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Most cetacean species are wide-ranging and highly mobile, creating significant challenges for researchers by limiting the scope of data that can be collected and leaving large areas un-surveyed. Aerial surveys have proven an effective way to locate and study cetacean movements but are costly and limited in spatial extent. Here we present a semi-automated pipeline for whale detection from very high-resolution (sub-meter) satellite imagery that makes use of a convolutional neural network (CNN). We trained ResNet, and DenseNet CNNs using down-scaled aerial imagery and tested each model on 31 cm-resolution imagery obtained from the WorldView-3 sensor. Satellite imagery was tiled and the trained algorithms were used to classify whether or not a tile was likely to contain a whale. Our best model correctly classified 100% of tiles with whales, and 94% of tiles containing only water. All model architectures performed well, with learning rate controlling performance more than architecture. While the resolution of commercially-available satellite imagery continues to make whale identification a challenging problem, our approach provides the means to efficiently eliminate areas without whales and, in doing so, greatly accelerates ocean surveys for large cetaceans. [ABSTRACT FROM AUTHOR]

The article informs that researcher P.T. Madsen and colleagues present groundbreaking research demonstrating that toothed whales possess a unique nasal structure that allows them to produce a diverse range of sounds across a broad frequency range. The research draws parallels between the vocal production of toothed whales and that of humans, terrestrial mammals, frogs and birds.

North Atlantic right whales ( Eubalaena glacialis Müller 1776) present an interesting problem for abundance and trend estimation in marine wildlife conservation. They are long lived, individually identifiable, highly mobile, and one of the rarest of cetaceans. Individuals are annually resighted at different rates, primarily due to varying stay durations among several principal habitats within a large geographic range. To date, characterizations of abundance have been produced that use simple accounting procedures with differing assumptions about mortality. To better characterize changing abundance of North Atlantic right whales between 1990 and 2015, we adapted a state-space formulation with Jolly-Seber assumptions about population entry (birth and immigration) to individual resighting histories and fit it using empirical Bayes methodology. This hierarchical model included accommodation for the effect of the substantial individual capture heterogeneity. Estimates from this approach were only slightly higher than published accounting procedures, except for the most recent years (when recapture rates had declined substantially). North Atlantic right whales' abundance increased at about 2.8% per annum from median point estimates of 270 individuals in 1990 to 483 in 2010, and then declined to 2015, when the final estimate was 458 individuals (95% credible intervals 444-471). The probability that the population's trajectory post-2010 was a decline was estimated at 99.99%. Of special concern was the finding that reduced survival rates of adult females relative to adult males have produced diverging abundance trends between sexes. Despite constraints in recent years, both biological (whales' distribution changing) and logistical (fewer resources available to collect individual photo-identifications), it is still possible to detect this relatively recent, small change in the population's trajectory. This is thanks to the massive dataset of individual North Atlantic right whale identifications accrued over the past three decades. Photo-identification data provide biological information that allows more informed inference on the status of this species. [ABSTRACT FROM AUTHOR]

The southern right whale (Eubalaena australis) has been placed in the category of "least concern" in the International Union for Conservation of Nature's Red List of Threatened Species and in the category of "endangered" in the Brazilian Red List of Threatened Fauna. The aim of this study was to update sighting and stranding records of right whales along the southeastern Brazilian coast between 2000 and 2015 and to assess the main threats they face. Records occurred mainly between May and October, and mother and calf pairs represented 78% of all sightings, evidencing the use of the southeast coast of Brazil as part of the breeding and possibly calving area. A total of eight strandings was reported. On 6 September 2012, the first confirmed ship strike on a right whale was reported in the surveyed area. The intensified conflicts between coastal development and the use of protected and calm waters along southeastern Brazil by southern right whales as breeding areas should be considered in management plans. [ABSTRACT FROM AUTHOR]

The origins of the enigmatic pygmy right whale Caperea marginata, the only living member of its subfamily (Neobalaeninae), are an outstanding mystery of cetacean evolution. Its strikingly disparate morphology sets Caperea apart from all other whales, and has turned it into a wildcard taxon that holds the key to understanding modern baleen whale diversity. Morphological cladistics generally ally this species with right whales, whereas molecular analyses consistently cluster it with rorquals and grey whales (Balaenopteroidea). A recent study potentially resolved this conflict by proposing that Caperea belongs with the otherwise extinct Cetotheriidae, but has been strongly criticised on morphological grounds. Evidence from the neobalaenine fossil record could potentially give direct insights into morphological transitions, but is currently limited to just a single species: the Late Miocene Miocaperea pulchra, from Peru. We show that Miocaperea has a highly unusual morphology of the auditory region, resulting from a–presumably feeding-related–strengthening of the articulation of the hyoid apparatus with the skull. This distinctive arrangement is otherwise only found in the extinct Cetotheriidae, which makes Miocaperea a “missing link” that demonstrates the origin of pygmy right whales from cetotheriids, and confirms the latter’s resurrection from the dead. [ABSTRACT FROM AUTHOR]

Daily charts of the aerial search effort (432 206 nautical miles) of the Union Whaling Company and 1 099 sightings of 10 497 whales were available from 628 flights off Durban between 1972 and 1975. Densities of whales were analysed by month and water depth distribution over the four-year period. Low observed densities of blueBalaenoptera musculus, rightEubalaena australis, seiB. borealisand humpbackMegaptera novaeangliaewhales most likely resulted from earlier whaling pressure. Seasonality of blue, sei and humpback whales was bimodal, indicative of winter migrations to the north of the Durban whaling grounds, whereas the unimodal seasonality of fin whalesB. physalusand minke whalesB. bonaerensisorB. acutorostratasuggest the offshore region as the northern terminus of their migrations. Sperm whalesPhyseter macrocephalusmigrate northwards offshore of the KwaZulu-Natal coast in autumn/early winter and southwards in late winter/spring, with larger males migrating later than the smaller males and females. Killer whaleOrcinus orcapresence was coincident with that of offshore minke whales and the southward migrations of other baleen whales, whereas densities of animals deemed as bottlenose whaleHyperoodon planifronssuggest strong early and late summer seasonal abundance in the offshore region. Such extensive surveys offshore of the KwaZulu-Natal coast are unlikely to be repeated; hence, data-extraction of whaling records provides a valuable source of seasonal and distributional information for marine management. [ABSTRACT FROM AUTHOR]

The article presents an study on the sound production by Southern right whales in the coast of Uruguay. It mentions several types of calls recorded during the study such as the up call, high call and pulsive call, which varies in tone, frequency and amplitude. The study used custom-built hydrophone to record sounds produced by the right whales when there are no other cetaceans present. Moreover, the data gathered in the study are essential for the analysis of the global differences of the species between vocalisations.

The article discusses a study which reports the sighting of the North Atlantic right whale or Eubalaena glacialis in the Azores on January 5, 2009 travelling in a westerly direction at a constant speed. It says that the right whale was resighted in the Bay of Fundy in September 2, 2009 after being seen in the Azores. It mentions that the whale was detected by land-based observers employed by whalewatching companies. Results show that 1,769 cetacean sightings were recorded. Furthermore, the sighting suggested that the right whale did not remain in or return to the area.

The origin of baleen whales, and their specialized mode of filter-feeding, marks an important event in the evolutionary history of mammals that gave rise to one of the most distinctive groups of animals alive today. Recent years have seen the description of a number of important new specimens, as well as the publication of a large number of phylogenetic analyses. Yet, despite this great effort, a broad consensus on even the most fundamental relationships within this group has so far remained elusive, a fact perhaps most strikingly reflected in the ongoing debate regarding the taxonomic placement of the extant gray and pygmy right whales, as well as the question of the relative closeness of relationship of all the extant members of the mysticete crown group. Here, I present the taxonomically most comprehensive phylogenetic analysis of extinct and extant baleen whales carried out to date, based on morphological data and utilizing both maximum parsimony and Bayesian methodologies. The results of this study were well resolved and consistent across methodologies. Apart from recovering a clade comprising the pygmy right whale, gray whales, and rorquals, a grouping new to morphological analyses but supported by a number of molecular studies, this investigation also revealed the former clade to be more closely related to a large number of extinct species than to right whales, thus contradicting previous notions of a closely related mysticete crown group. In addition, this analysis also identified a novel clade comprising nearly all the described archaic toothed mysticetes from the late Oligocene (about 23-28 Ma) to the exclusion of all toothless mysticetes. This finding is consistent with a basic assessment of the functional morphology of toothed mysticete vision, and may have implications for the evolution of mysticete filter-feeding and the recently proposed interpretation of some of these archaic taxa as transitional forms possessing both teeth and baleen at the same time. [ABSTRACT FROM AUTHOR]

During the 19th century, sail whalers hunted right whales throughout the southern oceans north of 50 degrees. This review seeks to document the recovery of southern right whales by comparing the northernmost recent sightings with older sightings that survive 'fossilised' in historical records of the sail whaling era. Despite a steady expansion northwards in recent years, the present distribution of right whales is still far short of that recorded by sail whalers over a century ago. [ABSTRACT FROM AUTHOR]

Abstract: Humans and cetaceans are exposed to a wide range of contaminants. In this study, we compared the cytotoxic and genotoxic effects of a metal pollutant, hexavalent chromium [Cr(VI)], which has been shown to cause damage in lung cells from both humans and North Atlantic right whales. Our results show that Cr induces increased cell death and chromosome damage in lung cells from both species with increasing intracellular Cr ion levels. Soluble Cr(VI) induced less of a cytotoxic and genotoxic effect based on administered dose in right whale (Eubalaena glacialis) cells than in human (Homo sapiens) cells. Whereas, particulate Cr(VI) induced a similar cytotoxic effect but less of a genotoxic effect based on administered dose in right whale cells than in human cells. Differences in chromium ion uptake explained soluble chromate-induced cell death but not all of the soluble chromate-induced chromosome damage. Uptake differences of lead ions could explain the differences in particulate chromate-induced toxicity. The data show that both forms of Cr(VI) are less genotoxic to right whale than human lung cells, and that soluble Cr(VI) induces a similar cytotoxic effect in both right whale and human cells, while particulate Cr(VI) is more cytotoxic to right whale lung cells. [Copyright &y& Elsevier]

Reconstructing the history of exploited populations of whales requires fitting a trajectory through at least three points in time: (i) prior to exploitation, when abundance is assumed to be at the maximum allowed by environmental carrying capacity; (ii) the point of minimum abundance or ‘bottleneck’, usually near the time of protection or the abandonment of the hunt; and (iii) near the present, when protected populations are assumed to have undergone some recovery. As historical abundance is usually unknown, this trajectory must be extrapolated according to a population dynamic model using catch records, an assumed rate of increase and an estimate of current abundance, all of which have received considerable attention by the International Whaling Commission (IWC). Relatively little attention has been given to estimating minimum abundance ( Nmin), although it is clear that genetic and demographic forces at this point are critical to the potential for recovery or extinction of a local population. We present a general analytical framework to improve estimates of Nmin using the number of mtDNA haplotypes (maternal lineages) surviving in a contemporary population of whales or other exploited species. We demonstrate the informative potential of this parameter as an a posteriori constraint on Bayesian logistic population dynamic models based on the IWC Comprehensive Assessment of the intensively exploited southern right whales ( Eubalaena australis) and published surveys of mtDNA diversity for this species. Estimated historical trajectories from all demographic scenarios suggested a substantial loss of mtDNA haplotype richness as a result of 19th century commercial whaling and 20th century illegal whaling by the Soviet Union. However, the relatively high rates of population increase used by the IWC assessment predicted a bottleneck that was implausibly narrow (median, 67 mature females), given our corrected estimates of Nmin. Further, high levels of remnant sequence diversity (theta) suggested that pre-exploitation abundance was larger than predicted by the logistic model given the catch record, which is known to be incomplete. Our results point to a need to better integrate evolutionary processes into population dynamic models to account for uncertainty in catch records, the influence of maternal fidelity on metapopulation dynamics, and the potential for inverse density dependence (an ‘Allee effect’) in severely depleted populations. [ABSTRACT FROM AUTHOR]

Right whales carry large populations of three ‘whale lice’ ( Cyamus ovalis, Cyamus gracilis, Cyamus erraticus) that have no other hosts. We used sequence variation in the mitochondrial COI gene to ask (i) whether cyamid population structures might reveal associations among right whale individuals and subpopulations, (ii) whether the divergences of the three nominally conspecific cyamid species on North Atlantic, North Pacific, and southern right whales ( Eubalaena glacialis, Eubalaena japonica, Eubalaena australis) might indicate their times of separation, and (iii) whether the shapes of cyamid gene trees might contain information about changes in the population sizes of right whales. We found high levels of nucleotide diversity but almost no population structure within oceans, indicating large effective population sizes and high rates of transfer between whales and subpopulations. North Atlantic and Southern Ocean populations of all three species are reciprocally monophyletic, and North Pacific C. erraticus is well separated from North Atlantic and southern C. erraticus. Mitochondrial clock calibrations suggest that these divergences occurred around 6 million years ago (Ma), and that the Eubalaena mitochondrial clock is very slow. North Pacific C. ovalis forms a clade inside the southern C. ovalis gene tree, implying that at least one right whale has crossed the equator in the Pacific Ocean within the last 1–2 million years (Myr). Low-frequency polymorphisms are more common than expected under neutrality for populations of constant size, but there is no obvious signal of rapid, interspecifically congruent expansion of the kind that would be expected if North Atlantic or southern right whales had experienced a prolonged population bottleneck within the last 0.5 Myr. [ABSTRACT FROM AUTHOR]

A new small balaenid is described and compared to all fossil and living balaenid taxa. The specimen represents a new genus and species and is named Balaenella brachyrhynus. It was discovered in the Lower Pliocene of Kallo (north-west Antwerp, Belgium) and adds new information on the diversity and evolution of Balaenidae. Based on both comparative morphology and phylogenetic analysis, Balaenella brachyrhynus is morphologically closer to the genus Balaena, including the living Greenland Bowhead whale ( B. mysticetus), and two Pliocene species ( B. montalionis and B. ricei) from central Italy and the eastern USA. Balaenella brachyrhynus has very short nasals, a short rostrum relative to the total skull length and a horizontal supraoccipital. A cladistic treatment of 81 morphological character states scored for 10 balaenids and nine non-balaenid cetaceans revealed that the other small balaenids generally included in the genus Balaenula (including Balaenula astensis, B. balaenopsis and a Pliocene Balaenula sp. from Japan) are closer to the living genus Eubalaena (the Right whale). As the new skull is so different from the nominal Balaenula species, and as it is more closely related to Balaena than to Eubalaena, it is concluded that a small body size was a common condition in different Balaenidae clades. [ABSTRACT FROM AUTHOR]

Although trends in reproduction, mortality, and entanglement events have been analyzed for the endangered North Atlantic right whale (Eubalaena glacialis) population, no method has been available to assess individual right whale health. Here, we describe a technique for assessing health based on evaluation of selected physical parameters from archived photographs of right whales. A scoring system was developed to assess body and skin condition, blowhole cyamids, and rake marks in over 200000 photographs. Comparison of body condition scores of females during calving and noncalving years found that females were significantly thinner in calving years and in the year after calving compared with the year before calving, showing that changes in body condition known to occur during the reproductive cycle can be successfully evaluated from photographs. Comparison of scores for all parameters between living whales and whales with more than a 5-year gap in sighting history ("presumed dead") found that presumed dead whales received health assessment scores indicating compromised health with body condition emerging as a key visual indicator. This health assessment method provides a new tool to monitor health trends in right whales at individual and population levels and may provide a model for assessments of other well-photographed cetaceans. [ABSTRACT FROM AUTHOR]

The article focuses on the conservation of North Atlantic Ocean's right whales. Deaths of five adult North Atlantic right whales during the past 12 months have been an enormous jolt for the conservation effort. Female right whales produce about six calves during their life-span, giving birth to a new calf every four to five years. Once in plenty worldwide, right whales were killed to the brink of extinction. According to New England lore, the whales were named by whalers who treated them the right whales to hunt because of their dense blubber. They can often be seen swimming slowly on the water surface which has resulted in many ship strikes. Though right whales get lengths of 55 feet and weigh up to 100 tons, they are difficult to find and study. Biologists are working together to get the details of their lives. They have come to know that pregnant females migrate to an area off the coast of Georgia and Florida for delivery between December and March, after which they go to north to their feeding grounds in the Bay of Fundy, off Nova Scotia. Biologists have also learned to identify individuals based on the patterns of skin growths, called callosities which give each animal its characteristic head splotches. Biologists have estimated that only tens to a few hundred of right whales survive today.