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After the worldwide moratorium on whaling, humpback whale populations began to recover, reoccupying former areas of use, as also observed on the Brazilian coast. Abrolhos Bank represents the area of greatest humpback whale concentration but the number of individuals to the north has increased, as has happened in the region of Serra Grande. To compare relative abundance, habitat use, and movement patterns between a well‐established breeding and a reoccupation area, visual monitoring from land‐based stations was performed: 160 days in the Abrolhos Archipelago located on the Abrolhos Bank and 133 days in Serra Grande in 2014, 2015, 2018, and 2019. While relative abundance varied annually in the Abrolhos Archipelago, it gradually increased in Serra Grande, surpassing the number registered in Abrolhos in 2019. Group composition frequency was similar between areas except for mother and calf accompanied by one or more escorts, which were more frequent in Abrolhos. Despite similar movement speed and linearity values, whales in Serra Grande had a higher reorientation rate. Monitoring different areas occupied by this population supports decisions about spatial management of the Brazilian coast in relation to the implementation of anthropogenic activities, especially in areas where whales have recently returned to occupy. [ABSTRACT FROM AUTHOR]

The Southern Ocean ecosystem has undergone extensive changes in the past two centuries driven by industrial sealing and whaling, climate change and commercial fishing. However, following the end of commercial whaling, some populations of whales in this region are recovering. Baleen whales are reliant on Antarctic krill, which is also the largest Southern Ocean fishery. Since 1993, krill catch has increased fourfold, buoyed by nutritional supplement and aquaculture industries. In this Perspective, we approximate baleen whale consumption of Antarctic krill before and after whaling to examine if the ecosystem can support both humans and whales as krill predators. Our back-of-the-envelope calculations suggest that current krill biomass cannot support both an expanding krill fishery and the recovery of whale populations to pre-whaling sizes, highlighting an emerging human-wildlife conflict. We then provide recommendations for enhancing sustainability in this region by reducing encounters with whales and bolstering the krill population. The Southern Ocean ecosystem is recovering from 20th-century industrial whaling, while the krill fishery in this region has grown rapidly and may expand further, driven by demand for supplements and aquaculture feed. This Perspective discusses how current krill biomass is unlikely to support both a growing krill fishery and rebounding whale populations in the Southern Ocean. [ABSTRACT FROM AUTHOR]

The Salish Sea supports several baleen whale species, including humpback (Megaptera novaeangliae), gray (Eschrichtius robustus) and minke whales (Balaenoptera acutorostrata). With the exception of minke whales, these species were decimated by commercial whaling in the 1900s. Because recovery of these populations is monitored on broad spatial scales determined by stocks or populations, their use of the Salish Sea ecosystem is not well documented or understood. We collated 17,436 opportunistic sighting reports to assess patterns in mysticete presence and distribution in the Salish Sea (1976-2019). We used the proportion of sightings for each species and spatial models targeting comparisons between species to limit the influence of spatio-temporal variation in reporting efforts. Humpback whale sightings have increased dramatically since the late 2000s, mirroring population-wide increases and suggesting a renewed use of historically important feeding areas. Gray whale sightings increased most notably at two distinct times (1989, 2017), both of which align with periods of high mortality experienced by the delisted Eastern North Pacific stock of gray whales and may reflect individuals straying from their migration routes. Sightings of minke whales remained relatively stable over this study period and were likely driven by a group of 30-40 individuals that forage off shallow banks and bathymetrically complex habitats around the San Juan Archipelago. Though it can be difficult to separate the bias that accompanies public sightings databases, citizen science efforts are invaluable for monitoring the recovery of rebounding populations and can illuminate longitudinal patterns that would otherwise go unnoticed. [ABSTRACT FROM AUTHOR]

The International Whaling Commission (IWC) imposed limits on the catch of Antarctic minke whales close to the start of commercial whaling in the 1970s. These management efforts were hampered by the challenge of obtaining robust estimates of population size. Contemporary whale assessments largely relied on measuring changes in availability as a result of exploitation – usually catch per unit effort (CPUE). However, this approach was largely impractical for Antarctic minke whales due to: (a) the short time series of CPUE data; (b) the setting of relatively conservative catch limits, so that changes in CPUE due to exploitation were difficult to detect; and (c) the possibility that abundance had been increasing before this time due to over‐exploitation of other baleen whales. The IWC initiated a series of assessment cruises in 1978 designed to obtain abundance estimates for targeted management areas in the Antarctic. Designed by the IWC’s Scientific Committee, these cruises were independent of whaling operations. The vessels were chartered whale catchers provided by Japan for the duration of the programme – and by the Soviet Union for a period of seven years. With the eventual participation of 86 scientists from 16 IWC member states, this programme became a key part of the International Decade of Cetacean Research (IDCR), launched in 1975 as a response to the 1972 Stockholm Resolution that called for a 10‐year moratorium on commercial whaling and the intensification of research efforts. While originally planned as ‘Discovery’ marking and sighting cruises, the programme eventually relied almost exclusively on sighting methods. Lasting over 30 years and involving three circumnavigations of the Southern Ocean, it became one of the largest whale monitoring exercises ever undertaken. [ABSTRACT FROM AUTHOR]

A recent survey conducted in Cumberland Bay, South Georgia, has found that humpback whales have returned to the area after a century of whaling. The survey estimated that approximately 12,103 humpback whales were using South Georgia waters in the 2018/2019 season, representing a significant increase in abundance. Changes in oceanographic conditions and the distribution of their primary food source, Antarctic krill, may have influenced the whales' habitat preferences. The survey also observed mother-calf pairs and larger groups of whales outside the bay, suggesting limited feeding opportunities farther inside. The study provides a summary of the presence of humpback whales in Cumberland Bay, South Georgia, and discusses the potential impact of their return on the local marine ecosystem. [Extracted from the article]

Cooperative hunting between humans and killer whales (Orcinus orca) targeting baleen whales was reported in Eden, New South Wales, Australia, for almost a century. By 1928, whaling operations had ceased, and local killer whale sightings became scarce. A killer whale from the group, known as "Old Tom," washed up dead in 1930 and his skeleton was preserved. How these killer whales from Eden relate to other populations globally and whether their genetic descendants persist today remains unknown. We extracted and sequenced DNA from Old Tom using ancient DNA techniques. Genomic sequences were then compared with a global dataset of mitochondrial and nuclear genomes. Old Tom shared a most recent common ancestor with killer whales from Australasia, the North Atlantic, and the North Pacific, having the highest genetic similarity with contemporary New Zealand killer whales. However, much of the variation found in Old Tom's genome was not shared with these widespread populations, suggesting ancestral rather than ongoing gene flow. Our genetic comparisons also failed to find any clear descendants of Tom, raising the possibility of local extinction of this group. We integrated Traditional Custodian knowledge to recapture the events in Eden and recognize that Indigenous Australians initiated the relationship with the killer whales before European colonization and the advent of commercial whaling locally. This study rectifies discrepancies in local records and provides new insight into the origins of the killer whales in Eden and the history of Australasian killer whales. [ABSTRACT FROM AUTHOR]

The 20th century commercial whaling industry severely reduced populations of great whales throughout the Southern Hemisphere. The effect of this exploitation on genetic diversity and population structure remains largely undescribed. Here, we compare pre- and post-whaling diversity of mitochondrial DNA (mtDNA) control region sequences for 3 great whales in the South Atlantic, such as the blue, humpback, and fin whale. Pre-whaling diversity is described from mtDNA extracted from bones collected near abandoned whaling stations, primarily from the South Atlantic island of South Georgia. These bones are known to represent the first stage of 20th century whaling and thus pre-whaling diversity of these populations. Post-whaling diversity is described from previously published studies reporting large-scale sampling of living whales in the Southern Hemisphere. Despite relatively high levels of surviving genetic diversity in the post-whaling populations, we found evidence of a probable loss of mtDNA lineages in all 3 species. This is evidenced by the detection of a large number of haplotypes found in the pre-whaling samples that are not present in the post-whaling samples. A rarefaction analysis further supports a loss of haplotypes in the South Atlantic humpback and Antarctic blue whale populations. The bones from former whaling stations in the South Atlantic represent a remarkable molecular archive for further investigation of the decline and ongoing recovery in the great whales of the Southern Hemisphere. [ABSTRACT FROM AUTHOR]

Wildlife documentaries are a form of environmental media widely used in public engagement around sustainability and conservation issues, including biodiversity loss. Two recently released wildlife documentaries, Entangled (2020) and Last of the Right Whales (2021), are the first to tell stories focused on the critically endangered North Atlantic right whale (NARW) through film, despite the species having been imperiled for more than a century and experts sounding the alarm about the population's decline for decades. While whales are highly regarded worldwide and their conservation has strong public support, the NARW case study is a complicated one due not only to biological and ecological challenges, but also to sociopolitical ones. Without drastic policy actions and changes to industry practices throughout its migratory range, the NARW may disappear within decades, becoming the first great whale species to reach extinction since the industrial whaling era. In this article we address a gap in current environmental media and documentary studies by engaging critically with Entangled and Last of the Right Whales and considering them within the socioecological contexts they showcase and aim to influence. Our findings indicate that these two films share an important environmental problem with their viewers but fail to overcome some important pitfalls that limit the ability of environmental films to achieve collective action and policy change. We use this case study to highlight opportunities and challenges associated with wildlife documentaries more broadly, specifically, their role in biodiversity conservation in the Anthropocene. We conclude with opportunities for future interdisciplinary research and collaborative practice that can help wildlife films to achieve more than accolades for filmmakers and mere general awareness of conservation challenges. [ABSTRACT FROM AUTHOR]

Fin whales Balaenoptera physalus were hunted unsustainably across the globe in the 19th and 20th centuries, leading to vast reductions in population size. Whaling catch records indicate the importance of the Southern Ocean for this species; approximately 730,000 fin whales were harvested during the 20th century in the Southern Hemisphere (SH) alone, 94% of which were at high latitudes. Genetic samples from contemporary whales can provide a window to past population size changes, but the challenges of sampling in remote Antarctic waters limit the availability of data. Here, we take advantage of historical samples in the form of bones and baleen available from ex-whaling stations and museums to assess the pre-whaling diversity of this once abundant species. We sequenced 27 historical mitogenomes and 50 historical mitochondrial control region sequences of fin whales to gain insight into the population structure and genetic diversity of Southern Hemisphere fin whales (SHFWs) before and after the whaling. Our data, both independently and when combined with mitogenomes from the literature, suggest SHFWs are highly diverse and may represent a single panmictic population that is genetically differentiated from Northern Hemisphere populations. These are the first historic mitogenomes available for SHFWs, providing a unique time series of genetic data for this species. [ABSTRACT FROM AUTHOR]

The krill surplus hypothesis of unlimited prey resources available for Antarctic predators due to commercial whaling in the 20th century has remained largely untested since the 1970s. Rapid warming of the Western Antarctic Peninsula (WAP) over the past 50 years has resulted in decreased seasonal ice cover and a reduction of krill. The latter is being exacerbated by a commercial krill fishery in the region. Despite this, humpback whale populations have increased but may be at a threshold for growth based on these human‐induced changes. Understanding how climate‐mediated variation in prey availability influences humpback whale population dynamics is critical for focused management and conservation actions. Using an 8‐year dataset (2013–2020), we show that inter‐annual humpback whale pregnancy rates, as determined from skin‐blubber biopsy samples (n = 616), are positively correlated with krill availability and fluctuations in ice cover in the previous year. Pregnancy rates showed significant inter‐annual variability, between 29% and 86%. Our results indicate that krill availability is in fact limiting and affecting reproductive rates, in contrast to the krill surplus hypothesis. This suggests that this population of humpback whales may be at a threshold for population growth due to prey limitations. As a result, continued warming and increased fishing along the WAP, which continue to reduce krill stocks, will likely impact this humpback whale population and other krill predators in the region. Humpback whales are sentinel species of ecosystem health, and changes in pregnancy rates can provide quantifiable signals of the impact of environmental change at the population level. Our findings must be considered paramount in developing new and more restrictive conservation and management plans for the Antarctic marine ecosystem and minimizing the negative impacts of human activities in the region. [ABSTRACT FROM AUTHOR]

Investigating resource partitioning of marine predators is essential for understanding coexistence of sympatric species and the functional role they play in marine ecosystems. Baleen whales are a key component of sub-Antarctic ecosystems, foraging predominantly on zooplankton and small forage fish. During the twentieth century, baleen whales were unsustainably exploited across the Southern Ocean. Within the exclusive economic zone of South Georgia and the South Sandwich Islands (SGSSI EEZ) in the South Atlantic, approximately 98,000 fin whales (Balaenoptera physalus) and 16,000 sei whales (B.borealis) were harvested. Despite both species historically occurring in high numbers and feeding in sub-polar waters, little is known about the mechanisms of coexistence. Here, by measuring stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in archived baleen plates and analysing historic catch data, we investigate resource partitioning of fin and sei whale during the commercial whaling period. Temporal and spatial occupancy at SGSSI EEZ (inferred from whaling catches that occurred between 1904 and 1976), alongside historic stomach contents (from the literature), and δ13C and δ15N results (observed in this study), suggests that despite using a common prey resource there was limited overlap in isotopic niches between the two species, with sei whales using SGSSI waters later in the season and for a shorter period than fin whales. We hypothesise that the isotopic differences were most likely due to sei whales foraging at lower latitudes prior to arrival at SGSSI. Our data provide novel insight into how two sympatric whale species co-occurring at SGSSI during the commercial whaling period may have partitioned resources and provide a potential ecological baseline to assess changes in resource use in recovering whale populations. [ABSTRACT FROM AUTHOR]

The article discusses the eastern North Pacific population breeds in shallow lagoons along the west coast of Baja California, Mexico, and feeds in shallow coastal waters from northern California north along the coasts of Oregon, Washington, British Columbia, Alaska, and Russia.

Two of these papers, one listing Rodger as a coauthor, plainly recognized that gray whales responded to air gun sounds. In another paper from the same special issue, the authors, including Rodger, concluded that "the 2001 seismic survey had no measurable effect ( I i = 0.05) on bottom feeding activity of western gray whales off Sakhalin Island" (Yazvenko et al., [16]). This article is part of the Topical Collection on Western Gray Whales and Industry Seismic Operations For some time, people have known that baleen whales respond to underwater sounds. [Extracted from the article]

In zooplankton-feeding baleen whales, site fidelity on the feeding grounds is usually expressed at a relatively large scale: although the whales remain in the general area, they move broadly within it, covering tens of kilometers per day. The gray whale, Eschrichtius robustus, is the only dedicated bottom feeder among baleen whales and its largely infaunal and epibenthic invertebrate prey are more sedentary and therefore have a more predictable distribution than zooplankton. We analyzed movements of individually identified gray whales and humpback whales (Megaptera novaeangliae) in an Arctic feeding area to see if specialization on stationary benthic prey would result in finer-scale site fidelity than specializing in more mobile zooplankton prey in the same area. Compared to humpback whales, the number of feeding gray whales in Senyavin Strait, Eastern Chukotka over three study years was higher; however, the resighting rate between years was lower than for humpback whales in the same area over the same period. All humpback whales moved broadly within their feeding range, while individual gray whales tended to remain at specific locations, returning to these locations in subsequent years. Thus, the fine-scale site fidelity was higher for gray whales and this should be a consideration when estimating anthropogenic impacts—for example, the effects of shipping traffic, fishing, and aboriginal whaling. Gaining an understanding of whale movement patterns, including site fidelity, is crucial for the conservation and sustainable management of whales and their habitats, especially in light of increasing anthropogenic pressures in the warming Arctic. [ABSTRACT FROM AUTHOR]

It is generally recognized that large-scale whaling in the 19th and 20th century led to a substantial reduction of the size of many cetacean populations, particularly those of the baleen whales (Mysticeti). The impact of these operations on genomic diversity of one of the most hunted whales, the fin whale (Balaenoptera physalus), has remained largely unaddressed because of the paucity of adequate samples and the limitation of applicable techniques. Here, we have examined the effect of whaling on the North Atlantic fin whale based on genomes of 51 individuals from Icelandic waters, representing three temporally separated intervals, 1989, 2009 and 2018 and provide a reference genome for the species. Demographic models suggest a noticeable drop of the effective population size of the North Atlantic fin whale around a century ago. The present results suggest that the genome-wide heterozygosity is not markedly reduced and has remained comparable with other baleen whale species. Similarly, there are no signs of apparent inbreeding, as measured by the proportion of long runs of homozygosity, or of a distinctively increased mutational load, as measured by the amount of putative deleterious mutations. Compared with other baleen whales, the North Atlantic fin whale appears to be less affected by anthropogenic influences than other whales such as the North Atlantic right whale, consistent with the presence of long runs of homozygosity and higher levels of mutational load in an otherwise more heterozygous genome. Thus, genome-wide assessments of other species and populations are essential for future, more specific, conservation efforts. [ABSTRACT FROM AUTHOR]

The North Pacific right whale (hereafter NPRW), I Eubalaena japonica i , is currently divided into two populations, eastern and western (Brownell et al., 2001). The 2012 cruise occurred between July 13 and September 10 in the northern GoA, the 2017 cruise occurred from July 3 to September 25 in the eastern Bering Sea, and the 2018 cruise occurred from July 3 to September 25 in the central Bering Sea (Figure 1). Red polygons delineate the NPRW federally designated Critical Habitats. gl 1 TABLESummary of North Pacific right whale sightings, and life history information for the 16 right whales photographed during the 2012, 2017, and 2018 IWC-POWER cruises. Whale resighted 24 days later on August 18, 2018, in Penkigney Bay near Bering Strait. ht 1 I Note i : Whale ID corresponds to Alaska Fisheries Science Center's Marine Mammal Laboratory North Pacific right whale catalog number. [Extracted from the article]

Continued monitoring of body condition and hormone levels of this gray whale population will generate "health profiles" of individual whales, enabling assessment of change over time and potential identification and diagnosis for variations in population health. Hence, to increase our sample size for correlation analysis, we used BAI values measured within ± 14 days of a fecal sample collection from the same individual as gray whales do not significantly change their body condition within a period of two weeks (paired I t i -test using all BAI values of individuals assessed within 14 days in 2016, 2017, and 2018: I n i = 61, I p i =.86, I df i = 60, I t i = -0.174). In this study, we employed simultaneous multidisciplinary techniques to investigate the effects of body condition variability on hormones associated with stress (i.e., cortisol) and energy allocation (i.e., cortisol and thyroid hormones) in Eastern North Pacific (ENP) gray whales ( I Eschrichtius robustus i ). Conversely, the random factor of whale identity highly contributed to the Tm model ( I R i SP 2 sp c = 0.522, I R i SP 2 sp m = 0.835; Table 2). 2 TABLELinear mixed model selection parameters of gray whale glucocorticoid metabolite (GCm) and thyroid metabolite (Tm) concentrations relative to Body Area Index (BAI), sex, year, and day of the year (DOY). [Extracted from the article]

The North Atlantic blue whale was depleted by modern whaling and it is still considered to be highly endangered. Despite its protection in 1954, catches continued in the South European Atlantic Shelf (SEAS) region and immediately adjacent waters until 1979. We compiled catches and investigate abundance trends in the region using original data from whaling (1921–1985) and scientific surveys around the last years of exploitation (1981–1987). The struck and lost rate was estimated at 3.2% for sperm whales and 2.3% for baleen whales. The compiled records include 60 catches, with an additional 1–2 blue whales likely struck and lost. From these, 29 individuals had been correctly reported as blue whales but 31 were mislabelled as fin whales. After correcting for loss rates, the number of blue whales killed in the region was estimated at 61 in 55 years (1.12 individuals/year). The data from the 1950s shows some oversized fin whales but it is unclear whether they are due to an incorrect reporting of species or to incorrect measurements, so it cannot be discarded that the actual number of blue whales caught was slightly higher than estimated. Mean body length of reported blue whales was lower than in higher latitudes of the North Atlantic, probably reflecting geographical stratification with higher proportion of immatures in the SEAS. The ratio between catches or sightings of blue whales and those of fin whales was 5.9% in the southern part of the SEAS previous to exploitation, it declined to 0.02–0.18% in the 1920s, and increased thereafter up to 1.6% in the 1980–1990s. Taking as reference the population size of fin whales in the SEAS, that of blue whales at the end of the 1980s can be guessed to be at ca337-497 individuals. Considering accepted population estimates in other areas as well as the observed rates of increase, current abundance is thought to be over a thousand whales in the SEAs and at in the order of 4000–5000 individuals for the whole eastern North Atlantic basin. [ABSTRACT FROM AUTHOR]

Understanding the recovery of whale populations is critical for developing population-management and conservation strategies. The southern right whale (SRW) Eubalena australis was one of the baleen whale species that has experienced centuries of exploitation. We assess here for the first time the population dynamics of the SRW from the southwestern Atlantic Ocean at the regional level to measure numerically the effect of whaling and estimate the population trend and recovery level after depletion. We reconstructed the catch history of whaling for the period 1670–1973 by an extensive review of different literature sources and developed a Bayesian state-space model to estimate the demographic parameters. The population trajectory indicated that the pre-exploitation abundance was close to 58,000 individuals (median = 58,212; 95% CI = 33,329–100,920). The abundance dropped to its lowest abundance levels in the 1830s when fewer than 2,000 individuals remained. The current median population abundance was estimated at 4,742 whales (95% CI = 3,853–6,013), suggesting that the SRW population remains small relative to its pre-exploitation abundance (median depletion P2021 8.7%). We estimated that close to 36% of the SRW population visits the waters of the Península Valdés, the main breeding ground, every year. Our results provide insights into the severity of the whaling operation in the southwestern Atlantic along with the population´s response at low densities, thus contributing to understand the observed differences in population trends over the distributional range of the species worldwide. [ABSTRACT FROM AUTHOR]

Large cetaceans were heavily impacted by commercial whaling, so relatively little is known about their biogeography prior to historic times. On California's Channel Islands, maritime peoples hunted dolphins and porpoises for millennia, but ethnohistoric data suggest that larger cetaceans were not hunted. The Island Chumash scavenged beached whale carcasses for food and technological purposes, however, and the bones of large whales are relatively common in many Channel Island shell middens. Cetacean bones from such sites provide unique opportunities to document the ancient distribution and human use of larger whale species, but many bone fragments are not identifiable to the genus or species level based solely on osteological characteristics. Here, we report genomic data for two whale bones recovered from a 5850 year old shell midden on San Miguel Island. Both were identified as fin whale, the second largest of the great whales. Our analysis provides points in space and time for the distribution of fin whales in the past, but a wider identification of whale bones from coastal archaeological sites can potentially expand such data for numerous whale species, adding significantly to an understanding of their distributions, ecology, and utility for humans in the past. [ABSTRACT FROM AUTHOR]

The article presents a study which estimated the effects of El Ni&ño events on survival probabilities of Southwest (SW) Atlantic southern right whales (SRWs) and on the growth of their population and discussed how the ecosystem consequences of a slowdown in whale recovery may further limit population growth in southern Atlantic Ocean. Topics discussed include effect of El Niño events on SRW female survival, effect of climate change on population recovery, and modeling female survival.

Bryde's‐like whales are a complex of medium‐sized baleen whales that occur in tropical waters of all three major ocean basins. Currently, a single species of Bryde's whale, Balaenoptera edeni Anderson, 1879, is recognized, with two subspecies, Eden's whale, B. edeni edeni and Bryde's whale, B. edeni brydei (Olsen, 1913), although some authors have recognized these as separate species. Recently, a new, evolutionarily divergent lineage of Bryde's‐like whale was identified based on genetic data and was found to be restricted primarily to the northern Gulf of Mexico (GOMx). Here, we provide the first morphological examination of a complete skull from these whales and identify diagnostic characters that distinguish it from the other medium‐sized baleen whale taxa. In addition, we have increased the number of genetic samples of these Bryde's‐like whales in the GOMx from 23 to 36 individuals, all of which matched the GOMx lineage. A review of Bryde's‐like whale records in the Caribbean and greater Atlantic supports an isolated distribution for this unique lineage, augmenting the genetic and morphological body of evidence supporting the existence of an undescribed species of Balaenoptera from the Gulf of Mexico. [ABSTRACT FROM AUTHOR]

Omura's whales are an evolutionarily distant relative of I B. edeni i subspp., whereas sei whales ( I B. borealis i ) are a sister clade to I B. edeni i (Rosel et al., 2021, fig. 2). Two of them have other common names that are place specific, but do not identify their full spatial distribution: bowhead whales are known as the Greenland whale, and Eden's whale is also called Sittang whale. [Extracted from the article]

Historical harvesting pushed many whale species to the brink of extinction. Although most Southern Hemisphere populations are slowly recovering, the influence of future climate change on their recovery remains unknown. We investigate the impacts of two anthropogenic pressures—historical commercial whaling and future climate change—on populations of baleen whales (blue, fin, humpback, Antarctic minke, southern right) and their prey (krill and copepods) in the Southern Ocean. We use a climate–biological coupled "Model of Intermediate Complexity for Ecosystem Assessments" (MICE) that links krill and whale population dynamics with climate change drivers, including changes in ocean temperature, primary productivity and sea ice. Models predict negative future impacts of climate change on krill and all whale species, although the magnitude of impacts on whales differs among populations. Despite initial recovery from historical whaling, models predict concerning declines under climate change, even local extinctions by 2100, for Pacific populations of blue, fin and southern right whales, and Atlantic/Indian fin and humpback whales. Predicted declines were a consequence of reduced prey (copepods/krill) from warming and increasing interspecific competition between whale species. We model whale population recovery under an alternative scenario whereby whales adapt their migratory patterns to accommodate changing sea ice in the Antarctic and a shifting prey base. Plasticity in range size and migration was predicted to improve recovery for ice‐associated blue and minke whales. Our study highlights the need for ongoing protection to help depleted whale populations recover, as well as local management to ensure the krill prey base remains viable, but this may have limited success without immediate action to reduce emissions. We predict impacts of historical commercial whaling (black bars, top), and future climate change, including changing sea‐surface temperature (shown in red, top), primary productivity and sea‐ice extent, on populations of baleen whales and their prey (krill and copepods) across the Southern Hemisphere. Despite initial recovery from commercial harvesting, models predict concerning declines for whale populations due to climate change by 2,100 for populations of blue (blue bars, bottom), fin (green, bottom), humpback (purple, bottom) and Southern right whales (orange, bottom) as a consequence of reduced krill prey (grey line) from warming. [ABSTRACT FROM AUTHOR]

Bowhead whales generally migrate into high Arctic waters in the summer months and move to lower latitudes in the wintertime. During the 1800s and early 1900s commercial whaling greatly reduced the numbers of bowhead whales in waters adjacent to the North Atlantic Ocean. In recent decades their numbers have been increasing. Thirteen sightings of a bowhead whale were recorded in four areas of the Gulf of Maine in 2012, 2014, and 2017 between latitudes 44°43'N and 41°36'N, far south of the normal range (54°N) for this species. Photographs obtained during these sightings were compared by experienced photo analysts and, based on scarring patterns, the sightings were confirmed to be of the same individual. The bowhead whale was observed alone, in addition to interacting in a social group and engaged in coordinated feeding with other mysticetes at times. The feeding and social behaviour of the bowhead whale was typical for the species but well south of its normal Arctic waters range and in the absence of conspecifics. [ABSTRACT FROM AUTHOR]

Many baleen whales were commercially harvested during the 20th century almost to extinction. Reliable assessments of how this mass depletion impacted whale populations, and projections of their recovery, are crucial but there are uncertainties regarding the status of Southern Hemisphere whale populations. We developed a Southern Hemisphere spatial 'Model of Intermediate Complexity for Ecosystem Assessments' (MICE) for phytoplankton, krill ( Euphausia superba) and five baleen whale species, to estimate whale population trajectories from 1890 to present. To forward project to 2100, we couple the predator-prey model to a global climate model. We used the most up to date catch records, fitted to survey data and accounted for key uncertainties. We predict Antarctic blue ( Balaenoptera musculus intermedia), fin ( Balaenoptera physalus) and southern right ( Eubalaena australis) whales will be at less than half their pre-exploitation numbers ( K) even given 100 years of future protection from whaling, because of slow growth rates. Some species have benefited greatly from cessation of harvesting, particularly humpbacks ( Megaptera novaeangliae), currently at 32% of K, with full recovery predicted by 2050. We highlight spatial differences in the recovery of whale species between oceanic areas, with current estimates of Atlantic/Indian area blue (1,890, <1% of K) and fin (16,950, <4% of K) whales suggesting slower recovery from harvesting, whilst Pacific southern right numbers are <7% of K (2,680). Antarctic minke ( Balaenoptera bonaerensis) population trajectories track future expected increases in primary productivity. Population estimates and plausible future predicted trajectories for Southern Hemisphere baleen whales are key requirements for management and conservation. [ABSTRACT FROM AUTHOR]

No global synthesis of the status of baleen whales has been published since the 2008 IUCN Red List assessments. Many populations remain at low numbers from historical commercial whaling, which had ceased for all but a few by 1989. Fishing gear entanglement and ship strikes are the most severe current threats. The acute and long-term effects of anthropogenic noise and the cumulative effects of multiple stressors are of concern but poorly understood. The looming consequences of climate change and ocean acidification remain difficult to characterize. North Atlantic and North Pacific right whales are among the species listed as Endangered. Southern right, bowhead, and gray whales have been assessed as Least Concern but some subpopulations of these species - western North Pacific gray whales, Chile-Peru right whales, and Svalbard/Barents Sea and Sea of Okhotsk bowhead whales - remain at low levels and are either Endangered or Critically Endangered. Eastern North Pacific blue whales have reportedly recovered, but Antarctic blue whales remain at about 1% of pre-exploitation levels. Small isolated subspecies or subpopulations, such as northern Indian Ocean blue whales, Arabian Sea humpback whales, and Mediterranean Sea fin whales are threatened while most subpopulations of sei, Bryde's, and Omura's whales are inadequately monitored and difficult to assess. [ABSTRACT FROM AUTHOR]

It has previously been asserted that baleen whales compete with fisheries by consuming potentially harvestable marine resources. The regularly applied 'surplus-yield model' suggests that whale prey becomes available to fisheries if whales are removed, and has been presented as a justification for whaling. However, recent findings indicate that whales enhance ecosystem productivity by defecating iron that stimulates primary productivity in iron-limited waters. While juvenile whales and whales that are pregnant or lactating retain iron for growth and milk production, nonbreeding adult whales defecate most of the iron they consume. Here, we modify the surplus-yield model to incorporate iron defecation. After modeling a simplistic trajectory of blue whale recovery to historical abundances, the traditional surplus-yield model predicts that 1011 kg of carbon yr−1 would become unavailable to fisheries. However, this ignores the nutrient recycling role of whales. Our model suggests the population of blue whales would defecate 3 × 106 kg of iron yr−1, which would stimulate primary production equivalent to that required to support prey consumption by the blue whale population. Thus, modifying the surplus-yield model to include iron defecation indicates that blue whales do not render marine resources unavailable to fisheries. By defecating iron-rich feces, blue whales promote Southern Ocean productivity, rather than reducing fishery yields. [ABSTRACT FROM AUTHOR]

While it is known that population cycles are driven by delayed density-dependent feedbacks, the search for a common feedback mechanism in natural populations with cyclic dynamics has remained unresolved for almost a century. To identify the existence and cause of delayed feedbacks I apply six age- and sex-structured population dynamics models to seven species of baleen whales (suborder Mysticeti) that were heavily depleted by past commercial whaling. The six models include a predator-prey model with killer whale ( Orcinus orca) as the predator, and five singe-species models based on (1) exponential growth, (2) density-regulated growth, (3) density-regulated growth with depensation, (4) delayed density-regulated growth and (5) selection-delayed dynamics. The latter model has a density-regulated growth rate that is accelerated and decelerated by the intra-specific natural selection that arises from the density-dependent competitive interactions between the individuals in the population. Essential parameters are estimated by a Bayesian statistical framework, and it is shown that baleen whales have a delayed recovery relative to density-regulated growth. The time-lag is not explained by depensation, or by interactions with prey or predators. It is instead resolved by a selection-delayed acceleration of the intrinsic growth rate. The results are discussed in relation to the literature on cyclic dynamics, and it is noted (1) that selection-delayed dynamics is both theoretically and empirically sufficient for cyclic population dynamics, (2) that it is widespread in natural populations owing to the widespread occurrence of otherwise unexplained phenotypic cycles in populations with cyclic dynamics, and (3) that there is a lack of empirical evidence showing that predator-prey interactions is a sufficient cause for the cyclic dynamics of natural populations. The conclusion stresses the importance of intra-specific delays in cyclic dynamics, and suggests that it is the acceleration of the growth rate, and not the growth rate itself, that is determined by the density-dependent environment. [ABSTRACT FROM AUTHOR]

This paper presents empirical evidence which indicates that the introduction of petroleum based products on the American markets was a significant factor in reducing the demand for whale oil. As a result, the whaling industry, America's 5th largest industry at the time, soon collapsed. A counterfactual study is then presented which suggests that if the introduction of petroleum based products had been delayed, then the increase in demand as a result of rising GDP per capita, as well as rapid industrialization, would have given whalers incentive to continue chasing after a diminishing whale population. This could have resulted in the baleen whale population being subject to unsustainable harvest levels. [ABSTRACT FROM AUTHOR]

Herein we present an annotated translation of the classic paper by Tycho Tullberg on the structure and development of baleen in blue whales. The three blue whale fetuses on which this study was based were obtained from a whaling station in Norway during a time when blue whales were still abundant enough to support a whaling industry. The value of this text for the modern reader is that it provides a glimpse into the mechanisms of development of baleen in the largest rorqual whale, which is something that modern biologists are unlikely to be able to replicate for a long time. Tullberg's careful morphology, histology, and developmental thinking provide a coherent account of how the elaborate baleen racks develop from simple epidermal and dermal origins. The figures, which we have reproduced here, are superb and provide a rare window into the morphology of blue whale baleen at three fetal stages. The histology is excellent for its time and provides insights into the various keratin tissue phases that make up the baleen plates and bristles as well as the enigmatic Zwischensubstanz that acts as a spacer and possible shock-absorber between plates. [ABSTRACT FROM AUTHOR]

The article discusses the application of Catch Limit Algorithm (CLA) for commercial baleen whaling developed by the International Whaling Commission (IWC). It investigates the conservation and yield properties of CLA in plausible conditions through stochastic simulation over a management period of 100 years. It contends that the dynamics in many scenarios are too slow for the population of a managed whale stock to come close to a stationary state after 100 years. It points out that a management horizon of 300 years in more appropriate. Moreover, IWC agrees that whaling should be managed on a long term basis.

Punt, A. E. and Donovan, G. P. 2007. Developing management procedures that are robust to uncertainty: lessons from the International Whaling Commission. – ICES Journal of Marine Science, 64: 603–612.Traditionally, fisheries management advice has been based on stock assessments that considered merely the “best” set of assumptions while uncertainty arising only from observation and process error was quantified, if considered at all. Unfortunately, uncertainty attributable to lack of understanding of the true underlying system and to ineffective implementation may dominate the sources of error that must be accounted for if management is to be successful. The management procedure approach is advocated as the appropriate way to develop management advice for renewable resources. This approach, pioneered by the International Whaling Commission (IWC) Scientific Committee, takes politically agreed management objectives and incorporates all scientific aspects of management including data collection and analysis, development of robust harvest control laws or effort regulations, and monitoring. A primary feature is that uncertainty (including that arising from sources conventionally ignored) is taken into account explicitly through population simulations for a variety of scenarios. The nature of the management procedures developed for commercial and aboriginal subsistence whaling and the processes by which they have been developed is highlighted. We also identify lessons that have been learned from two decades of IWC experience and suggest how these can be applied to other fishery situations. [ABSTRACT FROM PUBLISHER]

Abstract: Large whales were extensively hunted in coastal waters off Alaska, but current distribution, population sizes and trends are poorly known. Line transect surveys were conducted in coastal waters of the Aleutian Islands and the Alaska Peninsula in the summer of 2001–2003. Abundances of three species were estimated by conventional and multiple covariate distance sampling (MCDS) methods. Time series of abundance estimates were used to derive rates of increase for fin whales (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae). Fin whales occurred primarily from the Kenai Peninsula to the Shumagin Islands, but were abundant only near the Semidi Islands and Kodiak. Humpback whales were found from the Kenai Peninsula to Umnak Island and were more abundant near Kodiak, the Shumagin Islands and north of Unimak Pass. Minke whales (B. acutorostrata) occurred primarily in the Aleutian Islands, with a few sightings south of the Alaska Peninsula and near Kodiak Island. Humpback whales were observed in large numbers in their former whaling grounds. In contrast, high densities of fin whales were not observed around the eastern Aleutian Islands, where whaling occurred. Average abundance estimates (95% CI) for fin, humpback and minke whales were 1652 (1142–2389), 2644 (1899–3680), and 1233 (656–2315), respectively. Annual rates of increase were estimated at 4.8% (95% CI=4.1–5.4%) for fin and 6.6% (5.2–8.6%) for humpback whales. This study provides the first estimate of the rate of increase of fin whales in the North Pacific Ocean. The estimated trends are consistent with those of other recovering baleen whales. There were no sightings of blue or North Pacific right whales, indicating the continued depleted status of these species. [Copyright &y& Elsevier]

The article examines the distribution of the North Atlantic right whale (Eubalaena glacialis) in historical times. Seventeenth- and eighteenth-century Danish, Norwegian, and Dutch sources mention whaling stations set up by foreign whalers in northern Norway. The presence of whales in coastal waters around the North Cape was known since the mid-16th century, when Magnus noted they were a hazard to ship traffic. Evidence for entrepreneurial interest in whaling in this region includes an inquiry in 1575 by a British merchant about the requirements for sending a whaling expedition to be based at Vardø. The existence of a northern Norway right whaling ground was so well known by the mid-1600.