Gray Whales Research Articles

Benthic studies adjacent to Sakhalin Island, Russia, 2015 II: energy content of the zoobenthos in western gray whale feeding grounds

The waters adjacent to the northeastern coast of Sakhalin Island, Russia, are an important feeding ground for the endangered western gray whale. Data on the energy available to foraging whales from their prey resources is required for researchers interested in modeling the bioenergetics of whale foraging, but little energy content information is available for the benthic prey communities of gray whales in this region. In this study, we describe the energy density (ED), biomass, and total energy availability (ED × biomass) of benthic prey sampled from two gray whale foraging areas adjacent to Sakhalin Island: the nearshore and offshore feeding areas. ED varied almost seven-fold among benthic taxa, ranging from 1.11 to 7.62 kJ/g wet mass. Although there was considerable variation within most prey groups, amphipods had the highest mean ED of all of groups examined (5.58 ± 1.44 kJ/g wet mass). Small sample sizes precluded us from detecting any seasonal or spatial differences in mean ED within or among taxa; however, mean biomass in the offshore feeding area was, in some cases, an order of magnitude higher than mean estimates in the nearshore feeding area, resulting in higher mean total energy available to foraging gray whales offshore (958–3313 kJ/m2) compared to nearshore (223–495 kJ/m2). While the proportion of total energy accounted for by amphipods was variable, this prey group generally made up a higher proportion of the total energy available in the benthos of the offshore feeding area than in the benthos of the nearshore feeding area. Data presented here will be used to inform bioenergetics modeling of the vital rates of mature females in an effort to improve understanding of population growth limits for western gray whales.

Real-time acoustic monitoring with telemetry to mitigate potential effects of seismic survey sounds on marine mammals: a case study offshore Sakhalin Island

Exxon Neftegas Ltd. (ENL) carried out three 4D seismic surveys during the summer of 2015. Seismic operations in two of these fields (Odoptu and Chayvo) ensonified the nearshore feeding area of Korean-Okhotsk (western) gray whales (Eschrichtius robustus), potentially disturbing feeding activities. Following model-based optimization of the source design to minimize its lateral acoustic footprint, pre-season modeling was used to compute the acoustic exposure along each survey line. Real-time acoustic data facilitated implementation of mitigation measures aimed to minimize disturbance of whales. Acoustic data originated from underwater recorders deployed on the seafloor. Two complementary approaches were used to transmit recorded sound data to a computer housed at the Central Post (CP), where decisions regarding mitigation shut downs were made. In the first approach, a limited bandwidth (2–2000 Hz) sampling of the data was transmitted via cable to a surface buoy, which relayed these data to a shore station up to 15 km away via digital VHF telemetry. At the shore station, acoustic impulses from the seismic surveys were processed to compute impulse characteristics in the form of estimates of sound exposure level and peak sound pressure level, as well as one-minute-average 1/3-octave power spectral density coefficients, which were then transmitted to the CP via the internet. In the second, the pulse characteristics were computed through algorithms running on an onboard processor in each recorder’s surface buoy and sent directly to the CP computer via an Iridium satellite uplink. Both methods of data transfer proved viable, but Iridium transmission achieved the goal without the need for any shore based relay stations and is therefore more operationally efficient than VHF transmission. At the CP, analysts used the real-time acoustic data to calibrate and adjust the output of pre-season acoustical model runs. The acoustic footprint for the active seismic source, advancing synchronously with the motion of the seismic vessel and changing as the sound propagation environment changed, was computed from the calibrated and adjusted model output and integrated through the software Pythagoras with locations of gray whales provided by shore-based observers. This enabled analysts to require air gun array shutdowns before whales were exposed to mean square sound pressure levels greater than the behavioral response threshold of 163 dB re 1 μPa2. The method described here provides a realistic means of mitigating the possible effects of air guns at a behavioral response level, whereas most seismic surveys rely on pre-established mitigation radii to manage the risk of injury to a whale.

Gray whale habitat use and reproductive success during seismic surveys near their feeding grounds: comparing state-dependent life history models and field data

We used a stochastic dynamic programming (SDP) model to quantify the consequences of disturbance on pregnant western gray whales during one foraging season. The SDP model has a firm basis in bioenergetics, but detailed knowledge of minimum reproductive length of females (Lmin) and the relationship between length and reproductive success (Rfit) was lacking. We varied model assumptions to determine their effects on predictions of habitat use, proportion of animals disturbed, reproductive success, and the effects of disturbance. Smaller Lmin values led to higher predicted nearshore habitat use. Changes in Lmin and Rfit had little effect on predictions of the effect of disturbance. Reproductive success increased with increased Lmin and with higher probability of reproductive success by length. Multiple seismic surveys were conducted in 2015 off the northeast coast of Sakhalin Island, with concomitant benthic prey surveys, photo-identification studies, and whale distribution sampling, thus providing a unique opportunity to compare output from SDP models with empirical observations. SDP model predictions of reproductive success and habitat use were similar with and without acoustic disturbance, and SDP predictions of reproductive success and large-scale habitat use were generally similar to values and trends in the data. However, empirical estimates of the proportion of pregnant females nearshore were much higher than SDP model predictions (a large effect, measured by Cohen’s d) during the first week, and the SDP model overestimated whale density in the south and underestimated density around the mouth of Piltun Bay. Such differences in nearshore habitat use would not affect SDP predictions of reproductive success or survival under the current seismic air gun disturbance scenario.

Benthic studies adjacent to Sakhalin Island, Russia, 2015 I: benthic biomass and community structure in the nearshore gray whale feeding area

Okhotsk or western gray whales feed in summer along the northeastern coast of Sakhalin Island, Russia, a region with oil and gas extraction facilities. Seismic surveys increased sound levels in the nearshore feeding area in 2015 for part of the summer, potentially displacing whales from preferred foraging habitat or reducing foraging efficiency. Since lost foraging opportunities might lead to vital rate effects on this endangered species, detailed benthic surveys were conducted to characterize benthic community biomass patterns and spatial and temporal differences. Benthic biomass demonstrated strong spatial–temporal interactions indicating that prey biomass differences among locations were dependent on sampling period. Of greatest interest, Amphipoda biomass declined from June to October in the northern and southern portions of the nearshore study area but increased in the middle and Actinopterygii biomass increased in the northern area in mid-summer. Water depth and sediment type were significant covariates with community structure, and water depth strongly covaried with bivalve biomass. Total average prey biomass was ~ 100 g/m2 within the nearshore feeding area with no evidence of reduced biomass among sampling periods or locations, although there were fewer amphipods in the south. Multi-prey investigations provide a stronger basis for inferences than single-prey studies of amphipods when gray whales feed on diverse prey. Benthic community-level variability was moderate to high as would be expected for a shallow-water nearshore area. Overall, spatial and temporal changes in dominant macrofauna biomass reflected small to medium-sized effects that were well within the natural boundaries expected for benthic communities.

Benthic studies adjacent to Sakhalin Island, Russia 2015 III: benthic energy density spatial models in the nearshore gray whale feeding area

Energy densities of six dominant benthic groups (Actinopterygii, Amphipoda, Bivalvia, Cumacea, Isopoda, and Polychaeta) and total prey energy were modeled for the nearshore western gray whale feeding area, Sakhalin Island, Russia, as part of a multi-disciplinary research program in the summer of 2015. Energy was modeled using generalized additive mixed models (GAMM) with accommodations for zero-inflation (logistic regression and hurdle models) and regression predictions combined with kriging to interpolate energy densities across the nearshore feeding area. Amphipoda energy density was the highest nearshore and in the south whereas Bivalvia energy density was the highest offshore and in the northern portion of the study area. Total energy was the highest in mid-range distances from shore and in the north. Amphipoda energy density was higher than minimum energy estimates defining gray whale feeding habitats (312–442 kJ/m2) in 13% of the nearshore feeding area whereas total prey energy density was higher than the minimum energy requirement in 49% of the habitat. Inverse distance-weighted interpolations of Amphipoda energy provided a broader scale representation of the data whereas kriging estimates were spatially limited but more representative of higher density in the southern portion of the study area. Both methods represented the general trend of higher Amphipoda energy density nearshore but with significant differences that highlight the value of using multiple methods to model patterns in highly complex environments.

LARGE WHALE OCCURRENCE IN NORTHEASTERN CHUKCHI AND SOUTHERN BEAUFORT SEAS FROM VESSEL SURVEYS, 2008–2014

With global climate change and increasing ocean-based human activities, large whales face novel challenges in the Arctic seas. Understanding and assessing large whale occurrence and the links between occurrence and environmental variables in this region is a key issue in current management and conservation strategies for Arctic marine mammal species. During the Chukchi Sea Environmental Studies Program, large whale occurrence data were collected from vessel surveys during >56,909 km of observation effort in summer and autumn, 2008 to 2014, in the northeastern Chukchi, southern Beaufort, and Bering Seas. The most-recorded species were the Bowhead (Balaena mysticetus) and Gray (Eschrichtius robustus) Whales. Subarctic species recorded included the Humpback Whale (Megaptera novaeangliae), Fin Whale (Balaenoptera physalus), and Minke Whale (Balaenoptera acutorostrata). Sightings data were analyzed with respect to environmental variables: sea-surface temperature (SST), depth (m), and distance from shore (km), by month and year. Investigating occurrence associations with environmental parameters is a key element for predicting large whale trends in these Arctic seas and for understanding marine mammals as sentinels of oceanic shifts.

MARINE MAMMAL OCCURRENCE, DISTRIBUTION, AND BEHAVIOR IN THE INLAND WATERS OF WASHINGTON FROM AERIAL SURVEYS, 2013–2016

The inland waters of Washington State are inhabited regularly by 10 species of marine mammals. Updated and comprehensive information regarding marine mammal occurrence, distribution, and behavior in the area is critical when addressing local anthropogenic impact, management, and conservation concerns. We conducted a total of 16,198 km of observation effort during systematic line-transect surveys from a high-wing, twin-engine airplane throughout Puget Sound in all 4 seasons during 2013 to 2016, and in the Strait of Juan de Fuca and San Juan Islands area during summer 2014 and spring 2015. Ten marine mammal species were confirmed across 5772 groups of an estimated 10,673 individuals sighted, including some seasonal patterns of occurrence. The most commonly sighted species in terms of individuals were Harbor Seals (n = 8012), Harbor Porpoises (n = 2168), California Sea Lions (n = 238) and Steller Sea Lions (n = 77). The most common behavior states documented across species among the total 5670 groups were rest (73%) and medium travel (16%); probable foraging was observed among 13 groups (0.2%) and included Gray Whale foraging pits in tidal mudflats. Potential behavioral reactions to the aircraft were rare (0.3% of total individuals), primarily by Harbor Seals and Harbor Porpoises. Results of these surveys represent the most comprehensive up-to-date information available on marine mammal occurrence, distribution, and behavior across seasons in the Puget Sound region.

Recovery of the Eastern North Pacific Gray Whale: A Case Study

In 1994, the United States government removed the Eastern North Pacific gray whale from the Endangered Species List due to its recovery rather than extinction. This notable action also marked the first removal of a marine mammal from the List due to population recovery since its enactment in 1973. The gray whale case study is well documented, in large part due to the charismatic nature of whales, a deep regard for marine mammal species, multiple federal laws and international treaties involved in their management and recovery, and a series of legal cases involving the Makah tribe in its pursuit to resume cultural subsistence whaling. The events leading up to the gray whale’s listing as endangered, the actions taken by both the US and the international community, and some of the events since the species’ delisting creates a unique and comprehensive case study that provides space for reflection on the future use of environmental laws to protect and preserve species, including, but certainly not limited to, large cetaceans in the Anthropocene.

Naturally stressed? Glucocorticoid profiles in blubber of blue and gray whales in response to life history parameters.

The goal of the present study was to carry out a thorough methodological validation and describe baseline profiles for glucocorticoid hormones (cortisol and corticosterone) in blubber from blue (n = 77) and gray (n = 103) whales from the eastern North Pacific Ocean. For each species, we modelled cortisol and corticosterone concentrations in response to life history parameters (age, sex, reproductive status) and season or geographic location. In blue whales, cortisol concentrations did not vary significantly by age class, sex, or reproductive status, whereas corticosterone was significantly lower in immature than in adult females (p < .001). In gray whales, cortisol concentrations were significantly higher in lactating whales (p < .05), while corticosterone was significantly different between females and males (p = .001) and elevated in calves (p = .003). In gray whales, corticosterone concentrations were significantly lower in males sampled later in the year (August to November) compared to both sexes sampled between March and August (p = .05), but no seasonal trend occurred in blue whales. Our results indicate that glucocorticoid actions vary between species and sex in large whales. Analysis of multiple hormones improves our understanding of the physiology of maintaining metabolic homeostasis or coping with chronic stressors.

New Holocene grey whale (Eschrichtius robustus) material from North Carolina: the most complete North Atlantic grey whale skeleton to date.

Skeletal remains and historical accounts indicate that grey whales (Eschrichtius robustus) existed in the North Atlantic Ocean from the Pleistocene into the seventeenth century. Fossil and sub-fossil occurrences in this basin are rare, distributed from the east coast of the United States to Iceland and Europe. Here, we report an incomplete skeleton of a Holocene grey whale from Pender County, North Carolina, USA. This specimen represents a physically immature individual and is the most complete North Atlantic grey whale specimen reported to date. It comprises 42 cranial and postcranial elements, including the cranium, parts of the rostrum, both mandibles, both scapulae, humeri, radii and ulnae, most of the vertebral column anterior to the lumbar region and numerous ribs. Its provenance near the inlet of a large estuary is consistent with previous findings from the southeastern USA and parallels the species' habitat use in Baja California breeding and calving grounds in the North Pacific Ocean. Radiocarbon dating indicates an age of 827 ± 172 years before present. Cut marks on multiple skeletal elements indicate that the animal was butchered, suggesting some level of human exploitation of the species in the southeastern USA in the twelfth century, approximately 500 years prior to its extirpation in the North Atlantic.

Whales from space dataset, an annotated satellite image dataset of whales for training machine learning models

Monitoring whales in remote areas is important for their conservation; however, using traditional survey platforms (boat and plane) in such regions is logistically difficult. The use of very high-resolution satellite imagery to survey whales, particularly in remote locations, is gaining interest and momentum. However, the development of this emerging technology relies on accurate automated systems to detect whales, which are currently lacking. Such detection systems require access to an open source library containing examples of whales annotated in satellite images to train and test automatic detection systems. Here we present a dataset of 633 annotated whale objects, created by surveying 6,300 km2 of satellite imagery captured by various very high-resolution satellites (i.e. WorldView-3, WorldView-2, GeoEye-1 and Quickbird-2) in various regions across the globe (e.g. Argentina, New Zealand, South Africa, United States, Mexico). The dataset covers four different species: southern right whale (Eubalaena glacialis), humpback whale (Megaptera novaeangliae), fin whale (Balaenoptera physalus), and grey whale (Eschrichtius robustus).

Trichinosis of Marine Mammals in the Territory of Chukotka

Chukotka is the only region of the Russian Federation where traditional fishing of marine mammals, including the gray whale Eschrichtius gibbosus, is conducted. More than 70% of the indigenous population of the coastal settlements of the Chukchi Peninsula eat the meat of marine mammals. Due to the huge distances between communities, lack of infrastructure, limited access to medical and veterinary care, isolated studies of marine mammal infestation with trichinella larvae are being conducted.For the first time, trichinella in the Pacific walrus Odobenus rosmarus divergens in Chukotka were recorded in the coastal zone of the Bering and Chukchi Seas in the 1970s. In the future, trichinosis has not been studied in this region, which confirms the relevance of our work. Infection of marine mammals was studied by trichinelloscopy (compressor and biochemical). Bioassays were collected during fishing by sea St. John's wort in the village of Lorino. Infection rates were determined. Studies conducted on the Chukchi Peninsula confirmed the infection with trichinosis of the Pacific walrus and revealed the larvae of trichinella in lakhtak Erignathus b.nauticus and ringed seal Phoca hispida, and later in larga Phoca largha. The extent of invasion varied from 0.9% in larga to 4.3% in lakhtak. The gray whale is the most popular food item in the diet of the indigenous inhabitants of Chukotka. According to the results of the research, out of 119 individuals of gray whales, trichinella were not found. Given the trophic‐chorological connections of marine mammals, it is difficult to imagine a way of transmission of trichinella in marine ecosystems. However, previously obtained research results allow us to do this. On the Arctic coasts, especially near settlements, there are a large number of corpses of dogs, cats, rats, voles, carcasses of small seals that fall into marine ecosystems. Invertebrates, their adult and larval forms, as well as vertebrates ‐ fish and birds ‐ occupy an important place in the process of disposal of corpses. Studies have shown that various types of invertebrates from 1 to 59 hours, and vertebrates from 28 to 95 hours can be direct or indirect sources of the pathogen of invasion and contribute to their mechanical transfer. Thus, in the conditions of coastal Arctic marine ecosystems, successful circulation of trichinella is carried out, thanks to human economic activity and the specifics of the trophic‐horological relationships of obligate and potential host species. Therefore, monitoring of trichinella invasion in these regions is vital.

Annex G: Summary of gray whale stock structure hypotheses

How to cite: International Whaling Commission, 2022. Report of the Scientific Committee: Annex G. J. Cetacean Res. Manage. (Suppl.) 23: 250-255.

Isotopic composition of the eastern gray whale epidermis indicates contribution of prey outside Arctic feeding grounds

Eastern gray whales’ distribution range and plasticity in feeding behavior complicates the understanding of critical life-history such as pregnancy and lactation. Our goal was to determine if females who experienced gestation, gave birth, and lactated their calves, assimilated a high proportion of benthic amphipods from the Bering Sea, which are considered the species’ main prey. We used Bayesian stable isotope mixing models to estimate the probability of contribution of food items sampled along the species’ distributional range, using isotopic data on amphipods from the Bering Sea, mysids from Vancouver Island, and amphipods and polychaetes from Ojo de Liebre Lagoon. We sampled epidermal tissue from lactating females (n = 25) and calves (n = 34) and analyzed their carbon and nitrogen isotopic composition. Model outcome indicated that benthic amphipods from the Bering Sea were not the primary food for the eastern gray whale. Each mother performed a different feeding strategy, and prey from Vancouver Island were generally as important as that from the Bering Sea. Moreover, model results indicate a constant use of Ojo de Liebre Lagoon as a feeding ground. Our results appear to agree with previous studies that report continuous feeding by females to satisfy certain physiological requirements (e.g., fatty acids omega-6) during migration and breeding time. Future investigations of the isotopic composition of all those prey items that could be assimilated by the eastern gray whale emerge as critical. Both historical and recent information, that would provide insights in the species feeding ecology under past and present environmental conditions, should be considered as equally important to establish conservation and management plans.

Multi-UAV Cooperative Assisted RSU Data Acquisition Strategy considering Coverage Quality

The multiple Unmanned Aerial Vehicle (multi-UAV) assisted roadside unit (RSU) data acquisition problem considering the coverage quality is a multiobjective optimization problem, which is a NP-hard problem. Heuristic and hyperheuristic algorithms are effective to solve problems of this type. These algorithms can find the optimal or suboptimal solution in a reasonable time. However, such algorithms still have the problems of low convergence accuracy, slow convergence speed, and being easy to fall into the local optimal solution. In this paper, firstly, according to the specific problem scenarios of roadside unit data collection, minimum cost and maximum coverage models based on task cost and coverage quality are established. Then, to solve the optimization model, combined with the update characteristics of the gray wolf optimization algorithm (GWO) and the whale optimization algorithm (WOA), a hybrid weighted gray wolf and whale optimization algorithm (HWGWOA) is proposed. Finally, to verify the effectiveness of the proposed algorithm, extensive simulation experiments are conducted under four different task acquisition scenarios, and the results are compared with those of genetic algorithm (GA), GWO, and WOA. Simulation results show that the algorithm proposed in this paper not only can get lower task cost and higher coverage quality but also has faster convergence speed and better robustness. Specifically, in terms of task cost, the HWGWOA is about 9.54% lower than the GA, about 7.31% lower than the GWO, and about 5.8% lower than the WOA. In terms of coverage, the HWGWOA is up to about 27.87% higher than the GA, about 15.19% higher than the GWO, and about 9.86% higher than the WOA. Therefore, the algorithm is more suitable for large-scale optimization problems.

Range-Wide Comparison of Gray Whale Body Condition Reveals Contrasting Sub-Population Health Characteristics and Vulnerability to Environmental Change

Climate change is a global phenomenon, yet impacts on resource availability to predators may be spatially and temporally diverse and asynchronous. As capital breeders, whales are dependent on dense, predictable prey resources during foraging seasons. An Unusual Mortality Event (UME) of Eastern North Pacific (ENP) gray whales (Eschrichtius robustus) was declared in 2019 due to a dramatic rise in stranded animals, many emaciated. Climate change impacts may have affected prey availability on the primary foraging grounds of ENP gray whales (~20,000 individuals) in the Arctic and sub-Arctic region and in coastal habitats between northern California, USA and British Columbia, Canada where a small sub-group of ENP whales called the Pacific Coast Feeding Group (PCFG; ~230 individuals) forages. To investigate variability of gray whale body condition relative to changing ocean conditions, we compare two datasets of gray whale aerial photogrammetry images collectedviaUnoccupied Aircraft Systems (UAS) on the ENP wintering grounds in San Ignacio Lagoon, Mexico (SIL; n=111) and on the PCFG feeding grounds in Oregon, USA (n=72) over the same three-year period (2017–2019). We document concurrent body condition improvement of PCFG whales in Oregon while body condition of whales in SIL declined. This result indicates that the UME may have affected ENP whales due to reduced energetic gain on some Arctic/sub-Arctic foraging grounds, while PCFG whales are recovering from poor prey conditions during the NE Pacific marine heatwave event of 2014–2016. Surprisingly, we found that PCFG whales in Oregon had significantly worse body condition than whales in SIL, even when accounting for year and phenology. We derive support for this unexpected findingviaphotogrammetry analysis of opportunistic aerial images of gray whales on Arctic foraging grounds (n=18) compared to PCFG whales in Oregon (n=30): the body condition of PCFG whales was significantly lower (t=2.96, p=0.005), which may cause PCFG whales to have reduced reproductive capacity or resilience to environmental perturbations compared to ENP whales. Overall, our study elucidates divergent gray whale body condition across sub-groups and time, and we demonstrate the value of UAS to effectively monitor and identify the physiological response of whales to climate change.

Changes in gray whale phenology and distribution related to prey variability and ocean biophysics in the northern Bering and eastern Chukchi seas.

Changes in gray whale (Eschrichtius robustus) phenology and distribution are related to observed and hypothesized prey availability, bottom water temperature, salinity, sea ice persistence, integrated water column and sediment chlorophyll a, and patterns of wind-driven biophysical forcing in the northern Bering and eastern Chukchi seas. This portion of the Pacific Arctic includes four Distributed Biological Observatory (DBO) sampling regions. In the Bering Strait area, passive acoustic data showed marked declines in gray whale calling activity coincident with unprecedented wintertime sea ice loss there in 2017-2019, although some whales were seen there during DBO cruises in those years. In the northern Bering Sea, sightings during DBO cruises show changes in gray whale distribution coincident with a shrinking field of infaunal amphipods, with a significant decrease in prey abundance (r = -0.314, p<0.05) observed in the DBO 2 region over the 2010-2019 period. In the eastern Chukchi Sea, sightings during broad scale aerial surveys show that gray whale distribution is associated with localized areas of high infaunal crustacean abundance. Although infaunal crustacean prey abundance was unchanged in DBO regions 3, 4 and 5, a mid-decade shift in gray whale distribution corresponded to both: (i) a localized increase in infaunal prey abundance in DBO regions 4 and 5, and (ii) a correlation of whale relative abundance with wind patterns that can influence epi-benthic and pelagic prey availability. Specifically, in the northeastern Chukchi Sea, increased sighting rates (whales/km) associated with an ~110 km (60 nm) offshore shift in distribution was positively correlated with large scale and local wind patterns conducive to increased availability of krill. In the southern Chukchi Sea, gray whale distribution clustered in all years near an amphipod-krill 'hotspot' associated with a 50-60m deep trough. We discuss potential impacts of observed and inferred prey shifts on gray whale nutrition in the context of an ongoing unusual gray whale mortality event. To conclude, we use the conceptual Arctic Marine Pulses (AMP) model to frame hypotheses that may guide future research on whales in the Pacific Arctic marine ecosystem.

Cetacean Strandings in the US Pacific Northwest 2000–2019 Reveal Potential Linkages to Oceanographic Variability

Studying patterns in marine mammal stranding cases can provide insight into changes in population health, abundance, and distribution. Cetaceans along the United States West coast strand for a wide variety of reasons, including disease, injury, and poor nutritional status, all of which may be caused by both natural and anthropogenic factors. Examining the potential drivers of these stranding cases can reveal how populations respond to changes in their habitat, notably oceanographic variability and anthropogenic activities. In this study, we aim to synthesize recent patterns in 1,819 cetacean strandings across 26 species in the Pacific Northwest from 2000 to 2019 to compare with previous findings. Additionally, we aim to quantify the effects of localized and basin-scale oceanographic conditions on monthly stranding cases for five focal species using generalized additive models in order to explore potential relationships between strandings and changes in biophysical features that could affect foraging conditions or other important physiological cues. Our results suggest that strandings of harbor porpoises, gray whales, humpback whales, Dall’s porpoises, and striped dolphins are correlated with certain environmental variables, including sea surface temperature, chlorophyll concentration, and the Pacific Decadal Oscillation depending on the species. While it remains challenging to identify the causal mechanisms that underlie these relationships for a given species or population based on its utilization of such a complex ecosystem, improving our understanding of periods of increased strandings can enhance our knowledge of how these species interact with their environment and assist conservation and management efforts. This study enhances the utility of stranding records over time beyond simply reporting trends and has broader applicability to other geographic regions amid global climate change.

At the Time of the Dream

At the Time of the Dream Jourdan Imani Keith (bio) When we still slept together, in the time of the dream, when the whales rose outside our bedroom window, looked in through the white frame where I had known the garden to be, I thought, when did we move to a houseboat, when did we become adrift? At the time of the dream, when she slept her unbroken sleep, she was bringing ocean into our room. She woke breaching, with the sound of her breath, a quiet, puh shh, her exhale. It never woke her—only me. At the time of the dream, I did not know a gray whale, just off Arroyo Beach, was throwing its dying into the eye-light of a West Seattle view, ending all the distance between us, the sea, the factory-lined shores of the Duwamish River, the cranes that rise from the fog like teeth through a reversed sky, long-legged monsters walking their consumer walk, their red steel-knees bent above the waters of Puget Sound. At the time of the dream, I did not know that the whale, telling its gray story of sneakers and plastic bags in its belly and last breaths was my whale. It was the whale in my dream, or at least that is what we believed, weeks later when my now ex-spouse called from her work. "Jourdan. The whale that you were dreaming of, when you were dreaming of the whale, … a gray whale was dying on Alki. A whale died on Alki." It was not Alki Beach, but to us, it felt like the place we were most familiar with. The place where I proposed to her at a Cuban-owned, lesbian-owned restaurant some seven years before. The place where the scent of cigar smoke was a phantom comfort of Cuba. She walked toward me as though I was home. Seven years later, her co-worker showed her the story of the beached gray whale that died along the West Seattle shore. We did not have tv. We did not use smartphones. That was the first we'd heard about it. The blogs reported the tales around its dead body, rumors and questions like flies hovered above the carcass. Was it the one that had been spotted earlier in [End Page 55] the week, a hundred feet from houses, fifty feet from cars and pedestrians, little distance between the sand and children unable to stop the dying? She called. The whale. My spouse. She said my name, with a pause in her disbelief. The whale had come to me, looking into our home through our bedroom window. These are the things we did not know. We did not know the sound of coming up for air was for them, was for us. Didn't know their breath was voluntary, didn't know that it doesn't just happen, didn't know that every time they breathe, they choose it. Didn't know that we too had to come up for breath. We did not know that we were drowning on dry land. After the dream, I woke, haunted by urgency. I was always anxious by spring but why, why, why had whales come to my window—looked me in my eyes? I fretted that it was about the seventeen-day wilderness trip that I would be leading. By 2010 I was an expert, but was that a warning to keep "my babies" safe? I called the kids on the trips my babies, although they were all in high school. I was responsible for their lives. Somebody's children, they are somebody's babies. Risk management had always been my strength, my focus, my highest concern, but that summer as the dream resurfaced while I planned, it felt like a premonition I could not understand. I became more exacting, more detailed, more focused, more obsessed. Stressed. More stressed. How was I to know the warning was also direction, was also peril? I live in a world that I have come to understand from that dream. I had no language for it. No more than I understood the dream or the song of the whales...

Gray whale (Eschrichtius robustus) and killer whale (Orcinus orca) co-occurrence in the eastern Chukchi Sea, 2009–2019: evidence from gray whale carcasses observed during aerial surveys

Gray whale (Eschrichtius robustus) and killer whale (Orcinus orca) co-occurrence in the eastern Chukchi Sea, 2009–2019: evidence from gray whale carcasses observed during aerial surveys