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Koschinski S, Owen K, Lehnert K, Kamińska K. Current species protection does not serve its porpoise-Knowledge gaps on the impact of pressures on the Critically Endangered Baltic Proper harbour porpoise population, and future recommendations for its protection. Ecol Evol 2024; 14:e70156. [PMID: 39267689 PMCID: PMC11392595 DOI: 10.1002/ece3.70156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 06/13/2024] [Accepted: 07/29/2024] [Indexed: 09/15/2024] Open
Abstract
Successful management requires information on pressures that threaten a species and areas where conservation actions are needed. The Baltic Proper harbour porpoise population was first listed as Critically Endangered by the International Union for the Conservation of Nature in 2008. Now, 16 years later, there is no change in conservation status despite ample conservation policy calling for its protection and an urgent need for management action to protect this population. Here, we provide an overview of the current status of the population, highlight knowledge gaps on the impact of pressures, and make recommendations for management of anthropogenic activities. Based on an exceeded limit for anthropogenic mortality, the high concentrations of contaminants in the Baltic Sea, combined with reductions in prey availability and increases in underwater noise, it is inferred that this population is likely still decreasing in size and conservation action becomes more urgent. As bycatch and unprotected underwater explosions result in direct mortality, they must be reduced to zero. Inputs of contaminants, waste, and existing and emerging noise sources should be minimised and regulated. Additionally, ecosystem-based sustainable management of fisheries is paramount in order to ensure prey availability, and maintain a healthy Baltic Sea. Stranding networks to routinely assess individuals for genetic population assignment and health need to be expanded, to identify rare samples from this population. Knowledge is still scarce on the population-level impact of each threat, along with the cumulative impact of multiple pressures on the population. However, the current knowledge and management instruments are sufficient to apply effective protection for the population now. While bycatch is the main pressure impacting this population, urgent conservation action is needed across all anthropogenic activities. Extinction of the Baltic Proper harbour porpoise population is a choice: decision-makers have the fate of this genetically and biologically distinct marine mammal population in their hands.
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Affiliation(s)
| | - Kylie Owen
- Department of Population Analysis and Monitoring Swedish Museum of Natural History Stockholm Sweden
| | - Kristina Lehnert
- Institute for Terrestrial and Aquatic Wildlife Research University of Veterinary Medicine Hannover Hannover Germany
| | - Katarzyna Kamińska
- Department of Fisheries Ministry of Agriculture and Rural Development Warsaw Poland
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Branstetter BK, Nease K, Accomando AW, Davenport J, Felice M, Peters K, Robeck T. Temporal integration of tone signals by a killer whale (Orcinus orca). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:3906-3915. [PMID: 38117126 DOI: 10.1121/10.0023956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 11/29/2023] [Indexed: 12/21/2023]
Abstract
A psychophysical procedure was used to measure pure-tone detection thresholds for a killer whale (Orcinus orca) as a function of both signal frequency and signal duration. Frequencies ranged between 1 and 100 kHz and signal durations ranged from 50 μs to 2 s, depending on the frequency. Detection thresholds decreased with an increase in signal duration up to a critical duration, which represents the auditory integration time. Integration times ranged from 4 ms at 100 kHz and increased up to 241 ms at 1 kHz. The killer whale data are similar to other odontocete species that have participated in similar experiments. The results have implications for noise impact predictions for signals with durations less than the auditory integration time.
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Affiliation(s)
- Brian K Branstetter
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #204, San Diego, California 92106, USA
- Naval Facilities Engineering Systems Command Pacific, 528 Makalapa Drive, Suite 100, Honolulu, Hawaii 96860, USA
| | - Kayla Nease
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #204, San Diego, California 92106, USA
- SeaWorld San Diego, 500 SeaWorld Drive, San Diego, California 92109, USA
| | - Alyssa W Accomando
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #204, San Diego, California 92106, USA
- Naval Information Warfare Center Pacific, 53560 Hull Street, San Diego, California 92152, USA
| | - Jennifer Davenport
- SeaWorld San Diego, 500 SeaWorld Drive, San Diego, California 92109, USA
| | - Michael Felice
- SeaWorld San Diego, 500 SeaWorld Drive, San Diego, California 92109, USA
| | - Ken Peters
- SeaWorld San Diego, 500 SeaWorld Drive, San Diego, California 92109, USA
| | - Todd Robeck
- SeaWorld Parks and Entertainment, 7007 SeaWorld Drive, Orlando, Florida 21821, USA
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Brewer AM, Castellote M, Van Cise AM, Gage T, Berdahl AM. Communication in Cook Inlet beluga whales: Describing the vocal repertoire and masking of calls by commercial ship noise. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:3487-3505. [PMID: 38032263 DOI: 10.1121/10.0022516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023]
Abstract
Many species rely on acoustic communication to coordinate activities and communicate to conspecifics. Cataloging vocal behavior is a first step towards understanding how individuals communicate information and how communication may be degraded by anthropogenic noise. The Cook Inlet beluga population is endangered with an estimated 331 individuals. Anthropogenic noise is considered a threat for this population and can negatively impact communication. To characterize this population's vocal behavior, vocalizations were measured and classified into three categories: whistles (n = 1264, 77%), pulsed calls (n = 354, 22%), and combined calls (n = 15, 1%), resulting in 41 call types. Two quantitative analyses were conducted to compare with the manual classification. A classification and regression tree and Random Forest had a 95% and 85% agreement with the manual classification, respectively. The most common call types per category were then used to investigate masking by commercial ship noise. Results indicate that these call types were partially masked by distant ship noise and completely masked by close ship noise in the frequency range of 0-12 kHz. Understanding vocal behavior and the effects of masking in Cook Inlet belugas provides important information supporting the management of this endangered population.
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Affiliation(s)
- Arial M Brewer
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Manuel Castellote
- Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington, Seattle, Washington 98195, USA
| | - Amy M Van Cise
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Tom Gage
- Alaska Department of Fish and Game, Anchorage, Alaska 99518, USA
| | - Andrew M Berdahl
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
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Jones RA, Sills JM, Synnott M, Mulsow J, Williams R, Reichmuth C. Auditory masking in odobenid and otariid carnivoresa). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:1746-1756. [PMID: 37712749 DOI: 10.1121/10.0020911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/23/2023] [Indexed: 09/16/2023]
Abstract
As the only living species within the odobenid lineage of carnivores, walruses (Odobenus rosmarus) have no close relatives from which auditory information can be extrapolated. Sea lions and fur seals in the otariid lineage are the nearest evolutionary outgroup. To advance understanding of odobenid and otariid hearing, we conducted behavioral testing with two walruses and one California sea lion (Zalophus californianus). Detection thresholds for airborne sounds were measured from 0.08 to at least 16 kHz in ambient noise conditions and then re-measured in the presence of octave-band white masking noise. Walruses were more sensitive than the sea lion at lower frequencies and less sensitive at higher frequencies. Critical ratios for the walruses ranged from 20 dB at 0.2 kHz to 32 dB at 10 kHz, while critical ratios for the sea lion ranged from 16 dB at 0.2 kHz to 35 dB at 32 kHz. The masking values for these species are comparable to one another and to those of terrestrial carnivores, increasing by about 3 dB per octave with increasing frequency. Despite apparent differences in hearing range and sensitivity, odobenids and otariids have a similar ability to hear signals in noisy conditions.
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Affiliation(s)
- Ryan A Jones
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Jillian M Sills
- Institute of Marine Sciences, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, California 95060, USA
| | - Mitzi Synnott
- SeaWorld San Diego, San Diego, California 92109, USA
| | - Jason Mulsow
- National Marine Mammal Foundation, San Diego, California 92109, USA
| | - Rob Williams
- Oceans Initiative, Seattle, Washington 98102, USA
| | - Colleen Reichmuth
- Institute of Marine Sciences, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, California 95060, USA
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Graham IM, Gillespie D, Gkikopoulou KC, Hastie GD, Thompson PM. Directional hydrophone clusters reveal evasive responses of small cetaceans to disturbance during construction at offshore windfarms. Biol Lett 2023; 19:20220101. [PMID: 36651028 PMCID: PMC9845968 DOI: 10.1098/rsbl.2022.0101] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 12/19/2022] [Indexed: 01/19/2023] Open
Abstract
Mitigation measures to disperse marine mammals prior to pile-driving include acoustic deterrent devices and piling soft starts, but their efficacy remains uncertain. We developed a self-contained portable hydrophone cluster to detect small cetacean movements from the distributions of bearings to detections. Using an array of clusters within 10 km of foundation pile installations, we tested the hypothesis that harbour porpoises (Phocoena phocoena) respond to mitigation measures at offshore windfarm sites by moving away. During baseline periods, porpoise movements were evenly distributed in all directions. By contrast, animals showed significant directional movement away from sound sources during acoustic deterrent device use and piling soft starts. We demonstrate that porpoises respond to measures aimed to mitigate the most severe impacts of construction at offshore windfarms by swimming directly away from these sound sources. Portable directional hydrophone clusters now provide opportunities to characterize responses to disturbance sources across a broad suite of habitats and contexts.
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Affiliation(s)
- I M Graham
- Lighthouse Field Station, School of Biological Sciences, University of Aberdeen, Cromarty, Ross-shire IV11 8YL, Scotland
| | - D Gillespie
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, Scotland
| | - K C Gkikopoulou
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, Scotland
| | - G D Hastie
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, Scotland
| | - P M Thompson
- Lighthouse Field Station, School of Biological Sciences, University of Aberdeen, Cromarty, Ross-shire IV11 8YL, Scotland
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Hanke FD, Biolsi KL, Harley HE. "Cognition in marine mammals: the strength of flexibility in adapting to marine life". Anim Cogn 2022; 25:1015-1018. [PMID: 36152088 PMCID: PMC9617844 DOI: 10.1007/s10071-022-01681-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022]
Abstract
In this theme issue, our multidisciplinary contributors highlight the cognitive adaptations of marine mammals. The cognitive processes of this group are highly informative regarding how animals cope with specifics of and changes in the environment, because, not only did modern marine mammals evolve from numerous, non-related terrestrial animals to adapt to an aquatic lifestyle, but some of these species regularly move between two worlds, land and sea. Here, we bring together scientists from different fields and take the reader on a journey that begins with the ways in which modern marine mammals (whales, dolphins, seals, sea lions and manatees) utilize their perceptual systems, next moves into studies of the constraints and power of individuals' cognitive flexibility, and finally showcases how those systems are deployed in social and communicative contexts. Considering the cognitive processes of the different marine mammals in one issue from varying perspectives will help us understand the strength of cognitive flexibility in changing environments-in marine mammals and beyond.
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Affiliation(s)
- Frederike D Hanke
- Institute for Biosciences, Neuroethology, University of Rostock, Rostock, Germany.
| | - Kristy L Biolsi
- St. Francis College, Brooklyn Heights, NY, USA
- Center for the Study of Pinniped Ecology and Cognition (C-SPEC), Brooklyn Heights, USA
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