North Atlantic right whales Eubalaena glacialis are one of the most endangered species of large whales, with fewer than 400 individuals remaining. Anthropogenic factors driving their decline are morbidity and mortality from entanglement in fishing gear and collisions between whales and vessels. Two recent events spurred this paper’s reconsideration of possible options for improved mitigation of vessel strikes impacting North Atlantic right whales. These include a new analysis of the relationship between vessel size and speed and the likelihood of fatal injuries resulting from vessel collisions with whales, and the US government's decision in January 2025 not to extend regulations aimed at minimising the risk of vessel strikes along the US east coast. Here, a reanalysis of the vessel strike data on large whales, excluding humpback whales Megaptera novaeangliae , confirms its main findings. Whale mortalities can occur at speeds of less than 10 knots (18.5 km h -1 ), particularly when struck by very large (length >108 m) vessels. However, the model incorrectly assigned vessels from 2 categories as likely causing mortalities when they did not. This adds strength to the argument that the risk of mortalities of North Atlantic right whales posed by very large vessels is particularly concerning. However, results of management actions taken recently by the Canadian government in the Gulf of St Lawrence offer cause for some optimism. Direct approaches to shipping companies to mitigate their impacts on North Atlantic right whales are likely to be more effective at present than attempting to change US regulations.

Beaked whales (family Ziphiidae) are cryptic, deep-diving cetaceans found offshore. Passive acoustic monitoring of this family allows identification to species level and is instrumental in expanding knowledge of their behavior, distribution, and habitat use. From 28 June to 25 August 2016, 2 broadscale shipboard surveys towed a hydrophone array in the western North Atlantic. Concurrently, 11 bottom-mounted recorders collected continuous passive acoustic data along the 1000 m contour during July and August 2016. Five beaked whale species (goose-beaked, Ziphius cavirostris; Gervais’, Mesoplodon europaeus; True’s, M. mirus; Sowerby’s, M. bidens; and Blainville’s, M. densirostris) were present in both data sets. Beaked whales were commonly detected at the bottom-mounted sites (71% total days present), with sites off the US Mid-Atlantic Bight containing the greatest species diversity. Overall, daily co-occurrence was uncommon (35% of study period). Using the towed array, Blainville’s and Gervais’ beaked whales were found in the Gulf Stream, True’s beaked whales were more common in abyssal waters, and Sowerby’s beaked whales were more common on the continental slope. Goose-beaked whales were present throughout. Using multipath reflections, click depths were examined for 192 beaked whale detection events. Among 3 species tested (goose-beaked, Gervais’, and True’s), only goose-beaked whales were found to significantly forage in proximity to the seafloor. This is the first study of its kind to provide a comprehensive overview of how these whales utilize their habitat across latitudes, longitudes, and depths.

The world is currently facing a biodiversity crisis and for many species, this is exacerbated by historic exploitation. Monitoring programs provide an integral tool to understand changes in abundance and the impact of threats informing conservation actions. However, measures of absolute abundance for management can be misleading, particularly when there is a biased sex ratio. Here we recommend focusing on the rate-limiting cohort for management actions using the case of North Atlantic right whales. The North Atlantic right whale has a male-biased sex ratio, with reproductively active females making up less than a fifth of the species. We highlight the importance of understanding and incorporating reproductive potential into management actions to provide species with the best chance of recovery.

North Atlantic right whales are Critically Endangered and declining, with entanglements in fishing gear a key contributor to their decline. Entanglement events can result in lethal and sub-lethal (i.e. increased energetic demands and reduced foraging ability) impacts, with the latter influencing critical life-history states, such as reproduction. Using a multi-event framework, we developed a Bayesian mark-recapture model to investigate the influence of entanglement severity on survival and recruitment for female right whales. We used information from 199 known-aged females sighted between 1977 and 2018, combined with known entanglements of varying severity that were classified as minor, moderate or severe. Severe entanglements resulted in an average decline in survival of 27% for experienced non-breeders, 9% for breeders and 26% for pre-breeding females compared with other entanglements and unentangled individuals. Surviving individuals with severe entanglements had low transitional probabilities to breeders, but surprisingly, individuals with minor entanglements had the lowest transitional probabilities, contrary to expectations underpinning current management actions. Management actions are needed to address the lethal and sub-lethal impacts of entanglements, regardless of severity classification.

We fit ongoing 40+-year mark-recapture databases from the thriving southern right whale (SRW), Eubalaena australis , and highly endangered North Atlantic right whale (NARW), Eubalaena glacialis , to candidate survival models to estimate their life spans. Median life span for SRW was 73.4 years, with 10% of individuals surviving past 131.8 years. NARW life spans were likely anthropogenically shortened, with a median life span of just 22.3 years, and 10% of individuals living past 47.2 years. In the context of extreme longevity recently documented in other whale species, we suggest that all balaenid and perhaps most great whales have an unrecognized potential for great longevity that has been masked by the demographic disruptions of industrial whaling. This unrecognized longevity has profound implication for basic biology and conservation of whales.

In the Southern Hemisphere, humpback whales (Megaptera novaeangliae) migrate along the extended continental coastlines of Australia, South America, and South Africa. This study reports on photo-identification capture–recapture data from a long-term survey conducted in Hervey Bay, Queensland, where a substantial proportion of the population stop over early in the southern migration. Photo-identification data were collected over 10 weeks per year from 1997 to 2009. The migration through Hervey Bay is dominated and led by females with high fidelity to the site. Mature females, yearlings, and immature whales use the Bay during August, while mature lactating females with calves dominate during September and October. Complex social behaviours occur throughout the season and differ between the early and late cohorts. We argue that the composition of the two cohorts and their distinctively different behaviours indicate that Hervey Bay is not simply a resting site but an area of aggregation that serves important social and biological benefits. A multistate open robust design model was fitted to capture–recapture data to estimate the annual number of whales visiting the Bay, the permanent emigration rate, proportions of the visiting population that do not enter the Bay each year, the number present during each week, and their residency times. The number of annual visitors to the Bay increased approximately linearly from 857 in 1997 to 2175 at the end of sampling in 2009 with two-thirds migrating through during the first half of each season. The population rate of growth may have been slowing by 2009, but there was considerable uncertainty in the trajectory and little basis for projection into the future. While it is desirable to know the current status of the Hervey Bay population and what has occurred since 2009, the cost and effort required make further manual collection and matching of images unlikely. The development of AI algorithmic matching software may enable further research in future.

Without substantive reduction in anthropogenic trauma, Critically Endangered North Atlantic right whales Eubalaena glacialis (NARWs) risk extinction. Decreasing population size is attributable to 2 main issues besides vessel collision: entanglement in fishing gear and changes in food availability due to ecosystem changes in the face of climate disruption. Both can affect NARW energetics, leading to reduced body condition, decreased reproductive success of individuals, and deterioration of overall population health. To measure the impact of these stressors and their interaction, energetic costs associated with entanglement and starvation were incorporated in a bioenergetics model, established for a generic female right whale. We compared models for a NARW living now, one from 2 decades ago, when the species’ abundance was increasing at approximately 2% yr -1 , and a southern right whale (SRW) from a population increasing at approximately 6% yr -1 . Parameter uncertainty associated with daily estimates of energy income, basal metabolic rate, and possible influences of baleen rack disruption from entanglement was so great that differences between the 3 generic right whale females were indistinguishable. Therefore, we included a stunted whale in the model. It was also indistinguishable from our first 3 model whales. Further, it made robust predictions of NARW energy budgets, let alone the impact of specific stressors of varying intensity, impossible. The capacity of bioenergetic modeling to inform conservation management of NARWs will be substantially enhanced by resolving these parameter uncertainties.

Is the increased use in wildlife conservation of techniques derived from military and security services appropriate? One aspect of this issue that remains poorly considered is whether all actors engaged in conservation projects that have a security orientation are engaged primarily in conservation. Western intelligence agencies are known to have used non-government aid organizations (NGOs) as cover for clandestine operations. Does this happen in conservation? In one example, a previous US President expressed concern that ivory trafficking represented a national security threat to the USA, following a report claiming that ivory trafficking was funding terrorist networks in Africa. Coincident with this new reason for concern regarding elephant poaching, a US-based conservation NGO employed staff from US military intelligence to develop and run an intelligence fusion center with the Kenya Wildlife Service. After a few years, the head of the operation left the NGO and returned directly to her career in military intelligence. Without access to classified information, it is impossible to determine if this was coincidence. Analytical tools, including some developed by the intelligence community, could be used to better assess whether some conservation programs are cover for clandestine operations. In the meantime, conservation professionals need to consider the possibility that there could be serving officers of intelligence agencies inside conservation NGOs. In order to ensure the security of conservation workers and the acceptance of conservation programs worldwide, all national governments should offer unequivocal guarantees that conservation NGOs are not being used for covert intelligence operations.

Passive acoustic monitoring (PAM) is an efficient method for large-scale marine mammal monitoring. PAM technologies concurrently sample multiple soniferous marine mammal species, and when coupled with verified detectors, provide information that can be used to evaluate community composition. This analysis used data collected by an array of high-frequency PAM recorders at eight sites between 30°0’N and 42°0’N along the shelf-break in the western North Atlantic Ocean. Daily acoustic presence of 13 known marine mammal species and grouped unknown odontocetes was determined for all months between June 2016 and May 2019. Classification trees were generated from monthly summaries of daily detections to identify community composition dissimilarities. Detections of Gervais’s beaked whale (Mesoplodon europaeus) represented the root node and split sites by latitude, grouping the three sites south of 34°0’N and the five sites north of 38°0’N. Tree nodes were further divided by other odontocetes. The presence of mysticetes also varied by site and season. Distinctive communities were identified for each site, with odontocetes being resident and mysticetes more migratory. The root and secondary splits were all driven by beaked whale species, demonstrating the importance of identifying these whales to species instead of aggregating them as is common for visual survey data.

The Critically Endangered status of North Atlantic right whales Eubalaena glacialis (NARWs) warrants the development of new, less invasive technology to monitor the health of individuals. Combined with advancements in remotely piloted aircraft systems (RPAS, commonly ‘drones’), infrared thermography (IRT) is being increasingly used to detect and count marine mammals and study their physiology. We conducted RPAS-based IRT over NARWs in Cape Cod Bay, MA, USA, in 2017 and 2018. Observations demonstrated 3 particularly useful applications of RPAS-based IRT to study large whales: (1) exploring patterns of cranial heat loss and providing insight into the physiological mechanisms that produce these patterns; (2) tracking subsurface individuals in real-time (depending on the thermal stratification of the water column) using cold surface water anomalies resulting from fluke upstrokes; and (3) detecting natural changes in superficial blood circulation or diagnosing pathology based on heat anomalies on post-cranial body surfaces. These qualitative applications present a new, important opportunity to study, monitor, and conserve large whales, particularly rare and at-risk species such as NARWs. Despite the challenges of using this technology in aquatic environments, the applications of RPAS-based IRT for monitoring the health and behavior of endangered marine mammals, including the collection of quantitative data on thermal physiology, will continue to diversify.

People have held marine mammalsMarine mammals captive for public displayPublic display for centuries, and the history of peoples’ engagement with free-ranging marine mammals has an even longer history. Currently, most concern is expressed over keeping cetaceansCetacea/cetaceans captive, rather than other marine mammals, so cetaceans are the focus of this chapter. Conservation and animal welfareAnimal welfare arguments against catching free-ranging cetaceans have gained traction in many countries in recent decades. Few nations now have live-captureLive capture industries. The reasons for and against maintaining captive cetaceans continue to be debated. While some countries have banned keeping cetaceans captive for entertainmentEntertainment, the industry is growing in others, particularly China. As standards for captive husbandry in some of these new operations are poor, survivalSurvival and welfareWelfare there remain problematic. In some other nations, conditions for captive cetaceans have improved markedly, and captive dolphins live at least as long as their free-ranging conspecifics. The recent extinctionExtinction of the baijiBaiji and dire conservationConservation situation of other small odontocetes have led to a call for new thinking on the possible role of ex situ conservation conservation measures. For this, the veterinary and husbandry skills developed for captive cetaceans can play a role in integrated conservationConservation programs. There is a continuum of interactionsInteraction with cetaceansCetacea/cetaceans, from remote observation of free-ranging animals, through engagement with dolphins that seek human interaction, semi-natural reservesSemi-natural reserves used in the conservationConservation programs, to cetaceans kept in indoor pools far from the ocean. The development of oceanic sanctuariesSanctuary/ies to house cetaceans formerly held in entertainmentEntertainment facilities adds to this continuum, and allows more options for integrated conservationConservation. As humanity’s understanding of the complexity of the lives of cetaceans has improved, our ethicalEthical stance on some aspects of maintaining them in captivityCaptivity has shifted. At the same time, our need to engage the public with conservationConservation messaging, and to manage the welfareWelfare of free-ranging cetaceansCetacea/cetaceans injured by human actions, has also grown.

Abundance and population trends of Critically Endangered North Atlantic right whales (Eubalaena glacialis, NARW) have been estimated using mark-recapture analyses where an individual's state is based upon set delineations of age, using historical estimates of age at first reproduction. Here we assigned individual females to states based upon their reproductive experience, rather than age. We developed a Bayesian mark-recapture-recovery model to investigate how survival, recapture, site-fidelity and dead-recovery probabilities vary for female NARW in different states, using data collected from 1977-2018. States were assigned as calves for individuals in their first year; pre-breeder for individuals greater than one year of age who had yet to produce a calf, or breeder if an individual had reproduced. A decline in abundance of female NARW was seen starting in 2014, with 185 females declining yearly to 142 by 2018. The largest decline was seen in breeding females, with 72 estimated to be alive at the beginning of 2018, while female pre-breeder abundance plateaued at around 70 between 2011- 2018. Females born from 2000 onwards had an average 4% (95% CI:0.03-0.06) chance of transitioning from pre-breeder to breeder, compared to 8% (95%CI:0.06-0.1) for females born prior. This reduction in transition rate from non-breeder to breeder for the current cohort resulted in breeding females declining to 51% of the female population by 2018. We show that a collapse in fecundity of breeding females, and the failure of pre-breeders to start breeding, is an important factor in understanding the current decline in abundance of the NARW.

Mitigation of threats posed to marine mammals by human activities can be greatly improved with a better understanding of animal occurrence in real time. Recent advancements have enabled low-power passive acoustic systems to be integrated into long-endurance autonomous platforms for persistent near real-time monitoring of marine mammals via the sounds they produce. Here, the integration of a passive acoustic instrument capable of real-time detection and classification of low-frequency (LF) tonal sounds with a Liquid Robotics wave glider is reported. The goal of the integration was to enable monitoring of LF calls produced by baleen whales over periods of several months. Mechanical noises produced by the platform were significantly reduced by lubricating moving parts with polytetrafluoroethylene, incorporating rubber and springs to decelerate moving parts and shock mounting hydrophones. Flow noise was reduced with the development of a 21-element hydrophone array. Surface noise produced by breaking waves was not mitigated despite experimentation with baffles. Compared to a well-characterized moored passive acoustic monitoring buoy, the system greatly underestimated the occurrence of sei, fin, and North Atlantic right whales during a 37-d deployment, and therefore is not suitable in its current configuration for use in scientific or management applications for these species at this time.

North Atlantic right whales Eubalaena glacialis are most commonly observed along the eastern seaboard of North America; however, their distribution and occupancy patterns have become less predictable in the last decade. This study explored the individual right whales captured photographically from both dedicated and opportunistic sources from 2015 to 2019 in the Gulf of St. Lawrence (GSL), an area previously understudied for right whale presence. A total of 187 individuals, including reproductive females, were identified from all sources over this period. In years when more substantial survey effort occurred (2017-2019), similar numbers of individuals were sighted (mean = 133, SD = 1.5), and dedicated mark-recapture aerial surveys were highly effective at capturing almost all of the whales estimated in the region (2019: N = 137, 95% CI = 135-147). A high rate of inter-annual return was observed between all 5 study years, with 95% of the animals seen in 2019 sighted previously. Capture rates indicated potential residencies as long as 5 mo, and observed behaviors included feeding and socializing. Individuals were observed in the northern and southern GSL, regions divided by a major shipping corridor. Analyses suggest that individuals mostly moved less than 9.1 km d-1, although rates of up to 79.8 km d-1 were also calculated. The GSL is currently an important habitat for 40% of this Critically Endangered species, which underscores how crucial protection measures are in this area.

Marine Mammal ScienceVolume 37, Issue 4 p. 1572-1573 BOOK REVIEW The Bowhead Whale. Balaena mysticetus: Biology and Human Interactions , J. C. George and J. G. M. Thewissen, Eds. Academic Press. 2021. 668 pp. ISBN: 9780128189696, US$120 (Hardcover); ISBN: 9780128189702, US$84.00 (eBook). Peter Corkeron, Corresponding Author pcorkeron@neaq.org Anderson Cabot Center for Ocean Life, New England Aquarium, Central Wharf, Boston, Massachusetts Correspondence Email: pcorkeron@neaq.orgSearch for more papers by this author Peter Corkeron, Corresponding Author pcorkeron@neaq.org Anderson Cabot Center for Ocean Life, New England Aquarium, Central Wharf, Boston, Massachusetts Correspondence Email: pcorkeron@neaq.orgSearch for more papers by this author First published: 01 October 2021 https://doi.org/10.1111/mms.12857Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume37, Issue4October 2021Pages 1572-1573 RelatedInformation

In habitat modelling, environmental variables are assumed to be proxies of lower trophic levels distribution and by extension, of marine top predator distributions. More proximal variables, such as potential prey fields, could refine relationships between top predator distributions and their environment. In situ data on prey distributions are not available over large spatial scales but, a numerical model, the Spatial Ecosystem And POpulation DYnamics Model (SEAPODYM), provides simulations of the biomass and production of zooplankton and six functional groups of micronekton at the global scale. Here, we explored whether generalised additive models fitted to simulated prey distribution data better predicted deep-diver densities (here beaked whales Ziphiidae and sperm whales Physeter macrocephalus) than models fitted to environmental variables. We assessed whether the combination of environmental and prey distribution data would further improve model fit by comparing their explanatory power. For both taxa, results were suggestive of a preference for habitats associated with topographic features and thermal fronts but also for habitats with an extended euphotic zone and with large prey of the lower mesopelagic layer. For beaked whales, no SEAPODYM variable was selected in the best model that combined the two types of variables, possibly because SEAPODYM does not accurately simulate the organisms on which beaked whales feed on. For sperm whales, the increase model performance was only marginal. SEAPODYM outputs were at best weakly correlated with sightings of deep-diving cetaceans, suggesting SEAPODYM may not accurately predict the prey fields of these taxa. This study was a first investigation and mostly highlighted the importance of the physiographic variables to understand mechanisms that influence the distribution of deep-diving cetaceans. A more systematic use of SEAPODYM could allow to better define the limits of its use and a development of the model that would simulate larger prey beyond 1,000 m would probably better characterise the prey of deep-diving cetaceans.

Welfare assessments have been largely successful in improving management and quality of life for animals in human care. This has prompted an increased interest in their use for free-ranging wild animals to assess health, environment, and human-induced impacts that influence policy decisions. The North Atlantic Right Whale (NARW, Eubalaena glacialis) is one of the most endangered whale species. NARWs constantly face serious injuries and mortalities due to human activities, which poses both a species conservation and an individual welfare concern. Establishing a standardized welfare assessment for the NARW is a holistic way to understand the cumulative effects of anthropogenic activities at both the individual and population levels. To investigate the potential use of welfare assessments in NARWs, we performed a brief literature review to explore the history and utility of animal welfare assessments. Following the review, we developed a welfare assessment tool specific to the NARW. The goal is for biologists to apply this tool to understand NARW welfare in conjunction with research in the field. Ultimately, the information gained from this review can aid in public dissemination of the results of human impacts on NARW welfare and may help influence future conservation policies.