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Emergence of new technologies in remote sensing give scientists a new way to detect and monitor wildlife populations. In this study we assess the ability to detect and classify two emblematic Arctic cetaceans, the narwhal (Monodon monoceros) and beluga whale (Delphinapterus leucas), using very high-resolution (VHR) satellite imagery. We analyzed 12 VHR images acquired in August 2017 and 2019, collected by the WorldView-3 satellite, which has a maximum resolution of 0.31 m per pixel. The images covered Clearwater Fiord (138.8 km2), an area on eastern Baffin Island, Canada where belugas spend a large part of the summer, and Tremblay Sound (127.0 km2), a narrow water body located on the north shore of Baffin Island that is used by narwhals during the open water season. A total of 292 beluga whales and 109 narwhals were detected in the images. This study contributes to our understanding of Arctic cetacean distribution and highlights the capabilities of using satellite imagery to detect marine mammals.

Most of our knowledge on reproductive biology of gray whales dates back to scientific research conducted during commercial whaling in the late 1950s and 1960s. The goal of the present study was to provide updated insights on reproductive physiology of gray whales, using progesterone and testosterone as biomarkers. We measured hormone concentrations using enzyme immunoassay (EIA) techniques in blubber biopsies collected from 106 individual whales from March to November over a span of 12 years (2004–2016) between California and Alaska. We found testosterone concentrations in males to increase significantly with age (P = 0.03). Adult males showed significantly elevated testosterone concentrations when sampled in the fall compared to the summer (P = 0.01), likely indicating physiological preparation for mating. We measured testosterone concentrations in females of different age classes, but no statistical differences were found. We found significantly higher progesterone concentrations in pregnant females compared to non-pregnant females and adult males (P< 0.001), indicating progesterone is a valid biomarker for pregnancy in gray whales. Both female and male calves had elevated progesterone concentrations, suggesting maternal transfer via lactation. We fit a mixture of two normal distributions to progesterone data from all non-calf females to identify clusters of high and low progesterone and estimated the probability of being pregnant for whales of unknown reproductive status. With this approach we identified likely pregnant and non-pregnant animals. This study represents an important milestone on reproductive profiles in this population, that can be used to estimate more accurate and precise reproductive parameters to be used for better understanding population dynamics of gray whales.

Entanglements in Fishing Gear and Strandings Reported to the Whale Release and Strandings Group in Newfoundland and Labrador and a Summary of the Whale Release and Strandings Program During 2019. A Report to the Department of Fisheries and Oceans, Canada - Newfoundland and Labrador Region

Killer whales (Orcinus orca) and humpback whales (Megaptera novaeangliae) are two widely distributed cetacean species and both seasonally congregate in the waters off the fjords in Northern Norway to feast on the Norwegian Spring Spawning herring (Clupea harengus). With phylogenetic analysis of complete mitochondrial genomes, obtained by shotgun sequencing, from individuals sampled through four years, this study has attempted to shed light on the geographical origin and phylogenetic position of Norwegian killer whales and humpback whales in the global context of each species. In total, 19 haplotypes were identified among 134 killer whales, and 18 haplotypes were identified among 94 humpback whales. The killer whales sampled in Northern Norway showed structuring between individuals and cluster in a clade with other individuals from Eastern North Atlantic Ocean previously described in literature. The humpback whales showed less clear clustering within the global context but have revealed a potential connection of four individuals with haplotypes from the Southern Hemisphere. Overall, this study suggests that the feeding aggregations in Northern Norway gather killer whales mainly from Eastern North Atlantic Ocean, and humpback whales from the North Atlantic and possibly from the South Atlantic Ocean.

As global ocean-bound commerce increases, managing human activities has become important in reducing conflict with threatened wildlife. This study investigates environmental factors determining abundance and distribution of blue whales (Balaenoptera musculus), humpback whales (Megaptera novaeangliae) and their prey (Euphausia pacifica and Thysanoessa spinifera) in central California. We provide insights into environmental drivers of the ecology and distribution of these species, model whale distributions and determine coincident hotspots of whales and their prey that will help decrease human threats to whales and protect critical feeding habitat. We developed separate predictive models of whale abundances (using negative binomial regression on count data) and krill abundance (using a two-part hurdlemodel combining logistic and negative binomial regressions) over a 14 year period (2004-2017). Variables included in situ surface and midwater oceanographic measures (temperature, salinity, and fluorescence), basin-scale climate indices, and bathymetric- and distance-related data. Predictions were applied to 1 km2 cells spanning the study area for May, June, July, and September during each of the 14 years of surveys to identify persistent distribution patterns. Both whales and krill were found to consistently use the northeast region of Cordell Bank, the Farallon Escarpment, and the shelf-break waters. The main identified blue whale hotspots were also krill hotspots, while co-occurrence was more limited and varied seasonally for humpback whales and krill. These results are valuable in identifying patterns in important areas of ecological interaction to assist management of whales. Areas north of Cordell Bank are of particular management concern since they overlap with the end of the San Francisco Bay northern shipping lane. Our findings can help decrease threats to whales, particularly in important foraging areas, by supporting implementation of vessel management and informing potential conflicts with other human uses.

The recovery of whale populations from centuries of exploitation will have important management and ecological implications due to greater exposure to anthropogenic activities and increasing prey consumption. Here, a Bayesian population model integrates catch data, estimates of abundance, and information on genetics and biology to assess the recovery of western South Atlantic (WSA) humpback whales ( Megaptera novaeangliae ). Modelling scenarios evaluated the sensitivity of model outputs resulting from the use of different data, different model assumptions and uncertainty in catch allocation and in accounting for whales killed but not landed. A long period of exploitation drove WSA humpback whales to the brink of extinction. They declined from nearly 27 000 (95% PI = 22 800–33 000) individuals in 1830 to only 450 (95% PI = 200–1400) whales in the mid-1950s. Protection led to a strong recovery and the current population is estimated to be at 93% (95% PI = 73–100%) of its pre-exploitation size. The recovery of WSA humpback whales may result in large removals of their primary prey, the Antarctic krill ( Euphausia superba ), and has the potential to modify the community structure in their feeding grounds. Continued monitoring is needed to understand how these whales will respond to modern threats and to climate-driven changes to their habitats.

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.

Most physical oceanographic data and some biological data used in this study are available through servers supported by federal and state agencies, as specified in the Methods section. Glider data are available from UCSD: https://spraydata.ucsd.edu/ projects/CUGN/. All other data presented have been deposited in a repository and are available at: https://doi.org/10.6084/m9.figshare.c.4584026.v1. The article of record as published may be found at https://doi.org/10.1371/journal.pone.0222456 This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northeast Pacific from three years of continuous recordings off central California (36.713˚N, 122.186˚W). Song is prevalent in this feeding and migratory habitat, spanning nine months of the year (September–May), peaking in winter (November–January), and reaching a maximum of 86% temporal coverage (during November 2017). From the rise of song in fall through the end of peak occurrence in winter, song length increases significantly from month to month. The seasonal peak in song coincides with the seasonal trough in day length and sighting-based evidence of whales leaving Monterey Bay, consistent with seasonal migration. During the seasonal song peak, diel variation shows maximum occurrence at night (69% of the time), decreasing during dawn and dusk (52%), and further decreasing with increasing solar elevation during the day, reaching a minimum near solar noon (30%). Song occurrence increased 44% and 55% between successive years. Sighting data within the acoustic detection range of the hydrophone indicate that variation in local population density was an unlikely cause of this large interannual variation. Hydrographic data and modeling of acoustic transmission indicate that changes in neither habitat occupancy nor acoustic transmission were probable causes. Conversely, the positive interannual trend in song paralleled major ecosystem variations, including similarly large positive trends in winddriven upwelling, primary productivity, and krill abundance. Further, the lowest song occurrence during the first year coincided with anomalously warm ocean temperatures and an extremely toxic harmful algal bloom that affected whales and other marine mammals in the region. These major ecosystem variations may have influenced the health and behavior of humpback whales during the study period. David and Lucile Packard Foundation Central and Northern California Ocean Observing System Monterey Accelerated Research System (MARS) NOAA NOAA ECOHAB JPR DEC FPC JTP JTP CW RM KBB NOAA NA16NOS0120021 NOAA ECOHAB Program (NA11NOS4780030 NSF Award 1514756

Cetaceans have been suggested as ideal ocean sentinels for the evaluation of ecosystem health because they are long-lived, higher trophic foragers, often with high site-fidelity. The body condition of cetaceans provides an integrated picture of foraging success and energy expenditure and thus represents an effective ‘sentinel parameter’ for ecosystem monitoring. In addition, the body condition of an individual can serve as a predictor of reproductive success and offspring survival. The ability to monitor the body condition of cetaceans is therefore of direct relevance for conservation biology. Despite the value of this parameter, there is currently a lack of reliable, standardized, non-lethal methodologies for its evaluation across species and age-categories. The introduction chapter describes the natural history of the humpback whale (Megaptera novaeangliae) in the context of its Antarctic ecosystem and its energetic requirements. It sets out that the species is among the most vulnerable in a changing environment due to it being a specialised feeder depending on Antarctic krill. Krill is the keystone of the Antarctic ecosystem and is presently facing numerous threats. Humpback whales are capital breeders that spend summers feeding in high latitude feeding grounds, building up their energy reserves reflected in their body condition. During winter they migrate to tropical waters to reproduce, a journey that is fuelled by the energy stores previously accumulated. The seasonal dynamics of intensive feeding and lipid deposition, followed by high energy activities that are accompanied by fasting and lipid mobilisation, render the species ideal for the study of possible biomarkers of fluctuating energy stores. This thesis focuses on the evaluation of fluctuating adiposity of southern hemisphere humpback whales. The second chapter presents a critical review of the available approaches of assessing cetacean body condition. Currently the methodologies can be divided into four groups, namely: Blubber Measures, Body Composition, Body Morphometry, and Biochemical and Chemical Biomarkers. The last category is dedicated mainly to new developments and explores the emerging methodologies. This chapter describes and analyzes their applications as well as their respective strengths and weaknesses. The chapter concludes by advocating research priorities that fill the critical technical research needs for a reliable, non-lethal and standardized methodology that is applicable across species and age-categories and for large numbers of individuals. In response to the research need identified in chapter two, chapter three investigates adipocyte metrics as a potential biomarker of adiposity in humpback whales. Blubber is composed of adipocytes, which are filled with lipids according to the individual energy reserves. This means that a change in total energy reserve impacts the volume of individual adipocytes. Two adipocyte metrics were assessed histologically: the two-dimensional adipocytes area and the relative proportion of adipocyte space in the blubber tissue which is termed the adipocyte index. Both adipocyte metrics exceed the sensitivity of the most widely used proxy for energetic reserves, blubber lipid percentage, thus validating the implementation of adipocyte area and the adipocyte index as energetic reserve biomarkers. This published work therefore advocates the inclusion of these measures, obtained from superficial blubber biopsies, in long-term monitoring programs as a means of improving evaluation of fluctuating energy reserves. Following the molecular techniques’ potential to assessing body condition identified in the second chapter, chapter four explores the RNA extraction from humpback whale blubber for downstream applications. Good quality RNA is a prerequisite for successful downstream applications, however its extraction can be difficult, especially if the starting material is high in lipids. This chapter describes the strategic approach taken for method optimization and the difficulties encountered. The fifth chapter provides a theoretical basis for the use of blubber proteins “adipokines” as biomarkers of adiposity. The main physiological role of blubber is energy storage; however, the tissue is highly integrated into the overall physiological and metabolic control systems of mammals. This mechanism is carried out through the secretion of proteins, synthesized in the adipose tissue and actively involved in the lipid dynamics, with a profound effect on food intake and energy expenditure in model species. The different concentrations of these proteins, such as leptin and adiponectin inform the hypothalamus of the amount of energy stored. However, very little is known about the operation of adipokines in animals that experience extreme fluctuations in their energy reserves while at the same time using adipose tissue as insulation as cetaceans do. This chapter explores the possibility that the gene expression profile of selected adipokines may provide insight into the fluctuating energetic health of cetaceans. This chapter also outlines trialled approaches and advocates future priorities. The key findings and implications of this work are discussed in the concluding chapter. In summary, this study makes clear the importance of the energy reserves measurement and its ecological scope. It identifies the priorities for the improvement and standardization of the current methodologies and highlights the importance of new developments, pointing towards possible areas for further development. It proposes a simple and easily applicable methodology that improves precision and accuracy of the current method. In addition, it proposes advances in the optimization of the extraction of good quality RNA from blubber for downstream application. Finally, it explores the gene profile of the adipokines leptin and adiponectin, leaving the theoretical bases and some progress in the study of adipokines gene expression from humpback whale blubber.

Publisher's version (útgefin grein), Baleen whales face the challenge of finding patchily distributed food in the open ocean. Their relatively well-developed olfactory structures suggest that they could identify the specific odours given off by planktonic prey such as krill aggregations. Like other marine predators, they may also detect dimethyl sulfide (DMS), a chemical released in areas of high marine productivity. However, dedicated behavioural studies still have to be conducted in baleen whales in order to confirm the involvement of chemoreception in their feeding ecology. We implemented 56 behavioural response experiments in humpback whales using two food-related chemical stimuli, krill extract and DMS, as well as their respective controls (orange clay and vegetable oil) in their breeding (Madagascar) and feeding grounds (Iceland and Antarctic Peninsula). The whales approached the stimulus area and stayed longer in the trial zone during krill extract trials compared to control trials, suggesting that they were attracted to the chemical source and spent time exploring its surroundings, probably in search of prey. This response was observed in Iceland, and to a lesser extend in Madagascar, but not in Antarctica. Surface behaviours indicative of sensory exploration, such as diving under the stimulus area and stopping navigation, were also observed more often during krill extract trials than during control trials. Exposure to DMS did not elicit such exploration behaviours in any of the study areas. However, acoustic analyses suggest that DMS and krill extract both modified the whales’ acoustic activity in Madagascar. Altogether, these results provide the first behavioural evidence that baleen whales actually perceive prey-derived chemical cues over distances of several hundred metres. Chemoreception, especially olfaction, could thus be used for locating prey aggregations and for navigation at sea, as it has been shown in other marine predators including seabirds., This research was funded by the Fondation Total (www.fondation.total.com), grant #144903 to A.C., and the Ministère de l'Enseignement Supérieur et de la Recherche (www.enseignementsup-recherche.gouv.fr) to B.B., Bourse doctorale. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Cetacean stranding records can provide vital information on species richness and diversity through space and time. Here we collate stranding records from Victoria, Australia and assess them for temporal, spatial and demographic trends. Between 1920 and 2016, 424 stranding events involving 907 individuals were recorded across 31 Cetacea species from seven families, including five new species records for the state. Seven of these events were mass strandings, and six mother and calf strandings were recorded. Importantly, 48% of the species recorded are recognised as data deficient on the IUCN Red List. The most commonly recorded taxa were Tursiops spp. (n = 146) and Delphinus delphis (common dolphins, n = 81), with the greatest taxonomic richness (n = 24) and highest incidence of stranding events documented within the Otways mesoscale bioregion. We found no seasonal stranding patterns anywhere in the state. While our findings improve understanding of the spatial and temporal patterns of cetacean diversity within Victoria, we suggest greater effort to collect demographic data at stranding events in order to better study state-wide patterns through time. We conclude with guidelines for minimum data collection standards for future strandings to maximise information capture from each event.

Illegal driftnetting causes each year several entanglements and deaths of sperm whales in different Mediterranean areas, primarily in the Tyrrhenian Sea. In summer 2020, during the June-July fishing season, two sperm whales were found entangled in illegal driftnets in the Aeolian Archipelago waters, Southern Italy. These two rare events were an exceptional chance to collect behavioural and acoustics data about entangled sperm whales. We analysed 1132 one-minute sets of breathing/behavioural data and 1575 minutes of acoustic recording, when the whales were found entangled, during the rescue operation, immediately after release, and in the days thereafter. The first whale was generally quiet showing a general status of debilitation/weakness, numerous skin lesions, and low breathing rate (0.31 (0.60)); it collaborated during rescue operations. On the contrary, the second whale showed a high level of agitation with a high breathing rate (1.48 (1.31)) during both the entanglement period and the net cutting operations, vigorously moving its fluke and pectoral fins, opening its mouth, sideway rolling or side fluking and frequently defecating. Acoustically, the first whale produced mainly single clicks in all phases except for two series of creaks during rescuing operations while the second whale produced a wide range of vocalizations (single clicks, likely either slow clicks or regular clicks, creaks, and codas). Our observations indicate that acoustics, respiratory and behavioural parameters may be useful to monitor the physical/physiological status of sperm whales during disentanglement operations.

We document changes in the number of sightings and timing of humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and gray (Eschrichtius robustus) whale migratory phases in the vicinity of the Farallon Islands, California. We hypothesized that changes in the timing of migration off central California were driven by local oceanography, regional upwelling, and basin-scale climate conditions. Using 24 years of daily whale counts collected from Southeast Farallon Island, we developed negative binomial regression models to evaluate trends in local whale sightings over time. We then used linear models to assess trends in the timing of migration, and to identify potential environmental drivers. These drivers included local, regional and basin-scale patterns; the latter included the El Niño Southern Oscillation, the Pacific Decadal Oscillation, and the North Pacific Gyre Oscillation, which influence, wind-driven upwelling, and overall productivity in the California Current System. We then created a forecast model to predict the timing of migration. Humpback whale sightings significantly increased over the study period, but blue and gray whale counts did not, though there was variability across the time series. Date of breeding migration (departure) for all species showed little to no change, whereas date of migration towards feeding areas (arrival) occurred earlier for humpback and blue whales. Timing was significantly influenced by a mix of local oceanography, regional, and basin-scale climate variables. Earlier arrival time without concomitant earlier departure time results in longer periods when blue and humpback whales are at risk of entanglement in the Gulf of the Farallones. We maintain that these changes have increased whale exposure to pot and trap fishery gear off the central California coast during the spring, elevating the risk of entanglements. Humpback entanglement rates were significantly associated with increased counts and early arrival in central California. Actions to decrease the temporal overlap between whales and pot/trap fishing gear, particularly when whales arrive earlier in warm water years, would likely decrease the risk of entanglements.

A seismic survey was conducted off the northeastern coast of Sakhalin Island, Russia in 2010. The survey area was adjacent to the only known near-shore feeding ground of the Critically Endangered population of western gray whales Eschrichtius robustus in the western Pacific south of the Aleutian Islands. This study examined the effectiveness of efforts to minimize the behavioural responses of the whales to vessel proximity and sound during the survey. Two shore-based behavioural observation teams monitored whale movements and respirations pre-, during and post-seismic survey. Theodolite tracking and focal-animal follow methods were used to collect behavioural data. Mixed linear models were used to examine deviations from 'normal' patterns in 10 movement and 7 respiration response variables in relation to vessel proximity, vessel/ whale relative orientations and 8 received sound metrics to examine if seismic survey sound and/or vessel activity influenced the whales' behaviour. Behavioural state and water depth were the best 'natural' predictors of whale movements and respiration. After considering natural variation, none of the response variables were significantly associated with seismic survey or vessel sounds. A whale's distance from shore and its orientation relative to the closest vessel were found to be significantly influenced by vessel proximity, which suggested some non-sound related disturbance. The lack of evidence that the whales responded to seismic survey sound and vessel traffic by changing either their movement or respiration patterns could indicate that the current mitigation strategy is effective. However, power analyses suggest that our sample sizes were too small to detect subtle to moderate changes in gray whale behaviour.

In the context of a changing climate, understanding the environmental drivers of marine megafauna distribution is important for conservation success. The extent of humpback whale breeding habitats and the impact of temperature variation on their availability are both unknown. We used 19 years of dedicated survey data from seven countries and territories of Oceania (1,376 survey days), to investigate humpback whale breeding habitat diversity and adaptability to climate change. At a fine scale (1 km resolution), seabed topography was identified as an important influence on humpback whale distribution. The shallowest waters close to shore or in lagoons were favored, although humpback whales also showed flexible habitat use patterns with respect to shallow offshore features such as seamounts. At a coarse scale (1 degrees resolution), humpback whale breeding habitats in Oceania spanned a thermal range of 22.3-27.8 degrees C in August, with interannual variation up to 2.0 degrees C. Within this range, both fine and coarse scale analyses of humpback whale distribution suggested local responses to temperature. Notably, the most detailed dataset was available from New Caledonia (774 survey days, 1996-2017), where encounter rates showed a negative relationship to sea surface temperature, but were not related to the El Nino Southern Oscillation or the Antarctic Oscillation from previous summer, a proxy for feeding conditions that may impact breeding patterns. Many breeding sites that are currently occupied are predicted to become unsuitably warm for this species (>28 degrees C) by the end of the 21st century. Based on modeled ecological relationships, there are suitable habitats for relocation in archipelagos and seamounts of southern Oceania. Although distribution shifts might be restrained by philopatry, the apparent plasticity of humpback whale habitat use patterns and the extent of suitable habitats support an adaptive capacity to ocean warming in Oceania breeding grounds.

Wind energy is one of the most important renewable resources and plays a vital role in reducing carbon emission and solving global warming problem. Every country has made a corresponding energy policy to stimulate wind energy industry development based on wind energy production, consumption, and distribution. In this paper, we focus on forecasting wind energy consumption from a macro perspective. A novel power-driven fractional accumulated grey model (PFAGM) is proposed to solve the wind energy consumption prediction problem with historic annual consumption of the past ten years. PFAGM model optimizes the grey input of the classic fractional grey model with an exponential term of time. For boosting prediction performance, a heuristic intelligent algorithm WOA is used to search the optimal order of PFAGM model. Its linear parameters are estimated by using the least-square method. Then validation experiments on real-life data sets have been conducted to verify the superior prediction accuracy of PFAGM model compared with other three well-known grey models. Finally, the PFAGM model is applied to predict China's wind energy consumption in the next three years.

The U.S. Endangered Species Act (ESA) is a powerful environmental law protecting imperiled plants and animals, and a growing number of marine species have been protected under this law as extinction risk in the oceans has increased. Marine mammals and sea turtles comprise 38% of the 163 ESA-listed marine "species", which includes subspecies and distinct population segments, yet analyses of recovery trends after listing are lacking. Here we gathered the best available annual abundance estimates for geographically delimited populations of all 62 marine mammal and sea turtle species listed under the ESA. Of these, we chose representative populations of species that were listed before 2012, occur and reproduce in U.S. waters, and have data of sufficient quality and timespan for trend analyses. Thus, we quantitatively analyzed population trends, magnitude of population change, and recovery status for 23 and 8 representative populations of 14 marine mammal and 5 sea turtle species, respectively. Using generalized linear and non-linear models, we found that 18 marine mammal (78%) and 6 sea turtle (75%) populations significantly increased after listing; 3 marine mammal (13%) and 2 sea turtle (25%) populations showed non-significant changes; while 2 marine mammal (9%), but no sea turtle populations declined after ESA protection. Overall, the 24 populations that increased in abundance were from species listed for 20 years or more (e.g., large whales, manatees, and sea turtles). Conservation measures triggered by ESA listing such as ending exploitation, tailored species management, and fishery regulations, and other national and international measures, appear to have been largely successful in promoting species recovery, leading to the delisting of some species and to increases in most populations. These findings underscore the capacity of marine mammal and sea turtle species to recover from substantial geographical population declines when conservation actions are implemented in a timely and effective manner.

Contaminants monitoring in wild, large cetaceans may be performed using internal organs of stranded animals. Although extremely valuable, data obtained from dead animals can be biased by poor health conditions, modifying the concentrations of pollutants. Blubber biopsies represent the most feasible sampling technique from free ranging Mysticetes but are little used for trace elements quantification. Few data exist on trace elements in blubber, being this tissue not considered as a site of accumulation. Anyway, accumulation does occur in this tissue. Detected values are in the same range of magnitude of those observed in toothed whales (bottlenose, striped and common dolphins, harbour and Dall’s porpoises). Hg, Cd and As values are among the lowest determined, while Pb is the highest oneSome correlations have been detected among trace elements, excepted for Cd. These correlations can reflect different exposure levels and/or accumulation capacity and elimination pathways.

Large Whale Entanglements, Strandings, Ice Entrapments and Selective Sightings Reported to the Whale Release and Strandings Group in Newfoundland and Labrador and a Summary of the Whale Release and Strandings Program During 2018. A Report to the Department of Fisheries and Oceans, Canada - Newfoundland and Labrador Region.

Fin whales (Balaenoptera physalus) have a global distribution, but the population inhabiting the Gulf of California (GoC) is thought to be geographically and genetically isolated. However, their distribution and movements are poorly known. The goal of this study was to describe fin whale movements for the first time from 11 Argos satellite tags deployed in the southwest GoC in March 2001. A Bayesian Switching State-Space Model was applied to obtain improved locations and to characterize movement behavior as either "area-restricted searching" (indicative of patch residence, ARS) or "transiting" (indicative of moving between patches). Model performance was assessed with convergence diagnostics and by examining the distribution of the deviance and the behavioral parameters from Markov Chain Monte Carlo models. ARS was the predominant mode behavior 83% of the time during both the cool (December-May) and warm seasons (June-November), with slower travel speeds (mean = 0.84 km/h) than during transiting mode (mean = 3.38 km/h). We suggest ARS mode indicates either foraging activities (year around) or reproductive activities during the winter (cool season). We tagged during the cool season, when the whales were located in the Loreto-La Paz Corridor in the southwestern GoC, close to the shoreline. As the season progressed, individuals moved northward to the Midriff Islands and the upper gulf for the warm season, much farther from shore. One tag lasted long enough to document a whale's return to Loreto the following cool season. One whale that was originally of undetermined sex, was tagged in the Bay of La Paz and was photographed 10 years later with a calf in the nearby San Jose Channel, suggesting seasonal site fidelity. The tagged whales moved along the western GoC to the upper gulf seasonally and did not transit to the eastern GoC south of the Midriff Islands. No tagged whales left the GoC, providing supporting evidence that these fin whales are a resident population.

Marine megafauna has always elicited contrasting feelings. In the past, large marine animals were often depicted as fantastic mythological creatures and dangerous monsters, while also arousing human curiosity. Marine megafauna has been a valuable resource to exploit, leading to the collapse of populations and local extinctions. In addition, some species have been perceived as competitors of fishers for marine resources and were often actively culled. Since the 1970s, there has been a change in the perception and use of megafauna. The growth of marine tourism, increasingly oriented towards the observation of wildlife, has driven a shift from extractive to non-extractive use, supporting the conservation of at least some species of marine megafauna. In this paper, we review and compare the changes in the perception and use of three megafaunal groups, cetaceans, elasmobranchs and groupers, with a special focus on European cultures. We highlight the main drivers and the timing of these changes, compare different taxonomic groups and species, and highlight the implications for management and conservation. One of the main drivers of the shift in perception, shared by all the three groups of megafauna, has been a general increase in curiosity towards wildlife, stimulated inter alia by documentaries (from the early 1970s onwards), and also promoted by easy access to scuba diving. At the same time, environmental campaigns have been developed to raise public awareness regarding marine wildlife, especially cetaceans, a process greatly facilitated by the rise of Internet and the World Wide Web. Currently, all the three groups (cetaceans, elasmobranchs and groupers) may represent valuable resources for ecotourism. Strikingly, the economic value of live specimens may exceed their value for human consumption. A further change in perception involving all the three groups is related to a growing understanding and appreciation of their key ecological role. The shift from extractive to non-extractive use has the potential for promoting species conservation and local economic growth. However, the change in use may not benefit the original stakeholders (e.g. fishers or whalers) and there may therefore be a case for providing compensation for disadvantaged stakeholders. Moreover, it is increasingly clear that even non-extractive use may have a negative impact on marine megafauna, therefore regulations are needed. SFRH/BPD/102494/2014, UID/MAR/04292/2019, IS1403 info:eu-repo/semantics/publishedVersion

Sea noise collected over 2003 to 2017 from the Perth Canyon, Western Australia was analysed for variation in the South Eastern Indian Ocean pygmy blue whale song structure. The primary song-types were: P3, a three unit phrase (I, II and III) repeated with an inter-song interval (ISI) of 170-194 s; P2, a phrase consisting of only units II & III repeated every 84-96 s; and P1 with a phrase consisting of only unit II repeated every 45-49 s. The different ISI values were approximate multiples of each other within a season. When comparing data from each season, across seasons, the ISI value for each song increased significantly through time (all fits had p << 0.001), at 0.30 s/Year (95%CI 0.217-0.383), 0.8 s/Year (95%CI 0.655-1.025) and 1.73 s/Year (95%CI 1.264-2.196) for the P1, P2 and P3 songs respectively. The proportions of each song-type averaged at 21.5, 24.2 and 56% for P1, P2 and P3 occurrence respectively and these ratios could vary by up to ± 8% (95% CI) amongst years. On some occasions animals changed the P3 ISI to be significantly shorter (120-160 s) or longer (220-280 s). Hybrid song patterns occurred where animals combined multiple phrase types into a repeated song. In recent years whales introduced further complexity by splitting song units. This variability of song-type and proportions implies abundance measure for this whale sub population based on song detection needs to factor in trends in song variability to make data comparable between seasons. Further, such variability in song production by a sub population of pygmy blue whales raises questions as to the stability of the song types that are used to delineate populations. The high level of song variability may be driven by an increasing number of background whale callers creating 'noise' and so forcing animals to alter song in order to 'stand out' amongst the crowd.

Fin whales (Balaenoptera physalus) and blue whales (B. musculus) are the two largest species on Earth and are widely distributed across the world's oceans. Hybrids between these species appear to be relatively widespread and have been reported in both the North Atlantic and North Pacific; they are also relatively common, and have been proposed to occur once in every thousand fin whales. However, despite known hybridization, fin and blue whales are not sibling species. Rather, the closest living relative of fin whales are humpback whales (Megaptera novaeangliae). To improve the quality of fin whale data available for analysis, we assembled and annotated a fin whale nuclear genome using in-silico mate pair libraries and previously published short-read data. Using this assembly and genomic data from a humpback, blue, and bowhead whale, we investigated whether signatures of introgression between the fin and blue whale could be found. We find no signatures of contemporary admixture in the fin and blue whale genomes, although our analyses support ancestral gene flow between the species until 2.4-1.3 Ma. We propose the following explanations for our findings; i) fin/blue whale hybridization does not occur in the populations our samples originate from, ii) contemporary hybrids are a recent phenomenon and the genetic consequences have yet to become widespread across populations, or iii) fin/blue whale hybrids are under large negative selection, preventing them from backcrossing and contributing to the parental gene pools.

We present field results revealing improved surfing performance when a novel approach ("Real Whale", RW) is used for applying several of the humpback whale's passive flow control mechanisms, including tubercles, to surfboard fins. It is also the first study presenting evidence of dynamic performance of tubercled designs rotating on all three axes. We evaluated low aspect ratio, thruster-style 3-fin configurations used in high-performance surfing. Fieldwork involved surfing almost 2,000 ocean waves from around the world, comparing standard commercial fins with straight leading edges to RW fins. We collected surfing data from instrumentation attached to surfboards, including GPS and 9-axis motion sensors. Eighteen turn performance values were measured and calculated, including novel, surfing-specific rotational power coefficients. ANOVA revealed surfers using RW fins showed significant improvements in power generation compared to when they used standard commercial fins. Turn rates using RW fins also improved, although not significantly. We found using RW fins allowed a skilled surfer to improve their surfing performance relative to a professionally ranked surfer.

International audience; Mitochondrial DNA (mtDNA) differences between humpback whales on different feeding groundscan reflect the cultural transmission of migration destinations over generations, and thereforerepresent one of the very few cases of gene-culture coevolution identified in the animal kingdom.In Russian Pacific waters, photo-identification (photo-ID) studies have shown minimal interchangebetween whales feeding off the Commander Islands and those feeding in the Karaginsky Gulf,regions that are separated by only 500 km and have previously been lumped together as a singleRussian feeding ground. Here, we assessed whether genetic differentiation exists between these2 groups of humpback whales. We discovered a strong mtDNA differentiation between the 2feeding sites (FST = 0.18, ΦST = 0.14, P < 0.001). In contrast, nuclear DNA (nuDNA) polymorphisms,determined at 8 microsatellite loci, did not reveal any differentiation. Comparing our mtDNA resultswith those from a previous ocean-basin study reinforced the differences between the 2 feedingsites. Humpback whales from the Commanders appeared most similar to those of the westernGulf of Alaska and the Aleutian feeding grounds, whereas Karaginsky differed from all other NorthPacific feeding grounds. Comparison to breeding grounds suggests mixed origins for the 2 feedingsites; there are likely connections between Karaginsky and the Philippines and to a lesser extentto Okinawa, Japan, whereas the Commanders are linked to the Mexican breeding grounds. ThemtDNA differentiation between the Commander Islands and Karaginsky Gulf suggests a case ofgene-culture coevolution, correlated to fidelity to a specific feeding site within a particular feedingground. From a conservation perspective, our findings emphasize the importance of consideringthese 2 feeding sites as separate management units.

Publisher's version (útgefin grein), Central place foraging theory (CPF) has been used to predict the optimal patch residence time for air-breathing marine predators in response to patch quality. Humpback whales (Megaptera novaeangliae) forage on densely aggregated prey, which may induce drastic change in prey density in a single feeding event. Thus, the decision whether to leave or stay after each feeding event in a single dive in response to this drastic change, should have a significant effect on prey exploitation efficiency. However, whether humpback whales show adaptive behavior in response to the diminishing prey density in a single dive has been technically difficult to test. Here, we studied the foraging behavior of humpback whales in response to change in prey density in a single dive and calculated the efficiency of each foraging dive using a model based on CPF approach. Using animal-borne accelerometers and video loggers attached to whales, foraging behavior and change in relative prey density in front of the whales were successfully quantified. Results showed diminishing rate of energy intake in consecutive feeding events, and humpback whales efficiently fed by bringing the rate of energy intake close to maximum in a single dive cycle. This video-based method also enabled us to detect the presence of other animals around the tagged whales, showing an interesting trend in behavioral changes where feeding duration was shorter when other animals were present. Our results have introduced a new potential to quantitatively investigate the effect of other animals on free-ranging top predators in the context of optimal foraging theory.

Mortality from collisions with vessels is one of the main human causes of death for large whales. Ship strikes are rarely witnessed and the distribution of strike risk and estimates of mortality remain uncertain at best. We estimated ship strike mortality for blue humpback and fin whales in U.S. West Coast waters using a novel application of a naval encounter model. Mortality estimates from the model were far higher than current minimum estimates derived from stranding records and are closer to extrapolations adjusted for detection probabilities of dead whales. Our most conservative model estimated mortality to be 7.8x, 2.0x and 2.7x the U.S. recommended limit for blue, humpback and fin whales, respectively, suggesting that death from vessel collisions may be a significant impediment to population growth and recovery. Comparing across the study area, the majority of strike mortality occurs in waters off California, from Bodega Bay south and tends to be concentrated in a band approximately 24 Nm (44.5 km) offshore and in designated shipping lanes leading to and from major ports. While some mortality risk exists across nearly all West Coast waters, 74%, 82% and 65% of blue, humpback and fin whale mortality, respectively, occurs in just 10% of the study area, suggesting conservation efforts can be very effective if focused in these waters. Risk is highest in the shipping lanes off San Francisco and Long Beach, but only a fraction of total estimated mortality occurs in these proportionally small areas, making any conservation efforts exclusively within these areas insufficient to address overall strike mortality. We recommend combining shipping lane modifications and re-locations, ship speed reductions and creation of ‘Areas to be Avoided’ by vessels in ecologically important locations to address this significant source of whale mortality.

Background Matching animal movement with the behaviors that shape life history requires a rigorous connection between the observed patterns of space use and inferred behavioral states. As animal-borne dataloggers capture a greater diversity and frequency of three dimensional movements, we can increase the complexity of movement models describing animal behavior. One challenge in combining data streams is the different spatial and temporal frequency of observations. Nested movement models provide a flexible framework for gleaning data from long-duration, but temporally sparse, data sources. Results Using a two-layer nested model, we combined geographic and vertical movement to infer traveling, foraging and resting behaviors of Humpback whales off the West Antarctic Peninsula. This approach refined previous work using only geographic data to delineate coarser behavioral states. Our results showed increased intensity in foraging activity in late season animals as the whales prepared to migrate north to tropical calving grounds. Our model also suggests strong diel variation in movement states, likely linked to daily changes in prey distribution. Conclusions Using a combination of two-dimensional and three-dimensional movement data, we highlight the connection between whale movement and krill availability, as well as the complex spatial pattern of whale foraging in productive polar waters.

Many animals require intervals of rest or sleep in which their vigilance level is reduced. For marine fauna, including large baleen whales, resting potentially increases the risk of predation and vessel-strike. However, there is scarce information about how, and how often, whales rest which makes it difficult to assess the severity of this risk. Here we examine resting patterns of Bryde's whales (Baleaenoptera edeni/brydei), using data collected by sound and movement archival tags (DTAGs) deployed on four whales in the Hauraki Gulf, New Zealand. To identify low activity levels associated with resting, we used RMS jerk and mean flow noise (as proxies for activity and speed, respectively), as well as changes in dive patterns (dive depth and shape), fluking, and respiration rates. The tagged whales showed strong diel differences in behavior with long periods of low activity consistent with resting occurring exclusively during the night. This pattern indicates that either (i) Bryde's whales rely on senses that are less effective in the dark to locate prey, or (ii) that prey aggregate less densely at night, making foraging less efficient. Thus, Bryde's whales conserve energy through rest during times when the net benefit of foraging effort is low. However, by reducing their interaction level with their environment, night-time resting also makes Bryde's whales more vulnerable to vessel strikes, an important source of mortality for cetaceans.Significant statementAll mammals need to rest periodically and whales are no exception. But while resting land mammals can be observed directly, little is known about when and how whales rest; even though lower vigilance levels during resting could make them more vulnerable to threats such as collisions with boat traffic. We used sound and movement logging tags on resident Bryde'swhales in a busy gulf to study their daily activity patterns. We found that, while whales were active during daytime making energetic lunges to capture tonnes of plankton, they dedicated much of the night to rest. This suggests that whales may rely on vision to find prey or that prey are less densely aggregated at night making foraging less efficient. However, this near-surface resting behavior which may also be shared by the other giant baleen whales increases the risk of ship strikes.

We assessed the social structure and behavior of humpback whale ( Megaptera novaeangliae ) competitive groups off Ecuador between July and August 2010. During this time we followed 185 whales in 22 competitive groups for 41.45 hr. The average group size was 8.4 animals ( SD = 2.85). The average sighting time was 113.05 min/group ( SD = 47.1). We used photographs of dorsal fins and video to record interactions and estimate an association index (AI) between each pair of whales within the groups. Sightings were divided into periods, which were defined by changes in group membership. On average, group composition changed every 30.2 min, which confirms that the structure of competitive groups is highly dynamic. Interactions between escorts characterized by low level of aggression. At least 60% of escorts joined or left together the group in small subunits between two and five animals, suggesting some type of cooperative association. Although singletons, as well as pairs or trios were able to join competitive groups at any moment, escorts that joined together were able to stay longer with the group and displace dominant escorts. Genetic analysis showed that in three occasions more than one female was present within a competitive group, suggesting either males are herding females or large competitive groups are formed by subunits. Males and females performed similar surface displays. We propose that competition and cooperation are interrelated in humpback whales’ competitive groups and that male cooperation would be an adaptive strategy either to displace dominant escorts or to fend off challengers.