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The common dolphin (Delphinus delphis) is a widely distributed species exhibiting extensive morphological diversity, with previous taxonomies recognizing multiple Delphinus species primarily based on relative beak length. We sequenced mitochondrial genomes of D. delphis morphotypes from multiple regions, calculated mitogenome nucleotide diversity (π = 0.00504), dated Delphinus mitogenome diversification to 1.27 mya, and conducted phylogenetic and population‐level analyses focusing on morphotype and geographic origin. We present the first Delphinus sequencing data from Senegal, at the edge of where long‐ and short‐beaked dolphins co‐occur in the Atlantic, but only recovering stranded dolphins with long or indeterminate beak lengths. While we detected little genetic structure across most of the North Atlantic, fixation indices demonstrate that Senegalese dolphins are distinct. Geography did not reliably predict phylogeny, with few monophyletic localities, but we do infer a monophyletic group of long‐beaked dolphins from California, Peru, and possibly China. However, neither Senegalese long‐beaked dolphins nor long‐beaked D. d. tropicalis are closely related to Pacific long‐beaked dolphins, providing no support for a worldwide long‐beaked clade (formerly D. capensis). Our findings reveal a distinctive Senegal Delphinus population and provide a foundation for global genomic analyses to further investigate the evolution of Delphinus morphotypes. [ABSTRACT FROM AUTHOR]

Neritic, long‐beaked common dolphins have been described as species distinct from the more oceanic and globally distributed short‐beaked species, Delphinus delphis, although recent molecular studies have challenged this view. In the eastern North Pacific (ENP), the taxonomic status of the long‐beaked (bairdii) form has been controversial since its original description in 1873, and has vacillated between species, subspecies, and geographic forms several times. It is currently provisionally viewed as a subspecies of Delphinus delphis, D. d. bairdii. To clarify this situation, we reviewed the literature and conducted additional analyses using both newly obtained genetic and cranial morphometric data sets. The results indicate that there are diagnostic differences in skull morphology and coloration between the eastern Pacific long‐and short‐beaked forms, and near‐perfect diagnosability in mitochondrial DNA. These differences, along with indications of ecological distinctions, including important differences in life history parameters and reproductive timing, indicate that these forms are well on their way down separate evolutionary pathways. As such, we consider them to be distinct species in the eastern Pacific. The long‐beaked species is referable to Delphinus bairdii Dall, 1873, and is redescribed as such herein. [ABSTRACT FROM AUTHOR]

As highly social animals, Indo-Pacific humpback dolphins (Sousa chinensis) exhibit community differentiation. Nevertheless, our understanding of the external and internal factors influencing these dynamics, as well as their spatiotemporal variations, is still limited. In the present study, variations in the social structure of an endangered Indo-Pacific humpback dolphin population in Xiamen Bay, China, were monitored over two distinct periods (2007–2010 and 2017–2019) to analyze the effects of habitat utilization and the composition of individuals within the population. In both periods, the population demonstrated a strikingly similar pattern of social differentiation, characterized by the division of individuals into two main clusters and one small cluster. Spatially, the two primary clusters occupied the eastern and western waters, respectively, although the core distribution area of the eastern cluster shifted further eastward between the two periods. Despite this distribution shift, the temporal stability of the social structure and inter-associations within the eastern cluster remained unaffected. A subset of 16 individuals observed in both periods, comprising 51.6% and 43.2% of the population in each respective period, emerged as a foundational element of the social structure and may be responsible for sustaining social structure stability, especially during the 2007–2010 period. These observations suggest that the composition of dominant individuals, an internal factor, had a more substantial influence on the formation of the social network than changes in habitat use, an external factor. Consequently, the study proposes distinct conservation measures tailored to each of the two main clusters. [ABSTRACT FROM AUTHOR]

There is a mystery surrounding the disappearance of short-finned pilot whales (Globicephala macrorhynchus) from southern California. This species was very common in these waters through the early 1980s, with an apparently seasonally-resident population centered around Santa Catalina Island in the Southern California Bight. From 1980-1985, pilot whale numbers off Catalina Island declined dramatically, and they eventually disappeared. One theory has been proposed for this phenomenon, suggesting that a strong El Nino event in 1982/83 resulted in a failure of their main prey, market squid (Doryteuthis opalescens), which lead to their departure. However, we argue that previously underestimated impacts from fishery by-catch and other anthropogenic effects may have actually been the primary driver. Information from diverse sources show that from the 1950s to 1980s, pilot whales were subject to extensive by-catches in purse-seine nets, lampara nets, and oceanic driftnets, as well as intentional shooting by fishermen, and live-captures for the aquarium industry. As a result, dozens of animals may have been removed in some years. From 1952 to 2014, we have documented no less than 232 individuals removed from southern California, with >52% through known anthropogenic factors. If these removals primarily affected the Catalina Island 'residents', they would have had a severe impact on that population. We conclude that human interactions of various types almost certainly played an important, and previously unrecognized, role in the disappearance of short-finned pilot whales from southern California waters., One of the great mysteries in American marine mammal biology has to do with the short-finned pilot whale (Globicephala macrorhynchus) population or populations in southern California. This species has been [...]

Objective: The purpose of this study was to develop and validate the Transcendent Beliefs Scale (TBS). We defined transcendent experiences as an experience of unity with others and the whole of existence, which is associated with behavioural, cognitive, emotional, and transcendental factors. Our aim was to develop a very brief instrument that accurately reflected the phenomenology of transcendent states. Method: The factor structure, validity, and reliability of the TBS were assessed across a sample of university students and energy therapy practitioners (N = 305). Results: With respect to convergent validity, we found that transcendent experiences were positively correlated with daily spiritual experiences, trait hope, and meaning in life. Discriminant validity was demonstrated through a negative weak relationship to narcissistic personality traits. Exploratory factor analysis reduced the scale to 12 items and a two-factor model was found to fit the data. Conclusion: The results indicate that the TBS is a valid and reliable scale to measure transcendent beliefs in the general population. It is suitable for research projects in which a brief measure of transcendence is required. [ABSTRACT FROM AUTHOR]

The original descriptions of nine monodontid and 21 delphinid nominal taxa were revisited, thereby revealing necessary addenda and corrigenda elucidating and solving earlier problems of cetacean nomenclature. This report provides further notes and is an addition to the 2021 work of Jefferson entitled Nomenclature of the Dolphins, Porpoises, and Small Whales: A Review and Guide to the Early Taxonomic Literature (NOAA Professional Paper NMFS 21). [ABSTRACT FROM AUTHOR]

Describing feeding habits of cetaceans is crucial to understanding their feeding strategies and conservation status. Here, both morphological and molecular techniques were employed to identify the stomach contents of 122 finless porpoises (Neophocaena spp.) in the East China Sea for insight into their short-term feeding habits, and stable isotopes of [delta][sup.13]C and [delta][sup.15]N were used to analyze prey resource use and trophic position as a manifestation of their long-term feeding habits. In total, 33 prey species consisting of 19 teleosts, seven crustaceans, five cephalopods, and two gastropods were identified. In both short- and long-term analyses, teleosts represented primary prey, cephalopods and crustaceans were secondary prey, and gastropods were occasional prey; but the primary prey species composition differs between the short- and long-term diets. The composition of stomach contents showed sexual and age-related variation. This finding is supported by stable isotopic analyses, which indicated the separation of trophic position of adult males, adult females, and young males. In general, finless porpoises prey on species that are primarily caught by fisheries. La description des habitudes d'alimentation des cetaces est d'importance cle pour la comprehension de leurs strategies d'alimentation et leur statut de conservation. Des techniques morphologiques et moleculaires sont utilisees pour identifier le contenu stomacal de 122 marsouins (Neophocaena spp.) dans la mer de Chine orientale afin d'obtenir de l'information sur leurs habitudes d'alimentation a court terme, et des donnees d'isotopes stables ([delta][sup.13]C et [delta][sup.15]N) sont employees pour analyser l'utilisation des ressources de proies et la position trophique comme manifestations de leurs habitudes d'alimentation a long terme. Au total, 33 especes de proies comprenant 19 poissons teleosteens, sept crustaces, cinq cephalopodes et deux gasteropodes ont ete identifiees. Dans les analyses tant a court qu'a long terme, les poissons teleosteens constituaient les principales proies, les cephalopodes et les crustaces etaient des proies secondaires, et les gasteropodes, des proies occasionnelles; toutefois, la composition par especes des proies principales n'etait pas la meme pour les regimes alimentaires a court et a long terme. La composition des contenus stomacaux variait selon le sexe et l'age, ce qui est appuye par des analyses d'isotopes stables qui indiquent une separation des positions trophiques des males adultes, femelles adultes et jeunes males. En general, les proies des marsouins sont des especes qui sont principalement prises dans les peches. [Traduit par la Redaction], Introduction Detailed knowledge of the diets and feeding habits of apex predators contributes to a better understanding of the distribution of small cetaceans (Amir et al. 2005) and is important [...]

Two species of sea lions occur in the inland waters of Washington State: the California sea lion (Zalophus californianus) and the Steller sea lion (Eumetopias jubatus). Both species breed elsewhere, but they typically move into Puget Sound and adjacent waters of the Salish Sea from autumn through spring. There is a need for information on their current abundance and seasonal use patterns as both species prey heavily on threatened/ endangered stocks of salmon and steelhead trout (Oncorhynchus spp.), and empirical abundance estimates of these species are lacking for inland Washington waters. From 2013 to 2016, we conducted 39,399 km of aerial surveys for marine mammals in this area, sighting 255 groups of sea lions. We used a subset of 7,841 km of effort and 165 sea lion sightings made during surveys in good sighting conditions to estimate in-water abundance using line-transect methods. Historical tagging data collected in Pacific Northwest waters were used to evaluate the proportions of time that each species spent on land and conducting dives, and then to develop correction factors to derive total abundance for both sea lion species, providing the first empirical abundance estimates for these waters. We estimated that between 33 and 442 California sea lions were found in Puget Sound/ Hood Canal in different seasons, with nearly 3,000 being found in the broader inland Washington waters in the peak season (spring). Steller sea lions occurred in much smaller numbers, with a peak of 219 animals in Puget Sound/Hood Canal/Strait of Juan de Fuca in autumn (and possibly as many as 600 to 700 in the entire study area). While some estimates suffer from low precision, this study demonstrates that substantial numbers of sea lions use waters of the study area throughout much of the year. Our results provide an important step toward a better understanding of these two species in the inland waters of Washington, as well as their potential effects on protected salmonid prey species. [ABSTRACT FROM AUTHOR]

Abstract: The harbor porpoise (Phocoena phocoena (L., 1758)) used to be common in Puget Sound, Washington, but virtually disappeared from these waters by the 1970s. We conducted systematic aerial line-transect [...]

The United States Exploring Expedition of 1838–1842, in some ways, represents the beginning of American marine mammal biology. The expedition returned home with information on at least twelve marine mammal specimens (mostly small cetaceans or pinnipeds), seven of which were considered new species at the time. Commanded by Lieutenant Charles Wilkes, the expedition covered over 80,000 miles, surveyed new waters and lands, and brought back thousands of scientific specimens. Official publications of the expedition by Titian Peale and John Cassin cover the birds and mammals collected. The squadron's publications, and the journals of its officers and scientists also contain a good deal of information about sightings of marine mammals. Of particular interest were whaling operations and grounds, and the expedition did much to help expand the whaling prospects of the United States around the globe, with a focus on the South Pacific islands. Though largely forgotten today, the "U. S. Ex. Ex." played an important early role in establishing American influence in marine mammal biology and global whaling operations. [ABSTRACT FROM AUTHOR]

The title of Perrin's presentation was, "The problem of porpoise [= dolphin] mortality in the U. S. tropical tuna fishery" (Perrin, [5]). Bill invited Louella the following year to attend the IWC gill net meeting in La Jolla in 1991 (Perrin et al., [15]) where she presented the bycatch data she gathered from gill net fisheries in the Philippines. Besides being the first person to alert the world to the massive kills of dolphins that were happening in the eastern tropical Pacific tuna fishery in the 1960s, decades later Bill created a compilation of the thousands of documents related to the controversy, along with a searchable bibliography (Perrin, [9]). Bill's critical early research on oceanic dolphins brought world attention to the longstanding and growing problem of incidental mortality of cetaceans in fisheries, but it was also transformative given the huge and enduring impact it had on cetacean science. [Extracted from the article]

Despite the fact that cetaceans provide significant ecological contributions to the health and stability of aquatic ecosystems, many are highly endangered with nearly one‐third of species assessed as threatened with extinction. Nevertheless, to date, few studies have explicitly examined the patterns and processes of extinction risk and threats for this taxon, and even less between the two subclades (Mysticeti and Odontoceti). To fill this gap, we compiled a dataset of six intrinsic traits (active region, geographic range size, body weight, diving depth, school size, and reproductive cycle), six environmental factors relating to sea surface temperature and chlorophyll concentration, and two human‐related threat indices that are commonly recognized for cetaceans. We then employed phylogenetic generalized least squares models and model selection to identify the key predictors of extinction risk in all cetaceans, as well as in the two subclades. We found that geographic range size, sea surface temperature, and human threat index were the most important predictors of extinction risk in all cetaceans and in odontocetes. Interestingly, maximum body weight was positively associated with the extinction risk in mysticetes, but negatively related to that for odontocetes. By linking seven major threat types to extinction risk, we further revealed that fisheries bycatch was the most common threat, yet the impacts of certain threats could be overestimated when considering all species rather than just threatened ones. Overall, we suggest that conservation efforts should focus on small‐ranged cetaceans and species living in warmer waters or under strong anthropogenic pressures. Moreover, further studies should consider the threatened status of species when superimposing risk maps and quantifying risk severity. Finally, we emphasize that mysticetes and odontocetes should be conserved with different strategies, because their extinction risk patterns and major threat types are considerably different. For instance, large‐bodied mysticetes and small‐ranged odontocetes require special conservation priority. [ABSTRACT FROM AUTHOR]

For threatened marine megafauna, such as the Indo‐Pacific humpback dolphin (Sousa chinensis), sound conservation planning should aim to ensure demographic and ecological persistence of populations. One method to address this challenge is through ecosystem‐based conservation planning (ECP) based on threatened marine megafauna distribution, biodiversity richness, and ecosystem functionality.ECP exercises for the Indo‐Pacific humpback dolphin in Chinese and adjacent northern Vietnamese waters were conducted based on the Indo‐Pacific humpback dolphin distribution, Hill‐2 biodiversity index, and marine net primary productivity. Habitat protection priorities were scored using the program MARXAN and were used to identify special areas for conservation (SACs) for the Indo‐Pacific humpback dolphin.To ensure the minimal risk of local extinction, the SACs enclosed a total of 26,858 km2 of waters, accounting for 49.9% of core habitats of the Indo‐Pacific humpback dolphin and 24.3% of the IUCN Red List species in the study region. To enclose 30% of biodiversity richness and ecosystem functionality, a total of 40,179 km2 SACs was required.In the context of threatened marine megafauna conservation, megafauna distribution can be used to highlight focal areas, while information on biodiversity richness and ecosystem functionality should be factored in. Using surrogates with different ecological niches would be a better tactic to ensure sufficient protection coverage by minimizing the omission bias.The conservation of threatened marine megafauna in coastal and estuarine waters shares similar objectives with global marine biodiversity conservation. The challenges to conduct ECP exercises come from data scarcity and poor data quality in representing distributions of biodiversity features. A certified open‐access database that shares survey effort, occurrence, population density, and habitat mapping at national and local scales is recommended. Such a result requires national planning, investment, and policing. [ABSTRACT FROM AUTHOR]

The inland waters of Washington State are inhabited regularly by 10 species of marine mammals. Updated and comprehensive information regarding marine mammal occurrence, distribution, and behavior in the area is critical when addressing local anthropogenic impact, management, and conservation concerns. We conducted a total of 16,198 km of observation effort during systematic line-transect surveys from a high-wing, twin-engine airplane throughout Puget Sound in all 4 seasons during 2013 to 2016, and in the Strait of Juan de Fuca and San Juan Islands area during summer 2014 and spring 2015. Ten marine mammal species were confirmed across 5772 groups of an estimated 10,673 individuals sighted, including some seasonal patterns of occurrence. The most commonly sighted species in terms of individuals were Harbor Seals (n = 8012), Harbor Porpoises (n = 2168), California Sea Lions (n = 238) and Steller Sea Lions (n = 77). The most common behavior states documented across species among the total 5670 groups were rest (73%) and medium travel (16%); probable foraging was observed among 13 groups (0.2%) and included Gray Whale foraging pits in tidal mudflats. Potential behavioral reactions to the aircraft were rare (0.3% of total individuals), primarily by Harbor Seals and Harbor Porpoises. Results of these surveys represent the most comprehensive up-to-date information available on marine mammal occurrence, distribution, and behavior across seasons in the Puget Sound region. [ABSTRACT FROM AUTHOR]