Cetaceans - Science topic

Place-based approaches to marine conservation identify areas that are crucial to the success of populations, species, communities, or ecosystems, and that may be candidates for special management actions. In the United States, the National Oceanic and Atmospheric Administration defined Biologically Important Areas (BIAs) for cetaceans (whales, dolp...

Environmental DNA (eDNA) sampling of water is a powerful method for comprehensive and noninvasive monitoring of aquatic animal species. However, there have been few reports of its application to cetacean species. On June 29, 2021, a whale (nicknamed Xiaobu) appeared in Dapeng Bay off Guangdong Province, China. We used eDNA technology to obtain info...

Incidental catch in fishing gear (often known as bycatch) is a major mortality factor for the Black Sea harbour porpoise (Phocoena phocoena relicta), an endemic subspecies listed as Endangered in the IUCN Red List. The primary gear, responsible for porpoise bycatch in the Black Sea are bottom gillnets and trammel nets targeting turbot (Scophthalmus...

Photic niche shifts of mammals are associated with changing visual capabilities, primarily mediated by three visual pigments, two (SWS1 and M/LWS) of them for color vision and rhodopsin (RH1) for dim-light vision. To further elucidate molecular mechanisms of mammalian visual adaptations to different light environments, a systematic study incorporat...

A shipboard cetacean survey was conducted in July/August 1998 within an area to the west of Scotland, UK, commonly known as the Atlantic Frontier. The aim of the survey was to document the distribution and abundance of cetaceans to provide baseline population data for an area that is being increasingly explored and developed by oil companies. A dou...

The Northwest Region (NWR) Marine Mammal Stranding Network was created in the early 1980s to provide a consistent framework in which to collect and compile data about marine mammal strandings in Oregon and Washington. The NWR includes the nearshore waters and 4,243km (2,632 n.miles) of coastline. For the years 1930-2002, there were 904 stranding ev...

Alaskan marine ecosystems are undergoing unprecedented change and species are facing increasingly variable and potentially inhospitable habitats. As top predators, marine mammals serve an important role as sentinels of ecosystem health. With their high site fidelity, abundant numbers, coastal presence and role as a top predator, humpback whales (Me...

Dive studies across mammals, birds, reptiles and fish often focus on deep dives, and shallow water diving has tended to be overlooked. For air-breathers, foraging in shallow water poses challenges since the lungs generate buoyancy, and shallow divers must trade off the extent of inhalation against the negative buoyancy needed to avoid floating to t...

Understanding the vocal behavior of cetaceans is an important component of many passive acoustic applications. This study quantifies the vocal behavior of acoustic subgroups of false killer whales (Pseudorca crassidens) from the Hawaiian Archipelago. The acoustic subgroups (N = 523) exhibit diverse vocal behavior that varies between encounters. Ove...

Introduction: Anisakis pegreffii is a sibling species within the A. simplex (s.l.) complex requiring marine homeothermic (mainly cetaceans) and heterothermic (crustaceans, fish, and cephalopods) organisms to complete its life cycle. It is also a zoonotic species, able to accidentally infect humans (anisakiasis). To investigate the molecular signals...

Bulk filter feeding has enabled gigantism throughout evolutionary history. The largest animals, extant rorqual whales, utilize intermittent engulfment filtration feeding (lunge feeding), which increases in efficiency with body size, enabling their gigantism. The smallest extant rorquals (7–10 m minke whales), however, still exhibit short-term forag...

The killer whale (Orcinus orca) is a cosmopolitan cetacean distributed worldwide. Extensive studies have described its ecology and behavior across multiple polar and temperate regions. On the other hand, there is limited information on the distribution, ecological roles, and abundance of killer whales in tropical and subtropical regions. Herein, we...

Cetaceans are known for their intelligence and display of complex behaviours including object use. For example, bowhead whales (Balaena mysticetus) are known to rub on rocks and some humpback whale (Megaptera novaeangliae) populations undertake lateral bottom feeding. Such underwater behaviour is difficult to observe but can play a critical role in...

Monitoring marine mammals is of broad interest to governments and individuals around the globe. Very high-resolution (VHR) satellites hold the promise of reaching remote and challenging locations to fill gaps in our knowledge of marine mammal distribution. The time has come to create an operational platform that leverages the increased resolution o...

Opportunistic cetacean sightings were made during a 79-day fishing trip through southern and central Mozambican waters. Notable sightings included the first Mozambican records of Rough-toothed Dolphin Steno bredanensis and Fraser’s Dolphin Lagenodelphis hosei, although both species have been recorded from neighbouring South African and Tanzanian wa...

In early 2004 and in 2005, several unusual stranding events occurred in Taiwan during a period when large-scale naval exercises were conducted in and on nearby waters. Gross examination of the partial remains of two carcasses (a ginkgo-toothed beaked whale (Mesoplodon ginkgodens) and a pygmy killer whale (Feresa attenuata)) and an intact Risso’s do...

Whale sharks Rhincodon typus frequently appear to interact or associate with other species, which vary depending on the community structure and the demographic of the whale sharks at each location globally. Here, we present the species sighted frequently around whale sharks in the Galapagos Archipelago and reported by dive guides and scientists and...

Distance sampling surveys are commonly used to estimate animal abundance (N). The choice of survey design has only recently received attention in the line-transect research literature, which has tended to focus more on the violation of assumptions. In this study, simulation methods were used to assess the effect of line placement on the accuracy an...

Within the set of risk factors that compromise the conservation of marine biodiversity, one of the least understood concerns is the noise produced by human operations at sea and from land. Many aspects of how noise and other forms of energy may impact the natural balance of the oceans are still unstudied. Substantial attention has been devoted in t...

To better understand the interactions between orca, Orcinus orca (Linnaeus, 1758), killer whale (Mammalia Cetacea Delphinidae) and the large species of ocean sunfish (molids), Mola spp. and Masturus lanceolatus (Tetraodontiformes Molidae Actinopterygii), we searched for published and unpublished records of contact between these taxa. We reviewed a...

Within delphinoid cetaceans, snout shape is significantly correlated to diet, with long-snouted raptorial-feeding predators preying on smaller and more agile prey than shorter-snouted species. Although there have been several studies into longirostry from a functional perspective there have been no quantitative analyses of spatial variation in skul...

Compared with the history of seals in the Baltic Sea, the porpoise has received much less research attention. The harbor porpoise (Phocoena phocoena) has been quite rare in the eastern Baltic in recent centuries, but according to archaeological finds, its population was quite numerous here ca. 6000–4000 years ago (ca. 4000–2000 cal. BC). This paper...

Cetacean stranding data was obtained on the Crimean coast during the period from October 2017 to December 2019. A total of 963 cases of cetacean strandings were recorded: 21 individuals in October–December 2017, 472 individuals in 2018, and 470 individuals in 2019. Most of the animals were harbour porpoises (540 individuals, or 56% of the total); t...

Building on earlier work identifying Biologically Important Areas (BIAs) for cetaceans in U.S. waters (BIA I), we describe the methodology and structured expert elicitation principles used in the “BIA II” effort to update existing BIAs, identify and delineate new BIAs, and score BIAs for 25 cetacean species, stocks, or populations in seven U.S. reg...

A R T I C L E I N F O Keywords: Tourism impact Markov chains Behavioural budget Indo-Pacific bottlenose dolphin Management Mozambique A B S T R A C T Swim-with-dolphin (SWD) activities are popular but can negatively impact target populations. It is important to consider the behavioural responses of dolphins, and quantify the impact on individuals a...

To ensure effective cetacean management and conservation policies, it is necessary to collect and rigorously analyze data about these populations. Remote sensing allows the acquisition of images over large observation areas, but due to the lack of reliable automatic analysis techniques, biologists usually analyze all images by hand. In this paper,...

Multiple techniques have been used for estimating age in bottlenose dolphins (Tursiops truncatus). The longest established technique is via counts of growth later groups (GLGs) in the longitudinal section of an extracted mandibular tooth. Previous studies to validate GLGs have primarily used younger dolphins (less than 16yrs old) due to the limited...

Understanding the population history of wide-ranging species, especially those ranging over varying landscapes, helps in deciphering the evolutionary force (s) that shaped the present genetic diversity/structure of regional fauna. In the shelf region, evolution of coastal morphology through glacial oscillations played an important role in shaping t...

Trap feeding and tread-water feeding are cetacean hunting strategies first recorded in the 2000s in two whale species at opposite sides of the globe. In both behaviors, whales sit motionless at the surface with their mouths open. Fish are attracted into the whale's mouth and are trapped when the jaw is closed. We identify striking parallels with th...

We delineated and scored Biologically Important Areas (BIAs) in the Arctic region. The Arctic region extends from the Bering Strait to the Chukchi Sea, Beaufort Sea, Amundsen Gulf, and Viscount Melville Sound. This NOAA-led effort uses structured elicitation principles to build upon the first version of NOAA BIAs (BIA I) for cetaceans. In addition...

This article focuses on practical, ethical and political issues that arise in the context of cetacean conservation. Our point of departure is the controversy surrounding plans to assist J50, an ailing member of the southern resident orca population, during the summer of 2018. A brief history of cetacean captivity provides context for the current ba...

Freshwater cetaceans play a significant role as sentinel animals, providing important data on animal species and aquatic ecosystem health. They also may serve as potential reservoirs of emerging pathogens and host virulence genes in their microbiota. In this study, we evaluated virulence factors produced by Gram-negative bacteria recovered from ind...

Cetaceans (dolphins, whales, and porpoises) have large and anatomically sophisticated brains. To expand our understanding of the cellular makeup of cetacean brains and the similarities and divergence between the brains of cetaceans and terrestrial mammals, we here report a short-finned pilot whale (Globicephala macrorhynchus) single-nucleus transcr...

At this moment of climate crisis, deep-ocean carbon sequestration has been proposed as a strategy to curtail greenhouse gas emissions. The video article Sentience, Sentences, & Sentiment: Sensing Deep-Ocean Sediment through Artistic Practice explores ecological attunement and the role of language in perceiving the more-than-human—specifically the d...

Human activities are increasingly impacting our oceans and the focus tends to be on their environmental impacts, rather than consequences for animal welfare. Global shipping density has quadrupled since 1992. Unsurprisingly, increased levels of vessel collisions with cetaceans have followed this global expansion of shipping. This paper is the first...

The use of morphometrics in stock identification studies for cetaceans has been widely employed. In this study, 14 measurements of external body proportions of 172 Baird’s beaked whales caught by small-type whaling operations off the Pacific coast of Japan, the Sea of Japan and the Sea of Okhotsk from 1988 to 2004 were examined using canonical disc...

We investigated the presence and diversity of cetaceans in the Mediterranean Sea, analysing the data collected by 32 different research units, over a period of 15 years (2004–2018), and shared on the common web-GIS platform named Intercet. We used the encounter rate, the species prevalence, and the Shannon diversity index as parameters for data ana...

A multi-disciplinary and multi-institutional pilot expedition was organised by the National Centre for Antarctic and Ocean Research (NCAOR) to the ice-free areas of the Western Indian Ocean sector of the Southern Ocean onboard ORV Sagar Kanya during the austral summer of 2004 (January-March). This survey, conducted by the Central Marine Fisheries R...

The Agoa protected marine area, located in the French West Indies, eastern Caribbean, holds several cetacean species, of which the pantropical spotted dolphin Stenella attenuata is the most commonly observed. This species is the focus of whale-watching activities off the leeward coasts of Guadeloupe and Martinique, which has allowed the development...

Despite reduced fishing effort in many North Atlantic fisheries following collapse of fish stocks, concerns remain about levels of direct mortality of harbour porpoise (Phocoena phocoena), primarily through incidental catches in fishing gear. Although harbour porpoise incidental catch is known to occur in several fisheries along the coast of Newfou...

Historically, the seals and harbour porpoises of the Baltic Sea and North Sea have been subjected to hunting, chemical pollutants and repeated mass mortalities, leading to significant population fluctuations. Despite the conservation implications and the zoonotic potential associated with viral disease outbreaks in wildlife, limited information is...

Pennella balaenoptera Koren & Danielssen, 1877 (Crustacea, Siphonostomatoida, Pennellidae) is so far known as the largest copepod species and has only been found as a parasite on marine mammals. Previous studies on parasitic copepods in China only focused on those found on economic fishes, no records of P. balaenoptera having ever been reported bef...

Abstract In 2022 Biosphere Expeditions concluded its 16th year of cetacean photo-identification and distribution studies in the Azores, after a two-year break for COVID-19. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 21 March to 21 Apr...

Net entanglement in derelict fishing nets is a major threat to the conservation of endangered species of cetaceans, birds and reptiles. Nets made of nylon and plastics are non degradable and are a major source of risk to many species whether aquatic or terrestrial which often get trapped and killed which continue to be present in the environment ev...

Response facilitation has often been portrayed as a “low level” category of social learning, because the demonstrator’s action, which is already in the observer’s repertoire, automatically triggers that same action, rather than induces the learning of a new action. One way to rule out response facilitation consists of introducing a delay between th...

A vessel-based line-transect survey for cetaceans conducted during 23 February-6 March 2005 of the nearshore waters (to a depth of 40- 60m) of the Mergui (Myeik) Archipelago of southern Myanmar searched along 955km of trackline resulting in 30 cetacean sightings. These included Indo-Pacific bottlenose dolphins Tursiops aduncus (n=15), Indo-Pacific...

Deep seabed mining operations, if permitted, could present significant risks to ocean ecosystems. Disturbance on any scale is likely to be long lasting and irreversible. Scant research to date has examined the impact that deep sea minerals extraction would have on cetaceans. The Clarion-Clipperton Zone (CCZ) is of particular interest to mining comp...

The Canary Islands, known for their extraordinarily high cetacean species diversity, have witnessed a rapid expansion in fast and high speed ferry traffic during the past few years. At the same time, ship strikes have been increasingly reported. 556 cetacean carcasses, found ashore, or reported, in the Canary Islands between 1991 and 2007, were exa...

Although the Mediterranean Sea is a crucial hotspot in marine biodiversity, it has been threatened by numerous anthropogenic pressures. As flagship species, Cetaceans are exposed to those anthropogenic impacts and global changes. Assessing their conservation status becomes strategic to set effective management plans. The aim of this paper is to und...

In Europe, problems with the use of pingers on larger fishing vessels have raised the question as to whether pingers would be practical on smaller vessels, which are a large proportion of the European static net fishing fleet. In this study, four netting vessels less than 10m long used AQUAmark pingers on part of their nets off the southwest coast...

Occupants' perception of a space depends on their experience [1], [2], [3]. Four kinds of visiting experiences were carried out inside the Natural History Museum of the University of Pisa [4]. The museum is housed, together with the National Museum of the Charterhouse [5], inside the Monumental Charterhouse of Calci, near Pisa. Four of the permanen...

Many species are restricted to a marginal or suboptimal fraction of their historical range due to anthropogenic impacts, making it hard to interpret their ecological preferences from modern-day data alone. However, inferring past ecological states is limited by the availability of robust data and biases in historical archives, posing a challenge fo...

Data from bycaught, but otherwise presumed healthy individuals can contribute important biological data on species of cetaceans that are otherwise lacking. This study utilises data collected from systematic necropsies performed between October 1970 and May 2010 on 142 Indo-Pacific humpback dolphins (Sousa chinensis), 607 Indo-Pacific bottlenose dol...

The blue whale (Balaenoptera musculus) is one of the most common cetaceans in the waters around Sri Lanka and in a worldwide context one of the highest low-latitude sighting rates for this species has been recorded in these waters. As genetic analyses, acoustic studies and even long-term sighting surveys for blue whales in these waters are limited,...

The diversity of cetacean species in Indian waters is high, with 25 species recorded so far. Records of cetaceans from India during the last 200 years have provided insights into their spatiotemporal distribution, behaviour, feeding, reproduction, fishery interaction and pollution. The cetacean fauna is dominated by pantropical species, with a rela...

Black Sea cetaceans are isolated and nominated as endemic subspecies listed in the IUCN Red List of Endangered species: the harbour porpoise and bottlenose dolphin as Endangered (EN) and the common dolphin as Vulnerable (VU). Studies of their distribution and abundance are scarce but obligatory for assessment of their conservation status. Being hig...

Movement pattern and habitat use data are essential parameters for developing effective management strategies and successful conservation efforts for marine mammals across the world. Satellite telemetry is critical for collecting fine-scale, temporal and spatial data on individual animals that has broad-scale applicability at population and species...

Background Anisakiasis is a foodborne disease caused by the third-stage larvae (L3) of two species belonging to the genus Anisakis: Anisakis pegreffii and Anisakis simplex sensu stricto. Both species have been the subject of different -omics studies undertaken in the past decade, but a reliable in vitro culture protocol that would enable a more ver...

Have you ever heard about, or maybe even seen, a whale or a dolphin that was helplessly lying on the beach or stuck in very shallow water? These are called “stranding events” or “strandings,” and have been documented since the fourth century. Back then, strandings involving cetaceans (whales, dolphins, and porpoises) were welcome events because the...

Geotechnical survey is an important prerequisite to the construction of offshore wind farms. However, the impact of underwater survey noises has not yet been studied in details. In this paper, we studied transmission of underwater noises from offshore exploratory drilling (OED) at the Xiamen port. The noises were categorized into three types: hamme...

Empirical evidence about the role and interaction of immigration with local demographic processes in shaping population dynamics is still scarce. This knowledge gap limits our capability to derive a conceptual framework that can be used to inform conservation actions. Populations exposed to nonstationary environment do not converge to a stable stag...

Located in the eastern tropical Pacific, the Galápagos Islands are an oceanic insular ecosystem subject to strong environmental variability driven by local and regional processes. Past research has shown that such conditions can attract and sustain at least 23 cetacean species, out of which 14 are common, including nine Delphinids, one Ziphiid, one...

Collecting fine‐scale occurrence data for marine species across large spatial scales is logistically challenging but is important to determine species distributions and for conservation planning. Inaccurate descriptions of species ranges could result in designating protected areas with inappropriate locations or boundaries. Optimizing sampling stra...

In oceanic ecosystems, the nature of barriers to gene flow, and the processes by which populations may become isolated are different from the terrestrial environment, and less well understood. In this study we investigate a highly mobile species (the sperm whale, Physeter macrocephalus) that is genetically differentiated between an open North Atlan...

Coastal cetaceans are often selected as a biodiversity surrogate in ecosystem‐based conservation planning. In the northern Arabian Sea there is insufficient information on suitable habitats for the Indo‐Pacific finless porpoise and Indian Ocean humpback dolphin for planning protection. Suitable habitats for the Indo‐Pacific finless porpoise and Ind...