Abstract: As part of a long-term research program, Cook Inlet beluga (Delphinapterus leucas) presence was acoustically monitored with two types of acoustic sensors utilized in tandem in moorings deployed year-round: an ecological acoustic recorder (EAR) and a cetacean and porpoise detector (C-POD). The EAR was used primarily to record the calls, whistles, and buzzes produced by belugas and killer whales (Orcinus orca). The C-POD was used to log and classify echolocation clicks from belugas, killer whales, and porpoises. This paper describes mooring packages that maximized the chances of successful long-term data collection in the particularly challenging Cook Inlet environment, and presents an analytical comparison of odontocete detections obtained by the collocated EAR and C-POD instruments from two mooring locations in the upper inlet. Results from this study illustrate a significant improvement in detecting beluga and killer whale presence when the different acoustic signals detected by EARs and C-PODs are considered together. Further, results from concurrent porpoise detections indicating prey competition and feeding interference with beluga, and porpoise displacement due to ice formation are described.

Abstract: Socio-sexual and mating behaviors, to our knowledge, have not been previously documented among free-ranging beluga whales, Delphinapterus leucas, but they have been described in detail for captive belugas. We report on the fi rst photodocumented interaction and display of socio-sexual and apparent mating behavior of noncaptive beluga whales in Cook Inlet, Alaska. This behavior was seen on two different days in the same river mouth in uncharacteristically clear waters of upper Cook Inlet. On 24 April 2014, social and possible mating behaviors were observed and photographed for approximately 12 min within a group of nine adult beluga whales in the mouth of Middle River on the west central side of Cook Inlet. A total of 136 photographs were taken at a radial distance Introduction Socio-sexual behavioral interactions among free-ranging beluga whales, Delphinapterus leucas, have not been previously documented, to our knowledge, and are thus poorly understood. Although mating and social behaviors have been described for captive beluga whales (Hill et al., 2015), it is logistically diffi cult to observe undisturbed behavior among free-ranging beluga. They inhabit remote, and in the case of the Cook Inlet beluga whale (CIBW), typically muddy waters. Observations of socio-sexual behaviors of freeranging CIBW are needed to address critical information gaps on the natural history, mating behavior, and potential behavioral habitat preference of this declining insular population. Little is known about the mating behavior or mating season of beluga whales in the wild. Reported age of sexual maturity varies from 4 to 10 years for females and 8 to 15 years for males (Nowak, 1991; Suydam et al.1). Gestation is 14.0–14.5 months, with a single calf born in late spring or early summer (Sergeant, 1973). This would suggest mating occurs in early spring. In autumn, beluga whale populations migrate toward a few common wintering grounds in Bering Sea offshore waters characterized by unconsolidated pack ice where mating is believed to occur during late winter or early spring (Brodie, 1971; Sergeant, 1973; Brown Gladden et al., 1997). Unlike the Arctic stocks, the Cook Inlet beluga population is not thought 1Suydam, R., J. J. Burns, and G. Carroll. 1999. Age, growth, and reproduction of beluga whales from the eastern Chukchi Sea, Alaska. Paper presented to the Alaska Beluga Whale Committee workshop, March 30–April 1, 1999. 5 p. to undertake seasonal migrations outside of Cook Inlet (Laidre et al., 2000; Rugh et al., 2000). Specifi c breeding areas are unknown or possibly nonexistent (i.e. mating might occur anywhere throughout their range). Similar to Arctic beluga populations, CIBW calving is believed to occur in early summer (Hobbs et al., 2015a) although Native hunters have observed newborn CIBW calves from April through August (Huntington, 2000). Alaska natives described CIBW calving areas as the northern side of Kachemak Bay in April and May, off the Beluga and Susitna River mouths in May, and in Chickaloon Bay and Turnagain Arm during summer (Huntington, 2000). McGuire et al.2, during vessel-based surveys of the upper reaches of Cook Inlet in 2005–07, did not document any specifi c calving locations or a defi nitive calving season and calves were encountered in all surveyed location and months (April– October). Thus CIBW are reported to continue to calve later in the season than the Arctic stocks, although their calving season is unclear. In part, some confusion on calving dates may be a function of sightings of calves well into the summer that were actually born weeks or months earlier. Global observations of both wild and captive beluga whales indicate that breeding is seasonal. Among captive beluga whales, Robeck et al. (2005) reported that both testosterone in males and progesterone in females were elevated during late winter/ear2McGuire, T. L., C. C. Kaplan, M. K. Blees, and M. R. Link. 2008. Photo-identifi cation of beluga whales in upper Cook Inlet, Alaska. 2007 Annu. Rep. Prep. LGL Alaska Res. Assoc., Inc., Anchorage, AK, for Chevron, Natl. Fish Wildl. Found., and ConocoPhillips Alaska, Inc., 52 p. > 500 m. On 7 May 2014, similar behaviors were observed among four adult beluga whales in the same location for about 7 min. The second group was not photo-documented due to fl ight limitations. In both circumstances, affi liative behavioral events such as echelon and contact swimming, and socio-sexual behaviors such as ventrum-toventrum contact, ventral presentations, pelvic thrusting, nodding, and rubbing were observed. These behaviors resemble those previously reported for captive beluga mating behaviors and copulation. Similarities between these observations with captive mating behaviors, and the timing of ovulation and peak calving periods from other wild beluga populations, provide strong evidence that mating occurs during early spring months in Cook Inlet.

Abstract: This study uses an individual-based contaminant bioaccumulation model for marine mammals to explore factors controlling the transfer of PCBs from mother to calf via nursing in beluga from the St. Lawrence Estuary. Beluga blubber samples (n = 46), along with four matched milk samples from stranded animals over the 1986–1994 period were used for comparison with modelled results. Based on 68 POPs, including 48 PCBs and 20 other organochlorine compounds, milk:blubber ratios were 0.65 between log K OW 3–6.5, then decreased to 0.1 at log K OW 8. Model simulations based on this relationship indicated females were transferring PCBs that were relatively very hydrophobic and highly chlorinated less readily than their lower chlorinated counterparts, resulting in an enriched concentration of very hydrophobic congeners in nursing females relative to adult males. There was very good agreement between observed and modelled male:female PCB concentration ratios. Four females within our dataset (15 %) had male-like ΣPCB concentrations as well as male-like congener profiles, suggesting that these individuals may have had a reduced or limited nursing history.

Abstract: Carbon and nitrogen stable isotope ratios are ecological tracers that can provide insights into the diets of marine mammals. As a generalist predator, beluga whales (Delphinapterus leucas) consume a variety of prey; however, differences in lipid content and the presence of inorganic carbon in prey may cause variability in the δ13C signal that is not related to food sources. We examined the effects of carbonate and/or lipid removal in beluga and potential prey and tested whether the C:N ratio was a valid indicator of lipid content. The C:N ratio was a good predictor of the change in δ13C after lipid removal in capelin (Mallotus villosus), octopus (Cirroteuthis muelleri), green shrimp (Argis dentata), and circumpolar eualid (Eualus gaimardii). Despite relatively low C:N ratios, lipid removal significantly increased δ13C values, but also affected δ15N. Removal of carbonates from invertebrate samples significantly decreased δ13C values and had variable effects on δ15N. Overall, the variability in δ13C within a species decreased after removing lipids and carbonates. Variability in δ15N did not change for species requiring only lipid removal, but increased after acidification. We also evaluated the effect of these sample preparation methods on niche dispersion metrics. After lipid and carbonate treatments, centroid locations differed significantly in all species except beluga muscle, and niche breadth and mean distance to the centroid decreased. Failure to remove lipids and carbonates for δ13C values may lead to incorrect interpretations for isotopic niche, which may have major ecological implications, such as predicting the impacts of invasive species or determining the dietary linkages of beluga whales.

Abstract: Wild beluga whistle source levels (SLs) are estimated from 52 three-dimensional (3D) localized calls using a 4-hydrophone array. The probability distribution functions of the root-mean-square (rms) SL in the time domain, and the peak, the strongest 3-dB, and 10-dB SLs from the spectrogram, were non-Gaussian. The average rms SL was 143.8 ± 6.7 dB re 1 μPa at 1 m. SL spectral metrics were, respectively, 145.8 ± 8 dB, 143.2 ± 7.1 dB, and 138.5 ± 6.9 dB re 1 μPa(2)·Hz(-1) at 1 m.

Abstract: A workshop convened by C. Lockyer and A. A. Hohn to examine variation among readers in estimating beluga ages was held in Beaufort, North Carolina, US. Terms of Reference for the workshop included the following: 1. Provide a guide as to acceptable levels of accuracy and precision for age reading that will enable ages to be used in population models. 2. Conduct an inter-reader/laboratory comparison for calibration and standardization of age readings from GLG counts among all readers/laboratories. 3. Provide information on validation that will enable GLG counts to be translated to real age. 4. Produce a manual of guidelines for the preparation and reading of GLGs in beluga teeth. Presentations by participants are abstracted here. Then we report on the processes used to compare sections, images, and interpretation, and generate guidelines for best practices in beluga age estimation. A comparative study quantified differences among readers and found that precision of experienced readers was good, higher than reported for other odontocetes. Participants agreed that counting GLGs using well prepared thin sections was preferred because they are simpler to prepare than stained sections and there was more agreement among readers compared to using half sections. Examination of teeth from captive beluga as both untreated sections and stained sections and did not clarify the reading of wild beluga teeth. This Workshop concurred with Workshop 1 (Tampa 26-27 November 2011) that interpreting one GLG as an annual record is irrefutable. Guidelines for best practices were developed.

Abstract: The present study investigated the effects of prebiotic (α-mune), a mixture of mannan oligosaccharide, β-1,3 and β-1,6 glucan, on the growth performance, haematology and innate immunity of beluga sturgeon ( Huso huso ) juvenile. Fish (46±3 g) were allocated into 12 tanks (15 fish per tank) and triplicate groups were fed a control diet or diets containing 1.5, 3.0 and 4.5 g kg -1 prebiotic for 46 days. Fish fed 1.5 g kg -1 prebiotic displayed significantly higher final weight, specific growth rate and feed conversion ratio. WBC, RBC, MCV, MCH, haemoglobin, haematocrit and lymphocyte levels were also significantly higher in the fish fed 1.5 g kg -1 prebiotic. Furthermore, the highest haematocrit content and lymphocyte level were found in the fish fed a diet containing 1.5 g kg -1 prebiotic. Alternative complement activity (ACH50), lysozyme activity and Ig concentration were significantly higher in the fed 1.5 g kg -1 prebiotic. These results indicate that α-mune can be considered as a beneficial dietary supplement for improving the growth performance, haematological and immunological parameters of beluga sturgeon juvenile.

Abstract: To compare the reproductive performance of the wild and cultured stocks of beluga, Huso huso males, some spermatological parameters were measured including: sperm motility, sperm density, spermatocrit and also fertilization rate, hatching rate and larval growth and survival rates. The semen samples were sampled from 11 wild spawners and 12 cultured brooders. A half of each semen sample was allocated for spermatological analysis and remaining were used for artificial propagation. In wild beluga, sperm motility time was 339.09 ± 23.11 s; spermatozoa motility rate 83.64 ± 2.01%; sperm density 15.22 ± 3.46 ×109 and spermatocrit 5.88 ± 1.36% while in cultured beluga, sperm motility time was 199.35 ± 29.02 s; spermatozoa motility rate 74.22 ± 2.4 %; sperm density 8.37 ± 0.24 ×109 and spermatocrit 3.21 ± 0.29 %. The fertilization rate (%), hatching rate (%), larval growth (% g.day-1). and survival rate (%) in wild beluga were 61.72 ± 14.16, 43.33 ± 11.13, 12.28 ± 0.33 and 52.66 ± 7.77, while in cultured beluga were 49.98 ± 6.55, 31.47 ± 8.49, 12.28 ± 0.62 and 57.37 ± 7.89 respectively. The spermatozoa motility (the ratio and duration of motility) were significantly different between wild and cultured brooders (P 0.05).

Abstract: We examined the relationships between a number of sperm characteristics (motility, concentration and pH) and sperm fertility (egg fertilisation and hatching rate) in 10 mature females and four mature males of the beluga sturgeon, Huso huso. The fish were treated with luteinising hormone-releasing hormone agonists (LHRH- A2), at a dose of 5-10 µg/kg of body weight (BW) by injection into the muscle between the dorsal and lateral scutes. Significant linear relationships were found between sperm pH and fertilisation rate ( R 2 = 0.82, P < 0.01) and sperm pH and hatching rate ( R 2 = 0.75, P < 0.05). Highly negative relationships were also observed between sperm concentration and fertilisation rate ( R 2 =−0.71, P < 0.05) and sperm concentration and hatching rate ( R 2 = -0.83, P < 0.01). We suggest that understanding these correlations is critical in the evaluation of sperm quality and for the preparation of media (extender) for use in sperm dilution to improve sperm motility/fertility and therefore increase fertilisation success in beluga sturgeon production .

Abstract: The invention relates to an artificial breeding method of southern China beluga sturgeon. The method comprises the steps of 1, parent fish selection and winterization breeding; 2, parturition hastening and artificial insemination; 3, incubation management seedling emergency; 4, seedling breeding. The artificial breeding method has the advantages that the bred beluga sturgeon seedlings are high in fertilization rate and hatching rate (the insemination rate reaches 95% or above and the hatching rate reaches 90% or above) and have the advantages of being rapid in growth, large in adaptability, high in survival rate, high in stress resistance and good in other growth trait, has the higher economic benefits and is suitable for breeding of southern China beluga sturgeon.

Abstract: The invention relates to the field of beluga culture, particularly discloses a beluga artificial propagation method and application of a carp pituitary gland, and relates to a beluga artificial propagation method. The method comprises the steps that 1, nutrient enrichment culture is performed on a beluga milter parent and a beluga raun parent; 2, the beluga milter parent and the beluga raun parent obtained after nutrient enrichment culture are subjected to low temperature stimulation; 3, the water temperature is increased to the pre-spawning induction temperature, and spawning induction medicine administration is performed on the beluga milter parent and the beluga raun parent so as to be subjected to spawning induction; 4, free eggs and seminal fluid are collected to be subjected to artificial fertilization and incubation, wherein the spawning induction medicine is the carp pituitary gland. The invention further relates to application of the carp pituitary gland for beluga artificial propagation, and application of the carp pituitary gland for preparing medicine for artificial propagation of beluga. The beluga spawning induction medicine is easy to obtain and prepare, the spawning induction rate of spawning induction propagation performed by adopting the beluga spawning induction medicine is high, the fertilization incubation effect is good, and the postpartum parent fish survival condition is good.

Abstract: ![Figure][1] Beluga mother and calf. Photo credit: Shedd Aquarium/Brenna Hernandez. In the icy waters of the Arctic Ocean, a beluga mother gently noses her newborn to the surface for its first breath. These ocean-going mammals are as dependent on air as we are, and must visit the surface

Abstract: Climate change is expected to impact Arctic marine mammals, as they may be particularly vulnerable to large annual variability in the environment. Beluga whales (Delphinapterus leucas) occupy the circumpolar Arctic year-round, and seasonal movement patterns in this landscape are closely linked to sea ice and changing conditions. Here, we examine the association between beluga spring locations along the Mackenzie Shelf and three relevant habitat variables: sea ice (total concentration, floe size, and distance to ice edge), bathymetry and turbidity. Beluga locations in 2012 and 2013 were analyzed across the study area, as well as in three discrete subareas of the Mackenzie Shelf: Shallow Bay, Kugmallit Bay and Tuktoyaktuk Peninsula. In both years, beluga were found more than expected by chance in locations of open water/light ice concentrations and medium ice floes, and displayed a significant association with turbid water (i.e., increased freshwater flow). Largely ice-free conditions in 2012 led to a wide variation in habitat use in all three subareas. Beluga whales in 2012 preferred the ice edge and were found in heavier ice concentrations, larger floes and high turbidity water in the Shallow Bay subarea. Open water environments were preferred by beluga found in the Kugmallit Bay subarea. In contrast, heavy ice conditions in 2013 resulted in restricted habitat use and selection of shallow depth (<50 m) and low levels of turbidity. These results provide knowledge on spring habitat selection as well as insight into the adaptability of beluga under expected changes associated with climate and human activity in the Beaufort Sea.

Abstract: High trophic level arctic beluga whales (<i>Delphinapterus leucas</i>) are exposed to persistent organic pollutants (POP) originating primarily from southern latitudes. We collected samples from 43 male beluga harvested by Inuvialuit hunters (2008–2010) in the Beaufort Sea to evaluate the effects of POPs on the levels of 13 health-related gene transcripts using quantitative real-time polymerase chain reaction. Consistent with their role in detoxification, the aryl hydrocarbon receptor (<i>Ahr</i>) (<i>r</i>² = 0.18, <i>p</i> = 0.045 for 2008 and 2009) and cytochrome P450 1A1 (<i>Cyp1a1</i>) (<i>r</i>² = 0.20, <i>p</i> < 0.001 for 2008 and 2009; <i>r</i>² = 0.43, <i>p</i> = 0.049 for 2010) transcripts were positively correlated with polychlorinated biphenyls (PCBs), the dominant POP in beluga. Principal Components Analysis distinguished between these two toxicology genes and 11 other genes primarily involved in growth, metabolism, and development. Factor 1 explained 56% of gene profiles, with these latter 11 gene transcripts displaying greater abundance in years coinciding with periods of low sea ice extent (2008 and 2010). δ¹³C results suggested a shift in feeding ecology and/or change in condition of these ice edge-associated beluga whales during these two years. While this provides insight into the legacy of PCBs in a remote environment, the possible impacts of a changing ice climate on the health of beluga underscores the need for long-term studies.

Abstract: An isolated population of beluga (Delphinapterus leucas) inhabits the St Lawrence Estuary, Quebec, Canada. This population has failed to recover despite the prohibition of hunting >30 years ago, suggesting the presence of other limiting factors. The authors summarize the reported causes of death and propose risk factors to explain the lack of recovery of this population. From 1983 to 2012, a total of 472 beluga were found stranded. Complete necropsies were carried out on 222 beluga, including 178 adults, 25 juveniles, and 19 newborn calves. Infectious diseases, the most prevalent cause of mortality in this population, accounted for the death of one-third of all beluga (32%). Verminous pneumonia was the cause of mortality of 13 juvenile beluga (52% of juvenile beluga). A total of 39 malignant neoplasms, diagnosed in 35 beluga, caused the death of 31 beluga (20% of beluga >19 years old). Median age at diagnosis of cancer was 48 years (range, 30-61 years). Dystocia and postpartum complications were the cause of death in 18 beluga, accounting for 19% of the females >19 years old examined. The occurrence of parturition-associated complications, as well as mortality of calves <1 year old, have increased recently in this population and may be the probable cause of the recent decrease in the size of this population. One of the hypotheses proposed to explain the unusually high occurrence of some of the pathologic conditions observed in this population is chronic exposure to environmental contaminants.

Abstract: Individual specialization (IS), where individuals within populations irrespective of age, sex, and body size are either specialized or generalized in terms of resource use, has implications on ecological niches and food web structure. Niche size and degree of IS of near-top trophic-level marine predators have been little studied in polar regions or with latitude. We quantified the large-scale latitudinal variation of population- and individual-level niche size and IS in ringed seals (Pusa hispida) and beluga whales (Delphinapterus leucas) using stable carbon and nitrogen isotope analysis on 379 paired ringed seal liver and muscle samples and 124 paired beluga skin and muscle samples from eight locations ranging from the low to high Arctic. We characterized both within- and between-individual variation in predator niche size at each location as well as accounting for spatial differences in the isotopic ranges of potential prey. Total isotopic niche width (TINW) for populations of ringed seals and beluga decreased with increasing latitude. Higher TINW values were associated with greater ecological opportunity (i.e., prey diversity) in the prey fish community which mainly consists of Capelin (Mallotus villosus) and Sand lance (Ammodytes sp.) at lower latitudes and Arctic cod (Boreogadus saida) at high latitudes. In beluga, their dietary consistency between tissues also known as the within-individual component (WIC) increased in a near 1:1 ratio with TINW (slope = 0.84), suggesting dietary generalization, whereas the slope (0.18) of WIC relative to TINW in ringed seals indicated a high degree of individual specialization in ringed seal populations with higher TINWs. Our findings highlight the differences in TINW and level of IS for ringed seals and beluga relative to latitude as a likely response to large-scale spatial variation in ecological opportunity, suggesting species-specific variation in dietary plasticity to spatial differences in prey resources and environmental conditions in a rapidly changing ecosystem.

Abstract: Genetic profiling links changing sea ice to shifting beluga whale migration patterns - supplementary material

Abstract: Caspian biodiversity protection is mainly focused on the recovery of a few valuable commercial species such as beluga (Huso huso Linnaeus), Russian sturgeon (Acipenser gueldenstaedtii Brandt), Persian Sturgeon (Acipenser persicus Borodin), Ship Sturgeon (Acipenser nudiventris Lovetsky) and stellate sturgeon (Acipenser stellatus Pallas) and Caspian Salmon (Salmo trutta caspius Kessler) which are currently endangered. Apart from these species, biodiversity change and especially habitats destruction are poorly traced and managed in the region. The Caspian genetic biodiversity is insufficiently known and restocking programmes have hardly taken into consideration the need to protect it.

Abstract: Genetic profiling links changing sea ice to shifting beluga whale migration patterns.

Abstract: Genetic profiling links changing sea ice to shifting beluga whale migration patterns - Supplementary Material

Abstract: Polybrominated diphenyl ethers (PBDEs) were determined in blubber samples of 54 stranded adult beluga whales (<i>Delphinapterus leucas</i>) collected between 1988 and 1999 in the St. Lawrence Estuary (SLE), Quebec, Canada. Summed concentrations of 10 PBDE congeners (∑PBDEs) measured in beluga samples varied between 20 and almost 1000 ng/g wet weight. According to the PBDE concentrations in marine mammals reported in the scientific literature, SLE belugas appear to be relatively lightly contaminated. Only a few predominant congeners (namely, PBDE-47, -99, and -100) represent on average more than 75% of ∑PBDEs in SLE belugas. The accumulation of ∑PBDEs in both male and female belugas showed significant exponential increase throughout the 1988−1999 time period. The time necessary for beluga to double their blubber concentration of the most prevalent PBDE congeners was no longer than 3 years. The PBDE temporal changes reported in this study are generally faster but in agreement with the trend observed in other organisms collected in Canada, such as lake trout (<i>Salvelinus namaycush</i>) from the Great Lakes, ringed seal (<i>Phoca hispida</i>), and beluga whale from the Canadian Arctic. Some changes in the pattern of PBDEs in belugas were also observed during the time period investigated. The recent and important increase of PBDE levels in SLE belugas could explain the unexpected lack of statistical difference in PBDE contamination between males and females. This suggests that to date PBDEs tend to be accumulated by both male and female belugas, masking the elimination of PBDEs by females through post-natal transfer to their offspring. This study confirms that the growing use of PBDEs as flame retardants has resulted in rising contamination of Canadian aquatic environments. Additional studies are needed to assess the toxicological implications of the PBDE tissue levels found in SLE belugas.

Abstract: Visual lateralization during observation of a novel object was studied in beluga whale (Delphinapterus leucas) under natural conditions. As a novel object we used the underwater video camera, which simultaneously recorded whale behaviour. Video camera was placed on the bottom in the area of the beluga summer mating aggregation. After appearance of the novel object in the environment belugas demonstrated exploratory behavior: closely approached to the object and observed it monocularly. Belugas were found to possess visual lateralization on a group level during perceiving of the novel object. While observing it, whales used the left eye significantly more frequently and for a longer time, demonstrating the contralateral (right) hemisphere dominance in recognition of novel stimuli.

Abstract: Genetic profiling links changing sea ice to shifting beluga whale migration patterns - Tables SM1 and SM2