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Beltran RS, Lozano RR, Morris PA, Robinson PW, Holser RR, Keates TR, Favilla AB, Kilpatrick AM, Costa DP. Individual variation in life-history timing: synchronous presence, asynchronous events and phenological compensation in a wild mammal. Proc Biol Sci 2024; 291:20232335. [PMID: 38628129 PMCID: PMC11021928 DOI: 10.1098/rspb.2023.2335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 03/14/2024] [Indexed: 04/19/2024] Open
Abstract
Many animals and plants have species-typical annual cycles, but individuals vary in their timing of life-history events. Individual variation in fur replacement (moult) timing is poorly understood in mammals due to the challenge of repeated observations and longitudinal sampling. We examined factors that influence variation in moult duration and timing among elephant seals (Mirounga angustirostris). We quantified the onset and progression of fur loss in 1178 individuals. We found that an exceptionally rapid visible moult (7 days, the shortest of any mammals or birds), and a wide range of moult start dates (spanning 6-10× the event duration) facilitated high asynchrony across individuals (only 20% of individuals in the population moulting at the same time). Some of the variation was due to reproductive state, as reproductively mature females that skipped a breeding season moulted a week earlier than reproductive females. Moreover, individual variation in timing and duration within age-sex categories far outweighed (76-80%) variation among age-sex categories. Individuals arriving at the end of the moult season spent 50% less time on the beach, which allowed them to catch up in their annual cycles and reduce population-level variance during breeding. These findings underscore the importance of individual variation in annual cycles.
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Affiliation(s)
- Roxanne S. Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Raquel R. Lozano
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Patricia A. Morris
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Patrick W. Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Rachel R. Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Theresa R. Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Arina B. Favilla
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - A. Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95060, USA
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2
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Hoelzel AR, Gkafas GA, Kang H, Sarigol F, Le Boeuf B, Costa DP, Beltran RS, Reiter J, Robinson PW, McInerney N, Seim I, Sun S, Fan G, Li S. Genomics of post-bottleneck recovery in the northern elephant seal. Nat Ecol Evol 2024; 8:686-694. [PMID: 38383849 PMCID: PMC11009102 DOI: 10.1038/s41559-024-02337-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 01/19/2024] [Indexed: 02/23/2024]
Abstract
Populations and species are threatened by human pressure, but their fate is variable. Some depleted populations, such as that of the northern elephant seal (Mirounga angustirostris), recover rapidly even when the surviving population was small. The northern elephant seal was hunted extensively and taken by collectors between the early 1800s and 1892, suffering an extreme population bottleneck as a consequence. Recovery was rapid and now there are over 200,000 individuals. We sequenced 260 modern and 8 historical northern elephant seal nuclear genomes to assess the impact of the population bottleneck on individual northern elephant seals and to better understand their recovery. Here we show that inbreeding, an increase in the frequency of alleles compromised by lost function, and allele frequency distortion, reduced the fitness of breeding males and females, as well as the performance of adult females on foraging migrations. We provide a detailed investigation of the impact of a severe bottleneck on fitness at the genomic level and report on the role of specific gene systems.
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Affiliation(s)
| | - Georgios A Gkafas
- Department of Ichthyology and Aquatic Environment, University of Thessaly, Volos, Greece
| | - Hui Kang
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Innovation Research Center for Aquatic Mammals, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | | | - Burney Le Boeuf
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Daniel P Costa
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Roxanne S Beltran
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Joanne Reiter
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Patrick W Robinson
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Nancy McInerney
- Center for Conservation Genomics, National Zoo and Conservation Biology Institute, Smithsonian Institution, Washington, DC, USA
| | - Inge Seim
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | | | | | - Songhai Li
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.
- Innovation Research Center for Aquatic Mammals, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
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3
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Peterson SH, Peterson MG, Ackerman JT, Debier C, Goetsch C, Holser RR, Hückstädt LA, Johnson JC, Keates TR, McDonald BI, McHuron EA, Costa DP. Foraging behavior and age affect maternal transfer of mercury to northern elephant seal pups. Sci Rep 2024; 14:4693. [PMID: 38409311 PMCID: PMC10897339 DOI: 10.1038/s41598-024-54527-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 02/13/2024] [Indexed: 02/28/2024] Open
Abstract
Deep ocean foraging northern elephant seals (Mirounga angustirostris) consume fish and squid in remote depths of the North Pacific Ocean. Contaminants bioaccumulated from prey are subsequently transferred by adult females to pups during gestation and lactation, linking pups to mercury contamination in mesopelagic food webs (200-1000 m depths). Maternal transfer of mercury to developing seal pups was related to maternal mercury contamination and was strongly correlated with maternal foraging behavior (biotelemetry and isotopes). Mercury concentrations in lanugo (hair grown in utero) were among the highest observed worldwide for young pinnipeds (geometric mean 23.01 μg/g dw, range 8.03-63.09 μg/g dw; n = 373); thus, some pups may be at an elevated risk of sub-lethal adverse health effects. Fetal mercury exposure was affected by maternal foraging geographic location and depth; mercury concentrations were highest in pups of the deepest diving, pelagic females. Moreover, pup lanugo mercury concentrations were strongly repeatable among successive pups of individual females, demonstrating relative consistency in pup mercury exposure based on maternal foraging strategies. Northern elephant seals are biosentinels of a remote deep-sea ecosystem. Our results suggest that mercury within North Pacific mesopelagic food webs may also pose an elevated risk to other mesopelagic-foraging predators and their offspring.
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Affiliation(s)
- Sarah H Peterson
- Western Ecological Research Center, Dixon Field Station, U.S. Geological Survey, 800 Business Park Drive Suite D, Dixon, CA, USA.
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA.
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.
| | - Michael G Peterson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Joshua T Ackerman
- Western Ecological Research Center, Dixon Field Station, U.S. Geological Survey, 800 Business Park Drive Suite D, Dixon, CA, USA
| | - Cathy Debier
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Chandra Goetsch
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- CSS, Inc, Fairfax, VA, USA
| | - Rachel R Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Luis A Hückstädt
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - Jennifer C Johnson
- Moss Landing Marine Labs, San Jose State University, Moss Landing, CA, USA
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | | | - Elizabeth A McHuron
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel P Costa
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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4
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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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5
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Condit R, Hatfield B, Morris PA, Costa DP. Quantifying dispersal between two colonies of northern elephant seals across 17 birth cohorts. PLoS One 2023; 18:e0288921. [PMID: 38032885 PMCID: PMC10688689 DOI: 10.1371/journal.pone.0288921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 07/06/2023] [Indexed: 12/02/2023] Open
Abstract
Dispersal drives extinction-recolonization dynamics of metapopulations and is necessary for endangered species to recolonize former ranges. Yet few studies quantify dispersal and even fewer examine consistency of dispersal over many years. The northern elephant seal (Mirounga angustirostris) provides an example of the importance of dispersal. It quickly recolonized its full range after near extirpation by 19th century hunting, and though dispersal was observed it was not quantified. Here we enumerate lifetime dispersal events among females marked as pups at two colonies during 1994-2010, then correct for detection biases to estimate bidirectional dispersal rates. An average of 16% of females born at the Piedras Blancas colony dispersed northward 200 km to breed at Año Nuevo, while 8.0% of those born at Año Nuevo dispersed southward to Piedras Blancas. The northward rate fluctuated considerably but was higher than southward in 15 of 17 cohorts. The population at Piedras Blancas expanded 15-fold during the study, while Año Nuevo's declined slightly, but the expectation that seals would emigrate away from high density colonies was not supported. During the 1990s, dispersal was higher away from the small colony toward the large. Moreover, cohorts born later at Piedras Blancas, when the colony had grown, dispersed no more than early cohorts. Consistently high natal dispersal in northern elephant seals means the population must be considered a single large unit in terms of response to environmental change. High dispersal was fortuitous to the past recovery of the species, and continued dispersal means elephant seals will likely expand their range further.
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Affiliation(s)
- Richard Condit
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | | | - Patricia A. Morris
- Institute for Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | - Daniel P. Costa
- Institute for Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, United States of America
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6
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Costa DP, Favilla AB. Field physiology in the aquatic realm: ecological energetics and diving behavior provide context for elucidating patterns and deviations. J Exp Biol 2023; 226:jeb245832. [PMID: 37843467 DOI: 10.1242/jeb.245832] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Comparative physiology has developed a rich understanding of the physiological adaptations of organisms, from microbes to megafauna. Despite extreme differences in size and a diversity of habitats, general patterns are observed in their physiological adaptations. Yet, many organisms deviate from the general patterns, providing an opportunity to understand the importance of ecology in determining the evolution of unusual adaptations. Aquatic air-breathing vertebrates provide unique study systems in which the interplay between ecology, physiology and behavior is most evident. They must perform breath-hold dives to obtain food underwater, which imposes a physiological constraint on their foraging time as they must resurface to breathe. This separation of two critical resources has led researchers to investigate these organisms' physiological adaptations and trade-offs. Addressing such questions on large marine animals is best done in the field, given the difficulty of replicating the environment of these animals in the lab. This Review examines the long history of research on diving physiology and behavior. We show how innovative technology and the careful selection of research animals have provided a holistic understanding of diving mammals' physiology, behavior and ecology. We explore the role of the aerobic diving limit, body size, oxygen stores, prey distribution and metabolism. We then identify gaps in our knowledge and suggest areas for future research, pointing out how this research will help conserve these unique animals.
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Affiliation(s)
- Daniel P Costa
- Institute of Marine Sciences, Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95060, USA
| | - Arina B Favilla
- Institute of Marine Sciences, Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95060, USA
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7
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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.
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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
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8
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Pérez-Jorge S, Oliveira C, Rivas EI, Prieto R, Cascão I, Wensveen PJ, Miller PJO, Silva MA. Predictive model of sperm whale prey capture attempts from time-depth data. MOVEMENT ECOLOGY 2023; 11:33. [PMID: 37291674 DOI: 10.1186/s40462-023-00393-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/11/2023] [Indexed: 06/10/2023]
Abstract
BACKGROUND High-resolution sound and movement recording tags offer unprecedented insights into the fine-scale foraging behaviour of cetaceans, especially echolocating odontocetes, enabling the estimation of a series of foraging metrics. However, these tags are expensive, making them inaccessible to most researchers. Time-Depth Recorders (TDRs), which have been widely used to study diving and foraging behaviour of marine mammals, offer a more affordable alternative. Unfortunately, data collected by TDRs are bi-dimensional (time and depth only), so quantifying foraging effort from those data is challenging. METHODS A predictive model of the foraging effort of sperm whales (Physeter macrocephalus) was developed to identify prey capture attempts (PCAs) from time-depth data. Data from high-resolution acoustic and movement recording tags deployed on 12 sperm whales were downsampled to 1 Hz to match the typical TDR sampling resolution and used to predict the number of buzzes (i.e., rapid series of echolocation clicks indicative of PCAs). Generalized linear mixed models were built for dive segments of different durations (30, 60, 180 and 300 s) using multiple dive metrics as potential predictors of PCAs. RESULTS Average depth, variance of depth and variance of vertical velocity were the best predictors of the number of buzzes. Sensitivity analysis showed that models with segments of 180 s had the best overall predictive performance, with a good area under the curve value (0.78 ± 0.05), high sensitivity (0.93 ± 0.06) and high specificity (0.64 ± 0.14). Models using 180 s segments had a small difference between observed and predicted number of buzzes per dive, with a median of 4 buzzes, representing a difference in predicted buzzes of 30%. CONCLUSIONS These results demonstrate that it is possible to obtain a fine-scale, accurate index of sperm whale PCAs from time-depth data alone. This work helps leveraging the potential of time-depth data for studying the foraging ecology of sperm whales and the possibility of applying this approach to a wide range of echolocating cetaceans. The development of accurate foraging indices from low-cost, easily accessible TDR data would contribute to democratize this type of research, promote long-term studies of various species in several locations, and enable analyses of historical datasets to investigate changes in cetacean foraging activity.
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Affiliation(s)
- Sergi Pérez-Jorge
- Institute of Marine Sciences - OKEANOS & Institute of Marine Research - IMAR, University of the Azores, Horta, Portugal.
| | - Cláudia Oliveira
- Institute of Marine Sciences - OKEANOS & Institute of Marine Research - IMAR, University of the Azores, Horta, Portugal
| | | | - Rui Prieto
- Institute of Marine Sciences - OKEANOS & Institute of Marine Research - IMAR, University of the Azores, Horta, Portugal
| | - Irma Cascão
- Institute of Marine Sciences - OKEANOS & Institute of Marine Research - IMAR, University of the Azores, Horta, Portugal
| | - Paul J Wensveen
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavik, Iceland
| | - Patrick J O Miller
- Sea Mammal Research Unit, School of Biology, University of St Andrews, St Andrews, Scotland
| | - Mónica A Silva
- Institute of Marine Sciences - OKEANOS & Institute of Marine Research - IMAR, University of the Azores, Horta, Portugal
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9
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Holser RR, Crocker DE, Favilla AR, Adachi T, Keates TR, Naito Y, Costa DP. Effects of disease on foraging behaviour and success in an individual free-ranging northern elephant seal. CONSERVATION PHYSIOLOGY 2023; 11:coad034. [PMID: 37250476 PMCID: PMC10214463 DOI: 10.1093/conphys/coad034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 04/14/2023] [Accepted: 05/17/2023] [Indexed: 05/31/2023]
Abstract
Evaluating consequences of stressors on vital rates in marine mammals is of considerable interest to scientific and regulatory bodies. Many of these species face numerous anthropogenic and environmental disturbances. Despite its importance as a critical form of mortality, little is known about disease progression in air-breathing marine megafauna at sea. We examined the movement, diving, foraging behaviour and physiological state of an adult female northern elephant seal (Mirounga angustirostris) who suffered from an infection while at sea. Comparing her to healthy individuals, we identified abnormal behavioural patterns from high-resolution biologging instruments that are likely indicators of diseased and deteriorating condition. We observed continuous extended (3-30 minutes) surface intervals coinciding with almost no foraging attempts (jaw motion) during 2 weeks of acute illness early in her post-breeding foraging trip. Elephant seals typically spend ~ 2 minutes at the surface. There were less frequent but highly extended (30-200 minutes) surface periods across the remainder of the trip. Dive duration declined throughout the trip rather than increasing. This seal returned in the poorest body condition recorded for an adult female elephant seal (18.3% adipose tissue; post-breeding trip average is 30.4%). She was immunocompromised at the end of her foraging trip and has not been seen since that moulting season. The timing and severity of the illness, which began during the end of the energy-intensive lactation fast, forced this animal over a tipping point from which she could not recover. Additional physiological constraints to foraging, including thermoregulation and oxygen consumption, likely exacerbated her already poor condition. These findings improve our understanding of illness in free-ranging air-breathing marine megafauna, demonstrate the vulnerability of individuals at critical points in their life history, highlight the importance of considering individual health when interpreting biologging data and could help differentiate between malnutrition and other causes of at-sea mortality from transmitted data.
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Affiliation(s)
- Rachel R Holser
- Corresponding author: Institute of Marine Sciences, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA. Tel.: +1 253-514-0110.
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, California, 94928, USA
| | - Arina R Favilla
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, 95064 USA
| | - Taiki Adachi
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, 95064 USA
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California, 95064, USA
| | - Yasuhiko Naito
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
| | - Daniel P Costa
- Institute of Marine Sciences, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, 95064 USA
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10
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Kendall-Bar JM, Williams TM, Mukherji R, Lozano DA, Pitman JK, Holser RR, Keates T, Beltran RS, Robinson PW, Crocker DE, Adachi T, Lyamin OI, Vyssotski AL, Costa DP. Brain activity of diving seals reveals short sleep cycles at depth. Science 2023; 380:260-265. [PMID: 37079694 DOI: 10.1126/science.adf0566] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Sleep is a crucial part of the daily activity patterns of mammals. However, in marine species that spend months or entire lifetimes at sea, the location, timing, and duration of sleep may be constrained. To understand how marine mammals satisfy their daily sleep requirements while at sea, we monitored electroencephalographic activity in wild northern elephant seals (Mirounga angustirostris) diving in Monterey Bay, California. Brain-wave patterns showed that seals took short (less than 20 minutes) naps while diving (maximum depth 377 meters; 104 sleeping dives). Linking these patterns to accelerometry and the time-depth profiles of 334 free-ranging seals (514,406 sleeping dives) revealed a North Pacific sleepscape in which seals averaged only 2 hours of sleep per day for 7 months, rivaling the record for the least sleep among all mammals, which is currently held by the African elephant (about 2 hours per day).
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Affiliation(s)
- Jessica M Kendall-Bar
- Scripps Institution of Oceanography, University of California San Diego, San Diego, CA, USA
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Terrie M Williams
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Ritika Mukherji
- Department of Neuroscience, University of Oxford, Oxford, UK
| | - Daniel A Lozano
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | | | - Rachel R Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Theresa Keates
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Roxanne S Beltran
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Patrick W Robinson
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| | - Taiki Adachi
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Oleg I Lyamin
- Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA, USA
- A.N. Severtsov Institute of Ecology and Evolution, Moscow, Russia
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich and Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Daniel P Costa
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
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11
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Peterson SH, Ackerman JT, Holser RR, McDonald BI, Costa DP, Crocker DE. Mercury Bioaccumulation and Cortisol Interact to Influence Endocrine and Immune Biomarkers in a Free-Ranging Marine Mammal. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5678-5692. [PMID: 36996077 DOI: 10.1021/acs.est.2c08974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Mercury bioaccumulation from deep-ocean prey and the extreme life history strategies of adult female northern elephant seals (Mirounga angustirostris) provide a unique system to assess the interactive effects of mercury and stress on animal health by quantifying blood biomarkers in relation to mercury (skeletal muscle and blood mercury) and cortisol concentrations. The thyroid hormone thyroxine (tT4) and the antibody immunoglobulin E (IgE) were associated with mercury and cortisol concentrations interactively, where the magnitude and direction of the association of each biomarker with mercury or cortisol changed depending on the concentration of the other factor. For example, when cortisol concentrations were lowest, tT4 was positively related to muscle mercury, whereas tT4 had a negative relationship with muscle mercury in seals that had the highest cortisol concentrations. Additionally, we observed that two thyroid hormones, triiodothyronine (tT3) and reverse triiodothyronine (rT3), were negatively (tT3) and positively (rT3) associated with mercury concentrations and cortisol in an additive manner. As an example, tT3 concentrations in late breeding seals at the median cortisol concentration decreased by 14% across the range of observed muscle mercury concentrations. We also observed that immunoglobulin M (IgM), the pro-inflammatory cytokine IL-6 (IL-6), and a reproductive hormone, estradiol, were negatively related to muscle mercury concentrations but were not related to cortisol. Specifically, estradiol concentrations in late molting seals decreased by 50% across the range of muscle mercury concentrations. These results indicate important physiological effects of mercury on free-ranging apex marine predators and interactions between mercury bioaccumulation and extrinsic stressors. Deleterious effects on animals' abilities to maintain homeostasis (thyroid hormones), fight off pathogens and disease (innate and adaptive immune system), and successfully reproduce (endocrine system) can have significant individual- and population-level consequences.
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Affiliation(s)
- Sarah H Peterson
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, California 95620, United States of America
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California 95064, United States of America
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California 95064, United States of America
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, California 95620, United States of America
| | - Rachel R Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California 95064, United States of America
| | - Birgitte I McDonald
- Moss Landing Marine Labs, San Jose State University, Moss Landing, California 95039, United States of America
| | - Daniel P Costa
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California 95064, United States of America
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California 95064, United States of America
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, California 94928, United States of America
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12
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Adachi T, Lovell P, Turnbull J, Fedak MA, Picard B, Guinet C, Biuw M, Keates TR, Holser RR, Costa DP, Crocker DE, Miller PJO. Body condition changes at sea: Onboard calculation and telemetry of body density in diving animals. Methods Ecol Evol 2023. [DOI: 10.1111/2041-210x.14089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Affiliation(s)
- Taiki Adachi
- Sea Mammal Research Unit University of St Andrews St Andrews UK
- Department of Ecology and Evolutionary Biology University of California Santa Cruz Santa Cruz California USA
| | - Philip Lovell
- Sea Mammal Research Unit University of St Andrews St Andrews UK
| | - James Turnbull
- Sea Mammal Research Unit University of St Andrews St Andrews UK
| | - Mike A. Fedak
- Sea Mammal Research Unit University of St Andrews St Andrews UK
| | - Baptiste Picard
- CNRS Centre of Biology Studies of Chizé Villiers‐en‐Bois France
| | | | | | - Theresa R. Keates
- Department of Ocean Sciences University of California Santa Cruz Santa Cruz California USA
| | - Rachel R. Holser
- Institute of Marine Sciences, University of California Santa Cruz Santa Cruz California USA
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology University of California Santa Cruz Santa Cruz California USA
- Institute of Marine Sciences, University of California Santa Cruz Santa Cruz California USA
| | - Daniel E. Crocker
- Department of Biology Sonoma State University Rohnert Park California USA
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13
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Beltran RS, Hernandez KM, Condit R, Robinson PW, Crocker DE, Goetsch C, Kilpatrick AM, Costa DP. Physiological tipping points in the relationship between foraging success and lifetime fitness of a long-lived mammal. Ecol Lett 2023; 26:706-716. [PMID: 36888564 DOI: 10.1111/ele.14193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 03/09/2023]
Abstract
Although anthropogenic change is often gradual, the impacts on animal populations may be precipitous if physiological processes create tipping points between energy gain, reproduction or survival. We use 25 years of behavioural, diet and demographic data from elephant seals to characterise their relationships with lifetime fitness. Survival and reproduction increased with mass gain during long foraging trips preceding the pupping seasons, and there was a threshold where individuals that gained an additional 4.8% of their body mass (26 kg, from 206 to 232 kg) increased lifetime reproductive success three-fold (from 1.8 to 4.9 pups). This was due to a two-fold increase in pupping probability (30% to 76%) and a 7% increase in reproductive lifespan (6.0 to 6.4 years). The sharp threshold between mass gain and reproduction may explain reproductive failure observed in many species and demonstrates how small, gradual reductions in prey from anthropogenic disturbance could have profound implications for animal populations.
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Affiliation(s)
- Roxanne S Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Keith M Hernandez
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA.,Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, USA
| | - Richard Condit
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, California, USA
| | - Chandra Goetsch
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - A Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA.,Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, USA
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14
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Guo X, Cui Y, Irwin DM, Liu Y. Accelerated evolution of dim-light vision-related arrestin in deep-diving amniotes. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1069088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Arrestins are key molecules involved in the signaling of light-sensation initiated by visual pigments in retinal photoreceptor cells. Vertebrate photoreceptor cells have two types of arrestins, rod arrestin, which is encoded by SAG and is expressed in both rods and cones, and cone arrestin, encoded by ARR3 in cones. The arrestins can bind to visual pigments, and thus regulate either dim-light vision via interactions with rhodopsin or bright-light vision together with cone visual pigments. After adapting to terrestrial life, several amniote lineages independently went back to the sea and evolved deep-diving habits. Interestingly, the rhodopsins in these species exhibit specialized phenotypes responding to rapidly changing dim-light environments. However, little is known about whether their rod arrestin also experienced adaptive evolution associated with rhodopsin. Here, we collected SAG coding sequences from >250 amniote species, and examined changes in selective pressure experienced by the sequences from deep-diving taxa. Divergent patterns of evolution of SAG were observed in the penguin, pinniped and cetacean clades, suggesting possible co-adaptation with rhodopsin. After verifying pseudogenes, the same analyses were performed for cone arrestin (ARR3) in deep-diving species and only sequences from cetacean species, and not pinnipeds or penguins, have experienced changed selection pressure compared to other species. Taken together, this evidence for changes in selective pressures acting upon arrestin genes strengthens the suggestion that rapid dim-light adaptation for deep-diving amniotes require SAG, but not ARR3.
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15
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Raab T, Madhav MS, Jayakumar RP, Henninger J, Cowan NJ, Benda J. Advances in non-invasive tracking of wave-type electric fish in natural and laboratory settings. Front Integr Neurosci 2022; 16:965211. [PMID: 36118117 PMCID: PMC9478915 DOI: 10.3389/fnint.2022.965211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/10/2022] [Indexed: 11/15/2022] Open
Abstract
Recent technological advances greatly improved the possibility to study freely behaving animals in natural conditions. However, many systems still rely on animal-mounted devices, which can already bias behavioral observations. Alternatively, animal behaviors can be detected and tracked in recordings of stationary sensors, e.g., video cameras. While these approaches circumvent the influence of animal-mounted devices, identification of individuals is much more challenging. We take advantage of the individual-specific electric fields electric fish generate by discharging their electric organ (EOD) to record and track their movement and communication behaviors without interfering with the animals themselves. EODs of complete groups of fish can be recorded with electrode arrays submerged in the water and then be tracked for individual fish. Here, we present an improved algorithm for tracking electric signals of wave-type electric fish. Our algorithm benefits from combining and refining previous approaches of tracking individual specific EOD frequencies and spatial electric field properties. In this process, the similarity of signal pairs in extended data windows determines their tracking order, making the algorithm more robust against detection losses and intersections. We quantify the performance of the algorithm and show its application for a data set recorded with an array of 64 electrodes distributed over a 12 m2 section of a stream in the Llanos, Colombia, where we managed, for the first time, to track Apteronotus leptorhynchus over many days. These technological advances make electric fish a unique model system for a detailed analysis of social and communication behaviors, with strong implications for our research on sensory coding.
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Affiliation(s)
- Till Raab
- Department for Neuroethology, Institute for Neurobiology, Eberhard Karls Universität, Tübingen, Germany
- Centre for Integrative Neuroscience, Eberhard Karls Universität, Tübingen, Germany
- *Correspondence: Till Raab
| | - Manu S. Madhav
- Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, United States
| | | | - Jörg Henninger
- Charité-Universitätsmedizin Berlin, Einstein Center for Neurosciences, NeuroCure Cluster of Excellence, Berlin, Germany
| | - Noah J. Cowan
- Mechanical Engineering Department, Johns Hopkins University, Baltimore, MD, United States
| | - Jan Benda
- Department for Neuroethology, Institute for Neurobiology, Eberhard Karls Universität, Tübingen, Germany
- Centre for Integrative Neuroscience, Eberhard Karls Universität, Tübingen, Germany
- Bernstein Centre for Computational Neuroscience, Eberhard Karls Universität, Tübingen, Germany
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16
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Whiskers as hydrodynamic prey sensors in foraging seals. Proc Natl Acad Sci U S A 2022; 119:e2119502119. [PMID: 35696561 PMCID: PMC9231483 DOI: 10.1073/pnas.2119502119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unlike humans, most mammals have mobile facial whiskers, yet their natural movement and function are unknown due to observational difficulties, even in well-studied terrestrial whisker specialists (rodents). We report a remarkable case of whiskers contributing to mammal foraging in an extreme underwater environment: the deep, dark ocean. Our animal-borne video cameras revealed that elephant seals captured moving prey by sensing water movement. Their whiskers extended forward ahead of the mouth. Seals performed rhythmic whisker movement to search for hydrodynamic cues, a whisker movement homologous to terrestrial mammals exploring their environment. Based on direct observations, we show how deep-diving seals locate their prey without the biosonar used by whales, revealing another mammalian adaptation to complete darkness. The darkness of the deep ocean limits the vision of diving predators, except when prey emit bioluminescence. It is hypothesized that deep-diving seals rely on highly developed whiskers to locate their prey. However, if and how seals use their whiskers while foraging in natural conditions remains unknown. We used animal-borne tags to show that free-ranging elephant seals use their whiskers for hydrodynamic prey sensing. Small, cheek-mounted video loggers documented seals actively protracting their whiskers in front of their mouths with rhythmic whisker movement, like terrestrial mammals exploring their environment. Seals focused their sensing effort at deep foraging depths, performing prolonged whisker protraction to detect, pursue, and capture prey. Feeding-event recorders with light sensors demonstrated that bioluminescence contributed to only about 20% of overall foraging success, confirming that whiskers play the primary role in sensing prey. Accordingly, visual prey detection complemented and enhanced prey capture. The whiskers’ role highlights an evolutionary alternative to echolocation for adapting to the extreme dark of the deep ocean environment, revealing how sensory abilities shape foraging niche segregation in deep-diving mammals. Mammals typically have mobile facial whiskers, and our study reveals the significant function of whiskers in the natural foraging behavior of a marine predator. We demonstrate the importance of field-based sensory studies incorporating multimodality to better understand how multiple sensory systems are complementary in shaping the foraging success of predators.
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17
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Knochel AM, Hussey NE, Kessel ST, Braun CD, Cochran JEM, Hill G, Klaus R, Checkchak T, Elamin El Hassen NM, Younnis M, Berumen ML. Home sweet home: spatiotemporal distribution and site fidelity of the reef manta ray (Mobula alfredi) in Dungonab Bay, Sudan. MOVEMENT ECOLOGY 2022; 10:22. [PMID: 35484613 PMCID: PMC9052681 DOI: 10.1186/s40462-022-00314-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 03/16/2022] [Indexed: 05/08/2023]
Abstract
BACKGROUND Reef manta ray (Mobula alfredi) populations along the Northeastern African coastline are poorly studied. Identifying critical habitats for this species is essential for future research and conservation efforts. Dungonab Bay and Mukkawar Island National Park (DMNP), a component of a UNESCO World Heritage Site in Sudan, hosts the largest known M. alfredi aggregation in the Red Sea. METHODS A total of 19 individuals were tagged using surgically implanted acoustic tags and tracked within DMNP on an array of 15 strategically placed acoustic receivers in addition to two offshore receivers. Two of these acoustically monitored M. alfredi were also equipped with satellite linked archival tags and one individual was fitted with a satellite transmitting tag. Together, these data are used to describe approximately two years of residency and seasonal shifts in habitat use. RESULTS Tagged individuals were detected within the array on 96% of monitored days and recorded an average residence index of 0.39 across all receivers. Detections were recorded throughout the year, though some individuals were absent from the receiver array for weeks or months at a time, and generalized additive mixed models showed a clear seasonal pattern in presence with the highest probabilities of detection occurring in boreal fall. The models indicated that M. alfredi presence was highly correlated with increasing chlorophyll-a levels and weakly correlated with the full moon. Modeled biological factors, including sex and wingspan, had no influence on animal presence. Despite the high residency suggested by acoustic telemetry, satellite tag data and offshore acoustic detections in Sanganeb Atoll and Suedi Pass recorded individuals moving up to 125 km from the Bay. However, all these individuals were subsequently detected in the Bay, suggesting a strong degree of site fidelity at this location. CONCLUSIONS The current study adds to growing evidence that M. alfredi are highly resident and site-attached to coastal bays and lagoons but display seasonal shifts in habitat use that are likely driven by resource availability. This information can be used to assist in managing and supporting sustainable ecotourism within the DMNP, part of a recently designated UNESCO World Heritage Site.
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Affiliation(s)
- Anna M Knochel
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia.
| | - Nigel E Hussey
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada
- Equipe Cousteau, Paris, France
| | - Steven T Kessel
- Equipe Cousteau, Paris, France
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL, 60605, USA
| | - Camrin D Braun
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Jesse E M Cochran
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia
| | | | | | | | | | | | - Michael L Berumen
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia
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18
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Chouvelon T, Munschy C, Bruzac S, Caurant F, Churlaud C, Crochet S, Guillou G, Mauffret A, Méndez-Fernandez P, Niol J, Sireau T, Steinberg C, Wessel N, Spitz J. High inter-species variability in elemental composition of the twilight zone fauna varies implications for predators and exploitation by humans. ENVIRONMENTAL RESEARCH 2022; 204:112379. [PMID: 34780788 DOI: 10.1016/j.envres.2021.112379] [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: 08/02/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
While the importance of oceanic micronektonic species in biogeochemical cycles and in the transfer of matter in food webs is globally recognized, specific knowledge on elemental concentrations and their variability within this community is still poorly documented. Here, we report for the first time in the Bay of Biscay, North-East Atlantic, the body composition in various biological parameters and chemical elements of a meso-to bathypelagic micronektonic community. Stable carbon and nitrogen isotope compositions (δ13C, δ15N), C:N ratios, energy density, as well as the concentrations in 6 macro-minerals and 13 trace elements including essential (micro-nutrients) and non-essential elements (undesirables, with no know biological function) were measured in whole organisms of 4 crustacean and 11 fish species caught simultaneously around 800 m depth. The results showed a low variability of δ13C values, confirming that all studied species share the same habitat. On the contrary, large differences were observed among species for several elements. Trace elements showed the greatest variability (i.e. larger range of values), especially silver (Ag), arsenic (As), cadmium (Cd), cobalt and vanadium. Significant differences were also revealed among taxa for Ag, As, Cd, copper and strontium concentrations (with crustaceans > fish), as well as for δ15N values and phosphorus concentrations (with fish > crustaceans). Although concentrations varied greatly among species, they could be grouped according to their energy density and composition in 19 chemical elements, through hierarchical clustering analysis. Six functional groups of species have been thus identified, reflecting contrasted nutritional benefit and/or exposure to undesirables for predators feeding on this deep pelagic community. Finally, the concentrations measured for the potentially toxic trace elements (undesirables) exceeded the existing European thresholds for Cd and to a lesser extent mercury (Hg), which point out potential risks in the perspective of a future exploitation of these deep living resources by humans.
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Affiliation(s)
- Tiphaine Chouvelon
- Observatoire Pelagis, UMS 3462 La Rochelle Université/CNRS, 5 Allées de L'Océan, 17000, La Rochelle, France; Ifremer, Unité Biogéochimie et Écotoxicologie, Laboratoire de Biogéochimie des Contaminants Métalliques (BE/LBCM), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France.
| | - Catherine Munschy
- Ifremer, Unité Biogéochimie et Écotoxicologie, Laboratoire de Biogéochimie des Contaminants Organiques (BE/LBCO), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Sandrine Bruzac
- Ifremer, Unité Biogéochimie et Écotoxicologie, Laboratoire de Biogéochimie des Contaminants Métalliques (BE/LBCM), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Florence Caurant
- Observatoire Pelagis, UMS 3462 La Rochelle Université/CNRS, 5 Allées de L'Océan, 17000, La Rochelle, France; Centre D'Etudes Biologiques de Chizé (CEBC), UMR 7372 La Rochelle Université/CNRS, 405 Route de Prissé La Charrière, 79360, Villiers-en-Bois, France
| | - Carine Churlaud
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 La Rochelle Université/CNRS, 2 Rue Olympe de Gouges, 17000, La Rochelle, France
| | - Sylvette Crochet
- Ifremer, Unité Biogéochimie et Écotoxicologie, Laboratoire de Biogéochimie des Contaminants Métalliques (BE/LBCM), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Gaël Guillou
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 La Rochelle Université/CNRS, 2 Rue Olympe de Gouges, 17000, La Rochelle, France
| | - Aourell Mauffret
- Ifremer, Unité Biogéochimie et Écotoxicologie (BE), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Paula Méndez-Fernandez
- Observatoire Pelagis, UMS 3462 La Rochelle Université/CNRS, 5 Allées de L'Océan, 17000, La Rochelle, France
| | - Jasmin Niol
- Observatoire Pelagis, UMS 3462 La Rochelle Université/CNRS, 5 Allées de L'Océan, 17000, La Rochelle, France
| | - Teddy Sireau
- Ifremer, Unité Biogéochimie et Écotoxicologie, Laboratoire de Biogéochimie des Contaminants Métalliques (BE/LBCM), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Claire Steinberg
- Ifremer, Unité Biogéochimie et Écotoxicologie, Laboratoire de Biogéochimie des Contaminants Métalliques (BE/LBCM), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Nathalie Wessel
- Ifremer, Service Valorisation de L'Information pour La Gestion Intégrée et La Surveillance (VIGIES), Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Jérôme Spitz
- Observatoire Pelagis, UMS 3462 La Rochelle Université/CNRS, 5 Allées de L'Océan, 17000, La Rochelle, France; Centre D'Etudes Biologiques de Chizé (CEBC), UMR 7372 La Rochelle Université/CNRS, 405 Route de Prissé La Charrière, 79360, Villiers-en-Bois, France
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Khudyakov JI, Holser RR, Vierra CA, Ly ST, Niel TK, Hasan BM, Crocker DE, Costa DP. Changes in apolipoprotein abundance dominate proteome responses to prolonged fasting in elephant seals. J Exp Biol 2022; 225:274459. [DOI: 10.1242/jeb.243572] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 01/27/2022] [Indexed: 01/10/2023]
Abstract
ABSTRACT
Unlike many animals that reduce activity during fasting, northern elephant seals (NES) undergo prolonged fasting during energy-intensive life-history stages such as reproduction and molting, fueling fasting energy needs by mobilizing fat stores accrued during foraging. NES display several unique metabolic features such as high fasting metabolic rates, elevated blood lipid and high-density lipoprotein (HDL) cholesterol levels, efficient protein sparing and resistance to oxidative stress during fasting. However, the cellular mechanisms that regulate these adaptations are still not fully understood. To examine how metabolic coordination is achieved during prolonged fasting, we profiled changes in blubber, skeletal muscle and plasma proteomes of adult female NES over a 5 week fast associated with molting. We found that while blubber and muscle proteomes were remarkably stable over fasting, over 50 proteins changed in abundance in plasma, including those associated with lipid storage, mobilization, oxidation and transport. Apolipoproteins dominated the blubber, plasma and muscle proteome responses to fasting. APOA4, APOE and APOC3, which are associated with lipogenesis and triglyceride accumulation, decreased, while APOA1, APOA2 and APOM, which are associated with lipid mobilization and HDL function, increased over fasting. Our findings suggest that changes in apolipoprotein composition may underlie the maintenance of high HDL levels and, together with adipokines and hepatokines that facilitate lipid catabolism, may mediate the metabolic transitions between feeding and fasting in NES. Many of these proteins have not been previously studied in this species and provide intriguing hypotheses about metabolic regulation during prolonged fasting in mammals.
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Affiliation(s)
- Jane I. Khudyakov
- Biological Sciences Department, University of the Pacific, Stockton, CA 95211, USA
| | - Rachel R. Holser
- Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA
| | - Craig A. Vierra
- Biological Sciences Department, University of the Pacific, Stockton, CA 95211, USA
| | - Serena T. Ly
- Biological Sciences Department, University of the Pacific, Stockton, CA 95211, USA
| | - Theron K. Niel
- Biological Sciences Department, University of the Pacific, Stockton, CA 95211, USA
| | - Basma M. Hasan
- Biological Sciences Department, University of the Pacific, Stockton, CA 95211, USA
| | - Daniel E. Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA 94928, USA
| | - Daniel P. Costa
- Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA
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20
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Beltran RS, Yuen AL, Condit R, Robinson PW, Czapanskiy MF, Crocker DE, Costa DP. Elephant seals time their long-distance migrations using a map sense. Curr Biol 2022; 32:R156-R157. [DOI: 10.1016/j.cub.2022.01.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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21
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Braun CD, Arostegui MC, Thorrold SR, Papastamatiou YP, Gaube P, Fontes J, Afonso P. The Functional and Ecological Significance of Deep Diving by Large Marine Predators. ANNUAL REVIEW OF MARINE SCIENCE 2022; 14:129-159. [PMID: 34416123 DOI: 10.1146/annurev-marine-032521-103517] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Many large marine predators make excursions from surface waters to the deep ocean below 200 m. Moreover, the ability to access meso- and bathypelagic habitats has evolved independently across marine mammals, reptiles, birds, teleost fishes, and elasmobranchs. Theoretical and empirical evidence suggests a number of plausible functional hypotheses for deep-diving behavior. Developing ways to test among these hypotheses will, however, require new ways to quantify animal behavior and biophysical oceanographic processes at coherent spatiotemporal scales. Current knowledge gaps include quantifying ecological links between surface waters and mesopelagic habitats and the value of ecosystem services provided by biomass in the ocean twilight zone. Growing pressure for ocean twilight zone fisheries creates an urgent need to understand the importance of the deep pelagic ocean to large marine predators.
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Affiliation(s)
- Camrin D Braun
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Martin C Arostegui
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
- Air-Sea Interaction and Remote Sensing Department, Applied Physics Laboratory, University of Washington, Seattle, Washington 98105, USA
| | - Simon R Thorrold
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
| | - Yannis P Papastamatiou
- Institute of Environment, Department of Biological Sciences, Florida International University, Miami, Florida 33181, USA
| | - Peter Gaube
- Air-Sea Interaction and Remote Sensing Department, Applied Physics Laboratory, University of Washington, Seattle, Washington 98105, USA
| | - Jorge Fontes
- Okeanos and Institute of Marine Research, University of the Azores, 9901-862 Horta, Portugal
| | - Pedro Afonso
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
- Okeanos and Institute of Marine Research, University of the Azores, 9901-862 Horta, Portugal
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22
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Kienle SS, Friedlaender AS, Crocker DE, Mehta RS, Costa DP. Trade-offs between foraging reward and mortality risk drive sex-specific foraging strategies in sexually dimorphic northern elephant seals. ROYAL SOCIETY OPEN SCIENCE 2022; 9:210522. [PMID: 35116140 PMCID: PMC8767210 DOI: 10.1098/rsos.210522] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 12/14/2021] [Indexed: 05/04/2023]
Abstract
Sex-specific phenotypic differences are widespread throughout the animal kingdom. Reproductive advantages provided by trait differences come at a cost. Here, we link sex-specific foraging strategies to trade-offs between foraging reward and mortality risk in sexually dimorphic northern elephant seals (Mirounga angustirostris). We analyse a decadal dataset on movement patterns, dive behaviour, foraging success and mortality rates. Females are deep-diving predators in open ocean habitats. Males are shallow-diving benthic predators in continental shelf habitats. Males gain six times more mass and acquire energy 4.1 times faster than females. High foraging success comes with a high mortality rate. Males are six times more likely to die than females. These foraging strategies and trade-offs are related to different energy demands and life-history strategies. Males use a foraging strategy with a high mortality risk to attain large body sizes necessary to compete for females, as only a fraction of the largest males ever mate. Females use a foraging strategy with a lower mortality risk, maximizing reproductive success by pupping annually over a long lifespan. Our results highlight how sex-specific traits can drive disparity in mortality rates and expand species' niche space. Further, trade-offs between foraging rewards and mortality risk can differentially affect each sex's ability to maximize fitness.
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Affiliation(s)
- Sarah S. Kienle
- Ecology and Evolutionary Biology, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
- Department of Biology, Baylor University, One Bear Place #97399, Waco, TX 76798, USA
| | - Ari S. Friedlaender
- Ocean Science, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Daniel E. Crocker
- Biology, Sonoma State University, 1801 East Cotati Avenue, Rohnert Park, CA 94928, USA
| | - Rita S. Mehta
- Ecology and Evolutionary Biology, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Daniel P. Costa
- Ecology and Evolutionary Biology, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
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23
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Xia Y, Cui Y, Wang A, Liu F, Chi H, Potter JHT, Williamson J, Chen X, Rossiter SJ, Liu Y. Convergent Phenotypic Evolution of Rhodopsin for Dim-Light Sensing across Deep-Diving Vertebrates. Mol Biol Evol 2021; 38:5726-5734. [PMID: 34463769 PMCID: PMC8662592 DOI: 10.1093/molbev/msab262] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Rhodopsin comprises an opsin attached to a retinal chromophore and is the only visual pigment conferring dim-light vision in vertebrates. On activation by photons, the retinal group becomes detached from the opsin, which is then inactive until it is recharged. Of all vertebrate species, those that dive face unique visual challenges, experiencing rapid decreases in light level and hunting in near darkness. Here, we combine sequence analyses with functional assays to show that the rhodopsin pigments of four divergent lineages of deep-diving vertebrates have undergone convergent increases in their retinal release rate. We compare gene sequences and detect parallel amino acids between penguins and diving mammals and perform mutagenesis to show that a single critical residue fully explains the observed increases in retinal release rate in both the emperor penguin and beaked whale. At the same time, we find that other shared sites have no significant effect on retinal release, implying that convergence does not always signify adaptive significance. We propose that accelerated retinal release confers rapid rhodopsin recharging, enabling the visual systems of diving species to adjust quickly to changing light levels as they descend through the water column. This contrasts with nocturnal species, where adaptation to darkness has been attributed to slower retinal release rates.
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Affiliation(s)
- Yu Xia
- College of Life Sciences, Shaanxi Normal University, Xi'an, China.,College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Yimeng Cui
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | | | - Fangnan Liu
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Hai Chi
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Joshua H T Potter
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| | - Joseph Williamson
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| | | | - Stephen J Rossiter
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| | - Yang Liu
- College of Life Sciences, Shaanxi Normal University, Xi'an, China.,Key Laboratory of Zoonosis of Liaoning Province, Shenyang Agricultural University, Shenyang, China
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24
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Holser RR, Crocker DE, Robinson PW, Condit R, Costa DP. Density-dependent effects on reproductive output in a capital breeding carnivore, the northern elephant seal ( Mirounga angustirostris). Proc Biol Sci 2021; 288:20211258. [PMID: 34641731 PMCID: PMC8511744 DOI: 10.1098/rspb.2021.1258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/17/2021] [Indexed: 11/12/2022] Open
Abstract
All organisms face resource limitations that will ultimately restrict population growth, but the controlling mechanisms vary across ecosystems, taxa, and reproductive strategies. Using four decades of data, we examine how variation in the environment and population density affect reproductive outcomes in a capital-breeding carnivore, the northern elephant seal (Mirounga angustirostris). This species provides a unique opportunity to examine the relative importance of resource acquisition and density-dependence on breeding success. Capital breeders accrue resources over large temporal and spatial scales for use during an abbreviated reproductive period. This strategy may have evolved, in part, to confer resilience to short-term environmental variability. We observed density-dependent effects on weaning mass, and maternal age (experience) was more important than oceanographic conditions or maternal mass in determining offspring weaning mass. Together these findings show that the mechanisms controlling reproductive output are conserved across terrestrial and marine systems and vary with population dynamics, an important consideration when assessing the effect of extrinsic changes, such as climate change, on a population.
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Affiliation(s)
- Rachel R. Holser
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Daniel E. Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA 94928, USA
| | - Patrick W. Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Richard Condit
- Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA
- Morton Arboretum, 4100 Illinois Route 53, Lisle, IL 60532, USA
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
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25
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Ponganis PJ. A Physio-Logging Journey: Heart Rates of the Emperor Penguin and Blue Whale. Front Physiol 2021; 12:721381. [PMID: 34413792 PMCID: PMC8369151 DOI: 10.3389/fphys.2021.721381] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/08/2021] [Indexed: 11/23/2022] Open
Abstract
Physio-logging has the potential to explore the processes that underlie the dive behavior and ecology of marine mammals and seabirds, as well as evaluate their adaptability to environmental change and other stressors. Regulation of heart rate lies at the core of the physiological processes that determine dive capacity and performance. The bio-logging of heart rate in unrestrained animals diving at sea was infeasible, even unimaginable in the mid-1970s. To provide a historical perspective, I review my 40-year experience in the development of heart rate physio-loggers and the evolution of a digital electrocardiogram (ECG) recorder that is still in use today. I highlight documentation of the ECG and the interpretation of heart rate profiles in the largest of avian and mammalian divers, the emperor penguin and blue whale.
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Affiliation(s)
- Paul J Ponganis
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States
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26
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Williams HJ, Shipley JR, Rutz C, Wikelski M, Wilkes M, Hawkes LA. Future trends in measuring physiology in free-living animals. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200230. [PMID: 34176330 PMCID: PMC8237165 DOI: 10.1098/rstb.2020.0230] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2021] [Indexed: 02/07/2023] Open
Abstract
Thus far, ecophysiology research has predominantly been conducted within controlled laboratory-based environments, owing to a mismatch between the recording technologies available for physiological monitoring in wild animals and the suite of behaviours and environments they need to withstand, without unduly affecting subjects. While it is possible to record some physiological variables for free-living animals using animal-attached logging devices, including inertial-measurement, heart-rate and temperature loggers, the field is still in its infancy. In this opinion piece, we review the most important future research directions for advancing the field of 'physiologging' in wild animals, including the technological development that we anticipate will be required, and the fiscal and ethical challenges that must be overcome. Non-invasive, multi-sensor miniature devices are ubiquitous in the world of human health and fitness monitoring, creating invaluable opportunities for animal and human physiologging to drive synergistic advances. We argue that by capitalizing on the research efforts and advancements made in the development of human wearables, it will be possible to design the non-invasive loggers needed by ecophysiologists to collect accurate physiological data from free-ranging animals ethically and with an absolute minimum of impact. In turn, findings have the capacity to foster transformative advances in human health monitoring. Thus, we invite biomedical engineers and researchers to collaborate with the animal-tagging community to drive forward the advancements necessary to realize the full potential of both fields. This article is part of the theme issue 'Measuring physiology in free-living animals (Part II)'.
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Affiliation(s)
- H. J. Williams
- Department of Migration, Max Planck Institute of Animal Behavior, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany
| | - J. Ryan Shipley
- Department of Migration, Max Planck Institute of Animal Behavior, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany
| | - C. Rutz
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, UK
| | - M. Wikelski
- Department of Migration, Max Planck Institute of Animal Behavior, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, 78457 Konstanz, Germany
| | - M. Wilkes
- Extreme Environments Research Group, University of Portsmouth, Spinnaker Building, Cambridge Road, Portsmouth PO1 2EF, UK
| | - L. A. Hawkes
- Hatherly Laboratories, University of Exeter, College of Life and Environmental Sciences, Exeter EX4 4PS, UK
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27
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Adachi T, Takahashi A, Costa DP, Robinson PW, Hückstädt LA, Peterson SH, Holser RR, Beltran RS, Keates TR, Naito Y. Forced into an ecological corner: Round-the-clock deep foraging on small prey by elephant seals. SCIENCE ADVANCES 2021; 7:7/20/eabg3628. [PMID: 33980496 PMCID: PMC8115928 DOI: 10.1126/sciadv.abg3628] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/22/2021] [Indexed: 06/01/2023]
Abstract
Small mesopelagic fishes dominate the world's total fish biomass, yet their ecological importance as prey for large marine animals is poorly understood. To reveal the little-known ecosystem dynamics, we identified prey, measured feeding events, and quantified the daily energy balance of 48 deep-diving elephant seals throughout their oceanic migrations by leveraging innovative technologies: animal-borne smart accelerometers and video cameras. Seals only attained positive energy balance after feeding 1000 to 2000 times per day on small fishes, which required continuous deep diving (80 to 100% of each day). Interspecies allometry suggests that female elephant seals have exceptional diving abilities relative to their body size, enabling them to exploit a unique foraging niche on small but abundant mesopelagic fish. This unique foraging niche requires extreme round-the-clock deep diving, limiting the behavioral plasticity of elephant seals to a changing mesopelagic ecosystem.
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Affiliation(s)
- Taiki Adachi
- National Institute of Polar Research, Tachikawa, Tokyo, Japan.
| | | | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Luis A Hückstädt
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Sarah H Peterson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Rachel R Holser
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Roxanne S Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Yasuhiko Naito
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
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28
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Beltran RS, Kilpatrick AM, Breed GA, Adachi T, Takahashi A, Naito Y, Robinson PW, Smith WO, Kirkham AL, Burns JM. Seasonal resource pulses and the foraging depth of a Southern Ocean top predator. Proc Biol Sci 2021; 288:20202817. [PMID: 33726591 PMCID: PMC8059541 DOI: 10.1098/rspb.2020.2817] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Seasonal resource pulses can have enormous impacts on species interactions. In marine ecosystems, air-breathing predators often drive their prey to deeper waters. However, it is unclear how ephemeral resource pulses such as near-surface phytoplankton blooms alter the vertical trade-off between predation avoidance and resource availability in consumers, and how these changes cascade to the diving behaviour of top predators. We integrated data on Weddell seal diving behaviour, diet stable isotopes, feeding success and mass gain to examine shifts in vertical foraging throughout ice break-out and the resulting phytoplankton bloom each year. We also tested hypotheses about the likely location of phytoplankton bloom origination (advected or produced in situ where seals foraged) based on sea ice break-out phenology and advection rates from several locations within 150 km of the seal colony. In early summer, seals foraged at deeper depths resulting in lower feeding rates and mass gain. As sea ice extent decreased throughout the summer, seals foraged at shallower depths and benefited from more efficient energy intake. Changes in diving depth were not due to seasonal shifts in seal diets or horizontal space use and instead may reflect a change in the vertical distribution of prey. Correspondence between the timing of seal shallowing and the resource pulse was variable from year to year and could not be readily explained by our existing understanding of the ocean and ice dynamics. Phytoplankton advection occurred faster than ice break-out, and seal dive shallowing occurred substantially earlier than local break-out. While there remains much to be learned about the marine ecosystem, it appears that an increase in prey abundance and accessibility via shallower distributions during the resource pulse could synchronize life-history phenology across trophic levels in this high-latitude ecosystem.
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Affiliation(s)
- Roxanne S Beltran
- Department of Biology and Wildlife, University of Alaska Fairbanks, 2090 Koyukuk Drive, Fairbanks, AK 99775, USA.,Department of Biological Sciences, University of Alaska Anchorage, 3101 Science Circle, Anchorage, AK 99508, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - A Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Greg A Breed
- Institute of Arctic Biology, University of Alaska Fairbanks, P.O. Box 757000, Fairbanks, AK 99775, USA
| | - Taiki Adachi
- Department of Biological Sciences, University of Tokyo, 2-11-16 Yayoi, Bunkyō, Tokyo 113-0032, Japan
| | - Akinori Takahashi
- National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
| | - Yasuhiko Naito
- National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Walker O Smith
- Virginia Institute of Marine Science, College of William and Mary, 1375 Greate Rd, Gloucester Point, VA 23062, USA.,Institute of Oceanography, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200240, People's Republic of China
| | - Amy L Kirkham
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 17101 Point Lena Loop Road, Juneau, AK 99801, USA
| | - Jennifer M Burns
- Department of Biological Sciences, University of Alaska Anchorage, 3101 Science Circle, Anchorage, AK 99508, USA.,Department of Biological Sciences, Texas Tech University, Box 43131 Lubbock, TX 79409, USA
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29
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Beltran RS, Kendall-Bar JM, Pirotta E, Adachi T, Naito Y, Takahashi A, Cremers J, Robinson PW, Crocker DE, Costa DP. Lightscapes of fear: How mesopredators balance starvation and predation in the open ocean. SCIENCE ADVANCES 2021; 7:7/12/eabd9818. [PMID: 33731347 PMCID: PMC7968837 DOI: 10.1126/sciadv.abd9818] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 01/27/2021] [Indexed: 05/06/2023]
Abstract
Like landscapes of fear, animals are hypothesized to strategically use lightscapes based on intrinsic motivations. However, longitudinal evidence of state-dependent risk aversion has been difficult to obtain in wild animals. Using high-resolution biologgers, we continuously measured body condition, time partitioning, three-dimensional movement, and risk exposure of 71 elephant seals throughout their 7-month foraging migrations (N = 16,000 seal days). As body condition improved from 21 to 32% fat and daylength declined from 16 to 10 hours, seals rested progressively earlier with respect to sunrise, sacrificing valuable nocturnal foraging hours to rest in the safety of darkness. Seals in superior body condition prioritized safety over energy conservation by resting >100 meters deeper where it was 300× darker. Together, these results provide empirical evidence that marine mammals actively use the three-dimensional lightscape to optimize risk-reward trade-offs based on ecological and physiological factors.
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Affiliation(s)
- Roxanne S Beltran
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA.
| | - Jessica M Kendall-Bar
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Enrico Pirotta
- Department of Mathematics and Statistics, Washington State University, Vancouver, WA, USA
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Taiki Adachi
- School of Biology, University of St Andrews, St Andrews, Fife, Scotland, UK
| | - Yasuhiko Naito
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
| | | | - Jolien Cremers
- Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
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30
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Hindell MA, McMahon CR, Jonsen I, Harcourt R, Arce F, Guinet C. Inter- and intrasex habitat partitioning in the highly dimorphic southern elephant seal. Ecol Evol 2021; 11:1620-1633. [PMID: 33613994 PMCID: PMC7882946 DOI: 10.1002/ece3.7147] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/25/2020] [Accepted: 12/02/2020] [Indexed: 01/15/2023] Open
Abstract
Partitioning resources is a key mechanism for avoiding intraspecific competition and maximizing individual energy gain. However, in sexually dimorphic species it is difficult to discern if partitioning is due to competition or the different resource needs of morphologically distinct individuals. In the highly dimorphic southern elephant seal, there are intersexual differences in habitat use; at Iles Kerguelen, males predominantly use shelf waters, while females use deeper oceanic waters. There are equally marked intrasexual differences, with some males using the nearby Kerguelen Plateau, and others using the much more distant Antarctic continental shelf (~2,000 km away). We used this combination of inter and intrasexual behavior to test two hypotheses regarding habitat partitioning in highly dimorphic species. (a) that intersexual differences in habitat use will not appear until the seals diverge in body size and (b) that some habitats have higher rates of energy return than others. In particular, that the Antarctic shelf would provide higher energy returns than the Kerguelen Shelf, to offset the greater cost of travel. We quantified the habitat use of 187 southern elephant seals (102 adult females and 85 subadult males). The seals in the two groups were the same size (~2.4 m) removing the confounding effect of body size. We found that the intersexual differences in habitat use existed before the divergence in body size. Also, we found that the amount of energy gained was the same in all of the major habitats. This suggests that the use of shelf habitats by males is innate, and a trade-off between the need to access the large benthic prey available on shelf waters, against the higher risk of predation there. Intrasexual differences in habitat use are another trade-off; although there are fewer predators on the Antarctic shelf, it is subject to considerable interannual fluctuations in sea-ice extent. In contrast, the Kerguelen Plateau presents more consistent foraging opportunities, but contains higher levels of predation. Habitat partitioning in this highly dimorphic species is therefore the result of complex interplay of life history strategies, environmental conditions and predation pressure.
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Affiliation(s)
- Mark A. Hindell
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Clive R. McMahon
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
- IMOS Animal Tagging, Sydney Institute of Marine ScienceMosmanNew South WalesAustralia
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Ian Jonsen
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Robert Harcourt
- IMOS Animal Tagging, Sydney Institute of Marine ScienceMosmanNew South WalesAustralia
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Fernando Arce
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Christophe Guinet
- Centre d’Etudes Biologiques de Chizé (CEBC)UMR 7372Université de la Rochelle‐CNRSVilliers en BoisFrance
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31
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Wright TJ, Davis RW, Holser RR, Hückstädt LA, Danesi CP, Porter C, Widen SG, Williams TM, Costa DP, Sheffield-Moore M. Changes in Northern Elephant Seal Skeletal Muscle Following Thirty Days of Fasting and Reduced Activity. Front Physiol 2020; 11:564555. [PMID: 33123026 PMCID: PMC7573231 DOI: 10.3389/fphys.2020.564555] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/17/2020] [Indexed: 12/21/2022] Open
Abstract
Northern elephant seals (NES, Mirounga angustirostris) undergo an annual molt during which they spend ∼40 days fasting on land with reduced activity and lose approximately one-quarter of their body mass. Reduced activity and muscle load in stereotypic terrestrial mammalian models results in decreased muscle mass and capacity for force production and aerobic metabolism. However, the majority of lost mass in fasting female NES is from fat while muscle mass is largely preserved. Although muscle mass is preserved, potential changes to the metabolic and contractile capacity are unknown. To assess potential changes in NES skeletal muscle during molt, we collected muscle biopsies from 6 adult female NES before the molt and after ∼30 days at the end of the molt. Skeletal muscle was assessed for respiratory capacity using high resolution respirometry, and RNA was extracted to assess changes in gene expression. Despite a month of reduced activity, fasting, and weight loss, skeletal muscle respiratory capacity was preserved with no change in OXPHOS respiratory capacity. Molt was associated with 162 upregulated genes including those favoring lipid metabolism. We identified 172 downregulated genes including those coding for ribosomal proteins and genes associated with skeletal muscle force transduction and glucose metabolism. Following ∼30 days of molt, NES skeletal muscle metabolic capacity is preserved although mechanotransduction may be compromised. In the absence of exercise stimulus, fasting-induced shifts in muscle metabolism may stimulate pathways associated with preserving the mass and metabolic capacity of slow oxidative muscle.
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Affiliation(s)
- Traver J Wright
- Department of Health and Kinesiology, Texas A&M University, College Station, TX, United States.,Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Randall W Davis
- Department of Marine Biology, Texas A&M University, Galveston, TX, United States
| | - Rachel R Holser
- Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Luis A Hückstädt
- Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Christopher P Danesi
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Craig Porter
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Steven G Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States
| | - Terrie M Williams
- Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Daniel P Costa
- Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Melinda Sheffield-Moore
- Department of Health and Kinesiology, Texas A&M University, College Station, TX, United States.,Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
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32
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Valenzuela-Toro AM, Zicos MH, Pyenson ND. Extreme dispersal or human-transport? The enigmatic case of an extralimital freshwater occurrence of a Southern elephant seal from Indiana. PeerJ 2020; 8:e9665. [PMID: 32953258 PMCID: PMC7474520 DOI: 10.7717/peerj.9665] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/15/2020] [Indexed: 11/20/2022] Open
Abstract
Elephant seals (Mirounga spp.) are the largest living pinnipeds, and the spatial scales of their ecology, with dives over 1 km in depth and foraging trips over 10,000 km long, are unrivalled by their near relatives. Here we report the discovery of an incomplete Holocene age Southern elephant seal (M. leonina) rostrum from Indiana, USA. The surviving material are two casts of the original specimen, which was collected in a construction excavation close to the Wabash River near Lafayette, Indiana. The original specimen was mostly destroyed for radiometric dating analyses in the 1970s, which resulted in an age of 1,260 ± 90 years before the present. The existence of sediments in the original specimen suggests some type of post depositional fluvial transportation. The prevalent evidence suggests that this male Southern elephant seal crossed the equator and the Gulf of Mexico, and then entered the Mississippi River system, stranding far upriver in Indiana or adjacent areas, similar to other reported examples of lost marine mammals in freshwater systems. Based on potential cut marks, we cannot exclude human-mediated transportation or scavenging by Indigenous peoples as a contributing factor of this occurrence. The material reported here represents by far the northernmost occurrence of a Southern elephant seal in the Northern Hemisphere ever recorded. The unusual occurrence of a top marine predator >1,000 km from the closest marine effluent as a potential extreme case of dispersal emphasizes how marine invasions of freshwater systems have happened frequently through historical (and likely geological) time.
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Affiliation(s)
- Ana M Valenzuela-Toro
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, United States of America.,Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America
| | - Maria H Zicos
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.,Department of Earth Sciences, Natural History Museum, London, United Kingdom
| | - Nicholas D Pyenson
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America.,Department of Paleontology and Geology, Burke Museum of Natural History and Culture, Seattle, WA, United States of America
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Bird DJ, Hamid I, Fox‐Rosales L, Van Valkenburgh B. Olfaction at depth: Cribriform plate size declines with dive depth and duration in aquatic arctoid carnivorans. Ecol Evol 2020; 10:6929-6953. [PMID: 32760503 PMCID: PMC7391337 DOI: 10.1002/ece3.6343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 12/05/2022] Open
Abstract
It is widely accepted that obligate aquatic mammals, specifically toothed whales, rely relatively little on olfaction. There is less agreement about the importance of smell among aquatic mammals with residual ties to land, such as pinnipeds and sea otters. Field observations of marine carnivorans stress their keen use of smell while on land or pack ice. Yet, one dimension of olfactory ecology is often overlooked: while underwater, aquatic carnivorans forage "noseblind," diving with nares closed, removed from airborne chemical cues. For this reason, we predicted marine carnivorans would have reduced olfactory anatomy relative to closely related terrestrial carnivorans. Moreover, because species that dive deeper and longer forage farther removed from surface scent cues, we predicted further reductions in their olfactory anatomy. To test these hypotheses, we looked to the cribriform plate (CP), a perforated bone in the posterior nasal chamber of mammals that serves as the only passageway for olfactory nerves crossing from the periphery to the olfactory bulb and thus covaries in size with relative olfactory innervation. Using CT scans and digital quantification, we compared CP morphology across Arctoidea, a clade at the interface of terrestrial and aquatic ecologies. We found that aquatic carnivoran species from two lineages that independently reinvaded marine environments (Pinnipedia and Mustelidae), have significantly reduced relative CP than terrestrial species. Furthermore, within these aquatic lineages, diving depth and duration were strongly correlated with CP loss, and the most extreme divers, elephant seals, displayed the greatest reductions. These observations suggest that CP reduction in carnivorans is an adaptive response to shifting selection pressures during secondary invasion of marine environments, particularly to foraging at great depths. Because the CP is fairly well preserved in the fossil record, using methods presented here to quantify CP morphology in extinct species could further clarify evolutionary patterns of olfactory loss across aquatic mammal lineages that have independently committed to life in water.
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Affiliation(s)
- Deborah J. Bird
- Department of Ecology and Evolutionary BiologyUniversity of California Los AngelesLos AngelesCAUSA
| | - Iman Hamid
- Department of Ecology and Evolutionary BiologyUniversity of California Los AngelesLos AngelesCAUSA
| | - Lester Fox‐Rosales
- Department of Ecology and Evolutionary BiologyUniversity of California Los AngelesLos AngelesCAUSA
| | - Blaire Van Valkenburgh
- Department of Ecology and Evolutionary BiologyUniversity of California Los AngelesLos AngelesCAUSA
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Yoshino K, Takahashi A, Adachi T, Costa DP, Robinson PW, Peterson SH, Hückstädt LA, Holser RR, Naito Y. Acceleration-triggered animal-borne videos show a dominance of fish in the diet of female northern elephant seals. J Exp Biol 2020; 223:jeb212936. [PMID: 32041802 DOI: 10.1242/jeb.212936] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 01/31/2020] [Indexed: 01/04/2023]
Abstract
Knowledge of the diet of marine mammals is fundamental to understanding their role in marine ecosystems and response to environmental change. Recently, animal-borne video cameras have revealed the diet of marine mammals that make short foraging trips. However, novel approaches that allocate video time to target prey capture events is required to obtain diet information for species that make long foraging trips over great distances. We combined satellite telemetry and depth recorders with newly developed date-/time-, depth- and acceleration-triggered animal-borne video cameras to examine the diet of female northern elephant seals during their foraging migrations across the eastern North Pacific. We obtained 48.2 h of underwater video, from cameras mounted on the head (n=12) and jaw (n=3) of seals. Fish dominated the diet (78% of 697 prey items recorded) across all foraging locations (range: 37-55°N, 122-152°W), diving depths (range: 238-1167 m) and water temperatures (range: 3.2-7.4°C), while squid comprised only 7% of the diet. Identified prey included fish such as myctophids, Merluccius sp. and Icosteus aenigmaticus, and squid such as Histioteuthis sp., Octopoteuthis sp. and Taningia danae Our results corroborate fatty acid analysis, which also found that fish are more important in the diet, and are in contrast to stomach content analyses that found cephalopods to be the most important component of the diet. Our work shows that in situ video observation is a useful method for studying the at-sea diet of long-ranging marine predators.
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Affiliation(s)
- Kaori Yoshino
- Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
| | - Akinori Takahashi
- Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
- National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
| | - Taiki Adachi
- Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
- National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
- School of Biology, University of St Andrews, Scottish Oceans Institute, East Sands, St Andrews, Fife KY16 9TS, UK
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Sarah H Peterson
- Department of Ecology and Evolutionary Biology, Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Luis A Hückstädt
- Department of Ecology and Evolutionary Biology, Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Rachel R Holser
- Department of Ecology and Evolutionary Biology, Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Yasuhiko Naito
- National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
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Spraker TR, Kuzmina TA, DeLong RL. Causes of mortality in northern elephant seal pups on San Miguel Island, California. J Vet Diagn Invest 2020; 32:312-316. [PMID: 32081093 DOI: 10.1177/1040638720907100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In February 2015, we conducted a field study of causes of mortality of northern elephant seal (Mirounga angustirostris) pups on San Miguel Island, California. Autopsies were performed on 18 freshly dead pups. Ages of pups ranged from stillborn to 6-8 wk. Gross and histologic lesions included trauma (9 of 18 pups), multifocal necrotizing myopathy (8 of 18), starvation with emaciation (7 of 18), congenital anomalies (3 of 18), bacterial infections (3 of 18), and perinatal mortality (stillbirths and neonates; 2 of 18). Trauma and emaciation or starvation were the most significant contributors to death. Bacterial infections included hemolytic Escherichia coli isolated from the lungs of 2 pups with pneumonia. Additionally, non-hemolytic Streptococcus sp. and hemolytic E. coli were isolated from the liver of an emaciated pup that had mild multifocal suppurative hepatitis. Other lesions, including a previously described necrotizing myopathy, congenital anomalies, and bacterial infections, were detected concurrently in cases with starvation and/or emaciation or trauma.
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Affiliation(s)
- Terry R Spraker
- College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO (Spraker).,Institute of Zoology, National Academy of Sciences of Ukraine, Kyiv, Ukraine (Kuzmina).,National Marine Mammal Laboratory, Seattle, WA (DeLong)
| | - Tetiana A Kuzmina
- College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO (Spraker).,Institute of Zoology, National Academy of Sciences of Ukraine, Kyiv, Ukraine (Kuzmina).,National Marine Mammal Laboratory, Seattle, WA (DeLong)
| | - Robert L DeLong
- College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO (Spraker).,Institute of Zoology, National Academy of Sciences of Ukraine, Kyiv, Ukraine (Kuzmina).,National Marine Mammal Laboratory, Seattle, WA (DeLong)
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Espinheira Gomes F, Abou-Madi N, Ledbetter EC, McArt J. Spectral-domain optical coherence tomography imaging of normal foveae: A pilot study in 17 diurnal birds of prey. Vet Ophthalmol 2020; 23:347-357. [PMID: 31981286 DOI: 10.1111/vop.12732] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To describe and to establish normative data for the foveae of diurnal birds of prey using spectral-domain optical coherence tomography (SD-OCT). METHODS All animals (9 red-tailed hawks, 3 Cooper's hawks, 3 American kestrels, 1 sharp-shinned hawk, and 1 broad-winged hawk) had an ophthalmic examination performed with slit lamp biomicroscopy and indirect ophthalmoscopy. Following ophthalmic examination, SD-OCT was performed in each eye that had a visible fundus and normal fovea on SD-OCT. Temporal foveae depth, central foveae depth, pecten-temporal foveae distance, and pecten-central foveae distance (PCFD) were measured using SD-OCT. Differences in measured outcomes between species were determined using generalized linear mixed effects models. RESULTS The central foveae (mean ± SD) displayed a small but significant depth variation between species (P = .002) and was deepest in red-tailed hawks (293 ± 16 µm), followed by American kestrels (260 ± 12 µm), broad-winged hawks (256 ± 16 µm), Cooper's hawks (250 ± 9 µm), and sharp-shinned hawks (239 ± 16 µm). The temporal foveae were shallower than the central foveae in all species tested, and there was a significant variation between species (P < .001). The temporal foveae (mean ± SD) were deepest in American kestrels (137 ± 8 µm), followed by red-tailed hawks (129 ± 3 µm), broad-winged hawks (59.5 ± 3.5 µm), Cooper's hawks (20.3 ± 6.4 µm), and sharp-shinned hawks (17.5 ± 0.7 µm). Pecten-temporal foveae distance was approximately 30% shorter than PCFD in all species. There were no differences in the parameters tested between the eyes within each species (P ≥ .47). CONCLUSION Normative foveae SD-OCT data were obtained in four species of diurnal birds of prey. Further studies are warranted to provide structural and functional information regarding normal and pathologic changes that can affect the foveae.
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Affiliation(s)
| | - Noha Abou-Madi
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Eric C Ledbetter
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Jessica McArt
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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Abstract
Mesopelagic fish and squid occupy ocean depths extending below the photic zone and their vertical migrations represent a massive pathway moving energy and carbon through the water column. Their spatio-temporal distribution is however, difficult to map across remote regions particularly the vast Southern Ocean. This represents a key gap in understanding biogeochemical processes, marine ecosystem structure, and how changing ocean conditions will affect marine predators, which depend upon mesopelagic prey. We infer mesopelagic prey vertical distribution and relative abundance in the Indian sector of the Southern Ocean (20° to 130°E) with a novel approach using predator-derived indices. Fourteen years of southern elephant seal tracking and dive data, from the open ocean between the Antarctic Polar Front and the southern Antarctic Circumpolar Current front, clearly show that the vertical distribution of mesopelagic prey is influenced by the physical hydrographic processes that structure their habitat. Mesopelagic prey have a more restricted vertical migration and higher relative abundance closer to the surface where Circumpolar Deep Water rises to shallower depths. Combining these observations with a future projection of Southern Ocean conditions we show that changes in the coupling of surface and deep waters will potentially redistribute mesopelagic prey. These changes are small overall, but show important spatial variability: prey will increase in relative abundance to the east of the Kerguelen Plateau but decrease to the west. The consequences for deep-diving specialists such as elephant seals and whales over this time scale will likely be minor, but the changes in mesoscale vertical energy flow have implications for predators that forage within the mesopelagic zone as well as the broader pelagic ecosystem.
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38
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Le Boeuf B, Condit R, Reiter J. Lifetime reproductive success of northern elephant seals (Mirounga angustirostris). CAN J ZOOL 2019. [DOI: 10.1139/cjz-2019-0104] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lifetime reproductive success of individuals in a natural population provides an estimate of Darwinian fitness. We calculated lifetime reproductive success in a colony of female northern elephant seals (Mirounga angustirostris (Gill, 1866)) by monitoring annual breeding throughout life of 7735 female weanlings marked individually at Año Nuevo, California, USA, from 1963 to 2005. Great variation in lifetime reproductive success was evident in three aspects of life history: (1) 75% of the females died before reaching breeding age and produced no pups; (2) nearly half of the survivors bred for only a few years before dying, and young females had low weaning success; (3) less than 1% of the females in the sample were exceptionally successful producing up to 20 pups in life. Many females that bred early, while still growing, had decreased lifespan, low weaning success, and lower lifetime reproductive success than females that postponed first breeding. Exceptional reproductive success was associated with giving birth annually, living long (up to age 23), and weaning large pups that were more likely to survive and breed. We conclude that there is strong selection for increased lifespan and multiparous supermoms that contribute significantly to pup production in the next generation.
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Affiliation(s)
- Burney Le Boeuf
- Department of Ecology and Evolutionary Biology and Long Marine Laboratory, 130 McAllister Way, University of California at Santa Cruz, Santa Cruz, CA 95060, USA
| | - Richard Condit
- Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA
- Morton Arboretum, 4100 Illinois Route 53, Lisle, IL 60532, USA
| | - Joanne Reiter
- Institute for Marine Sciences, Long Marine Laboratory, 115 McAllister Way, University of California Santa Cruz, Santa Cruz, CA 95060, USA
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Shero MR, Reiser PJ, Simonitis L, Burns JM. Links between muscle phenotype and life history: differentiation of myosin heavy chain composition and muscle biochemistry in precocial and altricial pinniped pups. J Comp Physiol B 2019; 189:717-734. [DOI: 10.1007/s00360-019-01240-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/15/2019] [Accepted: 09/30/2019] [Indexed: 11/29/2022]
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Khudyakov JI, Abdollahi E, Ngo A, Sandhu G, Stephan A, Costa DP, Crocker DE. Expression of obesity-related adipokine genes during fasting in a naturally obese marine mammal. Am J Physiol Regul Integr Comp Physiol 2019; 317:R521-R529. [DOI: 10.1152/ajpregu.00182.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Northern elephant seals ( Mirounga angustirostris) are exceptional among fasting-adapted animals in coupling prolonged fasting with energetically costly activities, relying on oxidation of fat stores accrued during foraging to power metabolic demands of reproduction and molting. We hypothesized that high rates of energy expenditure, insulin resistance, and immune responses to colonial breeding in fasting seals are mediated by adipokines, or signaling molecules secreted by adipose tissue that are associated with obesity and inflammation in humans. We measured mRNA expression of 10 adipokine genes in blubber tissue of adult female elephant seals sampled early and late during their lactation and molting fasts and correlated gene expression with adiposity and circulating levels of corticosteroid and immune markers. Expression of adiponectin ( ADIPOQ) and its receptor ADIPOR2, leptin receptor ( LEPR), resistin ( RETN), retinol binding protein 4 ( RBP4), and visfatin/nicotinamide phosphoribosyltransferase ( NAMPT) was increased, whereas that of fat mass and obesity-associated protein ( FTO) was decreased in late-fasted compared with early-fasted groups. Abundance of adipokine transcripts that increased in late fasting was negatively associated with body mass and positively associated with cortisol, suggesting that they may mediate local metabolic effects of cortisol in blubber during fasting. Expression of several adipokines was correlated with the immune markers IL-6, haptoglobin, IgM, and IgE, suggesting a potential role in modulating immune responses to colonial breeding and molting. Since many of these adipokines have not been measured in other wild animals, this study provides preliminary insights into their local regulation in fat tissue and targeted assays for future studies.
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Affiliation(s)
- Jane I. Khudyakov
- Department of Biological Sciences, University of the Pacific, Stockton, California
- National Marine Mammal Foundation, San Diego, California
| | - Eileen Abdollahi
- Department of Biological Sciences, University of the Pacific, Stockton, California
| | - Angela Ngo
- Department of Biological Sciences, University of the Pacific, Stockton, California
| | - Gureet Sandhu
- Department of Biological Sciences, University of the Pacific, Stockton, California
| | - Alicia Stephan
- Department of Biological Sciences, University of the Pacific, Stockton, California
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California
| | - Daniel E. Crocker
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California
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Allen KN, Vázquez-Medina JP. Natural Tolerance to Ischemia and Hypoxemia in Diving Mammals: A Review. Front Physiol 2019; 10:1199. [PMID: 31620019 PMCID: PMC6763568 DOI: 10.3389/fphys.2019.01199] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 09/03/2019] [Indexed: 12/15/2022] Open
Abstract
Reperfusion injury follows ischemia/reperfusion events occurring during myocardial infarction, stroke, embolism, and other peripheral vascular diseases. Decreased blood flow and reduced oxygen tension during ischemic episodes activate cellular pathways that upregulate pro-inflammatory signaling and promote oxidant generation. Reperfusion after ischemia recruits inflammatory cells to the vascular wall, further exacerbating oxidant production and ultimately resulting in cell death, tissue injury, and organ dysfunction. Diving mammals tolerate repetitive episodes of peripheral ischemia/reperfusion as part of the cardiovascular adjustments supporting long duration dives. These adjustments allow marine mammals to optimize the use of their body oxygen stores while diving but can result in selectively reduced perfusion to peripheral tissues. Remarkably, diving mammals show no apparent detrimental effects associated with these ischemia/reperfusion events. Here, we review the current knowledge regarding the strategies marine mammals use to suppress inflammation and cope with oxidant generation potentially derived from diving-induced ischemia/reperfusion.
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Sequeira AMM, Heupel MR, Lea MA, Eguíluz VM, Duarte CM, Meekan MG, Thums M, Calich HJ, Carmichael RH, Costa DP, Ferreira LC, Fernandéz-Gracia J, Harcourt R, Harrison AL, Jonsen I, McMahon CR, Sims DW, Wilson RP, Hays GC. The importance of sample size in marine megafauna tagging studies. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2019; 29:e01947. [PMID: 31183944 DOI: 10.1002/eap.1947] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 04/10/2019] [Accepted: 04/17/2019] [Indexed: 06/09/2023]
Abstract
Telemetry is a key, widely used tool to understand marine megafauna distribution, habitat use, behavior, and physiology; however, a critical question remains: "How many animals should be tracked to acquire meaningful data sets?" This question has wide-ranging implications including considerations of statistical power, animal ethics, logistics, and cost. While power analyses can inform sample sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different sample sizes. We considered sample sizes from one to >100 individuals and synthesized empirical findings, detailing the information that can be gathered with increasing sample sizes. We complement this review with simulations, using real data, to show the impact of sample size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance sample sizes and broaden the range, scale, and scope of questions that can be answered.
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Affiliation(s)
- A M M Sequeira
- IOMRC and The University of Western Australia Oceans Institute, School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - M R Heupel
- Australian Institute of Marine Science, PMB No 3, Townsville, Queensland, 4810, Australia
| | - M-A Lea
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, Tasmania, 7000, Australia
| | - V M Eguíluz
- Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC - UIB), E-07122, Palma de Mallorca, Spain
| | - C M Duarte
- Red Sea Research Centre (RSRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - M G Meekan
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre (M096), University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009 Australia
| | - M Thums
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre (M096), University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009 Australia
| | - H J Calich
- IOMRC and The University of Western Australia Oceans Institute, Oceans Graduate School, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - R H Carmichael
- Dauphin Island Sea Lab and, University of South Alabama, 101 Bienville Boulevard, Dauphin Island, Alabama, 36528, USA
| | - D P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California, 95060, USA
| | - L C Ferreira
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre (M096), University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009 Australia
| | - J Fernandéz-Gracia
- Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC - UIB), E-07122, Palma de Mallorca, Spain
| | - R Harcourt
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - A-L Harrison
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, PO Box 37012 MRC 5503 MBC, Washington, D.C., 20013, USA
| | - I Jonsen
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - C R McMahon
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
- Sydney Institute of Marine Science, 19 Chowder Bay Road, Mosman, 2088, New South Wales, Australia
| | - D W Sims
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, United Kingdom
- Ocean and Earth Science, National Oceanography Centre Southampton, Waterfront Campus, University of Southampton, Southampton, SO14 3ZH, United Kingdom
| | - R P Wilson
- Department of Biosciences, Swansea University, Swansea, United Kingdom
| | - G C Hays
- Deakin University, Geelong, Victoria, Australia
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Oosthuizen WC, Postma M, Altwegg R, Nevoux M, Pradel R, Bester MN, Bruyn PJN. Individual heterogeneity in life‐history trade‐offs with age at first reproduction in capital breeding elephant seals. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.12015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- W. Chris Oosthuizen
- Mammal Research Institute, Department of Zoology and Entomology University of Pretoria Hatfield South Africa
| | - Martin Postma
- Mammal Research Institute, Department of Zoology and Entomology University of Pretoria Hatfield South Africa
| | - Res Altwegg
- Centre for Statistics in Ecology Environment and Conservation, Department of Statistical Sciences University of Cape Town Rondebosch South Africa
- African Climate and Development Initiative, University of Cape Town Rondebosch South Africa
| | - Marie Nevoux
- Mammal Research Institute, Department of Zoology and Entomology University of Pretoria Hatfield South Africa
- UMRESE, Ecology and Ecosystem Health, Agrocampus Ouest, INRA Rennes France
| | - Roger Pradel
- Biostatistics and Population Biology Group, CEFE, CNRS, University of Montpellier Montpellier France
| | - Marthán N. Bester
- Mammal Research Institute, Department of Zoology and Entomology University of Pretoria Hatfield South Africa
| | - P. J. Nico Bruyn
- Mammal Research Institute, Department of Zoology and Entomology University of Pretoria Hatfield South Africa
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Hurme E, Gurarie E, Greif S, Herrera M. LG, Flores-Martínez JJ, Wilkinson GS, Yovel Y. Acoustic evaluation of behavioral states predicted from GPS tracking: a case study of a marine fishing bat. MOVEMENT ECOLOGY 2019; 7:21. [PMID: 31223482 PMCID: PMC6567457 DOI: 10.1186/s40462-019-0163-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/23/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Multiple methods have been developed to infer behavioral states from animal movement data, but rarely has their accuracy been assessed from independent evidence, especially for location data sampled with high temporal resolution. Here we evaluate the performance of behavioral segmentation methods using acoustic recordings that monitor prey capture attempts. METHODS We recorded GPS locations and ultrasonic audio during the foraging trips of 11 Mexican fish-eating bats, Myotis vivesi, using miniature bio-loggers. We then applied five different segmentation algorithms (k-means clustering, expectation-maximization and binary clustering, first-passage time, hidden Markov models, and correlated velocity change point analysis) to infer two behavioral states, foraging and commuting, from the GPS data. To evaluate the inference, we independently identified characteristic patterns of biosonar calls ("feeding buzzes") that occur during foraging in the audio recordings. We then compared segmentation methods on how well they correctly identified the two behaviors and if their estimates of foraging movement parameters matched those for locations with buzzes. RESULTS While the five methods differed in the median percentage of buzzes occurring during predicted foraging events, or true positive rate (44-75%), a two-state hidden Markov model had the highest median balanced accuracy (67%). Hidden Markov models and first-passage time predicted foraging flight speeds and turn angles similar to those measured at locations with feeding buzzes and did not differ in the number or duration of predicted foraging events. CONCLUSION The hidden Markov model method performed best at identifying fish-eating bat foraging segments; however, first-passage time was not significantly different and gave similar parameter estimates. This is the first attempt to evaluate segmentation methodologies in echolocating bats and provides an evaluation framework that can be used on other species.
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Affiliation(s)
- Edward Hurme
- Department of Biology, University of Maryland, College Park, MD 20742 USA
| | - Eliezer Gurarie
- Department of Biology, University of Maryland, College Park, MD 20742 USA
| | - Stefan Greif
- School of Zoology, Faculty of Life Sciences, Tel-Aviv University, 6997801 Tel-Aviv, Israel
- Sagol School of Neuroscience, Tel-Aviv University, 6997801 Tel-Aviv, Israel
| | - L. Gerardo Herrera M.
- Estación de Biología de Chamela, Instituto de Biología, Universidad Nacional Autónoma de México, 48980 San Patricio, Mexico
| | - José Juan Flores-Martínez
- Laboratorio de Sistemas de Información Geográfica, Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico
| | | | - Yossi Yovel
- School of Zoology, Faculty of Life Sciences, Tel-Aviv University, 6997801 Tel-Aviv, Israel
- Sagol School of Neuroscience, Tel-Aviv University, 6997801 Tel-Aviv, Israel
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45
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Tift MS, Ponganis PJ. Time Domains of Hypoxia Adaptation-Elephant Seals Stand Out Among Divers. Front Physiol 2019; 10:677. [PMID: 31214049 PMCID: PMC6558045 DOI: 10.3389/fphys.2019.00677] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 05/13/2019] [Indexed: 11/17/2022] Open
Affiliation(s)
- Michael S. Tift
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Paul J. Ponganis
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States
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Moxley JH, Nicholson TE, Van Houtan KS, Jorgensen SJ. Non-trophic impacts from white sharks complicate population recovery for sea otters. Ecol Evol 2019; 9:6378-6388. [PMID: 31236228 PMCID: PMC6580303 DOI: 10.1002/ece3.5209] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/09/2019] [Accepted: 04/10/2019] [Indexed: 01/22/2023] Open
Abstract
Complex interactions between protected populations may challenge the recovery of whole ecosystems. In California, white sharks (Carcharodon carcharias) mistargeting southern sea otters (Enhydra lutris nereis) are an emergent impact to sea otter recovery, inhibiting the broader ecosystem restoration sea otters might provide. Here, we integrate and analyze tracking and stranding data to compare the phenology of interactions between white sharks and their targeted prey (elephant seals, Mirounga angustirostris) with those of mistargeted prey (sea otters, humans). Pronounced seasonal peaks in shark bites to otters and humans overlap in the late boreal summer, immediately before the annual adult white shark migration to elephant seal rookeries. From 1997 to 2017, the seasonal period when sharks bite otters expanded from 2 to 8 months of the year and occurred primarily in regions where kelp cover declined. Immature and male otters, demographics most associated with range expansion, were disproportionately impacted. While sea otters are understood to play a keystone role in kelp forests, recent ecosystem shifts are revealing unprecedented bottom-up and top-down interactions. Such shifts challenge ecosystem management programs that rely on static models of species interactions.
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Affiliation(s)
| | | | - Kyle S. Van Houtan
- Monterey Bay AquariumMontereyCalifornia
- Nicholas School of the EnvironmentDuke UniversityDurhamNorth Carolina
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47
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Hooper AW, Berger RW, Rubin LS, McDonald BI, Crocker DE. Maternal age influences offspring behaviour and growth efficiency during provisioning in northern elephant seals. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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48
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Siegelman L, O'Toole M, Flexas M, Rivière P, Klein P. Submesoscale ocean fronts act as biological hotspot for southern elephant seal. Sci Rep 2019; 9:5588. [PMID: 30944405 PMCID: PMC6447572 DOI: 10.1038/s41598-019-42117-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/25/2019] [Indexed: 01/22/2023] Open
Abstract
The area west of the Kerguelen Islands (20-70°E/45-60°S) is characterized by a weak mesoscale activity except for a standing meander region of the Antarctic Circumpolar Current (ACC) localized between 20 and 40°E. A unique bio-physical dataset at high-resolution collected by a southern elephant seal (Mirounga leonina) reveals a conspicuous increase in foraging activity at the standing meander site up to 5 times larger than during the rest of her three-month trip west of the Kerguelen Islands. Here, we propose a physical explanation for such high biological activity based on the study of small-scale fronts with scales of 5 to 20 km, also called submesoscales. The standing meander is associated with intensified frontal dynamics at submesoscale, not observed in the rest of the region. Results shed new light on the spatial distribution of submesoscale fronts in the under-sampled area west of the Kerguelen plateau and emphasize their importance for upper trophic levels. Despite that most elephant seals target foraging grounds east of the Kerguelen Plateau, our findings suggest that excursions to the west are not accidental, and may be explained by the recurrently elevated physical and biological activity of the site. As such, other standing meanders of the ACC may also act as biological hotspots where trophic interactions are stimulated by submesoscale turbulence.
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Affiliation(s)
- Lia Siegelman
- Univ. Brest, CNRS, IRD, Ifremer, LEMAR, Plouzané, France. .,California Institute of Technology, Pasadena, CA, USA. .,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
| | - Malcolm O'Toole
- UWA Oceans Institute, Indian Ocean Marine Research Centre, University of Western Australia, Crawley, WA, 6009, Australia
| | - Mar Flexas
- California Institute of Technology, Pasadena, CA, USA
| | - Pascal Rivière
- Univ. Brest, CNRS, IRD, Ifremer, LEMAR, Plouzané, France
| | - Patrice Klein
- California Institute of Technology, Pasadena, CA, USA.,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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Ponganis PJ. State of the art review: from the seaside to the bedside: insights from comparative diving physiology into respiratory, sleep and critical care. Thorax 2019; 74:512-518. [PMID: 30826734 DOI: 10.1136/thoraxjnl-2018-212136] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/20/2019] [Accepted: 01/28/2019] [Indexed: 11/04/2022]
Abstract
Anatomical and physiological adaptations of animals to extreme environments provide insight into basic physiological principles and potential therapies for human disease. In that regard, the diving physiology of marine mammals and seabirds is especially relevant to pulmonary and cardiovascular function, and to the pathology and potential treatment of patients with hypoxaemia and/or ischaemia. This review highlights past and recent progress in the field of comparative diving physiology with emphasis on its potential relevance to human medicine.
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Affiliation(s)
- Paul J Ponganis
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
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50
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Salogni E, Galimberti F, Sanvito S, Miller E. Male and female pups of the highly sexually dimorphic northern elephant seal (Mirounga angustirostris) differ slightly in body size. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In mammals, males generally are larger than females, though such sexual-size differences have been documented primarily in adults and are relatively poorly known in early life. We studied sexual-size differences in pups of the northern elephant seal (Mirounga angustirostris (Gill, 1866)), which in adulthood is one of the most sexually dimorphic mammals. We studied body size at birth and weaning, at Islas San Benito, Mexico, at the southernmost limit of the species’ breeding range. Males were 10% heavier and 2% longer than females at birth. Sexes did not differ significantly in either measure of body size at weaning, although males were slightly heavier (4%) and longer (1%) than females. Neither growth rate nor suckling duration differed between the sexes. In previous studies in California, USA, pups at weaning were heavier than in our study, and males were heavier than females. These differences may reflect ecological, temporal, or life-history differences across populations. The modest difference in sexual-size dimorphism early in life in this species compared with the great difference in adulthood likely reflects multiple selective forces, including constraints on neonatal size set by body size of females, and the weakness of sexual selection at that stage of life.
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Affiliation(s)
- E. Salogni
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1B 3X9, Canada
- Elephant Seal Research Group, Sea Lion Island, Falkland Islands, FIQQ 1ZZ
| | - F. Galimberti
- Elephant Seal Research Group, Sea Lion Island, Falkland Islands, FIQQ 1ZZ
| | - S. Sanvito
- Elephant Seal Research Group, Sea Lion Island, Falkland Islands, FIQQ 1ZZ
| | - E.H. Miller
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1B 3X9, Canada
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