Pub Date : 2024-05-15DOI: 10.1578/am.50.3.2024.272
Martin Böye
{"title":"Marine Mammal Experts. Let’s Share Your Stories! An Open Letter Reflecting on the 52nd Annual Symposium of the European Association for Aquatic Mammals","authors":"Martin Böye","doi":"10.1578/am.50.3.2024.272","DOIUrl":"https://doi.org/10.1578/am.50.3.2024.272","url":null,"abstract":"","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140975706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.1578/am.50.3.2024.215
Romyna A. Cruz‐Vallejo, F. Elorriaga-Verplancken, A. B. Enríquez-García, E. Rodríguez-Rafael
Female northern elephant seals (Mirounga angustirostris) are migratory animals that form colonies along the coasts of California and the Baja California Peninsula, Mexico. A recent decline in abundance has been recorded in this species Mexican distribution, which is an important reason to investigate the different ecological processes operating in these colonies. The aim of this study was to determine values of stable isotope ratios (δ13C and δ15N) in pup fur as foraging maternal indicators. During the same breeding season (2015), pup fur samples were collected to investigate these foraging variations between the two major Mexican colonies—Guadalupe Island (GI) and the San Benito Archipelago (SBA). Isotopic areas were built using the ‘SIBER’ package in R, and a custom hierarchical Bayesian model was used to compare the values from both localities. Mean (± standard deviation [SD]) δ13C values for individuals from GI and the SBA were -16.9 ± 0.8‰ and -17.3 ± 0.4‰, respectively, while δ15N values were 17.4 ± 1.1‰ and 16.7 ± 1.1‰, respectively. The difference between the posterior means indicated a high probability (P > 99%) of GI having higher stable isotope ratio values than the SBA. For the posterior SDs, there were highly probable differences (P = 100%) only for δ13C, where GI had a higher dispersion. Such differences explained why GI presented a wider isotopic niche area than the SBA, indicating more diverse foraging habits along GI’s offshore-inshore gradient. Additionally, GI showed higher δ15N values than the SBA. Although this could be related to a slightly higher trophic position for GI individuals, the latitudinal effects of foraging grounds with distinct isotopic baselines remain a plausible explanation for the variations in both isotope ratios, suggesting that individuals from the SBA foraged in a more northerly location than those from GI. This study provides valuable knowledge about how females from both colonies partition resources, especially regarding habitat use.
雌性北象海豹（Mirounga angustirostris）是一种迁徙动物，它们在墨西哥加利福尼亚和下加利福尼亚半岛沿岸形成群落。据记录，最近该物种在墨西哥分布区的数量有所下降，这也是研究这些群落中不同生态过程的一个重要原因。本研究旨在确定幼鸟毛皮中的稳定同位素比值（δ13C 和 δ15N），作为觅食的母性指标。在同一繁殖季节（2015 年），收集了幼鸟毛皮样本，以研究墨西哥两大繁殖地--瓜达卢佩岛（Guadalupe Island，GI）和圣贝尼托群岛（San Benito Archipelago，SBA）之间的觅食差异。使用 R 中的 "SIBER "软件包建立了同位素区域，并使用定制的分层贝叶斯模型比较了两个地点的数值。来自大洋洲和南澳大利亚的个体的δ13C平均值（±标准差[SD]）分别为-16.9±0.8‰和-17.3±0.4‰，而δ15N值分别为17.4±1.1‰和16.7±1.1‰。后均值之间的差异表明，GI 的稳定同位素比值高于 SBA 的可能性很大（P > 99%）。就后标距而言，只有δ13C 的差异概率较高（P = 100%），而 GI 的离散度较高。这种差异解释了为什么 GI 比 SBA 呈现出更宽的同位素生态位区域，表明沿着 GI 的离岸-近岸梯度，觅食习性更加多样化。此外，GI的δ15N值高于SBA。虽然这可能是由于大洋洲个体的营养位置略高，但具有不同同位素基线的觅食地的纬度效应仍然是两种同位素比值变化的一个合理解释，表明南澳大利亚的个体比大洋洲的个体在更靠北的地方觅食。这项研究为了解两个群落的雌性个体如何分配资源，尤其是如何利用栖息地提供了宝贵的信息。
{"title":"Foraging Segregation Between Adult Female Northern Elephant Seals (Mirounga angustirostris) from Guadalupe Island and the San Benito Archipelago, Mexico","authors":"Romyna A. Cruz‐Vallejo, F. Elorriaga-Verplancken, A. B. Enríquez-García, E. Rodríguez-Rafael","doi":"10.1578/am.50.3.2024.215","DOIUrl":"https://doi.org/10.1578/am.50.3.2024.215","url":null,"abstract":"Female northern elephant seals (Mirounga angustirostris) are migratory animals that form colonies along the coasts of California and the Baja California Peninsula, Mexico. A recent decline in abundance has been recorded in this species Mexican distribution, which is an important reason to investigate the different ecological processes operating in these colonies. The aim of this study was to determine values of stable isotope ratios (δ13C and δ15N) in pup fur as foraging maternal indicators. During the same breeding season (2015), pup fur samples were collected to investigate these foraging variations between the two major Mexican colonies—Guadalupe Island (GI) and the San Benito Archipelago (SBA). Isotopic areas were built using the ‘SIBER’ package in R, and a custom hierarchical Bayesian model was used to compare the values from both localities. Mean (± standard deviation [SD]) δ13C values for individuals from GI and the SBA were -16.9 ± 0.8‰ and -17.3 ± 0.4‰, respectively, while δ15N values were 17.4 ± 1.1‰ and 16.7 ± 1.1‰, respectively. The difference between the posterior means indicated a high probability (P > 99%) of GI having higher stable isotope ratio values than the SBA. For the posterior SDs, there were highly probable differences (P = 100%) only for δ13C, where GI had a higher dispersion. Such differences explained why GI presented a wider isotopic niche area than the SBA, indicating more diverse foraging habits along GI’s offshore-inshore gradient. Additionally, GI showed higher δ15N values than the SBA. Although this could be related to a slightly higher trophic position for GI individuals, the latitudinal effects of foraging grounds with distinct isotopic baselines remain a plausible explanation for the variations in both isotope ratios, suggesting that individuals from the SBA foraged in a more northerly location than those from GI. This study provides valuable knowledge about how females from both colonies partition resources, especially regarding habitat use.","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.1578/am.50.3.2024.259
Lorenzo von Fersen, Dave Bader, James Danoff-Burg, Frank Cipriano, Laura R. Perry, Silvio Marchini
{"title":"The Human Dimensions of Small Cetacean Conservation: 2022 Workshop Report, Nuremberg, Germany","authors":"Lorenzo von Fersen, Dave Bader, James Danoff-Burg, Frank Cipriano, Laura R. Perry, Silvio Marchini","doi":"10.1578/am.50.3.2024.259","DOIUrl":"https://doi.org/10.1578/am.50.3.2024.259","url":null,"abstract":"","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140973002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.1578/am.50.3.2024.230
Jeroen Hofs, Jure Miočić-Stošić, M. Frleta-Valić, P. Mackelworth, D. Holcer
In the Adriatic Sea, a female common bottlenose dolphin named “Boa” was observed on 19 occasions between 2009 and 2019, inhaling via her mouth for every observed respiration. We provide some explanations for the potential cause of this behaviour using existing evidence. Boa appeared to be in good physical shape and displayed behaviour similar to other individuals. She mothered three calves, raising at least one to independence successfully. Because she lived a normal life, we believe she could vocalise and echolocate. Boa may have been forced to breathe through her mouth to deal with internal injuries, occlusion, or disease. Of the potential causes, an occlusion of the upper respiratory tract seems more likely than a perforation or permanent dislocation of the larynx. An occlusion could result from disease, a congenital disorder, and/or wrongly ingested or inhaled food items or foreign materials. To breathe via the mouth, Boa must have been able to circumvent the separation of the respiratory tract from the oral cavity. By relaxing the respiratory muscles, particularly the palatopharyngeus, she could have used the negative pressure of the lungs to pull in air from the oropharynx into the upper respiratory tract. The true cause of Boa’s condition will probably never be discovered.
{"title":"Defying Evolution: Observations of a Mouth-Breathing Bottlenose Dolphin (Tursiops truncatus)","authors":"Jeroen Hofs, Jure Miočić-Stošić, M. Frleta-Valić, P. Mackelworth, D. Holcer","doi":"10.1578/am.50.3.2024.230","DOIUrl":"https://doi.org/10.1578/am.50.3.2024.230","url":null,"abstract":"In the Adriatic Sea, a female common bottlenose dolphin named “Boa” was observed on 19 occasions between 2009 and 2019, inhaling via her mouth for every observed respiration. We provide some explanations for the potential cause of this behaviour using existing evidence. Boa appeared to be in good physical shape and displayed behaviour similar to other individuals. She mothered three calves, raising at least one to independence successfully. Because she lived a normal life, we believe she could vocalise and echolocate. Boa may have been forced to breathe through her mouth to deal with internal injuries, occlusion, or disease. Of the potential causes, an occlusion of the upper respiratory tract seems more likely than a perforation or permanent dislocation of the larynx. An occlusion could result from disease, a congenital disorder, and/or wrongly ingested or inhaled food items or foreign materials. To breathe via the mouth, Boa must have been able to circumvent the separation of the respiratory tract from the oral cavity. By relaxing the respiratory muscles, particularly the palatopharyngeus, she could have used the negative pressure of the lungs to pull in air from the oropharynx into the upper respiratory tract. The true cause of Boa’s condition will probably never be discovered.","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.1578/am.50.3.2024.199
Israel Huesca-Domínguez, Eduardo Morteo, L. G. Abarca-Arenas, Brian C. Balmer, Tara M. Cox, C. A. Delfín-Alfonso, Isabel C. Hernández-Candelario
Residency and site fidelity are important parameters in population ecology for many species as they indicate the temporal and spatial use for individuals. Although both terms are clearly different, they are used interchangeably due to lack of clarity in their definitions and the ways to assess them, especially in bottlenose dolphins (Tursiops spp.). Individuals with well-defined patterns of residency and site fidelity may be more vulnerable to anthropogenic disturbances; thus, the study of these parameters may help to better assess such impacts. However, interspecific differences and logistical restrictions for the study of dolphins have prevented consensus. We set out to investigate the factors that have influenced measurements of residency and site fidelity in bottlenose and a set of other dolphin species through a retrospective (~30 y: 1990 to 2019) literature review. We found 117 scientific papers with a two-fold increasing trend approximately every 15 years, with 50% published in only four journals. Most of the studies were developed in the United States, followed by Australia and Europe, likely due to strict policies for marine mammal conservation. Author collaboration network analysis showed highly atomized national groups in which North American organizations formed the biggest cluster, followed by Australia, Africa, and Europe. However, large worldwide gaps still exist, possibly because of the heterogeneity in marine mammal sampling efforts and limited information availability in the North Pacific, Central and South America, Africa, Asia, and the Indian Ocean. We found 30 different classification methods in which 12 were based on defined categories. We provide conceptual aid to distinguish between the use of both terms, as well as guidance to tackle the challenge of defining patterns of temporal use due to the variability of thresholds for classifying individuals. A paradigm shift is needed to create comprehensive, standardized, and generalized assessments of residency and site fidelity, which can be compared based on their performance across different populations of bottlenose dolphins around the world.
{"title":"Assessing Residency and Site Fidelity in Bottlenose Dolphins: A Literature Review and Bibliometric Analysis","authors":"Israel Huesca-Domínguez, Eduardo Morteo, L. G. Abarca-Arenas, Brian C. Balmer, Tara M. Cox, C. A. Delfín-Alfonso, Isabel C. Hernández-Candelario","doi":"10.1578/am.50.3.2024.199","DOIUrl":"https://doi.org/10.1578/am.50.3.2024.199","url":null,"abstract":"Residency and site fidelity are important parameters in population ecology for many species as they indicate the temporal and spatial use for individuals. Although both terms are clearly different, they are used interchangeably due to lack of clarity in their definitions and the ways to assess them, especially in bottlenose dolphins (Tursiops spp.). Individuals with well-defined patterns of residency and site fidelity may be more vulnerable to anthropogenic disturbances; thus, the study of these parameters may help to better assess such impacts. However, interspecific differences and logistical restrictions for the study of dolphins have prevented consensus. We set out to investigate the factors that have influenced measurements of residency and site fidelity in bottlenose and a set of other dolphin species through a retrospective (~30 y: 1990 to 2019) literature review. We found 117 scientific papers with a two-fold increasing trend approximately every 15 years, with 50% published in only four journals. Most of the studies were developed in the United States, followed by Australia and Europe, likely due to strict policies for marine mammal conservation. Author collaboration network analysis showed highly atomized national groups in which North American organizations formed the biggest cluster, followed by Australia, Africa, and Europe. However, large worldwide gaps still exist, possibly because of the heterogeneity in marine mammal sampling efforts and limited information availability in the North Pacific, Central and South America, Africa, Asia, and the Indian Ocean. We found 30 different classification methods in which 12 were based on defined categories. We provide conceptual aid to distinguish between the use of both terms, as well as guidance to tackle the challenge of defining patterns of temporal use due to the variability of thresholds for classifying individuals. A paradigm shift is needed to create comprehensive, standardized, and generalized assessments of residency and site fidelity, which can be compared based on their performance across different populations of bottlenose dolphins around the world.","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.1578/am.50.3.2024.252
Minmin Chen, Liang Fang, Xuequn Li, Dara Saing, Yuxi Lian, Ping Zhang, Kang Zhang, Daoping Yu
Information on the feeding habits of the critically endangered Irrawaddy dolphin (Orcaella brevirostris) in the Mekong River and how their diet overlaps with that of the species targeted by fisheries is limited. The information provided herein will be helpful for evaluating and protecting important dolphin food resources. The composition of large prey species of Irrawaddy dolphins and the extent of fish resources were surveyed in the Mekong River, Cambodia, using local ecological knowledge. The results showed that Irrawaddy dolphins fed on 13 species of large fish, with Pangasius conchophilus, Cyclocheilichthys enoplos, and Hemibagrus wyckii the most frequently consumed prey. Twelve of the 13 reported prey species were usually caught by fishers. The results also revealed that the average weight of fish caught daily by fishers was significantly lower in 2019 than about five years before that, regardless of the season. A significant decline in fish resources and a high overlap of dolphin diets with fishery target species indicate that Irrawaddy dolphins may also be threatened by prey depletion, especially during the dry season when dolphins are concentrated in deep pools.
{"title":"Composition of Large Prey Species of Irrawaddy Dolphins (Orcaella brevirostris) in the Mekong River: Implications for Conservation of the Prey Resources","authors":"Minmin Chen, Liang Fang, Xuequn Li, Dara Saing, Yuxi Lian, Ping Zhang, Kang Zhang, Daoping Yu","doi":"10.1578/am.50.3.2024.252","DOIUrl":"https://doi.org/10.1578/am.50.3.2024.252","url":null,"abstract":"Information on the feeding habits of the critically endangered Irrawaddy dolphin (Orcaella brevirostris) in the Mekong River and how their diet overlaps with that of the species targeted by fisheries is limited. The information provided herein will be helpful for evaluating and protecting important dolphin food resources. The composition of large prey species of Irrawaddy dolphins and the extent of fish resources were surveyed in the Mekong River, Cambodia, using local ecological knowledge. The results showed that Irrawaddy dolphins fed on 13 species of large fish, with Pangasius conchophilus, Cyclocheilichthys enoplos, and Hemibagrus wyckii the most frequently consumed prey. Twelve of the 13 reported prey species were usually caught by fishers. The results also revealed that the average weight of fish caught daily by fishers was significantly lower in 2019 than about five years before that, regardless of the season. A significant decline in fish resources and a high overlap of dolphin diets with fishery target species indicate that Irrawaddy dolphins may also be threatened by prey depletion, especially during the dry season when dolphins are concentrated in deep pools.","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140977253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.1578/am.50.3.2024.171
Achmad Sahri, Régis Hocdé, M. R. Nandika, Fahmi, Lay Tjarles, La O. Alifatri, J. F. Manuhutu, Mathias Taborat, Ferdinand I. P. Bata, Danielle Kreb, P. K. Mustika, L. Mannocci
{"title":"Updating the Cetacean Species List of Raja Ampat, Indonesia, with Additional Sightings of the Rarely Documented Omura’s Whale (Balaenoptera omurai) and a New Record of Melon-Headed Whales (Peponocephala electra)","authors":"Achmad Sahri, Régis Hocdé, M. R. Nandika, Fahmi, Lay Tjarles, La O. Alifatri, J. F. Manuhutu, Mathias Taborat, Ferdinand I. P. Bata, Danielle Kreb, P. K. Mustika, L. Mannocci","doi":"10.1578/am.50.3.2024.171","DOIUrl":"https://doi.org/10.1578/am.50.3.2024.171","url":null,"abstract":"","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1578/am.50.2.2024.107
R. Kastelein, Lean Helder-Hoek, Laura Van Acoleyen, Linde N. Defillet, J. Terhune
To determine their frequency-dependent susceptibility to noise-induced temporary hearing threshold shift (TTS), two California sea lions (Zalophus californianus) were exposed for 60 min to a continuous one-sixth-octave noise band (NB) centered at 32 kHz as the fatiguing sound, at sound pressure levels of 132 to 156 dB re 1 µPa (sound exposure levels [SELs] of 168 to 192 dB re 1 µPa2s). Using a psychoacoustic technique, TTSs were quantified at the center frequency of the fatiguing sound and at half an octave and one octave above the center frequency (at 32, 44.8, and 63 kHz). When significant TTS occurred, higher SELs resulted in greater TTSs. TTSs and hearing recovery patterns were similar in both sea lions. The mean onset of TTS1-4 min (defined as 6 dB TTS) in sea lion F01 is estimated to occur after exposure to an SEL of 179 dB re 1 µPa2s (at hearing test frequency 44.8 kHz). After exposure to an SEL of 180 dB re 1 µPa2s, a mean TTS1-4 min of 6.7 dB was measured at hearing test frequency 44.8 kHz. In California sea lions, TTS onset levels are not as closely related (especially at the lower and higher frequencies) to the unmasked hearing thresholds (audiograms) as was previously assumed.
为了确定它们对噪声引起的暂时性听阈偏移（TTS）的频率依赖性，两只加利福尼亚海狮（Zalophus californianus）被连续暴露在以 32 kHz 为中心的六分之一倍频程噪声带（NB）中 60 分钟，作为疲劳声，声压级为 132 至 156 dB re 1 µPa（声暴露级 [SELs] 为 168 至 192 dB re 1 µPa2s）。利用心理声学技术，在疲劳声的中心频率以及中心频率以上半个八度和一个八度（32、44.8 和 63 kHz）处对 TTS 进行量化。当出现明显的 TTS 时，SEL 越高，TTS 越大。两只海狮的 TTS 和听力恢复模式相似。据估计，海狮 F01 在暴露于 179 dB re 1 µPa2s（听力测试频率为 44.8 kHz）的 SEL 后，平均会出现 1-4 min 的 TTS（定义为 6 dB TTS）。暴露于 180 dB re 1 µPa2s 的 SEL 后，在听力测试频率 44.8 kHz 时测得平均 TTS1-4 min 为 6.7 dB。在加州海狮中，TTS 的起始水平（尤其是低频和高频）与未掩蔽听阈（听力图）之间的关系并不像之前假设的那样密切。
{"title":"Temporary Hearing Threshold Shift in California Sea Lions (Zalophus californianus) Due to a Noise Band Centered at 32 kHz","authors":"R. Kastelein, Lean Helder-Hoek, Laura Van Acoleyen, Linde N. Defillet, J. Terhune","doi":"10.1578/am.50.2.2024.107","DOIUrl":"https://doi.org/10.1578/am.50.2.2024.107","url":null,"abstract":"To determine their frequency-dependent susceptibility to noise-induced temporary hearing threshold shift (TTS), two California sea lions (Zalophus californianus) were exposed for 60 min to a continuous one-sixth-octave noise band (NB) centered at 32 kHz as the fatiguing sound, at sound pressure levels of 132 to 156 dB re 1 µPa (sound exposure levels [SELs] of 168 to 192 dB re 1 µPa2s). Using a psychoacoustic technique, TTSs were quantified at the center frequency of the fatiguing sound and at half an octave and one octave above the center frequency (at 32, 44.8, and 63 kHz). When significant TTS occurred, higher SELs resulted in greater TTSs. TTSs and hearing recovery patterns were similar in both sea lions. The mean onset of TTS1-4 min (defined as 6 dB TTS) in sea lion F01 is estimated to occur after exposure to an SEL of 179 dB re 1 µPa2s (at hearing test frequency 44.8 kHz). After exposure to an SEL of 180 dB re 1 µPa2s, a mean TTS1-4 min of 6.7 dB was measured at hearing test frequency 44.8 kHz. In California sea lions, TTS onset levels are not as closely related (especially at the lower and higher frequencies) to the unmasked hearing thresholds (audiograms) as was previously assumed.","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140239425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Josh D. McInnes, A. Trites, Chelsea R. Mathieson, M. Dahlheim, Jeff Moore, Paula Olson, Kevin M. Lester
{"title":"Evidence for an Oceanic Population of Killer Whales (Orcinus orca) in Offshore Waters of California and Oregon","authors":"Josh D. McInnes, A. Trites, Chelsea R. Mathieson, M. Dahlheim, Jeff Moore, Paula Olson, Kevin M. Lester","doi":"10.1578/am.50.2.2024.93","DOIUrl":"https://doi.org/10.1578/am.50.2.2024.93","url":null,"abstract":"","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Britney E. Pepper, Marina A. Piscitelli-Doshkov, Paul K. Doshkov, Andrew J. Read
{"title":"Heading South for the Winter: The Seasonal Occurrence of Harbor Seals (Phoca vitulina vitulina) Near Oregon Inlet, North Carolina, USA","authors":"Britney E. Pepper, Marina A. Piscitelli-Doshkov, Paul K. Doshkov, Andrew J. Read","doi":"10.1578/am.50.2.2024.86","DOIUrl":"https://doi.org/10.1578/am.50.2.2024.86","url":null,"abstract":"","PeriodicalId":8219,"journal":{"name":"Aquatic Mammals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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