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Jouma'a J, Orgeret F, Picard B, Robinson PW, Weimerskirch H, Guinet C, Costa DP, Beltran RS. Contrasting offspring dependence periods and diving development rates in two closely related marine mammal species. ROYAL SOCIETY OPEN SCIENCE 2024; 11:230666. [PMID: 38179081 PMCID: PMC10762441 DOI: 10.1098/rsos.230666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 11/23/2023] [Indexed: 01/06/2024]
Abstract
Understanding the ontogeny of diving behaviour in marine megafauna is crucial owing to its influence on foraging success, energy budgets, and mortality. We compared the ontogeny of diving behaviour in two closely related species-northern elephant seals (Mirounga angustirostris, n = 4) and southern elephant seals (Mirounga leonina, n = 9)-to shed light on the ecological processes underlying migration. Although both species have similar sizes and behaviours as adults, we discovered that juvenile northern elephant seals have superior diving development, reaching 260 m diving depth in just 30 days, while southern elephant seals require 160 days. Similarly, northern elephant seals achieve dive durations of approximately 11 min on their first day of migration, while southern elephant seals take 125 days. The faster physiological maturation of northern elephant seals could be related to longer offspring dependency and post-weaning fast durations, allowing them to develop their endogenous oxygen stores. Comparison across both species suggests that weaned seal pups face a trade-off between leaving early with higher energy stores but poorer physiological abilities or leaving later with improved physiology but reduced fat stores. This trade-off might be influenced by their evolutionary history, which shapes their migration behaviours in changing environments over time.
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Affiliation(s)
- Joffrey Jouma'a
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
| | - Florian Orgeret
- Marine Apex Predator Research Unit, Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Gqeberha 6031, South Africa
| | - Baptiste Picard
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Patrick W. Robinson
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Daniel P. Costa
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, CA, USA
| | - Roxanne S. Beltran
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
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Grecian WJ, Stenson GB, Biuw M, Boehme L, Folkow LP, Goulet PJ, Jonsen ID, Malde A, Nordøy ES, Rosing-Asvid A, Smout S. Environmental drivers of population-level variation in the migratory and diving ontogeny of an Arctic top predator. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211042. [PMID: 35316952 PMCID: PMC8889203 DOI: 10.1098/rsos.211042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
The development of migratory strategies that enable juveniles to survive to sexual maturity is critical for species that exploit seasonal niches. For animals that forage via breath-hold diving, this requires a combination of both physiological and foraging skill development. Here, we assess how migratory and dive behaviour develop over the first year of life for a migratory Arctic top predator, the harp seal Pagophilus groenlandicus, tracked using animal-borne satellite relay data loggers. We reveal similarities in migratory movements and differences in diving behaviour between 38 juveniles tracked from the Greenland Sea and Northwest Atlantic breeding populations. In both regions, periods of resident and transitory behaviour during migration were associated with proxies for food availability: sea ice concentration and bathymetric depth. However, while ontogenetic development of dive behaviour was similar for both populations of juveniles over the first 25 days, after this time Greenland Sea animals performed shorter and shallower dives and were more closely associated with sea ice than Northwest Atlantic animals. Together, these results highlight the role of both intrinsic and extrinsic factors in shaping early life behaviour. Variation in the environmental conditions experienced during early life may shape how different populations respond to the rapid changes occurring in the Arctic ocean ecosystem.
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Affiliation(s)
- W. James Grecian
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
| | - Garry B. Stenson
- Fisheries and Oceans Canada, St John's, Newfoundland and Labrador, Canada
| | - Martin Biuw
- Institute of Marine Research, FRAM—High North Research Centre for Climate and the Environment, Tromsø, Norway
| | - Lars Boehme
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
| | - Lars P. Folkow
- Department of Arctic and Marine Biology, University of Tromsø—the Arctic University of Norway, Tromsø, Norway
| | - Pierre J. Goulet
- Fisheries and Oceans Canada, St John's, Newfoundland and Labrador, Canada
| | - Ian D. Jonsen
- Department of Biological Sciences, Macquarie University, Sydney, Australia
| | - Aleksander Malde
- Department of Arctic and Marine Biology, University of Tromsø—the Arctic University of Norway, Tromsø, Norway
| | - Erling S. Nordøy
- Department of Arctic and Marine Biology, University of Tromsø—the Arctic University of Norway, Tromsø, Norway
| | | | - Sophie Smout
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
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A Review of Modeling Approaches for Understanding and Monitoring the Environmental Effects of Marine Renewable Energy. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10010094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Understanding the environmental effects of marine energy (ME) devices is fundamental for their sustainable development and efficient regulation. However, measuring effects is difficult given the limited number of operational devices currently deployed. Numerical modeling is a powerful tool for estimating environmental effects and quantifying risks. It is most effective when informed by empirical data and coordinated with the development and implementation of monitoring protocols. We reviewed modeling techniques and information needs for six environmental stressor–receptor interactions related to ME: changes in oceanographic systems, underwater noise, electromagnetic fields (EMFs), changes in habitat, collision risk, and displacement of marine animals. This review considers the effects of tidal, wave, and ocean current energy converters. We summarized the availability and maturity of models for each stressor–receptor interaction and provide examples involving ME devices when available and analogous examples otherwise. Models for oceanographic systems and underwater noise were widely available and sometimes applied to ME, but need validation in real-world settings. Many methods are available for modeling habitat change and displacement of marine animals, but few examples related to ME exist. Models of collision risk and species response to EMFs are still in stages of theory development and need more observational data, particularly about species behavior near devices, to be effective. We conclude by synthesizing model status, commonalities between models, and overlapping monitoring needs that can be exploited to develop a coordinated and efficient set of protocols for predicting and monitoring the environmental effects of ME.
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Bucol AA, Abesamis RA, Stockwell BL, Lowe JR, Russ GR. Development of reproductive potential in protogynous coral reef fishes within Philippine no-take marine reserves. JOURNAL OF FISH BIOLOGY 2021; 99:1561-1575. [PMID: 34312862 DOI: 10.1111/jfb.14861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 07/16/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Empirical evidence for increases in the reproductive potential (egg output per unit area) of coral reef fish in no-take marine reserves (NTMRs) is sparse. Here, we inferred the development of reproductive potential in two species of protogynous reef fishes, Chlorurus bleekeri (Labridae: Scarinae) and Cephalopholis argus (Epinephelidae), inside and outside of Philippine NTMRs. We estimated key reproductive parameters and applied these to species-specific density and length data from 17 NTMRs (durations of protection 0-11 years) and paired fished sites (controls) in a space-for-time substitution approach. For C. argus, we also used density and length data collected almost annually over 29 years from a NTMR and an adjacent control at Apo Island. The results suggest that C. bleekeri can develop 6.0 times greater reproductive potential in NTMRs than controls after 11 years of protection, equivalent to approximately 582,000 more eggs produced 500 m-2 inside NTMRs. Enhancement of reproductive potential in C. argus was not evident after 11 years in the space-for-time substitution. At Apo Island NTMR, reproductive potential of C. argus increased approximately 6-fold over 29 years but NTMR/control ratios in reproductive potential decreased through time (from 3.2 to 2.4), probably due to spillover of C. argus from the NTMR to the control. C. argus was estimated to produce approximately 113,000 more eggs 500 m-2 inside Apo Island NTMR at the 29th year of protection. Ratios of reproductive potential between NTMR and controls in C. bleekeri and C. argus were often greater than corresponding ratios in density or biomass. The study underscores the importance of species-specific reproductive life history traits that drive variation in the development of larval fish subsidies that originate from NTMRs.
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Affiliation(s)
- Abner A Bucol
- Silliman University-Angelo King Center for Research and Environmental Management, Dumaguete City, Philippines
| | - Rene A Abesamis
- Silliman University-Angelo King Center for Research and Environmental Management, Dumaguete City, Philippines
| | - Brian L Stockwell
- School of Agriculture, Geography, Ocean, and Natural Sciences, The University of South Pacific, Suva, Fiji
| | - Jake R Lowe
- College of Science and Engineering and Australian Research Council Centre of Excellence and ARC Centre of Coral Reef Studies, James Cook University, Townsville, Australia
| | - Garry R Russ
- College of Science and Engineering and Australian Research Council Centre of Excellence and ARC Centre of Coral Reef Studies, James Cook University, Townsville, Australia
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Planque Y, Spitz J, Authier M, Guillou G, Vincent C, Caurant F. Trophic niche overlap between sympatric harbour seals ( Phoca vitulina) and grey seals ( Halichoerus grypus) at the southern limit of their European range (Eastern English Channel). Ecol Evol 2021; 11:10004-10025. [PMID: 34367555 PMCID: PMC8328439 DOI: 10.1002/ece3.7739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 11/30/2022] Open
Abstract
Sympatric harbour (Phoca vitulina) and grey seals (Halichoerus grypus) are increasingly considered potential competitors, especially since recent local declines in harbour seal numbers while grey seal numbers remained stable or increased at their European core distributions. A better understanding of the interactions between these species is critical for conservation efforts. This study aimed to identify the trophic niche overlap between harbour and grey seals at the southern limit of their European range, in the Baie de Somme (BDS, Eastern English Channel, France), where numbers of resident harbour seals and visiting grey seals are increasing exponentially. Dietary overlap was identified from scat contents using hierarchical clustering. Isotopic niche overlap was quantified using δ13C and δ15N isotopic values from whiskers of 18 individuals, by estimating isotopic standard ellipses with a novel hierarchical model developed in a Bayesian framework to consider both intraindividual variability and interindividual variability. Foraging areas of these individuals were identified from telemetry data. The three independent approaches provided converging results, revealing a high trophic niche overlap due to consumption of benthic flatfish. Two diet clusters were dominated by either small or large benthic flatfish; these comprised 85.5% [CI95%: 80.3%-90.2%] of harbour seal scats and 46.8% [35.1%-58.4%] of grey seal scats. The narrower isotopic niche of harbour seals was nested within that of grey seals (58.2% [22.7%-100%] overlap). Grey seals with isotopic values similar to harbour seals foraged in coastal waters close to the BDS alike harbour seals did, suggesting the niche overlap may be due to individual grey seal strategies. Our findings therefore provide the basis for potential competition between both species (foraging on benthic flatfish close to the BDS). We suggest that a continued increase in seal numbers and/or a decrease in flatfish supply in this area could cause/amplify competitive interactions and have deleterious effects on harbour seal colonies.
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Affiliation(s)
- Yann Planque
- Centre d'Études Biologiques de ChizéCEBC, UMR 7372 CNRS/La Rochelle UniversitéLa RochelleFrance
| | - Jérôme Spitz
- Centre d'Études Biologiques de ChizéCEBC, UMR 7372 CNRS/La Rochelle UniversitéLa RochelleFrance
- Observatoire PelagisUMS 3462 CNRS/La Rochelle UniversitéLa RochelleFrance
| | - Matthieu Authier
- Observatoire PelagisUMS 3462 CNRS/La Rochelle UniversitéLa RochelleFrance
- ADERAPessac CedexFrance
| | - Gaël Guillou
- Littoral Environnement et Sociétés, LIENSsUMR 7266 CNRS/La Rochelle UniversitéLa RochelleFrance
| | - Cécile Vincent
- Centre d'Études Biologiques de ChizéCEBC, UMR 7372 CNRS/La Rochelle UniversitéLa RochelleFrance
| | - Florence Caurant
- Centre d'Études Biologiques de ChizéCEBC, UMR 7372 CNRS/La Rochelle UniversitéLa RochelleFrance
- Observatoire PelagisUMS 3462 CNRS/La Rochelle UniversitéLa RochelleFrance
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Chudzinska M, Nabe-Nielsen J, Smout S, Aarts G, Brasseur S, Graham I, Thompson P, McConnell B. AgentSeal: Agent-based model describing movement of marine central-place foragers. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2020.109397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Trigg LE, Chen F, Shapiro GI, Ingram SN, Vincent C, Thompson D, Russell DJF, Carter MID, Embling CB. Predicting the exposure of diving grey seals to shipping noise. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 148:1014. [PMID: 32873039 DOI: 10.1121/10.0001727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
There is high spatial overlap between grey seals and shipping traffic, and the functional hearing range of grey seals indicates sensitivity to underwater noise emitted by ships. However, there is still very little data regarding the exposure of grey seals to shipping noise, constraining effective policy decisions. Particularly, there are few predictions that consider the at-sea movement of seals. Consequently, this study aimed to predict the exposure of adult grey seals and pups to shipping noise along a three-dimensional movement track, and assess the influence of shipping characteristics on sound exposure levels. Using ship location data, a ship source model, and the acoustic propagation model, RAMSurf, this study estimated weighted 24-h sound exposure levels (10-1000 Hz) (SELw). Median predicted 24-h SELw was 128 and 142 dB re 1 μPa2s for the pups and adults, respectively. The predicted exposure of seals to shipping noise did not exceed best evidence thresholds for temporary threshold shift. Exposure was mediated by the number of ships, ship source level, the distance between seals and ships, and the at-sea behaviour of the seals. The results can inform regulatory planning related to anthropogenic pressures on seal populations.
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Affiliation(s)
- Leah E Trigg
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, United Kingdom
| | - Feng Chen
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, United Kingdom
| | - Georgy I Shapiro
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, United Kingdom
| | - Simon N Ingram
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, United Kingdom
| | - Cécile Vincent
- Centre d'Etudes Biologiques de Chizé, CNRS/University of La Rochelle, La Rochelle, France
| | - David Thompson
- Sea Mammal Research Unit, University of St Andrews, St Andrews, Fife KY16 8LB, United Kingdom
| | - Debbie J F Russell
- Sea Mammal Research Unit, University of St Andrews, St Andrews, Fife KY16 8LB, United Kingdom
| | - Matt I D Carter
- Sea Mammal Research Unit, University of St Andrews, St Andrews, Fife KY16 8LB, United Kingdom
| | - Clare B Embling
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, United Kingdom
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Brost BM, Hooten MB, Small RJ. Model‐based clustering reveals patterns in central place use of a marine top predator. Ecosphere 2020. [DOI: 10.1002/ecs2.3123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Brian M. Brost
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado 80523 USA
| | - Mevin B. Hooten
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado 80523 USA
- U.S. Geological Survey Colorado Cooperative Fish and Wildlife Research Unit Colorado State University Fort Collins Colorado 80523 USA
- Department of Statistics Colorado State University Fort Collins Colorado 80523 USA
| | - Robert J. Small
- Division of Wildlife Conservation Alaska Department of Fish and Game Juneau Alaska 99801 USA
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Jones KA, Wood H, Ashburner JP, Forcada J, Ratcliffe N, Votier SC, Staniland IJ. Risk exposure trade-offs in the ontogeny of sexual segregation in Antarctic fur seal pups. Behav Ecol 2020; 31:719-730. [PMID: 32595270 PMCID: PMC7303822 DOI: 10.1093/beheco/araa018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/31/2020] [Accepted: 02/26/2020] [Indexed: 11/21/2022] Open
Abstract
Sexual segregation has important ecological implications, but its initial development in early life stages is poorly understood. We investigated the roles of size dimorphism, social behavior, and predation risk on the ontogeny of sexual segregation in Antarctic fur seal, Arctocephalus gazella, pups at South Georgia. Beaches and water provide opportunities for pup social interaction and learning (through play and swimming) but increased risk of injury and death (from other seals, predatory birds, and harsh weather), whereas tussock grass provides shelter from these risks but less developmental opportunities. One hundred pups were sexed and weighed, 50 on the beach and 50 in tussock grass, in January, February, and March annually from 1989 to 2018. Additionally, 19 male and 16 female pups were GPS-tracked during lactation from December 2012. Analysis of pup counts and habitat use of GPS-tracked pups suggested that females had a slightly higher association with tussock grass habitats and males with beach habitats. GPS-tracked pups traveled progressively further at sea as they developed, and males traveled further than females toward the end of lactation. These sex differences may reflect contrasting drivers of pup behavior: males being more risk prone to gain social skills and lean muscle mass and females being more risk averse to improve chances of survival, ultimately driven by their different reproductive roles. We conclude that sex differences in habitat use can develop in a highly polygynous species prior to the onset of major sexual size dimorphism, which hints that these sex differences will increasingly diverge in later life.
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Affiliation(s)
- Kayleigh A Jones
- Ecosystems Team, British Antarctic Survey, High Cross, Madingley road, Cambridge, UK
- College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, UK
| | - Hannah Wood
- Ecosystems Team, British Antarctic Survey, High Cross, Madingley road, Cambridge, UK
| | - Jonathan P Ashburner
- Ecosystems Team, British Antarctic Survey, High Cross, Madingley road, Cambridge, UK
| | - Jaume Forcada
- Ecosystems Team, British Antarctic Survey, High Cross, Madingley road, Cambridge, UK
| | - Norman Ratcliffe
- Ecosystems Team, British Antarctic Survey, High Cross, Madingley road, Cambridge, UK
| | - Stephen C Votier
- College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, UK
| | - Iain J Staniland
- Ecosystems Team, British Antarctic Survey, High Cross, Madingley road, Cambridge, UK
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Carter MID, McClintock BT, Embling CB, Bennett KA, Thompson D, Russell DJF. From pup to predator: generalized hidden Markov models reveal rapid development of movement strategies in a naïve long‐lived vertebrate. OIKOS 2020. [DOI: 10.1111/oik.06853] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Matt I. D. Carter
- Sea Mammal Research Unit, Scottish Oceans Inst., Univ. of St Andrews St Andrews KY16 8LB UK
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, Univ. of Plymouth Plymouth UK
| | - Brett T. McClintock
- Marine Mammal Laboratory, Alaska Fisheries Science Center, NOAA NMFS Seattle USA
| | - Clare B. Embling
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, Univ. of Plymouth Plymouth UK
| | | | - Dave Thompson
- Sea Mammal Research Unit, Scottish Oceans Inst., Univ. of St Andrews St Andrews KY16 8LB UK
| | - Debbie J. F. Russell
- Sea Mammal Research Unit, Scottish Oceans Inst., Univ. of St Andrews St Andrews KY16 8LB UK
- Centre for Research into Ecological and Environmental Modelling, Univ. of St Andrew St Andrews UK
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Nowak BVR, Bowen WD, Whoriskey K, Lidgard DC, Mills Flemming JE, Iverson SJ. Foraging behaviour of a continental shelf marine predator, the grey seal ( Halichoerus grypus), is associated with in situ, subsurface oceanographic conditions. MOVEMENT ECOLOGY 2020; 8:41. [PMID: 33093960 PMCID: PMC7574573 DOI: 10.1186/s40462-020-00225-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/30/2020] [Indexed: 05/13/2023]
Abstract
BACKGROUND The heterogeneous oceanographic conditions of continental shelf ecosystems result in a three-dimensionally patchy distribution of prey available to upper-trophic level predators. The association of bio-physical conditions with movement patterns of large marine predators has been demonstrated in diverse taxa. However, obtaining subsurface data that are spatio-temporally relevant to the decisions made by benthically-foraging species can be challenging. METHODS Between 2009 and 2015, grey seals were captured on Sable Island, Nova Scotia, Canada during summer and fall and instrumented with high-resolution archival GPS tags. These tags recorded location data as well as depth (m), temperature (°C), and light level measurements during dives, until animals returned to the haulout site to breed. Hidden Markov models were used to predict apparent foraging along movement tracks for 79 individuals (59 females, 20 males) every 3 h. In situ measurements were used to estimate chlorophyll-a concentration (mg m- 3) and temperature within the upper-water column (50 m) and temperature and depth at the bottom of dives. As chlorophyll-a could only be estimated from 10:00 to 14:00 AST for dive depths ≥50 m, we formulated two generalized linear mixed-effects models to test the association of predicted grey seal behavioural states with oceanographic conditions and phytoplankton biomass: the first representing conditions of the upper-water column likely to influence primary productivity, and a second model including environmental conditions encountered by grey seals at the bottom of dives, when seals were more likely to be foraging. RESULTS Predicted grey seal behavioural states were associated with fine-scale chlorophyll-a concentrations and other environmental conditions they encountered across the continental shelf. In the Water Column Model, season had no influence on the probability of observing apparent foraging, but chlorophyll-a, upper-water column temperature, and sex did, with females having a greater probability of foraging than males. In the Bottom Conditions Model, again season had no influence on the probability of apparent foraging, but females were over twice as likely as males to be foraging. CONCLUSIONS The results of this study highlight the value of in situ measurements of oceanographic properties that can be collected at high temporal resolution by animal-borne data loggers. These data provide insight into how inferred behavioural decisions made by large marine predators, such as the grey seal, may be influenced by fine-scale oceanographic conditions.
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Affiliation(s)
- B. V. R. Nowak
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4JI Canada
| | - W. D. Bowen
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4JI Canada
- Population Ecology Division, Department of Fisheries and Oceans, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2 Canada
| | - K. Whoriskey
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia B3H 4JI Canada
| | - D. C. Lidgard
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4JI Canada
- Population Ecology Division, Department of Fisheries and Oceans, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2 Canada
| | - J. E. Mills Flemming
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia B3H 4JI Canada
| | - S. J. Iverson
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4JI Canada
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Cox SL, Authier M, Orgeret F, Weimerskirch H, Guinet C. High mortality rates in a juvenile free-ranging marine predator and links to dive and forage ability. Ecol Evol 2020; 10:410-430. [PMID: 31988734 PMCID: PMC6972805 DOI: 10.1002/ece3.5905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/30/2019] [Accepted: 11/03/2019] [Indexed: 12/04/2022] Open
Abstract
High juvenile mortality rates are typical of many long-lived marine vertebrate predators. Insufficient development in dive and forage ability is considered a key driver of this. However, direct links to survival outcome are sparse, particularly in free-ranging marine animals that may not return to land.In this study, we conduct exploratory investigations toward early mortality in juvenile southern elephant seals Mirounga leonina. Twenty postweaning pups were equipped with (a) a new-generation satellite relay data tag, capable of remotely transmitting fine-scale behavioral movements from accelerometers, and (b) a location transmitting only tag (so that mortality events could be distinguished from device failures). Individuals were followed during their first trip at sea (until mortality or return to land). Two analyses were conducted. First, the behavioral movements and encountered environmental conditions of nonsurviving pups were individually compared to temporally concurrent observations from grouped survivors. Second, common causes of mortality were investigated using Cox's proportional hazard regression and penalized shrinkage techniques.Nine individuals died (two females and seven males) and 11 survived (eight females and three males). All but one individual died before the return phase of their first trip at sea, and all but one were negatively buoyant. Causes of death were variable, although common factors included increased horizontal travel speeds and distances, decreased development in dive and forage ability, and habitat type visited (lower sea surface temperatures and decreased total [eddy] kinetic energy).For long-lived marine vertebrate predators, such as the southern elephant seal, the first few months of life following independence represent a critical period, when small deviations in behavior from the norm appear sufficient to increase mortality risk. Survival rates may subsequently be particularly vulnerable to changes in climate and environment, which will have concomitant consequences on the demography and dynamics of populations.
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Affiliation(s)
- Sam L. Cox
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
- UMR MARBECStation Ifremer SéteSéteFrance
- Centre National d'Études Spatiales (CNES)ToulouseFrance
| | - Matthieu Authier
- Observatoire PELAGISUMS 3462 ‐ Universitié de La Rochelle & CNRSLa RochelleFrance
- ADERAPessac CedexFrance
| | - Florian Orgeret
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
| | - Henri Weimerskirch
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
| | - Christophe Guinet
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
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Migratory strategies of juvenile northern fur seals (Callorhinus ursinus): bridging the gap between pups and adults. Sci Rep 2019; 9:13921. [PMID: 31558737 PMCID: PMC6763446 DOI: 10.1038/s41598-019-50230-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 09/02/2019] [Indexed: 11/08/2022] Open
Abstract
In species exhibiting differential migration by sex and age, understanding what differences exist, and the adaptive reasons for these differences is critical for determining how demographic groups will respond to environmental variability and anthropogenic perturbations. We used satellite-telemetered movement and diving data to investigate differential migration and its ontogeny in a highly migratory North Pacific Ocean predator, the northern fur seal (Callorhinus ursinus; NFS), with a focus on understudied juvenile (1- to 2-year-old) animals. We instrumented 71 juvenile NFS in two years (2006-07 and 2007-08) at three major North American breeding sites and compared their migratory strategies with pups and adults. Although sexual dimorphism is strong in adult NFS, only weak differences in body mass between sexes were found in juveniles, which had similar body mass to pups (~3-4 months). However, unlike widely-dispersed pups, juvenile male and female NFS dispersed in different directions, and used different habitats characterized by distinct hydrography and prey assemblages during migration, similar to breeding adults. Juvenile diving behavior differed only modestly among habitats and between sexes, consistent with weak differences in body mass. Evidence of habitat sexual segregation by juvenile NFS contradicts previous hypotheses that physiological differences predominantly drive the ontogeny of differential migration.
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15
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Kıraç CO, Ok M. Diet of a Mediterranean monk seal Monachus monachus in a transitional post-weaning phase and its implications for the conservation of the species. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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16
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van Beest FM, Mews S, Elkenkamp S, Schuhmann P, Tsolak D, Wobbe T, Bartolino V, Bastardie F, Dietz R, von Dorrien C, Galatius A, Karlsson O, McConnell B, Nabe-Nielsen J, Olsen MT, Teilmann J, Langrock R. Classifying grey seal behaviour in relation to environmental variability and commercial fishing activity - a multivariate hidden Markov model. Sci Rep 2019; 9:5642. [PMID: 30948786 PMCID: PMC6449369 DOI: 10.1038/s41598-019-42109-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/25/2019] [Indexed: 02/06/2023] Open
Abstract
Classifying movement behaviour of marine predators in relation to anthropogenic activity and environmental conditions is important to guide marine conservation. We studied the relationship between grey seal (Halichoerus grypus) behaviour and environmental variability in the southwestern Baltic Sea where seal-fishery conflicts are increasing. We used multiple environmental covariates and proximity to active fishing nets within a multivariate hidden Markov model (HMM) to quantify changes in movement behaviour of grey seals while at sea. Dive depth, dive duration, surface duration, horizontal displacement, and turning angle were used to identify travelling, resting and foraging states. The likelihood of seals foraging increased in deeper, colder, more saline waters, which are sites with increased primary productivity and possibly prey densities. Proximity to active fishing net also had a pronounced effect on state occupancy. The probability of seals foraging was highest <5 km from active fishing nets (51%) and decreased as distance to nets increased. However, seals used sites <5 km from active fishing nets only 3% of their time at sea highlighting an important temporal dimension in seal-fishery interactions. By coupling high-resolution oceanographic, fisheries, and grey seal movement data, our study provides a scientific basis for designing management strategies that satisfy ecological and socioeconomic demands on marine ecosystems.
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Affiliation(s)
- Floris M van Beest
- Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark.
| | - Sina Mews
- Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Svenja Elkenkamp
- Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Patrick Schuhmann
- Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Dorian Tsolak
- Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Till Wobbe
- Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Valerio Bartolino
- Department of Aquatic Resources, Swedish University of Agricultural Sciences, Lysekil, SE-45321, Sweden
| | - Francois Bastardie
- National Institute for Aquatic Resources, Technical University of Denmark, Kemitorvet, Kgs. Lyngby, DK-2800, Denmark
| | - Rune Dietz
- Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark
| | - Christian von Dorrien
- Thünen Institute of Baltic Sea Fisheries, Alter Hafen Süd 2, D-18069, Rostock, Germany
| | - Anders Galatius
- Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark
| | - Olle Karlsson
- Department of Environmental Research and Monitoring, Swedish Museum of Natural History, Box 50007, SE-104 05, Stockholm, Sweden
| | - Bernie McConnell
- Sea Mammal Research Unit, University of St Andrews, St Andrews, KY16 8LB, United Kingdom
| | - Jacob Nabe-Nielsen
- Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark
| | - Morten Tange Olsen
- Evolutionary Genomics Section, Natural History Museum of Denmark, Department of Biology, University of Copenhagen, Øster Voldgade 5-7, DK-1350, Copenhagen K, Denmark
| | - Jonas Teilmann
- Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark
| | - Roland Langrock
- Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
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Montalva F, Pérez‐Venegas D, Gutiérrez J, Seguel M. The contrasting hidden consequences of parasitism: Effects of a hematophagous nematode ( Uncinaria sp.) in the development of a marine mammal swimming behavior. Ecol Evol 2019; 9:3689-3699. [PMID: 31015959 PMCID: PMC6468065 DOI: 10.1002/ece3.4914] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/05/2018] [Accepted: 12/21/2018] [Indexed: 11/10/2022] Open
Abstract
Parasites are an important part of ecosystems, playing a critical role in their equilibrium. However, the consequences of parasitism beyond the direct effects associated with disease and mortality are not completely understood. This gap in knowledge is in part due to the difficulties to isolate the effect of single parasite species on physiological and behavioral traits in natural systems.The South American fur seal (Arctocephalus australis)-hookworm (Uncinaria sp.) interaction offers an ideal system to overcome these difficulties and study the behavioral and physiological effects of parasites in their hosts.Hookworms cause stunted growth and anemia in pinniped pups, which could affect early life active behaviors such as swimming. The aim of this study was to determine the effects of hookworms (Uncinaria sp.) on the development of swimming capabilities in A. australis through physiological and ethological analyses.Higher parasite burden was associated with reduced growth rates and lower blood hemoglobin concentrations, whereas scaled body mass and blood hemoglobin levels had an important positive effect on the water activity of the pups. However, antihookworm treatment did not affect the level of water activity of the pups, and pups with high hookworm burden increased their time budget in water. This was probably related to lower maternal attendance in heavily parasitized pups, leaving these pups more time to perform water activities. Therefore, pups with heavy hookworm burden, despite having decreased growth rates and blood hemoglobin concentrations, compensated for their handicap in physiological traits related to swimming by spending more time in the water.This work offers new insights to understand the contrasting effects of parasites on aquatic organisms, and the compensatory mechanisms employed by infected animals to avoid the worst consequences of parasitism.
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Affiliation(s)
- Felipe Montalva
- Facultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile
| | - Diego Pérez‐Venegas
- PhD Program in Conservation Medicine, Facultad de Ciencias de la VidaUniversidad Andrés BelloSantiagoChile
| | - Josefina Gutiérrez
- Instituto de Patología Animal, Facultad de Ciencias VeterinariasUniversidad Austral de ChileValdiviaChile
- Programa de Investigación Aplicada en Fauna Silvestre, Facultad de Ciencias VeterinariasUniversidad Austral de ChileValdiviaChile
| | - Mauricio Seguel
- Department of Pathology, College of Veterinary MedicineUniversity of GeorgiaAthensGeorgia
- Present address:
Odum School of EcologyUniversity of GeorgiaAthensGeorgia
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Gosch M, Cronin M, Rogan E, Hunt W, Luck C, Jessopp M. Spatial variation in a top marine predator's diet at two regionally distinct sites. PLoS One 2019; 14:e0209032. [PMID: 30601852 PMCID: PMC6314570 DOI: 10.1371/journal.pone.0209032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 11/27/2018] [Indexed: 11/18/2022] Open
Abstract
In ecological studies it is often assumed that predator foraging strategies and resource use are geographically and seasonally homogeneous, resulting in relatively static trophic relationships. However, certain centrally placed foragers (e.g. seals) often have terrestrial sites for breeding, resting, and moulting that are geographically distinct, and associated with different habitat types. Therefore, accurate estimations of predator diet at relevant spatial and temporal scales are key to understanding energetic requirements, predator-prey interactions and ecosystem structure. We investigate geographic variation in the diet of grey seals (Halichoerus grypus), a relatively abundant and widely distributed central place forager, to provide insights into geographic variation in resource use. Prey composition was identified using scat samples collected over concurrent timescales and a multivariate approach was used to analyse diet from two contrasting habitats. Regional differences in prey assemblages occurred within all years (2011-2013) and all seasons (ANOSIM, all p<0.05), apart from in winter. Telemetry data were used to identify core foraging areas and habitats most likely associated with scat samples collected at the two haul-out sites. Regional differences in the diet appear to reflect regional differences in the physical habitat features, with seals foraging in deeper waters over sandy substrates showing a higher prevalence of pelagic and bentho-pelagic prey species such as blue whiting and sandeels. Conversely, seals foraging in comparatively shallow waters had a greater contribution of demersal and groundfish species such as cephalopods and flatfish in their diet. We suggest that shallower waters enable seals to spend more time foraging along the benthos while remaining within aerobic dive limits, resulting in more benthic species in the diet. In contrast, the diet of seals hauled-out in areas adjacent to deeper waters indicates that either seals engage in a more pelagic foraging strategy, or that seals can spend less time at the benthos, resulting in comparatively more pelagic prey recovered in the diet. The substantial differences in prey assemblages over a small spatial scale (<300 km) demonstrates the importance of using regionally-specific diet information in ecosystem-based models to better account for different trophic interactions.
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Affiliation(s)
- Martha Gosch
- MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland
- School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland
- * E-mail:
| | - Michelle Cronin
- MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland
| | - Emer Rogan
- School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland
| | - William Hunt
- MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland
| | - Cian Luck
- MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland
- School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland
| | - Mark Jessopp
- MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland
- School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland
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Orgeret F, Cox SL, Weimerskirch H, Guinet C. Body condition influences ontogeny of foraging behavior in juvenile southern elephant seals. Ecol Evol 2019; 9:223-236. [PMID: 30680109 PMCID: PMC6341977 DOI: 10.1002/ece3.4717] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/12/2018] [Accepted: 10/26/2018] [Indexed: 11/21/2022] Open
Abstract
Ontogeny of diving and foraging behavior in marine top predators is poorly understood despite its importance in population recruitment. This lack of knowledge is partly due to the difficulties of monitoring juveniles in the wild, which is linked to high mortality early in life. Pinnipeds are good models for studying the development of foraging behaviors because juveniles are large enough to robustly carry tracking devices for many months. Moreover, parental assistance is absent after a juvenile departs for its first foraging trip, minimizing confounding effects of parental input on the development of foraging skills. In this study, we tracked 20 newly weaned juvenile southern elephant seals from Kerguelen Islands for up to 338 days during their first trip at sea following weaning. We used a new generation of satellite relay tags, which allow for the transmission of dive, accelerometer, and location data. We also monitored, at the same time, nine adult females from the colony during their post-breeding trips, in order to compare diving and foraging behaviors. Juveniles showed a gradual improvement through time in their foraging skills. Like adults females, they remarkably adjusted their swimming effort according to temporal changes in buoyancy (i.e., a proxy of their body condition). They also did not appear to exceed their aerobic physiological diving limits, although dives were constrained by their smaller size compared to adults. Changes in buoyancy appeared to also influence their decision to either keep foraging or return to land, alongside the duration of their haul outs and choice of foraging habitat (oceanic vs. plateau). Further studies are thus needed to better understand how patterns in juveniles survival, and therefore elephant seal populations, might be affected by their changes in foraging skills and changes in their environmental conditions.
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Affiliation(s)
- Florian Orgeret
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
| | - Sam L. Cox
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
- Centre National d'Études Spatiales (CNES)18 Avenue Edouard Belin31400 ToulouseFrance
- MARBEC (Institut de Recherche pour le Developpemente; IRD)Station Ifremer de Sete, Avenue Jean Monnet, CS 30171, 34203SèteFrance
| | - Henri Weimerskirch
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
| | - Christophe Guinet
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
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Isojunno S, Aoki K, Curé C, Kvadsheim PH, Miller PJO. Breathing Patterns Indicate Cost of Exercise During Diving and Response to Experimental Sound Exposures in Long-Finned Pilot Whales. Front Physiol 2018; 9:1462. [PMID: 30459631 PMCID: PMC6232938 DOI: 10.3389/fphys.2018.01462] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/26/2018] [Indexed: 02/05/2023] Open
Abstract
Air-breathing marine predators that target sub-surface prey have to balance the energetic benefit of foraging against the time, energetic and physiological costs of diving. Here we use on-animal data loggers to assess whether such trade-offs can be revealed by the breathing rates (BR) and timing of breaths in long-finned pilot whales (Globicephela melas). We used the period immediately following foraging dives in particular, for which respiratory behavior can be expected to be optimized for gas exchange. Breath times and fluke strokes were detected using onboard sensors (pressure, 3-axis acceleration) attached to animals using suction cups. The number and timing of breaths were quantified in non-linear mixed models that incorporated serial correlation and individual as a random effect. We found that pilot whales increased their BR in the 5–10 min period prior to, and immediately following, dives that exceeded 31 m depth. While pre-dive BRs did not vary with dive duration, the initial post-dive BR was linearly correlated with duration of >2 min dives, with BR then declining exponentially. Apparent net diving costs were 1.7 (SE 0.2) breaths per min of diving (post-dive number of breaths, above pre-dive breathing rate unrelated to dive recovery). Every fluke stroke was estimated to cost 0.086 breaths, which amounted to 80–90% average contribution of locomotion to the net diving costs. After accounting for fluke stroke rate, individuals in the small body size class took a greater number of breaths per diving minute. Individuals reduced their breathing rate (from the rate expected by diving behavior) by 13–16% during playbacks of killer whale sounds and their first exposure to 1–2 kHz naval sonar, indicating similar responses to interspecific competitor/predator and anthropogenic sounds. Although we cannot rule out individuals increasing their per-breath O2 uptake to match metabolic demand, our results suggest that behavioral responses to experimental sound exposures were not associated with increased metabolic rates in a stress response, but metabolic rates instead appear to decrease. Our results support the hypothesis that maximal performance leads to predictable (optimized) breathing patterns, which combined with further physiological measurements could improve proxies of field metabolic rates and per-stroke energy costs from animal-borne behavior data.
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Affiliation(s)
- Saana Isojunno
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Kagari Aoki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | | | | | - Patrick James O'Malley Miller
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, United Kingdom
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