1
|
Reynolds SD, Franklin CE, Norman BM, Richardson AJ, Everett JD, Schoeman DS, White CR, Lawson CL, Pierce SJ, Rohner CA, Bach SS, Comezzi FG, Diamant S, Jaidah MY, Robinson DP, Dwyer RG. Effects of climate warming on energetics and habitat of the world's largest marine ectotherm. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175832. [PMID: 39197762 DOI: 10.1016/j.scitotenv.2024.175832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 08/23/2024] [Accepted: 08/25/2024] [Indexed: 09/01/2024]
Abstract
Responses of organisms to climate warming are variable and complex. Effects on species distributions are already evident and mean global surface ocean temperatures are likely to warm by up to 4.1 °C by 2100, substantially impacting the physiology and distributions of ectotherms. The largest marine ectotherm, the whale shark Rhincodon typus, broadly prefers sea surface temperatures (SST) ranging from 23 to 30 °C. Whole-species distribution models have projected a poleward range shift under future scenarios of climate change, but these models do not consider intraspecific variation or phenotypic plasticity in thermal limits when modelling species responses, and the impact of climate warming on the energetic requirements of whale sharks is unknown. Using a dataset of 111 whale shark movement tracks from aggregation sites in five countries across the Indian Ocean and the latest Earth-system modelling produced from Coupled Model Intercomparison Project Phase 6 for the Intergovernmental Panel on Climate Change, we examined how SST and total zooplankton biomass, their main food source, may change in the future, and what this means for the energetic balance and extent of suitable habitat for whale sharks. Earth System Models, under three Shared Socioeconomic Pathways (SSPs; SSP1-2.6, SSP3-7.0 and SSP5-8.5), project that by 2100 mean SST in four regions where whale shark aggregations are found will increase by up to 4.9 °C relative to the present, while zooplankton biomass will decrease. This reduction in zooplankton is projected to be accompanied by an increase in the energetic requirements of whale sharks because warmer water temperatures will increase their metabolic rate. We found marked differences in projected changes in the extent of suitable habitat when comparing a whole-species distribution model to one including regional variation. This suggests that the conventional approach of combining data from different regions within a species' distribution could underestimate the amount of local adaptation in populations, although parameterising local models could also suffer from having insufficient data and lead to model mis-specification or highly uncertain estimates. Our study highlights the need for further research into whale shark thermal tolerances and energetics, the complexities involved in projecting species responses to climate change, and the potential importance of considering intraspecific variation when building species distribution models.
Collapse
Affiliation(s)
- Samantha D Reynolds
- School of the Environment, The University of Queensland, Brisbane, QLD, Australia; 162/3 Powell Rd, Coogee, WA, Australia; Harry Butler Institute, Murdoch University, Murdoch, WA, Australia.
| | - Craig E Franklin
- School of the Environment, The University of Queensland, Brisbane, QLD, Australia
| | - Bradley M Norman
- 162/3 Powell Rd, Coogee, WA, Australia; Harry Butler Institute, Murdoch University, Murdoch, WA, Australia
| | - Anthony J Richardson
- School of the Environment, The University of Queensland, Brisbane, QLD, Australia; Centre for Biodiversity and Conservation Science (CBCS), The University of Queensland, Brisbane, QLD, Australia; CSIRO Environment, Queensland Biosciences Precinct, St Lucia, QLD, AUSTRALIA
| | - Jason D Everett
- School of the Environment, The University of Queensland, Brisbane, QLD, Australia; CSIRO Environment, Queensland Biosciences Precinct, St Lucia, QLD, AUSTRALIA; Centre for Marine Science and Innovation, University of New South Wales, Sydney, NSW, Australia
| | - David S Schoeman
- Ocean Futures Research Cluster, School of Science, Technology, and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia; Centre for African Conservation Ecology, Department of Zoology, Nelson Mandela University, Gqeberha, South Africa
| | - Craig R White
- School of Biological Sciences and Centre for Geometric Biology, Monash University, Clayton, VIC, Australia
| | - Christopher L Lawson
- School of the Environment, The University of Queensland, Brisbane, QLD, Australia
| | - Simon J Pierce
- Marine Megafauna Foundation, West Palm Beach, FL, USA; School of Science, Technology and Engineering, The University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | | | - Steffen S Bach
- Ramboll, Copenhagen, Denmark; Qatar Whale Shark Research Project, Doha, Qatar
| | - Francesco G Comezzi
- Department of Natural Resources and Environment Tasmania, Marine Resources, Hobart, Tasmania, Australia
| | - Stella Diamant
- Marine Megafauna Foundation, West Palm Beach, FL, USA; Madagascar Whale Shark Project, Nosy Be, Madagascar
| | - Mohammed Y Jaidah
- Qatar Whale Shark Research Project, Doha, Qatar; Sundive Research, Byron Bay, New South Wales, Australia
| | - David P Robinson
- Qatar Whale Shark Research Project, Doha, Qatar; Sundive Research, Byron Bay, New South Wales, Australia
| | - Ross G Dwyer
- School of Science, Technology and Engineering, The University of the Sunshine Coast, Sippy Downs, QLD, Australia
| |
Collapse
|
2
|
Higgins E, Bouyoucos IA, Downie AT, Illing B, Martins APB, Simpfendorfer CA, Rummer JL. How hot is too hot? Thermal tolerance, performance, and preference in juvenile mangrove whiprays, Urogymnus granulatus. J Therm Biol 2024; 124:103943. [PMID: 39151217 DOI: 10.1016/j.jtherbio.2024.103943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 08/01/2024] [Accepted: 08/03/2024] [Indexed: 08/18/2024]
Abstract
Mangrove habitats can serve as nursery areas for sharks and rays. Such environments can be thermally dynamic and extreme; yet, the physiological and behavioural mechanisms sharks and rays use to exploit such habitats are understudied. This study aimed to define the thermal niche of juvenile mangrove whiprays, Urogymnus granulatus. First, temperature tolerance limits were determined via the critical thermal maximum (CTMax) and minimum (CTMin) of mangrove whiprays at summer acclimation temperatures (28 °C), which were 17.5 °C and 39.9 °C, respectively. Then, maximum and routine oxygen uptake rates (ṀO2max and ṀO2routine, respectively), post-exercise oxygen debt, and recovery were estimated at current (28 °C) and heatwave (32 °C) temperatures, revealing moderate temperature sensitivities (i.e., Q10) of 2.4 (ṀO2max) and 1.6 (ṀO2routine), but opposing effects on post-exercise oxygen uptake. Finally, body temperatures (Tb) of mangrove whiprays were recorded using external temperature loggers, and environmental temperatures (Te) were recorded using stationary temperature loggers moored in three habitat zones (mangrove, reef flat, and reef crest). As expected, environmental temperatures varied between sites depending on depth. Individual mangrove whiprays presented significantly lower Tb relative to Te during the hottest times of the day. Electivity analysis showed tagged individuals selected temperatures from 24.0 to 37.0 °C in habitats that ranged from 21.1 to 43.5 °C. These data demonstrate that mangrove whiprays employ thermotaxic behaviours and a thermally insensitive aerobic metabolism to thrive in thermally dynamic and extreme habitats. Tropical nursery areas may, therefore, offer important thermal refugia for young rays. However, these tropical nursery areas could become threatened by mangrove and coral habitat loss, and climate change.
Collapse
Affiliation(s)
- Emily Higgins
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, QLD, Australia
| | - Ian A Bouyoucos
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia; PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, Perpignan, France.
| | - Adam T Downie
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
| | - Björn Illing
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
| | - Ana P B Martins
- Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, QLD, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - Colin A Simpfendorfer
- Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, QLD, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - Jodie L Rummer
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| |
Collapse
|
3
|
Waller MJ, Humphries NE, Womersley FC, Loveridge A, Jeffries AL, Watanabe Y, Payne N, Semmens J, Queiroz N, Southall EJ, Sims DW. The vulnerability of sharks, skates, and rays to ocean deoxygenation: Physiological mechanisms, behavioral responses, and ecological impacts. JOURNAL OF FISH BIOLOGY 2024; 105:482-511. [PMID: 38852616 DOI: 10.1111/jfb.15830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/08/2024] [Accepted: 05/20/2024] [Indexed: 06/11/2024]
Abstract
Levels of dissolved oxygen in open ocean and coastal waters are decreasing (ocean deoxygenation), with poorly understood effects on marine megafauna. All of the more than 1000 species of elasmobranchs (sharks, skates, and rays) are obligate water breathers, with a variety of life-history strategies and oxygen requirements. This review demonstrates that although many elasmobranchs typically avoid hypoxic water, they also appear capable of withstanding mild to moderate hypoxia with changes in activity, ventilatory responses, alterations to circulatory and hematological parameters, and morphological alterations to gill structures. However, such strategies may be insufficient to withstand severe, progressive, or prolonged hypoxia or anoxia where anaerobic metabolic pathways may be used for limited periods. As water temperatures increase with climate warming, ectothermic elasmobranchs will exhibit elevated metabolic rates and are likely to be less able to tolerate the effects of even mild hypoxia associated with deoxygenation. As a result, sustained hypoxic conditions in warmer coastal or surface-pelagic waters are likely to lead to shifts in elasmobranch distributions. Mass mortalities of elasmobranchs linked directly to deoxygenation have only rarely been observed but are likely underreported. One key concern is how reductions in habitat volume as a result of expanding hypoxia resulting from deoxygenation will influence interactions between elasmobranchs and industrial fisheries. Catch per unit of effort of threatened pelagic sharks by longline fisheries, for instance, has been shown to be higher above oxygen minimum zones compared to adjacent, normoxic regions, and attributed to vertical habitat compression of sharks overlapping with increased fishing effort. How a compound stressor such as marine heatwaves alters vulnerability to deoxygenation remains an open question. With over a third of elasmobranch species listed as endangered, a priority for conservation and management now lies in understanding and mitigating ocean deoxygenation effects in addition to population declines already occurring from overfishing.
Collapse
Affiliation(s)
- Matt J Waller
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| | | | | | | | - Amy L Jeffries
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| | - Yuuki Watanabe
- Research Center for Integrative Evolutionary Science, The Graduate University for Advanced Studies, SOKENDAI, Kanagawa, Japan
| | - Nicholas Payne
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Jayson Semmens
- Institue for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Nuno Queiroz
- CIBIO/InBIO, Universidade do Porto, Vairão, Portugal
- BIOPOLIS, Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | | | - David W Sims
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| |
Collapse
|
4
|
Waller MJ, Queiroz N, da Costa I, Cidade T, Loureiro B, Womersley FC, Fontes J, Afonso P, Macena BCL, Loveridge A, Humphries NE, Southall EJ, Sims DW. Direct measurement of cruising and burst swimming speeds of the shortfin mako shark (Isurus oxyrinchus) with estimates of field metabolic rate. JOURNAL OF FISH BIOLOGY 2023; 103:864-883. [PMID: 37395550 PMCID: PMC10952363 DOI: 10.1111/jfb.15475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 07/04/2023]
Abstract
The shortfin mako shark is a large-bodied pursuit predator thought to be capable of the highest swimming speeds of any elasmobranch and potentially one of the highest energetic demands of any marine fish. Nonetheless, few direct speed measurements have been reported for this species. Here, animal-borne bio-loggers attached to two mako sharks were used to provide direct measurements of swimming speeds, kinematics and thermal physiology. Mean sustained (cruising) speed was 0.90 m s-1 (±0.07 s.d.) with a mean tail-beat frequency (TBF) of 0.51 Hz (±0.16 s.d.). The maximum burst speed recorded was 5.02 m s-1 (TBFmax = 3.65 Hz) from a 2 m long female. Burst swimming was sustained for 14 s (mean speed = 2.38 m s-1 ), leading to a 0.24°C increase in white muscle temperature in the 12.5 min after the burst. Routine field metabolic rate was estimated at 185.2 mg O2 kg-1 h-1 (at 18°C ambient temperature). Gliding behaviour (zero TBF) was more frequently observed after periods of high activity, especially after capture when internal (white muscle) temperature approached 21°C (ambient temperature: 18.3°C), indicating gliding probably functions as an energy recovery mechanism and limits further metabolic heat production. The results show shortfin mako sharks generally cruise at speeds similar to other endothermic fish - but faster than ectothermic sharks - with the maximum recorded burst speed being among the highest so far directly measured among sharks, tunas and billfishes. This newly recorded high-oxygen-demand performance of mako sharks suggests it may be particularly vulnerable to habitat loss due to climate-driven ocean deoxygenation.
Collapse
Affiliation(s)
- Matt J. Waller
- Marine Biological AssociationThe LaboratoryPlymouthUK
- Ocean and Earth Science, National Oceanography Centre SouthamptonUniversity of SouthamptonSouthamptonUK
| | - Nuno Queiroz
- Marine Biological AssociationThe LaboratoryPlymouthUK
- CIBIO/InBIO, Universidade do PortoCampus Agrário de Vairão, Rua Padre Armando QuintasVairãoPortugal
| | - Ivo da Costa
- Marine Biological AssociationThe LaboratoryPlymouthUK
- CIBIO/InBIO, Universidade do PortoCampus Agrário de Vairão, Rua Padre Armando QuintasVairãoPortugal
| | - Tiago Cidade
- CIBIO/InBIO, Universidade do PortoCampus Agrário de Vairão, Rua Padre Armando QuintasVairãoPortugal
| | - Bruno Loureiro
- CIBIO/InBIO, Universidade do PortoCampus Agrário de Vairão, Rua Padre Armando QuintasVairãoPortugal
| | - Freya C. Womersley
- Marine Biological AssociationThe LaboratoryPlymouthUK
- Ocean and Earth Science, National Oceanography Centre SouthamptonUniversity of SouthamptonSouthamptonUK
| | - Jorge Fontes
- Institute of Marine Research – IMARUniversidade dos AçoresHortaPortugal
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
| | - Pedro Afonso
- Institute of Marine Research – IMARUniversidade dos AçoresHortaPortugal
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
| | - Bruno C. L. Macena
- Institute of Marine Research – IMARUniversidade dos AçoresHortaPortugal
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
| | | | | | | | - David W. Sims
- Marine Biological AssociationThe LaboratoryPlymouthUK
- Ocean and Earth Science, National Oceanography Centre SouthamptonUniversity of SouthamptonSouthamptonUK
| |
Collapse
|
5
|
Arostegui MC, Muhling B, Culhane E, Dewar H, Koch SS, Braun CD. A shallow scattering layer structures the energy seascape of an open ocean predator. SCIENCE ADVANCES 2023; 9:eadi8200. [PMID: 37792940 PMCID: PMC10550225 DOI: 10.1126/sciadv.adi8200] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023]
Abstract
Large predators frequent the open ocean where subsurface light drives visually based trophic interactions. However, we lack knowledge on how predators achieve energy balance in the unproductive open ocean where prey biomass is minimal in well-lit surface waters but high in dim midwaters in the form of scattering layers. We use an interdisciplinary approach to assess how the bioenergetics of scattering layer forays by a model predator vary across biomes. We show that the mean metabolic cost rate of daytime deep foraging dives to scattering layers decreases as much as 26% from coastal to pelagic biomes. The more favorable energetics offshore are enabled by the addition of a shallow scattering layer that, if not present, would otherwise necessitate costlier dives to deeper layers. The unprecedented importance of this shallow scattering layer challenges assumptions that the globally ubiquitous primary deep scattering layer constitutes the only mesopelagic resource regularly targeted by apex predators.
Collapse
Affiliation(s)
- Martin C. Arostegui
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Barbara Muhling
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, USA
| | - Emmett Culhane
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Heidi Dewar
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, USA
| | - Stephanie S. Koch
- Department of Biological Sciences, Thomas More University, Crestview Hills, KY, USA
| | - Camrin D. Braun
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| |
Collapse
|
6
|
Iliou AS, Vanderwright W, Harding L, Jacoby DMP, Payne NL, Dulvy NK. Tail shape and the swimming speed of sharks. ROYAL SOCIETY OPEN SCIENCE 2023; 10:231127. [PMID: 37830029 PMCID: PMC10565402 DOI: 10.1098/rsos.231127] [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: 08/02/2023] [Accepted: 09/19/2023] [Indexed: 10/14/2023]
Abstract
Trait-based ecology is a rapidly growing approach for developing insights and predictions for data-poor species. Caudal tail fin shape has the potential to reveal much about the energetics, activity and ecology of fishes and can be rapidly measured from field guides, which is particularly helpful for data-sparse species. One outstanding question is whether swimming speed in sharks is related to two morphological traits: caudal fin aspect ratio (CFAR, height2/tail area) and caudal lobe asymmetry ratio (CLAR). We derived both metrics from the species drawings in Sharks of the world (Ebert et al. 2013 Sharks of the world: a fully illustrated guide) and related fin shape to two published datasets of (1) instantaneous swimming speeds (Jacoby et al. 2015 Biol. Lett. 11, 20150781 (doi:10.1098/rsbl.2015.0781)) and (2) cruising speeds (Harding et al. 2021 Funct. Ecol. 35, 1951-1959 (doi:10.1111/1365-2435.13869)) for 28 total unique shark species. Both estimates of swimming speed were positively related to CFAR (and weakly negatively to CLAR). Hence, shark species with larger CFAR and more symmetric tails (low CLAR) tended to be faster-moving and have higher average speeds. This relationship demonstrates the opportunity to use tail shape as an easily measured trait to index shark swimming speed to broader trait-based analyses of ecological function and extinction risk.
Collapse
Affiliation(s)
- Anthony S. Iliou
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Wade Vanderwright
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Lucy Harding
- Department of Zoology, Trinity College Dublin, Dublin D02 PN40, Ireland
| | - David M. P. Jacoby
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - Nicholas L. Payne
- Department of Zoology, Trinity College Dublin, Dublin D02 PN40, Ireland
| | - Nicholas K. Dulvy
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| |
Collapse
|
7
|
Gayford JH, Godfrey H, Whitehead DA. Ontogenetic morphometry of the brown smoothhound shark Mustelus henlei with implications for ecology and evolution. J Morphol 2023; 284:e21608. [PMID: 37458085 DOI: 10.1002/jmor.21608] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/17/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
The central tenet of ecomorphology links ecological and morphological variation through the process of selection. Traditionally used to rationalise morphological differences between taxa, an ecomorphological approach is increasingly being utilised to study morphological differences expressed through ontogeny. Elasmobranchii (sharks, rays and skates) is one clade in which such ontogenetic shifts in body form have been reported. Such studies are limited to a relatively small proportion of total elasmobranch ecological and morphological diversity, and questions remain regarding the extent to which ecological selection are driving observed morphometric trends. In this study, we report ontogenetic growth trajectories obtained via traditional linear morphometrics from a large data set of the brown smoothhound shark (Mustelus henlei). We consider various morphological structures including the caudal, dorsal and pectoral fins, as well as several girth measurements. We use an ecomorphological approach to infer the broad ecological characteristics of this population and refine understanding of the selective forces underlying the evolution of specific morphological structures. We suggest that observed scaling trends in M. henlei are inconsistent with migratory behaviour, but do not contradict a putative trophic niche shift. We also highlight the role of predation pressure and sex-based ecological differences in driving observed trends in morphometry, a factor which has previously been neglected when considering the evolution of body form in sharks.
Collapse
Affiliation(s)
- Joel H Gayford
- Department of Life Sciences, Imperial College London, Ascot, UK
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
- Shark Measurements, London, UK
| | - Hana Godfrey
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
| | - Darren A Whitehead
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, México
| |
Collapse
|
8
|
Lubitz N, Bradley M, Sheaves M, Hammerschlag N, Daly R, Barnett A. The role of context in elucidating drivers of animal movement. Ecol Evol 2022; 12:e9128. [PMID: 35898421 PMCID: PMC9309038 DOI: 10.1002/ece3.9128] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/10/2022] [Accepted: 07/01/2022] [Indexed: 11/26/2022] Open
Abstract
Despite its consequences for ecological processes and population dynamics, intra-specific variability is frequently overlooked in animal movement studies. Consequently, the necessary resolution to reveal drivers of individual movement decisions is often lost as animal movement data are aggregated to infer average or population patterns. Thus, an empirical understanding of why a given movement pattern occurs remains patchy for many taxa, especially in marine systems. Nonetheless, movement is often rationalized as being driven by basic life history requirements, such as acquiring energy (feeding), reproduction, predator-avoidance, and remaining in suitable environmental conditions. However, these life history requirements are central to every individual within a species and thus do not sufficiently account for the high intra-specific variability in movement behavior and hence fail to fully explain the occurrence of multiple movement strategies within a species. Animal movement appears highly context dependent as, for example, within the same location, the behavior of both resident and migratory individuals is driven by life history requirements, such as feeding or reproduction, however different movement strategies are utilized to fulfill them. A systematic taxa-wide approach that, instead of averaging population patterns, incorporates and utilizes intra-specific variability to enable predictions as to which movement patterns can be expected under a certain context, is needed. Here, we use intra-specific variability in elasmobranchs as a case study to introduce a stepwise approach for studying animal movement drivers that is based on a context-dependence framework. We examine relevant literature to illustrate how this context-focused approach can aid in reliably identifying drivers of a specific movement pattern. Ultimately, incorporating behavioral variability in the study of movement drivers can assist in making predictions about behavioral responses to environmental change, overcoming tagging biases, and establishing more efficient conservation measures.
Collapse
Affiliation(s)
- Nicolas Lubitz
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Michael Bradley
- Marine Data Technology HubCollege of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Marcus Sheaves
- Marine Data Technology HubCollege of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Neil Hammerschlag
- Rosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiamiFloridaUSA
| | - Ryan Daly
- Oceanographic Research InstituteDurbanSouth Africa
- South African Institute for Aquatic Biodiversity (SAIAB)MakhandaSouth Africa
| | - Adam Barnett
- Marine Data Technology HubCollege of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| |
Collapse
|
9
|
Di Santo V. EcoPhysioMechanics: Integrating energetics and biomechanics to understand fish locomotion under climate change. Integr Comp Biol 2022; 62:icac095. [PMID: 35759407 PMCID: PMC9494520 DOI: 10.1093/icb/icac095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/05/2022] [Accepted: 06/13/2022] [Indexed: 11/15/2022] Open
Abstract
Ecological physiologists and biomechanists have been broadly investigating swimming performance in a diversity of fishes, however the connection between form, function and energetics of locomotion has been rarely evaluated in the same system and under climate change scenarios. In this perspective I argue that working within the framework of 'EcoPhysioMechanics', i.e., integrating energetics and biomechanics tools, to measure locomotor performance and behavior under different abiotic factors, improves our understanding of the mechanisms, limits and costs of movement. To demonstrate how ecophysiomechanics can be applied to locomotor studies, I outline how linking biomechanics and physiology allows us to understand how fishes may modulate their movement to achieve high speeds or reduce the costs of locomotion. I also discuss how the framework is necessary to quantify swimming capacity under climate change scenarios. Finally, I discuss current dearth of integrative studies and gaps in empirical datasets that are necessary to understand fish swimming under changing environments.
Collapse
Affiliation(s)
- Valentina Di Santo
- Division of Functional Morphology, Department of Zoology, Stockholm University, Svante Arrhenius väg 18B, 11419 Stockholm, Sweden
| |
Collapse
|
10
|
Germanov ES, Pierce SJ, Marshall AD, Hendrawan IG, Kefi A, Bejder L, Loneragan N. Residency, movement patterns, behavior and demographics of reef manta rays in Komodo National Park. PeerJ 2022; 10:e13302. [PMID: 35602898 PMCID: PMC9119296 DOI: 10.7717/peerj.13302] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 03/29/2022] [Indexed: 01/13/2023] Open
Abstract
Background The reef manta ray (Mobula alfredi) is a globally threatened species and an iconic tourist attraction for visitors to Indonesia's Komodo National Park (NP). In 2013, manta ray fishing was banned in Komodo NP and its surroundings, preceding the nationwide manta ray protection in 2014. Over a decade ago, a previous acoustic telemetry study demonstrated that reef manta rays had high fidelity to sites within the park, while more recent photo-identification data indicated that some individuals move up to 450 km elsewhere. Characterization of manta ray demographics, behavior, and a focused assessment on site use of popular tourism locations within the park is vital to assist the Komodo NP Management Authority formulate appropriate manta ray conservation and management policies. Methods This study uses a long-term library (MantaMatcher.org) of photo-identification data collected by researchers and citizen scientists to investigate manta ray demographics and habitat use within the park at four sites frequented by tour operators: Cauldron, Karang Makassar, Mawan, and Manta Alley. Residency and movements of manta rays were investigated with maximum likelihood analyses and Markov movement models. Results A total of 1,085 individual manta rays were identified from photographs dating from 2013 to 2018. In general, individual manta rays displayed a higher affinity to specific sites than others. The highest re-sighting probabilities came from the remote southern site, Manta Alley. Karang Makassar and Mawan are only ~5 km apart; however, manta rays displayed distinct site affinities. Exchange of individuals between Manta Alley and the two central sites (~35.5 km apart) occurred, particularly seasonally. More manta rays were recorded traveling from the south to the central area than vice versa. Female manta rays were more mobile than males. Similar demographic groups used Karang Makassar, Mawan, and Manta Alley for foraging, cleaning, cruising, or courtship activities. Conversely, a higher proportion of immature manta rays used the northern site, Cauldron, where foraging was commonly observed. Fishing gear-related injuries were noted on 56 individuals (~5%), and predatory injuries were present on 32 individuals (~3%). Tourism within the park increased from 2014 to 2017, with 34% more dive boats per survey at Karang Makassar and Mawan. Discussion The Komodo NP contains several distinct critical habitats for manta rays that encompass all demographics and accommodate seasonal manta ray movements. While the present study has not examined population trends, it does provide foundational data for such work. Continued research into manta ray abundance, long-range movements, and identifying and protecting other critical aggregation areas within the region is integral to securing the species' recovery. We provide management recommendations to limit undue pressure on manta rays and their critical habitats from tourism.
Collapse
Affiliation(s)
- Elitza S. Germanov
- Marine Megafauna Foundation, West Palm Beach, Florida, United States of America,Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia,Environmental and Conservation Sciences, Murdoch University, Perth, Western Australia, Australia
| | - Simon J. Pierce
- Marine Megafauna Foundation, West Palm Beach, Florida, United States of America
| | - Andrea D. Marshall
- Marine Megafauna Foundation, West Palm Beach, Florida, United States of America
| | - I. Gede Hendrawan
- Faculty of Marine Sciences and Fisheries, Universitas Udayana, Denpassar, Bali, Indonesia
| | - Ande Kefi
- Komodo National Park, Labuan Bajo, Flores, Indonesia
| | - Lars Bejder
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia,Environmental and Conservation Sciences, Murdoch University, Perth, Western Australia, Australia,Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Honolulu, Hawaii, United States
| | - Neil Loneragan
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia,Environmental and Conservation Sciences, Murdoch University, Perth, Western Australia, Australia,Faculty of Fisheries and Marine Science, Bogor Institute of Agriculture, Bogor, West Java, Indonesia
| |
Collapse
|
11
|
Using Drones to Assess Volitional Swimming Kinematics of Manta Ray Behaviors in the Wild. DRONES 2022. [DOI: 10.3390/drones6050111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Drones have become increasingly popular tools to study marine megafauna but are underutilized in batoid research. We used drones to collect video data of manta ray (Mobula cf. birostris) swimming and assessed behavior-specific kinematics in Kinovea, a semi-automated point-tracking software. We describe a ‘resting’ behavior of mantas making use of strong currents in man-made inlets in addition to known ‘traveling’ and ‘feeding’ behaviors. No significant differences were found between the swimming speed of traveling and feeding behaviors, although feeding mantas had a significantly higher wingbeat frequency than traveling mantas. Resting mantas swam at a significantly slower speed and wingbeat frequency, suggesting that they were continuously swimming with the minimum effort required to maintain position and buoyancy. Swimming speed and wingbeat frequency of traveling and feeding behaviors overlapped, which could point to other factors such as prey availability and a transitional behavior, influencing how manta rays swim. These baseline swimming kinematic data have valuable applications to other emerging technologies in manta ray research.
Collapse
|
12
|
Lawson CL, Dudgeon CL, Richardson AJ, Broadhurst MK, Bennett MB. Flexibility for fuelling reproduction in a pelagic ray (Mobula eregoodoo) suggested by bioenergetic modelling. JOURNAL OF FISH BIOLOGY 2022; 100:783-792. [PMID: 35049041 DOI: 10.1111/jfb.14995] [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: 08/10/2020] [Revised: 10/13/2021] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
This study investigated the measurements of energy density and bioenergetic modelling for a pelagic ray, Mobula eregoodoo, to estimate its relative allocation to various bodily processes and especially reproduction. The data revealed M. eregoodoo uses up to 21.0% and 2.5% of its annual energy budget on growth and reproduction, respectively. During pregnancy, females depleted energy reserves in the liver, which, along with their biennial reproductive cycle, aligns with general theory that ectotherms are capital breeders and thus build energy reserves before reproduction. Nonetheless, the reduction in energy reserves did not account for all reproductive costs, and therefore, gravid females supplement reproductive costs through energy derived from the diet, according to an income-breeding strategy. These characteristics imply that M. eregoodoo exhibits some flexibility in fuelling reproduction depending on energy availability throughout the reproductive cycle, which may be prevalent in other elasmobranchs. The data represent the first estimates of both the metabolic costs of gestation in elasmobranchs and the relative cost of reproduction in rays. Energy costs and plasticity associated with highly variable reproductive strategies in elasmobranchs may influence long-term population viability under a rapidly changing environment.
Collapse
Affiliation(s)
- Christopher L Lawson
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Christine L Dudgeon
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Anthony J Richardson
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere, Queensland Biosciences Precinct (QBP), St Lucia, Queensland, Australia
- Centre for Applications in Natural Resource Mathematics, School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland, Australia
| | - Matt K Broadhurst
- New South Wales Department of Primary Industries, Fisheries Conservation Technology Unit, National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Michael B Bennett
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
| |
Collapse
|
13
|
Aquino‐Baleytó M, Leos‐Barajas V, Adam T, Hoyos‐Padilla M, Santana‐Morales O, Galván‐Magaña F, González‐Armas R, Lowe CG, Ketchum JT, Villalobos H. Diving deeper into the underlying white shark behaviors at Guadalupe Island, Mexico. Ecol Evol 2021; 11:14932-14949. [PMID: 34765151 PMCID: PMC8571628 DOI: 10.1002/ece3.8178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 11/13/2022] Open
Abstract
Fine-scale movement patterns are driven by both biotic (hunting, physiological needs) and abiotic (environmental conditions) factors. The energy balance governs all movement-related strategic decisions.Marine environments can be better understood by considering the vertical component. From 24 acoustic trackings of 10 white sharks in Guadalupe Island, this study linked, for the first time, horizontal and vertical movement data and inferred six different behavioral states along with movement states, through the use of hidden Markov models, which allowed to draw a comprehensive picture of white shark behavior.Traveling was the most frequent state of behavior for white sharks, carried out mainly at night and twilight. In contrast, area-restricted searching was the least used, occurring primarily in daylight hours.Time of day, distance to shore, total shark length, and, to a lesser extent, tide phase affected behavioral states. Chumming activity reversed, in the short term and in a nonpermanent way, the behavioral pattern to a general diel vertical pattern.
Collapse
Affiliation(s)
- Marc Aquino‐Baleytó
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias MarinasLa PazMexico
| | | | - Timo Adam
- University of St AndrewsSt AndrewsUK
| | | | | | - Felipe Galván‐Magaña
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias MarinasLa PazMexico
| | - Rogelio González‐Armas
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias MarinasLa PazMexico
| | - Christopher G. Lowe
- Department of Biological SciencesCalifornia State University Long BeachLong BeachCaliforniaUSA
| | | | - Héctor Villalobos
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias MarinasLa PazMexico
| |
Collapse
|
14
|
Watanabe YY, Goldbogen JA. Too big to study? The biologging approach to understanding the behavioural energetics of ocean giants. J Exp Biol 2021; 224:270831. [PMID: 34232316 DOI: 10.1242/jeb.202747] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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.
Collapse
Affiliation(s)
- Yuuki Y Watanabe
- National Institute of Polar Research, Tachikawa, Tokyo 190-8518, Japan.,Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, Tachikawa, Tokyo 190-8518, Japan
| | - Jeremy A Goldbogen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950, USA
| |
Collapse
|
15
|
Harris JL, Hosegood P, Robinson E, Embling CB, Hilbourne S, Stevens GMW. Fine-scale oceanographic drivers of reef manta ray ( Mobula alfredi) visitation patterns at a feeding aggregation site. Ecol Evol 2021; 11:4588-4604. [PMID: 33976833 PMCID: PMC8093739 DOI: 10.1002/ece3.7357] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/10/2021] [Accepted: 02/18/2021] [Indexed: 12/18/2022] Open
Abstract
Globally, reef manta rays (Mobula alfredi) are in decline and are particularly vulnerable to exploitation and disturbance at aggregation sites. Here, passive acoustic telemetry and a suite of advanced oceanographic technologies were used for the first time to investigate the fine-scale (5-min) influence of oceanographic drivers on the visitation patterns of 19 tagged M. alfredi to a feeding aggregation site at Egmont Atoll in the Chagos Archipelago. Boosted regression trees indicate that tag detection probability increased with the intrusion of cold-water bores propagating up the atoll slope through the narrow lagoon inlet during flood tide, potentially transporting zooplankton from the thermocline. Tag detection probability also increased with warmer near-surface temperature close to low tide, with near-surface currents flowing offshore, and with high levels of backscatter (a proxy of zooplankton biomass). These combinations of processes support the proposition that zooplankton carried from the thermocline into the lagoon during the flood may be pumped back out through the narrow inlet during an ebb tide. These conditions provide temporally limited feeding opportunities for M. alfredi, which are tied on the tides. Results also provide some evidence of the presence of Langmuir Circulation, which transports and concentrates zooplankton, and may partly explain why M. alfredi occasionally remained at the feeding location for longer than that two hours. Identification of these correlations provides unique insight into the dynamic synthesis of fine-scale oceanographic processes which are likely to influence the foraging ecology of M. alfredi at Egmont Atoll, and elsewhere throughout their range.
Collapse
Affiliation(s)
- Joanna L. Harris
- The Manta TrustDorsetUK
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| | - Phil Hosegood
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| | - Edward Robinson
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| | - Clare B. Embling
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| | | | | |
Collapse
|
16
|
Rudd JL, Exeter OM, Hall J, Hall G, Henderson SM, Kerry C, Witt MJ, Hawkes LA. High resolution biologging of breaching by the world's second largest shark species. Sci Rep 2021; 11:5236. [PMID: 33664360 PMCID: PMC7933335 DOI: 10.1038/s41598-021-84670-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 02/11/2021] [Indexed: 12/15/2022] Open
Abstract
Basking sharks, the world's second largest fish, are endangered globally following two centuries of large-scale exploitation for their oily livers. In the northeast Atlantic, they seasonally gather in key sites, including the western Scottish Isles, where they feed on plankton, but their breeding grounds are currently completely unknown. Using high-resolution three-axis accelerometry and depth logging, we present the first direct records of breaching by basking sharks over 41 days. We show that basking sharks breach both during the night and day, starting at approximately 20 m depth and can breach multiple times in short succession. We also present early evidence of potential lateralisation in basking sharks. Given the energetic nature of breaching, it should have an important biological function, but this remains unclear.
Collapse
Affiliation(s)
- Jessica L Rudd
- Hatherly Laboratories, College of Life and Environmental Sciences, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK
| | - Owen M Exeter
- Hatherly Laboratories, College of Life and Environmental Sciences, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK.,Environment and Sustainability Institute, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK.,Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK
| | - Jackie Hall
- Manx Basking Shark Watch, Glen Chass Farmhouse, Glen Chass, Port St Mary, Isle of Man, IM9 5PJ, UK
| | - Graham Hall
- Manx Basking Shark Watch, Glen Chass Farmhouse, Glen Chass, Port St Mary, Isle of Man, IM9 5PJ, UK
| | | | - Christopher Kerry
- Hatherly Laboratories, College of Life and Environmental Sciences, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK.,Environment and Sustainability Institute, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK.,Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK
| | - Matthew J Witt
- Hatherly Laboratories, College of Life and Environmental Sciences, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK. .,Environment and Sustainability Institute, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK.
| | - Lucy A Hawkes
- Hatherly Laboratories, College of Life and Environmental Sciences, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK.,Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK
| |
Collapse
|
17
|
Jorgensen SJ, Micheli F, White TD, Van Houtan KS, Alfaro-Shigueto J, Andrzejaczek S, Arnoldi NS, Baum JK, Block B, Britten GL, Butner C, Caballero S, Cardeñosa D, Chapple TK, Clarke S, Cortés E, Dulvy NK, Fowler S, Gallagher AJ, Gilman E, Godley BJ, Graham RT, Hammerschlag N, Harry AV, Heithaus M, Hutchinson M, Huveneers C, Lowe CG, Lucifora LO, MacKeracher T, Mangel JC, Barbosa Martins AP, McCauley DJ, McClenachan L, Mull C, Natanson LJ, Pauly D, Pazmiño DA, Pistevos JCA, Queiroz N, Roff G, Shea BD, Simpfendorfer CA, Sims DW, Ward-Paige C, Worm B, Ferretti F. Emergent research and priorities for shark and ray conservation. ENDANGER SPECIES RES 2021. [DOI: 10.3354/esr01169] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
18
|
A first look at the metabolic rate of Greenland sharks (Somniosus microcephalus) in the Canadian Arctic. Sci Rep 2020; 10:19297. [PMID: 33168918 PMCID: PMC7653932 DOI: 10.1038/s41598-020-76371-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 10/23/2020] [Indexed: 12/16/2022] Open
Abstract
Metabolic rate is intricately linked to the ecology of organisms and can provide a framework to study the behaviour, life history, population dynamics, and trophic impact of a species. Acquiring measures of metabolic rate, however, has proven difficult for large water-breathing animals such as sharks, greatly limiting our understanding of the energetic lives of these highly threatened and ecologically important fish. Here, we provide the first estimates of resting and active routine metabolic rate for the longest lived vertebrate, the Greenland shark (Somniosus microcephalus). Estimates were acquired through field respirometry conducted on relatively large-bodied sharks (33–126 kg), including the largest individual shark studied via respirometry. We show that despite recording very low whole-animal resting metabolic rates for this species, estimates are within the confidence intervals predicted by derived interspecies allometric and temperature scaling relationships, suggesting this species may not be unique among sharks in this respect. Additionally, our results do not support the theory of metabolic cold adaptation which assumes that polar species maintain elevated metabolic rates to cope with the challenges of life at extreme cold temperatures.
Collapse
|
19
|
Changes in diving behaviour and habitat use of provisioned whale sharks: implications for management. Sci Rep 2020; 10:16951. [PMID: 33046780 PMCID: PMC7550605 DOI: 10.1038/s41598-020-73416-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 09/15/2020] [Indexed: 12/14/2022] Open
Abstract
Whale shark (Rhincodon typus) tourism is increasingly popular at predictable aggregations around the world, but only a few use provisioning to ensure close interactions. Understanding the effects of provisioning on the behaviour of this endangered species is critical to manage this growing industry. We recorded the diving behaviour and habitat use of juvenile whale sharks (n = 4) for a mean of 49.5 provisioned and 33.8 non-provisioned days using temperature-depth-recorders. We found that time spent at the surface (< 2 m) between 6 am and 1 pm increased ~ sixfold, while timing of deep dives shifted from 4–10 am to 10 am–2 pm, i.e. near or at the end of the provisioning activities. The shift might be related to a need to thermoregulate following a prolonged period of time in warmer water. These changes could have fitness implications for individuals frequently visiting the provisioning site. Based on recorded amount of time spent in warm waters and published Q10 values for ectotherms, we estimate a 7.2 ± 3.7% (range 1.3–17.8%) higher metabolic rate when sharks frequent the provisioning site. The observed behavioural, habitat use, and potential fitness shifts should be considered when developing guidelines for sustainable tourism, particularly in light of new provisioning sites developing elsewhere.
Collapse
|
20
|
Andrzejaczek S, Gleiss AC, Lear KO, Pattiaratchi C, Chapple TK, Meekan MG. Depth-dependent dive kinematics suggest cost-efficient foraging strategies by tiger sharks. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200789. [PMID: 32968529 PMCID: PMC7481696 DOI: 10.1098/rsos.200789] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
Tiger sharks, Galeocerdo cuvier, are a keystone, top-order predator that are assumed to engage in cost-efficient movement and foraging patterns. To investigate the extent to which oscillatory diving by tiger sharks conform to these patterns, we used a biologging approach to model their cost of transport. High-resolution biologging tags with tri-axial sensors were deployed on 21 tiger sharks at Ningaloo Reef for durations of 5-48 h. Using overall dynamic body acceleration as a proxy for energy expenditure, we modelled the cost of transport of oscillatory movements of varying geometries in both horizontal and vertical planes for tiger sharks. The cost of horizontal transport was minimized by descending at the smallest possible angle and ascending at an angle of 5-14°, meaning that vertical oscillations conserved energy compared to swimming at a level depth. The reduction of vertical travel costs occurred at steeper angles. The absolute dive angles of tiger sharks increased between inshore and offshore zones, presumably to reduce the cost of transport while continuously hunting for prey in both benthic and surface habitats. Oscillatory movements of tiger sharks conform to strategies of cost-efficient foraging, and shallow inshore habitats appear to be an important habitat for both hunting prey and conserving energy while travelling.
Collapse
Affiliation(s)
- Samantha Andrzejaczek
- Oceans Graduate School and The UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia 6009, Australia
- The Australian Institute of Marine Science, Crawley, Western Australia 6009, Australia
| | - Adrian C. Gleiss
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Karissa O. Lear
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Charitha Pattiaratchi
- Oceans Graduate School and The UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Taylor K. Chapple
- Coastal Oregon Marine Experiment Station, Oregon State University, Newport, OR 97365, USA
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, USA
| | - Mark G. Meekan
- The Australian Institute of Marine Science, Crawley, Western Australia 6009, Australia
| |
Collapse
|
21
|
Cade DE, Levenson JJ, Cooper R, de la Parra R, Webb DH, Dove ADM. Whale sharks increase swimming effort while filter feeding, but appear to maintain high foraging efficiencies. J Exp Biol 2020; 223:jeb224402. [PMID: 32366692 DOI: 10.1242/jeb.224402] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 04/25/2020] [Indexed: 08/26/2023]
Abstract
Whale sharks (Rhincodon typus) - the largest extant fish species - reside in tropical environments, making them an exception to the general rule that animal size increases with latitude. How this largest fish thrives in tropical environments that promote high metabolism but support less robust zooplankton communities has not been sufficiently explained. We used open-source inertial measurement units (IMU) to log 397 h of whale shark behavior in Yucatán, Mexico, at a site of both active feeding and intense wildlife tourism. Here we show that the strategies employed by whale sharks to compensate for the increased drag of an open mouth are similar to ram feeders five orders of magnitude smaller and one order of magnitude larger. Presumed feeding constituted 20% of the total time budget of four sharks, with individual feeding bouts lasting up to 11 consecutive hours. Compared with normal, sub-surface swimming, three sharks increased their stroke rate and amplitude while surface feeding, while one shark that fed at depth did not demonstrate a greatly increased energetic cost. Additionally, based on time-depth budgets, we estimate that aerial surveys of shark populations should consider including a correction factor of 3 to account for the proportion of daylight hours that sharks are not visible at the surface. With foraging bouts generally lasting several hours, interruptions to foraging during critical feeding periods may represent substantial energetic costs to these endangered species, and this study presents baseline data from which management decisions affecting tourist interactions with whale sharks may be made.
Collapse
Affiliation(s)
- David E Cade
- Institute of Marine Science, University of California, Santa Cruz, 115 McAllister Way, Santa Cruz, CA 95060, USA
- Hopkins Marine Station, Stanford University, 120 Ocean View Blvd, Pacific Grove, CA 93950, USA
| | - J Jacob Levenson
- US Department of Interior, Bureau of Ocean Energy Management, 1849 C Street, NW, Washington, DC 20240, USA
| | - Robert Cooper
- Oceans Forward, 17 Hamilton St, Plymouth, MA 02360, USA
| | | | - D Harry Webb
- Research and Conservation Department, Georgia Aquarium, 225 Baker St, Atlanta, GA 30313, USA
| | - Alistair D M Dove
- Research and Conservation Department, Georgia Aquarium, 225 Baker St, Atlanta, GA 30313, USA
| |
Collapse
|