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Savoca MS, Kumar M, Sylvester Z, Czapanskiy MF, Meyer B, Goldbogen JA, Brooks CM. Whale recovery and the emerging human-wildlife conflict over Antarctic krill. Nat Commun 2024; 15:7708. [PMID: 39256348 PMCID: PMC11387826 DOI: 10.1038/s41467-024-51954-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 08/20/2024] [Indexed: 09/12/2024] Open
Abstract
The Southern Ocean ecosystem has undergone extensive changes in the past two centuries driven by industrial sealing and whaling, climate change and commercial fishing. However, following the end of commercial whaling, some populations of whales in this region are recovering. Baleen whales are reliant on Antarctic krill, which is also the largest Southern Ocean fishery. Since 1993, krill catch has increased fourfold, buoyed by nutritional supplement and aquaculture industries. In this Perspective, we approximate baleen whale consumption of Antarctic krill before and after whaling to examine if the ecosystem can support both humans and whales as krill predators. Our back-of-the-envelope calculations suggest that current krill biomass cannot support both an expanding krill fishery and the recovery of whale populations to pre-whaling sizes, highlighting an emerging human-wildlife conflict. We then provide recommendations for enhancing sustainability in this region by reducing encounters with whales and bolstering the krill population.
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Affiliation(s)
- Matthew S Savoca
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
| | - Mehr Kumar
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Zephyr Sylvester
- Department of Environmental Studies, University of Colorado, Boulder, Boulder, CO, USA
| | - Max F Czapanskiy
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Bettina Meyer
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB), University of Oldenburg, Oldenburg, Germany
| | - Jeremy A Goldbogen
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Cassandra M Brooks
- Department of Environmental Studies, University of Colorado, Boulder, Boulder, CO, USA
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2
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Hüppe L, Bahlburg D, Busack M, Lemburg J, Payton L, Reinhard N, Rieger D, Helfrich-Förster C, Meyer B. A new Activity Monitor for Aquatic Zooplankter (AMAZE) allows the recording of swimming activity in wild-caught Antarctic krill (Euphausia superba). Sci Rep 2024; 14:16963. [PMID: 39043920 PMCID: PMC11266396 DOI: 10.1038/s41598-024-67999-3] [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: 04/14/2024] [Accepted: 07/18/2024] [Indexed: 07/25/2024] Open
Abstract
Antarctic krill (Euphausia superba, hereafter krill) is a pelagic living crustacean and a key species in the Southern Ocean ecosystem. Krill builds up a huge biomass and its synchronized behavioral patterns, such as diel vertical migration (DVM), substantially impact ecosystem structure and carbon sequestration. However, the mechanistic basis of krill DVM is unknown and previous studies of krill behavior in the laboratory were challenged by complex behavior and large variability. Using a new experimental set-up, we recorded the swimming activity of individual wild-caught krill under light-dark cycles. Krill individuals exhibited differential phototactic responses to the light regime provided. However, using a new activity metric, we showed for the first time a consistent nocturnal increase in krill swimming activity in a controlled environment. Krill swimming activity in the new set-up was strongly synchronized with the light-dark cycle, similar to the diel vertical migration pattern of krill in the field when the krill were sampled for the experiment, demonstrated by hydroacoustic recordings. The new set-up presents a promising tool for investigating the mechanisms underlying krill behavioral patterns, which will increase our understanding of ecological interactions, the spatial distribution of populations, and their effects on biogeochemical cycles in the future.
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Affiliation(s)
- Lukas Hüppe
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany.
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
| | - Dominik Bahlburg
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Michael Busack
- Section Deep-Sea Ecology and Technology, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Johannes Lemburg
- Scientific Workshop, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Laura Payton
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- CNRS, INP, EPOC, UMR 5805, University of Bordeaux, 33120, Arcachon, Bordeaux, France
| | - Nils Reinhard
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany
| | - Dirk Rieger
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany
| | - Bettina Meyer
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Carl-Von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany.
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstrasse 231, 26129, Oldenburg, Germany.
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Hermanson VR, Cutter GR, Hinke JT, Dawkins M, Watters GM. A method to estimate prey density from single-camera images: A case study with chinstrap penguins and Antarctic krill. PLoS One 2024; 19:e0303633. [PMID: 38980882 PMCID: PMC11232977 DOI: 10.1371/journal.pone.0303633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 04/29/2024] [Indexed: 07/11/2024] Open
Abstract
Estimating the densities of marine prey observed in animal-borne video loggers when encountered by foraging predators represents an important challenge for understanding predator-prey interactions in the marine environment. We used video images collected during the foraging trip of one chinstrap penguin (Pygoscelis antarcticus) from Cape Shirreff, Livingston Island, Antarctica to develop a novel approach for estimating the density of Antarctic krill (Euphausia superba) encountered during foraging activities. Using the open-source Video and Image Analytics for a Marine Environment (VIAME), we trained a neural network model to identify video frames containing krill. Our image classifier has an overall accuracy of 73%, with a positive predictive value of 83% for prediction of frames containing krill. We then developed a method to estimate the volume of water imaged, thus the density (N·m-3) of krill, in the 2-dimensional images. The method is based on the maximum range from the camera where krill remain visibly resolvable and assumes that mean krill length is known, and that the distribution of orientation angles of krill is uniform. From 1,932 images identified as containing krill, we manually identified a subset of 124 images from across the video record that contained resolvable and unresolvable krill necessary to estimate the resolvable range and imaged volume for the video sensor. Krill swarm density encountered by the penguins ranged from 2 to 307 krill·m-3 and mean density of krill was 48 krill·m-3 (sd = 61 krill·m-3). Mean krill biomass density was 25 g·m-3. Our frame-level image classifier model and krill density estimation method provide a new approach to efficiently process video-logger data and estimate krill density from 2D imagery, providing key information on prey aggregations that may affect predator foraging performance. The approach should be directly applicable to other marine predators feeding on aggregations of prey.
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Affiliation(s)
- Victoria R. Hermanson
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, United States of America
| | - George R. Cutter
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, United States of America
| | - Jefferson T. Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, United States of America
| | | | - George M. Watters
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, United States of America
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Pearman WS, Duffy GA, Gemmell NJ, Morales SE, Fraser CI. Long-distance movement dynamics shape host microbiome richness and turnover. FEMS Microbiol Ecol 2024; 100:fiae089. [PMID: 38857884 PMCID: PMC11212666 DOI: 10.1093/femsec/fiae089] [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: 10/06/2023] [Revised: 05/22/2024] [Accepted: 06/08/2024] [Indexed: 06/12/2024] Open
Abstract
Host-associated microbial communities are shaped by host migratory movements. These movements can have contrasting impacts on microbiota, and understanding such patterns can provide insight into the ecological processes that contribute to community diversity. Furthermore, long-distance movements to new environments are anticipated to occur with increasing frequency due to host distribution shifts resulting from climate change. Understanding how hosts transport their microbiota with them could be of importance when examining biological invasions. Although microbial community shifts are well-documented, the underlying mechanisms that lead to the restructuring of these communities remain relatively unexplored. Using literature and ecological simulations, we develop a framework to elucidate the major factors that lead to community change. We group host movements into two types-regular (repeated/cyclical migratory movements, as found in many birds and mammals) and irregular (stochastic/infrequent movements that do not occur on a cyclical basis, as found in many insects and plants). Ecological simulations and prior research suggest that movement type and frequency, alongside environmental exposure (e.g. internal/external microbiota) are key considerations for understanding movement-associated community changes. From our framework, we derive a series of testable hypotheses, and suggest means to test them, to facilitate future research into host movement and microbial community dynamics.
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Affiliation(s)
- William S Pearman
- Department of Marine Science, University of Otago, 310 Castle St, Dunedin 9016, New Zealand
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 270 Great King Street, Dunedin 9016, New Zealand
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, 720 Cumberland St, Dunedin 9016, New Zealand
| | - Grant A Duffy
- Department of Marine Science, University of Otago, 310 Castle St, Dunedin 9016, New Zealand
| | - Neil J Gemmell
- Department of Anatomy, School of Biomedical Sciences, University of Otago, 270 Great King Street, Dunedin 9016, New Zealand
| | - Sergio E Morales
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, 720 Cumberland St, Dunedin 9016, New Zealand
| | - Ceridwen I Fraser
- Department of Marine Science, University of Otago, 310 Castle St, Dunedin 9016, New Zealand
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Bahlburg D, Hüppe L, Böhrer T, Thorpe SE, Murphy EJ, Berger U, Meyer B. Plasticity and seasonality of the vertical migration behaviour of Antarctic krill using acoustic data from fishing vessels. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230520. [PMID: 37771962 PMCID: PMC10523065 DOI: 10.1098/rsos.230520] [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: 04/20/2023] [Accepted: 09/06/2023] [Indexed: 09/30/2023]
Abstract
Understanding the vertical migration behaviour of Antarctic krill is important for understanding spatial distribution, ecophysiology, trophic interactions and carbon fluxes of this Southern Ocean key species. In this study, we analysed an eight-month continuous dataset recorded with an ES80 echosounder on board a commercial krill fishing vessel in the southwest Atlantic sector of the Southern Ocean. Our analysis supports the existing hypothesis that krill swarms migrate into deeper waters during winter but also reveals a high degree of variability in vertical migration behaviour within seasons, even at small spatial scales. During summer, we found that behaviour associated with prolonged surface presence primarily occurred at low surface chlorophyll a concentrations whereas multiple ascent-descent cycles per day occurred when surface chlorophyll a concentrations were elevated. The high plasticity, with some krill swarms behaving differently in the same location at the same time, suggests that krill behaviour is not a purely environmentally driven process. Differences in life stage, physiology and type of predator are likely other important drivers. Finally, our study demonstrates new ways of using data from krill fishing vessels, and with the routine collection of additional information in potential future projects, they have great potential to significantly advance our understanding of krill ecology.
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Affiliation(s)
- Dominik Bahlburg
- Forstliche Biometrie und Systemanalyse, Technische Universität Dresden, Pienner Straße 8, 01737 Tharandt, Dresden, Germany
- Helmholtz Centre for Environmental Research Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | - Lukas Hüppe
- Neurobiology and Genetics, Julius-Maximilian-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Alfred-Wegener-Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Thomas Böhrer
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Schloßplatz 4, 91054 Erlangen, Germany
| | - Sally E. Thorpe
- Ecosystems, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Eugene J. Murphy
- Ecosystems, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Uta Berger
- Forstliche Biometrie und Systemanalyse, Technische Universität Dresden, Pienner Straße 8, 01737 Tharandt, Dresden, Germany
| | - Bettina Meyer
- Alfred-Wegener-Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111 Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity, Ammerländer Heerstraße 231, 26129 Oldenburg, Germany
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6
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Pallin LJ, Kellar NM, Steel D, Botero-Acosta N, Baker CS, Conroy JA, Costa DP, Johnson CM, Johnston DW, Nichols RC, Nowacek DP, Read AJ, Savenko O, Schofield OM, Stammerjohn SE, Steinberg DK, Friedlaender AS. A surplus no more? Variation in krill availability impacts reproductive rates of Antarctic baleen whales. GLOBAL CHANGE BIOLOGY 2023; 29:2108-2121. [PMID: 36644792 DOI: 10.1111/gcb.16559] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/01/2022] [Indexed: 05/28/2023]
Abstract
The krill surplus hypothesis of unlimited prey resources available for Antarctic predators due to commercial whaling in the 20th century has remained largely untested since the 1970s. Rapid warming of the Western Antarctic Peninsula (WAP) over the past 50 years has resulted in decreased seasonal ice cover and a reduction of krill. The latter is being exacerbated by a commercial krill fishery in the region. Despite this, humpback whale populations have increased but may be at a threshold for growth based on these human-induced changes. Understanding how climate-mediated variation in prey availability influences humpback whale population dynamics is critical for focused management and conservation actions. Using an 8-year dataset (2013-2020), we show that inter-annual humpback whale pregnancy rates, as determined from skin-blubber biopsy samples (n = 616), are positively correlated with krill availability and fluctuations in ice cover in the previous year. Pregnancy rates showed significant inter-annual variability, between 29% and 86%. Our results indicate that krill availability is in fact limiting and affecting reproductive rates, in contrast to the krill surplus hypothesis. This suggests that this population of humpback whales may be at a threshold for population growth due to prey limitations. As a result, continued warming and increased fishing along the WAP, which continue to reduce krill stocks, will likely impact this humpback whale population and other krill predators in the region. Humpback whales are sentinel species of ecosystem health, and changes in pregnancy rates can provide quantifiable signals of the impact of environmental change at the population level. Our findings must be considered paramount in developing new and more restrictive conservation and management plans for the Antarctic marine ecosystem and minimizing the negative impacts of human activities in the region.
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Affiliation(s)
- Logan J Pallin
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Nick M Kellar
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, USA
| | - Debbie Steel
- Department of Fisheries, Wildlife & Conservation Sciences, Marine Mammal Institute, Oregon State University, Hatfield Marine Science Center, Newport, Oregon, USA
| | - Natalia Botero-Acosta
- Fundación Macuáticos Colombia, Medellín, Colombia
- Programa Antártico Colombiano, Edificio World Business Center - WBC, Bogotá, Colombia
| | - C Scott Baker
- Department of Fisheries, Wildlife & Conservation Sciences, Marine Mammal Institute, Oregon State University, Hatfield Marine Science Center, Newport, Oregon, USA
| | - Jack A Conroy
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, Virginia, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Chris M Johnson
- World Wide Fund for Nature (WWF), Melbourne, Australia
- Centre for Marine Science & Technology, Curtin University, Perth, Australia
| | - David W Johnston
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, North Carolina, USA
| | - Ross C Nichols
- Institute for Marine Science, University of California Santa Cruz, Santa Cruz, California, USA
| | - Doug P Nowacek
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, North Carolina, USA
| | - Andrew J Read
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, North Carolina, USA
| | - Oksana Savenko
- National Antarctic Scientific Center of Ukraine, Kyiv, Ukraine
- Ukrainian Scientific Center of Ecology of the Sea, Odesa, Ukraine
| | - Oscar M Schofield
- Center of Ocean Observing Leadership, Rutgers University, New Brunswick, New Jersey, USA
| | - Sharon E Stammerjohn
- Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA
| | - Deborah K Steinberg
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, Virginia, USA
| | - Ari S Friedlaender
- Institute for Marine Science, University of California Santa Cruz, Santa Cruz, California, USA
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California, USA
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Pallin LJ, Botero-Acosta N, Steel D, Baker CS, Casey C, Costa DP, Goldbogen JA, Johnston DW, Kellar NM, Modest M, Nichols R, Roberts D, Roberts M, Savenko O, Friedlaender AS. Variation in blubber cortisol levels in a recovering humpback whale population inhabiting a rapidly changing environment. Sci Rep 2022; 12:20250. [PMID: 36424421 PMCID: PMC9686265 DOI: 10.1038/s41598-022-24704-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022] Open
Abstract
Glucocorticoids are regularly used as biomarkers of relative health for individuals and populations. Around the Western Antarctic Peninsula (WAP), baleen whales have and continue to experience threats, including commercial harvest, prey limitations and habitat change driven by rapid warming, and increased human presence via ecotourism. Here, we measured demographic variation and differences across the foraging season in blubber cortisol levels of humpback whales (Megaptera novaeangliae) over two years around the WAP. Cortisol concentrations were determined from 305 biopsy samples of unique individuals. We found no significant difference in the cortisol concentration between male and female whales. However, we observed significant differences across demographic groups of females and a significant decrease in the population across the feeding season. We also assessed whether COVID-19-related reductions in tourism in 2021 along the WAP correlated with lower cortisol levels across the population. The decline in vessel presence in 2021 was associated with a significant decrease in humpback whale blubber cortisol concentrations at the population level. Our findings provide critical contextual data on how these hormones vary naturally in a population over time, show direct associations between cortisol levels and human presence, and will enable comparisons among species experiencing different levels of human disturbance.
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Affiliation(s)
- L J Pallin
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA, 95060, USA.
| | - N Botero-Acosta
- Fundación Macuáticos Colombia, Calle 27 # 79-167, Medellín, Colombia
- Programa Antártico Colombiano, Avenida Ciudad de Cali #51 - 66, Oficina 306, Edificio World Business Center - WBC, Bogotá, D.C., Colombia
| | - D Steel
- Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR, 97365, USA
| | - C S Baker
- Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR, 97365, USA
| | - C Casey
- Institute for Marine Science, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA, 95060, USA
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA, 95003, USA
| | - D P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - J A Goldbogen
- Department of Biology, Hopkins Marine Station, Stanford University, 120 Ocean View Blvd, Pacific Grove, CA, 93950, USA
| | - D W Johnston
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, NC, 28516, USA
| | - N M Kellar
- Marine Mammal Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA, 92037, USA
| | - M Modest
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - R Nichols
- Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - D Roberts
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA, 95003, USA
| | - M Roberts
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA, 95003, USA
| | - O Savenko
- National Antarctic Scientific Center of Ukraine, 16 Taras Shevchenko Blvd., Kyiv, 01601, Ukraine
- Ukrainian Scientific Center of Ecology of the Sea, 89 Frantsuzsky Blvd., Odesa, 65009, Ukraine
| | - A S Friedlaender
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA, 95003, USA
- Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA, 95060, USA
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