Gray Whales Eschrichtius Robustus Research Articles

The Lipid Profile of the Tissues of the Gray Whale (<i>Eschrichtius robustus</i>): to the Relationship of Composition of Lipids and Their Physiological and Biochemical Role in Maintaining Tissue Function

A study was made of the composition of lipids in different tissues of gray whales Eschrichtius robustus, and the lipid profiles of tissues with different functional loads were compared. Five types of tissues (skin, muscle, liver, outer and inner layers of fat) were collected from seventeen individuals of eastern gray whales during the permitted aboriginal fishing in the village. Lorino of the Chukotka Autonomous Okrug in the summer of 2020. For all of the listed tissues, the composition of total lipids and their individual lipid classes was studied by high-performance thin-layer chromatography (HPTLC), the identification and description of lipid profiles of different types of tissues was carried out, which made it possible to identify their general and specific features of lipid metabolism according to the studied parameters. Comparative analysis of lipid profiles of tissues revealed individual lipid classes that make the greatest contribution to discrimination between different tissues. Both the content of total lipids and individual lipid classes varied significantly in different tissues. At the same time, 93% of the differences between tissues are two functions that are most closely related to the content of metabolically associated diacylglycerols (DAG), monoacylglycerols (MAG), triacylglycerols (TAG) and waxes, mainly energetic lipids, in tissues. The paper discusses the relationship between the qualitative and quantitative composition of lipids and the functional load and the physiological role of tissues. The metabolic features of the accumulation and consumption of lipid classes during the feeding period were noted. The revealed differences in certain parameters of lipid metabolism of the outer and inner layers of fat are due to different metabolic activity of tissues and their function in the body, which, among other things, is provided by lipids.

The role of sea ice in the distribution, habitat use, and phenology of eastern North Pacific gray whales

A strong negative relationship has been observed between calf production of eastern North Pacific gray whales Eschrichtius robustus and Pacific Arctic sea ice area with the exception of 2 potentially anomalous periods: 2013-2014 and 2017-2019. Sea ice may play a role in reproductive variability by blocking gray whale access to foraging hotspot habitats. We tested this ‘sea ice exclusion’ hypothesis using complementary aerial survey and moored hydrophone data sets that together provide broad spatial and temporal coverage. A negative relationship (generalized additive model, p < 0.001) was found between gray whale aerial counts and ice concentration in the northeast Chukchi Sea (2008-2019), with a nonlinear increase in negative slope above 45-55% concentration. A comparison of distribution patterns between years further indicated the absence of sightings within northern Bering and northeastern Chukchi foraging hotspots during years with delayed ice break-up versus years with an early-to-average ice retreat. Passive acoustic recordings likewise showed the near-absence of detections during periods of dense ice cover and indicated a strongly positive relationship between ice break-up dates and the timing of acoustic detection onset. Together, these analyses point to the important role of sea ice in gray whale distribution, habitat use, and phenology. However, a relatively consistent 10-15 d lag observed between ice break-up and acoustic onset dates suggested that the mechanism(s) underpinning gray whale interactions with sea ice may be more complex than simply ‘sea ice exclusion.’ Here, we propose ‘prey quality timing’ as a potential alternative hypothesis that warrants further investigation.

Quantifying a stopover of killer whales preying on gray whales rounding the Alaska Peninsula

Predation by killer whales Orcinus orca on recovering populations of baleen whales is being increasingly reported, but there have been no direct quantitative assessments of its importance, for either the predators or prey. We used photographic mark-recapture and satellite telemetry to assess the abundance and behavior of killer whales gathering to feed on gray whale Eschrichtius robustus calves and juveniles that were migrating around the Alaska Peninsula into the Bering Sea. We quantitatively describe this aggregation as a stopover, used in May and early June 2003-2008 by at least 197 different killer whales. Estimates of average stopover duration (1.8-3.6 wk) and annual abundance (89-128 killer whales) were variable and correlated with annual gray whale calf production (404-1528 calves). In years with more gray whale calves, killer whales spent more time at this geographic pinch point where they could presumably access adequate prey. In years with fewer calves, more killer whales used the study area but remained for a shorter time, presumably searching more widely when calves were scarcer. The presence of killer whales increased through May into early June, when satellite tags tracked northerly movements into the Bering Sea, and as far as 1620 km into the Chukchi Sea, likely following migrating gray whales. These data indicate focused and prolonged predation by killer whales on a recovered population of baleen whales and provide the first evidence of the importance of such predation in structuring killer whale populations and influencing their dynamics.

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).

Trade-offs in prey quantity and quality in gray whale foraging

To forage optimally, predators face complex decisions regarding target prey distribution, quantity, and quality. We paired theodolite tracking of gray whalesEschrichtius robustusin Port Orford, Oregon, USA, with concurrent sampling of their zooplankton prey to examine foraging decisions relative to prey quantity (abundance) and quality (caloric content). We tested the hypotheses that whales (1) feed more than search or transit in areas with high quantity and quality prey and (2) select foraging habitat dominated by the calorically rich mysidNeomysis rayii. Relative prey abundance was assessed through standardized image analysis of camera drops, and zooplankton prey community was determined from net tows. These data were spatially interpolated and modeled to generate daily layers of species-specific prey abundance and calories (20 m grid) for comparison to whale behavior derived from tracking data. Whales fed significantly more in areas with higher prey abundance and calories than where they searched and transited. Whales increased foraging effort as overall prey availability increased, yet foraging probability was significantly correlated with the quantity and quality of the mysidHolmesimysis sculpta, which has significantly lower calories thanN. rayii. However, during the study period, the maximum abundance ofN. rayiiwas 4 times lower than that ofH. sculptaand never reached the quantity threshold determined by a logistic regression needed to support whale foraging behavior. Hence, gray whale prey selection involves trade-offs between prey quantity and quality to maximize energetic gain, and prey quality should be considered alongside abundance in ecological studies investigating predator decision-making.

An Assessment of Commercial Fleet Applications of Management Measures in Clayoquot Sound, British Columbia, Canada, Aimed to Mitigate Whale-watching Impacts

The interactions between wildlife tourism operators and the animals that they rely on are complex. For commercial whale watching, the recognition of the potential disturbance from the vessels generates uncertainty regarding the effectiveness of management strategies for it to remain a "no-take" practice. This warrants further evaluation. In this study, we analyzed the activities of the whale-watching fleet in Tofino, Vancouver Island, British Columbia, Canada, to evaluate industry sustainability and its ability to meet legislated conservation objectives. Visual observations gave context to an analysis of the communications of the fleet, made using very high frequency (VHF) marine radio. Transcription of these communications demonstrated three main themes: whale location, whale "transfers" between operators, and encounter or "show" quality. Cumulative encounter times from the fleet far exceeded the 30-min limit recommended in the whale-watching guidelines. Killer whales (Orcinus orca) were subject to the longest periods of vessel presence, with an average time spent in active encounters of 4.21 ±1.96 hr. This extended to almost the full operating day if whales remained within a feasible traveling distance of Tofino. Humpback (Megaptera novaeangliae) and gray whale (Eschrichtius robustus) encounters also exceeded the suggested time limit by 2.40 ± 1.73 hr and 1.31 ± 1.07 hr, respectively. Increased education and the addition of spatial and temporal restrictions in management regimes could address the shortcomings of the current system to minimize potential disturbance to whales from commercial whale-watching encounters and facilitate sustainable industry practices.

Cetacean occurrence in the Gulf of Alaska from long-term passive acoustic monitoring

The Gulf of Alaska is an important habitat for a diverse array of marine mammals, many of which were severely depleted by historical whaling. To study current cetacean distributions in this region, passive acoustic monitoring was used to detect species-specific call types between 2011 and 2015 at five locations spanning the continental shelf, slope, and offshore seamounts. Spatial and temporal detection patterns were examined for nine species to compare differences in behavior and habitat use. Mysticetes showed seasonal increases in calling that indicated possible behavioral shifts between feeding and breeding in blue (Balaenoptera musculus), fin (B. physalus), and humpback (Megaptera novaeangliae) whales, and matched known migration timing of gray whales (Eschrichtius robustus). Interannual changes in blue and fin whale calling may relate to the marine heat wave that began in 2013 and lasted through the end of the monitoring period. Odontocete detections revealed unique spatial distributions, with killer whales (Orcinus orca) most common on the continental shelf and sperm whales (Physeter macrocephalus) most common on the continental slope, where detections occurred year-round. Beaked whales showed both spatial and temporal separation: Baird’s beaked whale (Berardius bairdii) detections were highest at Quinn Seamount in the spring, Cuvier’s (Ziphius cavirostris) at Pratt Seamount in winter, and Stejneger’s (Mesoplodon stejnegeri) on the continental slope in the fall. The year-round presence of many species highlights the ecological importance of the Gulf of Alaska and the spatiotemporal information reported here should inform future conservation efforts.

Co-occurrence of gray whales and vessel traffic in the North Pacific Ocean

All species of large whales are susceptible to vessel strikes, but the true scale and geographical extent of such strikes is not known. This paper provides a qualitative assessment of the range-wide risks posed to gray whalesEschrichtius robustusby vessels, by comparing patterns of whale distribution with the density of vessel traffic seasonally throughout the North Pacific in 2019. Areas of very high vessel density were evident year-round near many coastlines, along inter-continental trade routes, and at hubs of commercial shipping near port entrances. Gray whales were exposed to vessel strikes throughout their range and in their feeding, southbound migration, wintering, and northbound migration periods. Areas of apparently high risk were in the Russian Far East (Kamchatka peninsula and Okhotsk Sea), Bering Sea (including the Aleutian Islands), Gulf of Alaska, and along the entire west coast of North America. Risk appeared greatest during south- and northbound migration when much of the gray whale population is moving through waters near shore. Tanker, container, and bulk-carrier ships represent considerable risk to whales in the North Pacific Ocean, but the large geographical extent of commercial fishing activities suggests that fisheries are also a substantial source of risk. Vessel-strike risk maps indicate the relative extent of exposure of gray (and other) whales to underwater vessel noise. The number of gray whales killed by ship strikes each year may be in the tens, or perhaps the low hundreds. Additional analyses, including quantitative assessments, are warranted to further clarify the risk of vessel strikes to gray whales.

Poor body condition associated with an unusual mortality event in gray whales

The eastern North Pacific gray whaleEschrichtius robustusexperienced an unusual mortality event (UME) in 2019-2020, with 384 whales found dead along the Pacific coasts of Mexico, USA and Canada. A similar UME in 1999-2000 was speculated to have been caused by starvation, but body condition data were not available to test this hypothesis. Between 2017 and 2019, we used unmanned aerial vehicles (drones) and photogrammetry methods to measure the body condition of gray whales in San Ignacio Lagoon, Baja California Sur, Mexico. Body condition was calculated from the residual of the relationship between body volume and length. The body condition of gray whales was significantly lower in 2018 (-11.1%, SE = 1.74, n = 531) and 2019 (-9.7%, SE = 1.76, n = 628) compared to 2017 (n = 59) for all reproductive classes (calves, juveniles, adults and lactating females). Overall, lactating females were in good body condition. The reduction in body condition of whales in 2018-2019 is unlikely to have affected their survival, but could have reduced their reproductive rate by prolonging the post-weaning recovery time. This could explain the low number of mother-calf pairs observed in the San Ignacio Lagoon in 2018 and 2019. For juveniles and adults that arrived in the lagoons with less energy reserves, their reduced body condition may have been close to their survival threshold. This could explain the high proportion of juveniles and adults among the stranded dead whales in 2019-2020. Although the underlying cause of the reduction in gray whale body condition is unknown, starvation likely contributed to the 2019-2020 UME.

Lipid Status of Gray Whales Eschrichtius robustus in the Piltun Feeding Area.

For the first time, the relationship of lipid and fatty acid composition with individual, gender and age characteristics of the gray whale Eschrichtius robustus in the Piltun feeding area is shown using the methods of biochemical analysis.

Trophic basis of dominant amphipods in the gray whale feeding grounds near northeastern Sakhalin Island (the Sea of Okhotsk) inferred from fatty acid and stable isotope analyses

The shelf waters off northeastern Sakhalin Island are the main feeding ground for the endangered western subpopulation of the gray whale Eschrichtius robustus. Amphipods, which dominate the benthic communities, are key dietary sources for the gray whales foraging in this area. To elucidate the trophic base supporting the large local amphipod biomass, fatty acid (FA) compositions and the stable isotope ratios δ13C and δ15N of the five most abundant amphipod species in the area were studied. The FA compositions were unusually similar (85% similarity) across the amphipod species although these species were represented by suspension-feeders, deposit-feeders and carnivores. The FAs of diatom origin predominated in the FA profiles of all amphipods and decreased in accordance with the increase in trophic position as determined by δ15N values and the FA trophic markers of carnivorous feeding. These results suggested that diatoms are the single, main trophic basis that underpins the food web of the feeding grounds on the northeastern Sakhalin shelf. Further studies on factors influencing the local production of large diatoms on the Sakhalin shelf can be important for the prognosis of future changes of foraging resources of the gray whales.

A PLIOCENE GRAY WHALE ( ESCHRICHTIUS SP.) FROM THE EASTERN NORTH ATLANTIC

The gray whale Eschrichtius robustus, the only living member of the eschrichtiid lineage, currently inhabits only the North Pacific. Interestingly, however, the holotypes of both E. robustus and the late Miocene Archaeschrichtius ruggieroi (the oldest known eschrichtiid species) come from the North Atlantic and the Mediterranean, respectively. Here we describe a partial mysticete mandible from the Pliocene (3.71–2.76 Ma) of Belgium (Eastern North Atlantic). This new fossil displays a combination of morphological features that makes it nearly identical to modern E. robustus. Nevertheless, given its incomplete nature, the studied specimen is here identified in open nomenclature as belonging to Eschrichtius sp. The recognition of such an early record of Eschrichtius in the North Atlantic suggests that this genus developed a circum-Northern Hemisphere distribution not later than in Pliocene times, thus complicating our understanding of its origin, evolutionary history, and palaeobiogeographic patterns.

A machine-learning approach to assign species to ‘unidentified’ entangled whales

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 36:89-98 (2018) - DOI: https://doi.org/10.3354/esr00894 ESR Special: Marine pollution and endangered species A machine-learning approach to assign species to ‘unidentified’ entangled whales James V. Carretta* Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037, USA *Corresponding author: jim.carretta@noaa.gov ABSTRACT: Whale entanglements in US west coast fishing gear are largely represented by opportunistic sightings, and some reports lack species identifications due to rough seas, distance from whales, or a lack of cetacean identification expertise. Unidentified entanglements are often ignored in species risk assessments and thus, entanglement risk is underestimated. To address this negative bias, a species identification model was built from random forest (RF) classification trees using 199 identified entanglements (‘model data’). Humpback Megaptera novaeangliae and gray whales Eschrichtius robustus represented 92% of identified entanglements; the remaining 8% were minke whales Balaenoptera acutorostrata, fin whales B. physalus, blue whales B. musculus, and sperm whales Physeter macrocephalus. Predictor variables included year, gear type, location, season, sea surface temperature, water depth, and a multivariate El Niño index. Cross-validated species classifications were correct in 78% (155/199) of cases, significantly higher (p < 0.001, permutation test) than the 49% correct classification rate expected by chance. The RF model correctly classified 91% of humpback whale cases, 64% of gray whale cases, and 100% of sperm whale cases, but misclassified all minke, blue, and fin whale cases. The cross-validated RF classification-tree species model was used to classify 35 entanglements without species identifications (‘novel data’) and each case was assigned a probability of belonging to each of 6 model data species. This approach eliminates the negative bias associated with ignoring unidentified entanglements in species risk assessments. Applications to other wildlife studies where some detections are unidentified include fisheries bycatch, line-transect surveys, and large-whale vessel strikes. KEY WORDS: Fishery entanglement · Humpback whale · Gray whale · Species assignment · Random forest Full text in pdf format PreviousNextCite this article as: Carretta JV (2018) A machine-learning approach to assign species to ‘unidentified’ entangled whales. Endang Species Res 36:89-98. https://doi.org/10.3354/esr00894 Export citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 36. Online publication date: June 13, 2018 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2018 Inter-Research.

Organochlorine pesticide accumulation in seabirds and marine mammals from the Northwest Pacific

Bioaccumulation of organochlorine pesticides by marine organisms is one of the methods of environmental quality. Concentrations of organochlorine pesticides (HCH isomers (α-, β-, γ-HCH), p,p′-DDT and its metabolites (p,p′-DDD, p,p′-DDE)) in samples of seabirds (Northern fulmar Fulmarus glacialis, Crested auklet Aethia cristatella, Auklet-crumb Aethia pusilla, Pacific gull Larus schistisagus, and Gray petrel Oceanodroma furcate) and marine mammals (Gray whales Eschrichtius robustus and Pacific walrus Odobenus rosmarus divergens) were measured by a GC–MS. The total concentration of OCPs in mammals was higher than in seabirds. Environmental biomonitoring with the use of seabirds and marine mammals, as a long-lived species, is used for global monitoring, since bioaccumulation in these organisms occurs throughout life. The environmental assessment of the Northwest Pacific marine ecosystems revealed that the levels of OCP contamination in this area are similar to the other subarctic regions of the World Ocean.

First Photographic Match of an Anomalously White Gray Whale (Eschrichtius robustus) in the Northeastern Chukchi Sea, Alaska, and Baja California, Mexico

First Photographic Match of an Anomalously White Gray Whale (Eschrichtius robustus) in the Northeastern Chukchi Sea, Alaska, and Baja California, Mexico

Characterization of the Gray Whale Eschrichtius robustus Genome and a Genotyping Array Based on Single-Nucleotide Polymorphisms in Candidate Genes.

Genetic and genomic approaches have much to offer in terms of ecology, evolution, and conservation. To better understand the biology of the gray whale Eschrichtius robustus (Lilljeborg, 1861), we sequenced the genome and produced an assembly that contains ∼95% of the genes known to be highly conserved among eukaryotes. From this assembly, we annotated 22,711 genes and identified 2,057,254 single-nucleotide polymorphisms (SNPs). Using this assembly, we generated a curated list of candidate genes potentially subject to strong natural selection, including genes associated with osmoregulation, oxygen binding and delivery, and other aspects of marine life. From these candidate genes, we queried 92 autosomal protein-coding markers with a panel of 96 SNPs that also included 2 sexing and 2 mitochondrial markers. Genotyping error rates, calculated across loci and across 69 intentional replicate samples, were low (0.021%), and observed heterozygosity was 0.33 averaged over all autosomal markers. This level of variability provides substantial discriminatory power across loci (mean probability of identity of 1.6 × 10-25 and mean probability of exclusion >0.999 with neither parent known), indicating that these markers provide a powerful means to assess parentage and relatedness in gray whales. We found 29 unique multilocus genotypes represented among our 36 biopsies (indicating that we inadvertently sampled 7 whales twice). In total, we compiled an individual data set of 28 western gray whales (WGSs) and 1 presumptive eastern gray whale (EGW). The lone EGW we sampled was no more or less related to the WGWs than expected by chance alone. The gray whale genomes reported here will enable comparative studies of natural selection in cetaceans, and the SNP markers should be highly informative for future studies of gray whale evolution, population structure, demography, and relatedness.

Bioindicators of Organochlorine Pesticides in the Sea of Okhotsk and the Western Bering Sea.

Organochlorine pesticides (OCPs), such as HCHs and DDTs, are still used as pesticides in the Southern Hemisphere and can reach the North Pacific due to long range atmospheric transfer. Marine mammals (Pacific walrus Odobenus rosmarus divergens, gray whale Eschrichtius robustus), the seabirds (Pacific gull Larus schistisagus, crested auklet Aethia cristatella, auklet crumb Aethia pusilla, northern fulmar Fulmarus glacialis, and grey petrel Oceanodroma furcata) and Pacific salmon (pink Oncorhynchus gorbuscha, chum O. keta, chinook O. tshawytscha, and sockeye O. nerka) were collected near the Kuril Islands (the northern-western part of the Pacific Ocean), in the Sea of Okhotsk and the Bering Sea. The total OCPs concentration (HCHs+DDTs) was found in each organism, including the Pacific walrus (70-90,263ng/g lipid), the seabirds (29-16,095ng/g lipid), and the Pacific salmon (41-7103ng/g lipid). The concentrations and possible sources of OCPs in marine organisms as biological indicators are discussed.

Nowhere to go: noise impact assessments for marine mammal populations with high site fidelity

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 32:391-413 (2017) - DOI: https://doi.org/10.3354/esr00820 Theme Section: 21st century paradigms for measuring and managing the effects of anthropogenic ocean noise Nowhere to go: noise impact assessments for marine mammal populations with high site fidelity Karin A. Forney1,*, Brandon L. Southall2,3,4, Elisabeth Slooten5, Steve Dawson6, Andrew J. Read4, Robin W. Baird7, Robert L. Brownell Jr.8 1Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, c/o MLML Norte, 7544 Sandholdt Rd, Moss Landing, CA 95039, USA 2Southall Environmental Associates, Inc., 9099 Soquel Dr, Suite 8, Aptos, CA 95003, USA 3University of California, Institute of Marine Science, Long Marine Laboratory, 100 McAllister Way, Santa Cruz, CA 95060, USA 4Nicholas School of the Environment, Duke University, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USA 5Department of Zoology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand 6Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9016, New Zealand 7Cascadia Research Collective, 218 1/2 4th Ave W, Olympia, WA 98501, USA 8Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 34500 Highway 1, Monterey, CA 93940, USA *Corresponding author: karin.forney@noaa.gov ABSTRACT: As awareness of the effects of anthropogenic noise on marine mammals has grown, research has broadened from evaluating physiological responses, including injury and mortality, to considering effects on behavior and acoustic communication. Most mitigation efforts attempt to minimize injury by enabling animals to move away as noise levels are increased gradually. Recent experiences demonstrate that this approach is inadequate or even counterproductive for small, localized marine mammal populations, for which displacement of animals may itself cause harm. Seismic surveys within the ranges of harbor porpoise Phocoena phocoena in California and Māui dolphin Cephalorhynchus hectori maui in New Zealand highlight the need to explicitly consider biological risks posed by displacement during survey planning, monitoring, and mitigation. Consequences of displacement are poorly understood, but likely include increased stress and reduced foraging success, with associated effects on survival and reproduction. In some cases, such as the Critically Endangered Māui dolphin, displacement by seismic activities risks exposing the remaining 55 dolphins to bycatch in nearby fisheries. Similar concerns about military and industrial activities exist for island-associated species such as melon-headed whales Peponocephala electra in Hawai'i; shelf-break associated species such as Cuvier’s beaked whales Ziphius cavirostris off the US Atlantic coast, and whales foraging in coastal habitats, such as the Critically Endangered western gray whale Eschrichtius robustus. We present an expanded framework for considering disturbance effects that acknowledges scientific uncertainty, providing managers and operators a more robust means of assessing and avoiding potential harm associated with both displacement and direct effects of intense anthropogenic noise exposure. KEY WORDS: Anthropogenic noise · Marine mammals · Impact assessment · Mitigation · Monitoring · Small populations Full text in pdf format PreviousNextCite this article as: Forney KA, Southall BL, Slooten E, Dawson S, Read AJ, Baird RW, Brownell RL Jr (2017) Nowhere to go: noise impact assessments for marine mammal populations with high site fidelity. Endang Species Res 32:391-413. https://doi.org/10.3354/esr00820 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 32. Online publication date: May 08, 2017 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2017 Inter-Research.

Matching of the Gray Whales of off Sakhalin and the Pacific Coast of Japan, with a Note on the Stranding at Wadaura, Japan in March, 2016

The coast of Japan is a migratory corridor for the western stock of the gray whales (Eschrichtius robustus), which was once considered as extinct and remains endangered. According to the historical records, from 1955 to 2014, only 21 gray whales occurrence has been recorded in 59 years. However, from 2015 to 2016, intensive occurrence including the seven sightings and the two strandings were noted. In this paper, we found that those sightings were re-sightings of the same individual, which was initially sighted off Sakhalin during August, 2014. On 4 March, 2016, a young female gray whale (8.9 m in body length) was stranded at Wadaura beach, Chiba prefecture. We also conducted research on this animal including taking pictures and external measurements. In addition, we flensed this animal to observe the internal organs and collect a skeletal specimen. The reason for the death of this animal remains unclear; however, from its external characteristics, we identified that this animal was not an identical one, sighted off Sakhalin and the coast of Japan from 2014 to 2016. On 5 April, 2016, another young female gray whale (7 m in body length) was stranded at Arai beach, Shizuoka prefecture. We concluded that from 2015 to 2016, at least three distinct gray whales have migrated along the coast of Japan.

Технохимическая характеристика органов и тканей серого кита Eschrichtius robustus

Chemical composition, content of protein, minerals, free amino acids and fatty acids in the muscles, heart, tongue, kidneys, liver, and lungs of California grey whale Eschrichtius robustus are examined. All eatable parts of the grey whale body are significantly watered (water content 78.5-80.5 %), with the minimum water content in the tongue and the maximum in the kidneys. The meat of grey whale has low lipid content and is similar to low-fat beef, lamb or horsemeat. All essential amino acids are presented in the proteins with slight differences in their content depending on localization. Lysine and leucine have the high level in all eatable parts of the whale (15.3-22.6 mg/g WW). The highest content of polyunsaturated fatty acids is found in the heart (36.49 %). The content of water-soluble protein varies from 17.9 % for the tongue to 57.9 % for the liver, the content of myofibrillar proteins in the meat, kidneys, tongue and heart ranges between 12.8-25.2 % but they are absent in the lungs and liver. Concentration of toxic elements (As and Cd) depends on localization, with the highest level in kidneys: As 0.42-2.80 mg/kg WW, Cd 0.05-1.22 mg/kg WW.