here, we constructed a simple hydrodynamic model to predict the longitudinal-axis roll performance of fin whales, and we tested its predictions against kinematic data recorded by on-board movement sensors from 27 free-swimming fin whales. We found that for a given swimming speed and roll excursion, the roll velocity of fin whales calculated from our field data agrees well with that predicted by our hydrodynamic model. Although fluke and body torsion may further influence performance, our results indicate that lift generated by the flippers is sufficient to drive most of the longitudinal-axis rolls used by fin whales for feeding and maneuvering.
View details for PubMedID 27591304
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How to tag a jellyfish? A methodological review and guidelines to successful jellyfish tagging
JOURNAL OF PLANKTON RESEARCH
2016; 38 (6): 1347-1363
View details for DOI 10.1093/plankt/fbw073
View details for Web of Science ID 000393031000001
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Studying cetacean behaviour: new technological approaches and conservation applications
ANIMAL BEHAVIOUR
2016; 120: 235-244
View details for DOI 10.1016/j.anbehav.2016.07.019
View details for Web of Science ID 000385375900025
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Development of an automated method of detecting stereotyped feeding events in multisensor data from tagged rorqual whales.
Ecology and evolution
2016; 6 (20): 7522-7535
Abstract
The introduction of animal-borne, multisensor tags has opened up many opportunities for ecological research, making previously inaccessible species and behaviors observable. The advancement of tag technology and the increasingly widespread use of bio-logging tags are leading to large volumes of sometimes extremely detailed data. With the increasing quantity and duration of tag deployments, a set of tools needs to be developed to aid in facilitating and standardizing the analysis of movement sensor data. Here, we developed an observation-based decision tree method to detect feeding events in data from multisensor movement tags attached to fin whales (Balaenoptera physalus). Fin whales exhibit an energetically costly and kinematically complex foraging behavior called lunge feeding, an intermittent ram filtration mechanism. Using this automated system, we identified feeding lunges in 19 fin whales tagged with multisensor tags, during a total of over 100 h of continuously sampled data. Using movement sensor and hydrophone data, the automated lunge detector correctly identified an average of 92.8% of all lunges, with a false-positive rate of 9.5%. The strong performance of our automated feeding detector demonstrates an effective, straightforward method of activity identification in animal-borne movement tag data. Our method employs a detection algorithm that utilizes a hierarchy of simple thresholds based on knowledge of observed features of feeding behavior, a technique that is readily modifiable to fit a variety of species and behaviors. Using automated methods to detect behavioral events in tag records will significantly decrease data analysis time and aid in standardizing analysis methods, crucial objectives with the rapidly increasing quantity and variety of on-animal tag data. Furthermore, our results have implications for next-generation tag design, especially long-term tags that can be outfitted with on-board processing algorithms that automatically detect kinematic events and transmit ethograms via acoustic or satellite telemetry.
View details for DOI 10.1002/ece3.2386
View details for PubMedID 28725418
View details for PubMedCentralID PMC5513260
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Development of an automated method of detecting stereotyped feeding events in multisensor data from tagged rorqual whales
ECOLOGY AND EVOLUTION
2016; 6 (20): 7522-7535
Abstract
The introduction of animal-borne, multisensor tags has opened up many opportunities for ecological research, making previously inaccessible species and behaviors observable. The advancement of tag technology and the increasingly widespread use of bio-logging tags are leading to large volumes of sometimes extremely detailed data. With the increasing quantity and duration of tag deployments, a set of tools needs to be developed to aid in facilitating and standardizing the analysis of movement sensor data. Here, we developed an observation-based decision tree method to detect feeding events in data from multisensor movement tags attached to fin whales (Balaenoptera physalus). Fin whales exhibit an energetically costly and kinematically complex foraging behavior called lunge feeding, an intermittent ram filtration mechanism. Using this automated system, we identified feeding lunges in 19 fin whales tagged with multisensor tags, during a total of over 100 h of continuously sampled data. Using movement sensor and hydrophone data, the automated lunge detector correctly identified an average of 92.8% of all lunges, with a false-positive rate of 9.5%. The strong performance of our automated feeding detector demonstrates an effective, straightforward method of activity identification in animal-borne movement tag data. Our method employs a detection algorithm that utilizes a hierarchy of simple thresholds based on knowledge of observed features of feeding behavior, a technique that is readily modifiable to fit a variety of species and behaviors. Using automated methods to detect behavioral events in tag records will significantly decrease data analysis time and aid in standardizing analysis methods, crucial objectives with the rapidly increasing quantity and variety of on-animal tag data. Furthermore, our results have implications for next-generation tag design, especially long-term tags that can be outfitted with on-board processing algorithms that automatically detect kinematic events and transmit ethograms via acoustic or satellite telemetry.
View details for DOI 10.1002/ece3.2386
View details for Web of Science ID 000386429200033
View details for PubMedCentralID PMC5513260
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Discrimination of fast click-series produced by tagged Risso's dolphins (Grampus griseus) for echolocation or communication
JOURNAL OF EXPERIMENTAL BIOLOGY
2016; 219 (18): 2898-2907
View details for DOI 10.1242/jeb.144295
View details for Web of Science ID 000384250600022
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Prey-mediated behavioral responses of feeding blue whales in controlled sound exposure experiments
ECOLOGICAL APPLICATIONS
2016; 26 (4): 1075-1085
Abstract
Behavioral response studies provide significant insights into the nature, magnitude, and consequences of changes in animal behavior in response to some external stimulus. Controlled exposure experiments (CEEs) to study behavioral response have faced challenges in quantifying the importance of and interaction among individual variability, exposure conditions, and environmental covariates. To investigate these complex parameters relative to blue whale behavior and how it may change as a function of certain sounds, we deployed multi-sensor acoustic tags and conducted CEEs using simulated mid-frequency active sonar (MFAS) and pseudo-random noise (PRN) stimuli, while collecting synoptic, quantitative prey measures. In contrast to previous approaches that lacked such prey data, our integrated approach explained substantially more variance in blue whale dive behavioral responses to mid-frequency sounds (r2 = 0.725 vs. 0.14 previously). Results demonstrate that deep-feeding whales respond more clearly and strongly to CEEs than those in other behavioral states, but this was only evident with the increased explanatory power provided by incorporating prey density and distribution as contextual covariates. Including contextual variables increases the ability to characterize behavioral variability and empirically strengthens previous findings that deep-feeding blue whales respond significantly to mid-frequency sound exposure. However, our results are only based on a single behavioral state with a limited sample size, and this analytical framework should be applied broadly across behavioral states. The increased capability to describe and account for individual response variability by including environmental variables, such as prey, that drive foraging behavior underscores the importance of integrating these and other relevant contextual parameters in experimental designs. Our results suggest the need to measure and account for the ecological dynamics of predator-prey interactions when studying the effects of anthropogenic disturbance in feeding animals.
View details for DOI 10.1002/15-0783
View details for Web of Science ID 000378092900009
View details for PubMedID 27509749
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Multiple-stage decisions in a marine central-place forager
ROYAL SOCIETY OPEN SCIENCE
2016; 3 (5)
Abstract
Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator-prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies.
View details for DOI 10.1098/rsos.160043
View details for Web of Science ID 000377969800009
View details for PubMedID 27293784
View details for PubMedCentralID PMC4892446
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Insights into the Underwater Behavior, Species Interactions, and Biomechanics of Baleen Whales using Suction-Cup Attached Video and Inertial Sensors
FEDERATION AMER SOC EXP BIOL. 2016
View details for Web of Science ID 000406444000530
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Feeding mechanisms
MARINE MAMMAL PHYSIOLOGY: REQUISITES FOR OCEAN LIVING
2016: 95–117
View details for Web of Science ID 000486089100007
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Hydrodynamics
MARINE MAMMAL PHYSIOLOGY: REQUISITES FOR OCEAN LIVING
2016: 3-28
View details for Web of Science ID 000486089100003
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Using morphology to infer physiology: case studies on rorqual whales (Balaenopteridae)
CANADIAN JOURNAL OF ZOOLOGY
2015; 93 (9): 687-700
View details for DOI 10.1139/cjz-2014-0311
View details for Web of Science ID 000360946900003
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Prey density and distribution drive the three-dimensional foraging strategies of the largest filter feeder
FUNCTIONAL ECOLOGY
2015; 29 (7): 951-961
View details for DOI 10.1111/1365-2435.12395
View details for Web of Science ID 000357738300010
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Mechanical challenges to freshwater residency in sharks and rays.
journal of experimental biology
2015; 218: 1099-1110
Abstract
Major transitions between marine and freshwater habitats are relatively infrequent, primarily as a result of major physiological and ecological challenges. Few species of cartilaginous fish have evolved to occupy freshwater habitats. Current thought suggests that the metabolic physiology of sharks has remained a barrier to the diversification of this taxon in freshwater ecosystems. Here, we demonstrate that the physical properties of water provide an additional constraint for this species-rich group to occupy freshwater systems. Using hydromechanical modeling, we show that occurrence in fresh water results in a two- to three-fold increase in negative buoyancy for sharks and rays. This carries the energetic cost of lift production and results in increased buoyancy-dependent mechanical power requirements for swimming and increased optimal swim speeds. The primary source of buoyancy, the lipid-rich liver, offers only limited compensation for increased negative buoyancy as a result of decreasing water density; maintaining the same submerged weight would involve increasing the liver volume by very large amounts: 3- to 4-fold in scenarios where liver density is also reduced to currently observed minimal levels and 8-fold without any changes in liver density. The first data on body density from two species of elasmobranch occurring in freshwater (the bull shark Carcharhinus leucas, Müller and Henle 1839, and the largetooth sawfish Pristis pristis, Linnaeus 1758) support this hypothesis, showing similar liver sizes as marine forms but lower liver densities, but the greatest negative buoyancies of any elasmobranch studied to date. Our data suggest that the mechanical challenges associated with buoyancy control may have hampered the invasion of freshwater habitats in elasmobranchs, highlighting an additional key factor that may govern the predisposition of marine organisms to successfully establish in freshwater habitats.
View details for DOI 10.1242/jeb.114868
View details for PubMedID 25573824
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Feeding performance by sympatric blue and fin whales exploiting a common prey resource
MARINE MAMMAL SCIENCE
2015; 31 (1): 345-354
View details for DOI 10.1111/mms.12134
View details for Web of Science ID 000346769200018
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Formal Comment on Schorr GS, Falcone EA, Moretti DJ, Andrews RD (2014) First Long-Term Behavioral Records from Cuvier's Beaked Whales (Ziphius cavirostris) Reveal Record-Breaking Dives. PLoS ONE 9(3): e92633. doi:10.1371/journal.pone.0092633.
PloS one
2015; 10 (12): e0142287
View details for PubMedID 26678487
View details for PubMedCentralID PMC4683059
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Simultaneous tracking of blue whales and large ships demonstrates limited behavioral responses for avoiding collision
ENDANGERED SPECIES RESEARCH
2015; 27 (3): 219-232
View details for DOI 10.3354/esr00666
View details for Web of Science ID 000353916900003
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Acoustic and foraging behavior of a Baird's beaked whale, Berardius bairdii, exposed to simulated sonar
SCIENTIFIC REPORTS
2014; 4
View details for DOI 10.1038/srep07031
View details for Web of Science ID 000344762200006
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Feeding rates and under-ice foraging strategies of the smallest lunge filter feeder, the Antarctic minke whale (Balaenoptera bonaerensis).
journal of experimental biology
2014; 217: 2851-2854
Abstract
Body size and feeding mode are two fundamental characteristics that determine foraging performance and ecological niche. As the smallest obligate lunge filter feeders, minke whales represent an ideal system for studying the physical and energetic limits of filter feeding in endotherms. We used multi-sensor suction cup tags to quantify the feeding performance of Antarctic minke whales. Foraging dives around and beneath sea ice contained up to 24 lunges per dive, the highest feeding rates for any lunge-feeding whale. Their small size allows minke whales access to krill in sea-ice environments not easily accessible to larger baleen whales. Furthermore, their ability to filter feed provides an advantage over other smaller sympatric krill predators such as penguins and seals that feed on individual prey. The unique combination of body size, feeding mechanism and sea-ice habitat of Antarctic minke whales defines a previously undocumented energetic niche that is unique among aquatic vertebrates.
View details for DOI 10.1242/jeb.106682
View details for PubMedID 25122916
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Using accelerometers to determine the calling behavior of tagged baleen whales.
journal of experimental biology
2014; 217: 2449-2455
Abstract
Low-frequency acoustic signals generated by baleen whales can propagate over vast distances, making the assignment of calls to specific individuals problematic. Here, we report the novel use of acoustic recording tags equipped with high-resolution accelerometers to detect vibrations from the surface of two tagged fin whales that directly match the timing of recorded acoustic signals. A tag deployed on a buoy in the vicinity of calling fin whales and a recording from a tag that had just fallen off a whale were able to detect calls acoustically but did not record corresponding accelerometer signals that were measured on calling individuals. Across the hundreds of calls measured on two tagged fin whales, the accelerometer response was generally anisotropic across all three axes, appeared to depend on tag placement and increased with the level of received sound. These data demonstrate that high-sample rate accelerometry can provide important insights into the acoustic behavior of baleen whales that communicate at low frequencies. This method helps identify vocalizing whales, which in turn enables the quantification of call rates, a fundamental component of models used to estimate baleen whale abundance and distribution from passive acoustic monitoring.
View details for DOI 10.1242/jeb.103259
View details for PubMedID 24803468
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The device that revolutionized marine organismal biology.
journal of experimental biology
2014; 217: 167-168
View details for DOI 10.1242/jeb.092189
View details for PubMedID 24431140
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Tracking fitness in marine vertebrates: current knowledge and opportunities for future research
MARINE ECOLOGY PROGRESS SERIES
2014; 496: 1-17
View details for DOI 10.3354/meps10691
View details for Web of Science ID 000330356500001