Abstract: This study found that arctic beluga whales (Delphinapterus leucas) transferred, on average, 11.4% (7.5 mg) and 11.1% (0.1 mg) of their polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) blubber burden to their near-term fetuses. A single physicochemical parameter, log KOW, largely explained this transplacental transfer for PCBs (r2 = 0.79, p < 0.00001) and PBDEs (r2 = 0.37, p = 0.007), with congeners having a log KOW < 6.5 preferentially transferred to the fetus. Blubber concentrations of 257 ng/g lipid weight (lw) PCBs and 3.8 ng/g (lw) PBDEs in beluga fetuses highlights the exposure to endocrine-disrupting compounds during a critical developmental stage. The implications of detecting these levels of legacy PCBs and the flame retardant PBDEs in unborn arctic beluga are unclear. Environ. Toxicol. Chem. 2012;31:296–300. © 2011 SETAC

Abstract: In response to the critically low numbers of beluga whales Delphinapterus leucas in Cook Inlet, Alaska, USA, the US federal government listed this isolated population as endangered in 2008. Despite the curtailment of subsistence hunting in 1999, the abundance of Cook Inlet bel- ugas has remained low (<400 whales), with no obvious signs of recovery. As habitat is a critical component of population viability, our goal was to identify habitat selected by beluga whales. We developed predictive habitat models from the distribution and group size of beluga whales observed between 1994 and 2008. We fit a 2-part hurdle model to describe the physical and anthropogenic factors that influence (1) beluga presence (mixed model logistic regression) and (2) beluga count data (mixed model Poisson regression). Beluga presence was negatively associated with sources of anthropogenic disturbance and positively associated with fish availability and access to tidal flats and sandy substrate. Beluga group size was positively associated with tidal flats and proxies for seasonally available fish. We produced habitat maps for beluga presence, group size, and the expected number of belugas in each 1 km 2 cell of Cook Inlet. These maps dis- tinguish suitable habitat which could prove integral to the sustainability and recovery of the Cook Inlet beluga whale population.

Abstract: The present study aimed to investigate the effects of dietary nucleotide on serum biochemical and hematological parameters as well as stress response in Beluga sturgeon Huso huso juveniles. Fish (12.6 ± 0.5 g) were fed diets containing 0%, 0.15%, 0.25%, 0.35%, and 0.50% nucleotide over a 62-day period. The experiment was carried out in 600-L tanks with 30 fish per tank. Fish were fed five times a day until apparent satiation. At the end of the experiment, blood samples were collected from treatments for investigation of biochemical and hematological parameters. Then, fish were subjected to an acute stress. Blood samples were collected at 0 and 6 h post stress, and plasma cortisol and glucose levels were determined. The results showed that total protein, cholesterol, triglycerides, albumin, and globulin were not affected by dietary nucleotide (P > 0.05). Hematocrit and hemoglobin values were significantly higher in the 0.35% treatment compared to those of the control (P < 0.05). Beluga juveniles fed 0.5% dietary nucleotide had a significantly lower hemoglobin value (P < 0.05). Lymphocyte proportion was significantly higher in the 0.25 and 0.35 nucleotide groups than in the control group (P < 0.05). Cortisol and glucose levels in all groups were significantly affected by time; nevertheless, in fish fed nucleotides, stress-induced cortisol elevation was lower compared to that of the control group (P < 0.05). The results indicated that dietary nucleotide supplementation was capable of affecting hematological parameters and physiological stress responses of Beluga juveniles.

Abstract: Migratory connectivity between areas frequented by wide-ranging animals provides crucial information for conservation and management. In and around Hudson Bay (Canada), three stocks of beluga whales (Delphinapterus leucas) are associated with distinct summering areas. We analyzed genetic variation at mtDNA and 13 microsatellite loci among individuals (N > 1400) harvested by 23 Inuit communities to identify mating units and assess temporal and spatial differences in the way stocks use common migratory pathways. Strong structure at mtDNA and a lack of convincing evidence for nuclear genetic differentiation indicate that both males and females adopt distinct migratory routes towards summering grounds while probably interbreeding on wintering grounds. Spatiotemporal variation in stock composition indicates that subsistence hunting targets all three stocks. While representing ca. 5% of belugas in Hudson Bay, the endangered Eastern Hudson Bay stock accounts for 17% of the overall subsistence harvest by Inuit communities of northern Nunavik (Quebec), and ca. 30% of the spring harvest along northeastern Hudson Bay. Despite interbreeding, cultural conservatism of maternally transmitted migration routes seems to prevent the re-establishment of stocks in previously frequented estuaries. This phenomenon supports the current use of demographic population models based on stock composition for developing behavior-based management strategies.

Abstract: During the course of our studies of in-use chlorinated flame retardants, such as Dechlorane Plus® and Dechloranes 602 and 604, blubber of beluga whales from the Canadian Arctic and lake trout and whitefish from the North American Great Lakes were found to contain two novel dechlorination products of Dechlorane 602 (Dec602). The structures of these compounds were characterized by experiments performed using both gas chromatography–high resolution mass spectrometry and Fourier transform mass spectrometry with a prepared technical mixture of monohydro and dihydroDec602 derivatives. These Dec602 derivatives are analogous to the well-known monohydro and dihydro photochemical degradation products of Mirex. The ratio of the two monohydroDec602 diastereomers varied between Lake Ontario fish and those from the upper lakes, but only one isomer was found in Arctic beluga, indicating that one isomer is either more stable or more bioaccumulative. Dechlorane Plus®, Dec603, and Dec 604 were not detected in Arctic beluga, but Dec602 and its monohydroDec602 derivative were measured in approximately equal concentrations, ranging from 25 to 300 pg/g lipid. In Great Lakes fish, concentrations of the monohydroDec602 derivatives were also close to those of Dec602, ranging from 2 to 67 ng/g lipid and were greatest in Lake Ontario. This study reports on the first measurements of dechlorane-related compounds in Arctic biota and the first detection of monohydroDec602 degradation products and their accumulation in biota.

Abstract: The development of high-performance tracking and analytical tools has greatly facili- tated the study of animal movements, which, in turn, are increasingly employed to study habitat use. However, data on individual movements are rarely available at both broad spatial and temporal scales, limiting their utility for the study of habitat use at population levels. In this study, we propose a novel approach to investigate habitat profitability and population residency patterns by combining the analysis of fine-scale tracking data from individual animals with coarser, short- term movement patterns of herds. We used this approach to identify areas of high residency (AHR) for the St. Lawrence beluga whale Delphinapterus leucas, a population classified as 'threatened' under the Canadian Species At Risk Act. We used radio telemetry and a first passage time approach to study the fine-scale daily movements of 30 belugas. Information obtained from these animals on variation of search effort during displacements, scales at which area-restricted search (ARS) oc- curred, and associated swimming speeds was used to grid our study area and define a criterion for high residency of beluga herds. The beluga herd database used to identify AHR was composed of 772 visual 'herd follows' covering a large portion of the beluga population summer distribution. Thirty-three ARS zones were identified at 2 different spatial scales (~500 m and ~1500 m). Using these scales and the swimming speeds associated with ARS to study the residency of herds resulted in the identification of 28 AHRs used by beluga within their summer distribution.

Abstract: The results are presented that have been obtained during long-term studies (1991–2009) on the efficiency of natural reproduction of the beluga, Russian sturgeon, stellate sturgeon, and sterlet in different spawning zones of the Volga. The influence of major environmental factors on the formation of the offspring of these fishes is analyzed. It is shown that the productivity of Volga spawning grounds varies depending on the river flow volume during spring floods and the abundance of active spawners. Practical recommendations are proposed for enhancing sturgeon reproduction in the Volga.

Abstract: Harvest and global climate change are among the major ongoing threats to most Arc- tic marine mammal populations. Affected by commercial hunting in the past, beluga whales Del- phinapterus leucas are still harvested for subsistence in many coastal areas of the Canadian Arc- tic, while ongoing climate changes are suspected to modify factors that may have determined the distribution and degree of interaction of the different populations. Although several populations have been clearly identified, the global discreteness of the Arctic metapopulation is not yet clearly established. In this study, seasonal diving activity and movement patterns of 46 belugas from 2 neighbouring groups in Hudson Bay (Canada) were analysed in relation to physical environmen- tal characteristics and revealed significantly different migratory and habitat use patterns. Likely affected by local environmental conditions, the Eastern Hudson Bay beluga migrate, while the James Bay beluga remain resident, suggesting little overlap between the groups at all times of the year. This study provides useful baseline data for determining population interactions and habitat use. The information is also potentially useful in identifying critical habitat, which is an essential component to design and implement management and conservation policy, e.g. quota and har- vesting regulations and the design of marine protected areas.

Abstract: In order to have a sustainable management on Persian sturgeon as a highly commercial species in the South Caspian Sea, we need to identify its population structure and the level as well as its conservation status in their natural habitat. To develop a conservation program for this all Caspian Sea' sturgeon species it requires knowledge of its genetic diversity using reliable molecular marker to study population genetic structure. For these purposes, an enriched library was prepared based on a modified biotin-capture method. Approximately 1800 positive clones were screened for microsatellites in an Acipenser persicus genomic library. Of these 350 positively hybridizing clones were sequenced, and 81 clones were identified as having microsatellites with adequate flanking regions. We developed and tested 68 microsatellite primer pairs for Persian sturgeon. Out of 68 primer pairs developed, 11 pairs resulted in poor or no amplification, 13 were ambiguous, 6 were monomorphic, 20 were tetrasomic and 18 were octosomic in Persian sturgeon. While none of the markers showed disomic inheritance in Persian sturgeon and Russian sturgeon (A. gueldenstaedtii). Several of the markers appeared useful for studies stellate sturgeon (A. stellatus), ship sturgeon (A.nudiventris) and beluga (Huso huso). Nearly all the polymorphic pattern for ship, stellate and beluga displayed the simple banding patterns characteristic of disomic loci, while those for Russian sturgeon displayed banding patterns characteristic of tetraploid or higher polyploid levels. These markers may prove useful in a variety of future sturgeon population genetic studies in the Caspian Sea.

Abstract: Based on the data from long-term research in 1999–2009 we studied the population dynamics of Beluga whales in the Solovetsky reproductive gathering (RG) in the White Sea. This aggregation of Beluga whales is formed each year in the second half of May after the break-up of fast ice and persists to September inclusive. The aggregation numbers about 100 individuals from visual observations, with long-term variations of 20–30 individuals. The percentage of whales of different age groups also varied in the gathering depending on year, but typically one half was formed by mature animals and the other half consisted of immature whales and yearlings. There are two pronounced peaks in numbers for the summer season in the Solovetsky Beluga RG. The number of Belugas increased with the appearance of males and females that were ready to breed and females that were ready to bear calves. The daily dynamics of Belugas in the gathering largely depended on the time of day and tidal regime. In the summer season, the state of the sea and human impacts were key factors in number fluctuations of the Belugas of the Solovetsky RG. The revealed negative correlation of the long-term population of Belugas in the gathering on air temperature is considered as a special instance of general laws of the migration activities of Beluga whales in the White Sea.

Abstract: Ice edges and polynyas have long been noted for their high biological productivity within the Arctic environment. In June 2008, an aggregation of belugas and bowheads was identified at the Franklin Bay ice edge in the eastern Beaufort Sea, adjacent to the Cape Bathurst polynya. We conducted five ice-edge surveys by helicopter to study the distribution and behaviour of the whales. Bowheads were sighted in significantly shallower water than belugas. In addition, we used the helicopter platform to observe behaviour. Belugas and bowheads were engaged in directed travel and diving near and under the ice. Five beluga dives were timed and found to have an average duration of 106 ± 61 s (± SD) and a range of 30 – 197 s. One bowhead under-ice dive was timed and had a duration of 417 s. The under-ice dives are consistent with feeding behaviour observed for belugas and bowheads in other ice-edge locations. We hypothesize that higher prey densities along the Franklin Bay ice edge than in the adjacent open water may attract belugas and bowheads to the ice edge in June. Further research is needed to identify the abundance and type of prey species consumed and to assess the relative energetic importance of spring ice-edge feeding to the eastern Beaufort Sea beluga and bowhead populations.

Abstract: Concentration levels of 16 polycyclic aromatic hydrocarbons (PAHs) consisting of naphthalene, acenaphthylene, acenaphthene, fluorine, phenantherene, anthracene, fluor?anthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)p?yrene, dibenzo(a,h)ant?hracene, indeno(1,2,3-cd) pyrene and benzo(g,h,i)perylene were measured in water and sediment samples collected from the southern Caspian Sea coasts at four stations of Noshahr, Freydoonkenar, Sari and Amirabad during autumn, winter and spring of 2005-2006. Also, tissue samples from five sturgeon species including stellate sturgeon, Persian sturgeon, beluga, Russian sturgeon and ship sturgeon were obtained. Samples were analyzed by gas chromatography after the extraction process and the obtained data were statistically analyzed using one-way ANNOVA analysis at confidence level 95%. The mean concentrations of PAHs in water and sediment samples were in the range of 0.004-2.946 mgl-1 and 0.024-2.336 ?g g-1, respectively. No significant difference was seen in the mean concentrations of PAHs among stations and seasons of the examined samples. Also, mean concentration of PAHs in the liver, muscle, gill, kidney and gonad five of sturgeon species was 0.81-1.34 ?gg-1. The results of this study show that the levels of PAHs in water, sediment and sturgeon organs were below the acceptable levels of PAHs for the south Caspian Sea coastal regions.

Abstract: An 8-week feeding experiment was carried out on beluga ( Huso huso) juvenile to evaluate the effects of different levels of fish oil containing n-3 highly unsaturated fatty acids (n-3 HUFAs) on fish growth and fatty acid composition The requirements of beluga juvenile for n-3 HUFAs were studied by feeding fish diets containing six different levels of n-3 HUFAs ranging from 156 to 1725% (% of total fatty acids) Weight gain, feed conversion ratio, condition factor, specific growth rate and protein efficiency ratio were not significantly different among dietary treatments, nor was the body composition (including: moisture, protein, lipid and ash) of beluga juvenile (P> 005) There were no significant differences among plasma protein, glucose, cholesterol and triglyceride contents of dietary treatments (P> 005) However, haematocrit values were significantly lower in diets 1 and 2 (P< 005) The fatty acid composition of fish showed a pronounced change from the initial carcass with fatty acid composition changes in experimental diets The fatty acid composition of the beluga carcass fed on diets containing various levels of n-3 HUFAs reflected the dietary fatty acid composition The n-3 HUFAs contents of the lipids of fish increased with an increase in dietary n-3 HUFAs levels Results suggested that minimum levels of n-3 HUFAs in diet have no effect on growth and n-3 HUFAs are not a restrictive factor on growth in beluga

Abstract: This study is to evaluate the impacts of two levels of fat on the fish growth, feed intake, and compositions of muscle, liver, and viscera on the juvenile Huso huso. There were four treatments: two experimental diets (high-fat: 30% and low-fat: 15%) and two feeding levels (100 or 60% of satiation). The treatments were assigned to 16 tanks each with 15 fish, with four replicates for each treatment. Beluga sturgeon juveniles with an initial weight of 61.3 ± 4.4 g were reared for 3 months. Increasing fat content of the diets resulted in an increased final weight (621.8 vs. 467.5 g for high-fat and low-fat diets, respectively, at 100% feeding level; p 0.05). Total feed intake was increased by the use of high-fat diet (487.8 vs. 365.0 g for high-fat and low-fat diets, respectively, at 100% feeding level; p < 0.01). Results also showed no interactions between fat level of the diets and feeding level in final weight and FCR. Beluga sturgeon muscle and liver fed high-fat diets contained higher fat than those fed low-fat diets (186.5 and 329.6 vs. 144.1 and 261.9 g kg−1 for high-fat and low-fat diets, respectively, at 100% feeding level; p < 0.01), and feeding levels did not change protein content of the examined organs. In conclusion, beluga sturgeon shows an enhanced growth on high-fat diet, and feed intake does not reduce by the use of high-fat diets.

Abstract: Almost all cetaceans have a dorsal fin, which acts as a surface to control attitude and prevent roll, yaw, and side-slip (Fish 2002, 2004). Among odontocetes, only right whale dolphins (Lissodelphis), the finless porpoise (Neophocaena), and both members of Monodontidae, the beluga or white whale (Delphinapterus) and narwhal (Monodon), lack a dorsal fin. Both Delphinapterus (whose generic name refers to its absence of a fin) and Monodon possess, like Neophocaena, an irregular, notched dorsal ridge running along the caudal portion of the back (Struthers 1895, Brodie 1989, Hay and Mansfield 1989), but the low (4–5 cm high) dorsal ridge of monodontids (also called a cuticular crest by Kleinenberg et al. 1964) appears insufficiently large to act as a suitable hydrodynamic control surface on these 4–5 m long odontocetes. Based on kinematic analysis of locomotion in captive and wild beluga whales and dissection of abdominal musculature of Delphinapterus, we present a previously undescribed morphological feature that we believe allows belugas to enhance vertical stabilization and especially to control roll during turns and during swimming while in a partially rotated or wholly inverted position. This stabilization involves a pair of distinct fat (blubber) pads running longitudinally along the ventrolateral aspect of the abdomen, parallel to the dorsal ridge. These pads form large, elevated ridges that can be seen clearly (Fig. 1–3) in various views of Delphinapterus. The ventrolateral fat pads are in line with the pectoral flippers and extend from just caudal of the axilla to the level of the pelvic bones. The abdominal fat comprising the elevated ridges does not consist of discrete, paired bodies of isolated, encapsulated adipose tissue (as in the mandibular fat body of odontocetes). Rather, it involves a pair of unusually thick, longitudinal blubber deposits; it entails more than mere bulging of uniformly thick abdominal blubber. We contend that during some swimming maneuvers (inverted swimming, longitudinal rolls, and whole body turns), the fat pads formed by these markedly thickened blubber deposits are tensed and raised by abdominal muscles to form a pair of large, rounded erect structures (elevated 10–14 cm higher than the adjacent trunk and tailstock; 107–119 cm in length and 8–12 cm in width, averaging roughly 128 cm2 in area), often including a focal bulging of the ridges near their caudal terminus which results in fin-like protuberances surrounding a crater-like, semicircular depression on the ventral surface of the animal (estimated at up to 16 cm deep; Fig. 3). Based on our qualitative and quantitative kinematic

Abstract: Co-feeding of fish larvae with live food and formulated diet has been at the focus of fish nutritionists since last decade. In this study we tried to refine the feeding practices of great beluga sturgeon (Huso huso) larvae using different combinations of newly hatched Artemia urmiana nauplii and trout starter diet. Three replicate groups (250 fish/replicate) of firstfeeding Huso huso larvae were fed on the basis of four main feeding regimens: (1) live food (live nauplii of brine shrimp Artemia urmiana); (2) indirect transition (5 days live food followed by gradual transition to formulated diet); (3) direct transition (using different combinations of live and formulated diet from start feeding); (4) formulated feed (FD). It was found that combining live food and manufactured diets (co-feeding) from first feeding stage (direct transition) significantly improves the weight gain in H. huso larvae followed by indirect transition, live food and FD. But survival was significantly higher in larvae fed on pure live food and direct transition regimens compared to indirect transition and FD. It was concluded that co-feeding of H. huso could be started immediately from commencement of exogenous feeding.

Abstract: In recent years, production of fossil fuel in Caspian sea has increased. The aim of the present study was to investigate acute effects of diesel oil as potential dangerous additives and to assess mortality effects of these petroleum products on valuable species of this large lake. Juveniles of Huso huso were exposed to the crude diesel oil (0, 10, 20, 40, 100, 500 and 1000 ppm). The median lethal concentration (LC50) was determined with probit analysis. The results showed 100% mortality after 48 h in 500 and 1000 ppm, after 72 h in 100 ppm and after 96 h in 40 ppm. LC50–96 h was 24.80 + 0.23 ppm. Our results confirmed sensitivity of Beluga to low diesel oil doses.

Abstract: The National Marine Fisheries Service (NMFS) conducted aerial surveys of the beluga population in Cook Inlet, Alaska, from 29 May to 7 June 2012 as a continuation of surveys conducted since 1993. Six of the days in 2012 resulted in complete surveys of the beluga habitat in the upper inlet (north of East Foreland and West Foreland); and three days included surveys of the lower inlet. One other survey day included an incomplete survey of the upper inlet that was cut short due to poor weather conditions. During the six surveys of the upper inlet, 30 beluga groups were observed, and up to 11 counting passes were made per group. This season there was a fairly typical presentation of beluga groups, with two or more large groups in the Susitna area and a few smaller groups in Chickaloon Bay and Turnagain Arm. A beluga group was also observed just south of West Foreland headed toward Trading Bay where this group remained (near the mouth of the McArthur River) for the duration of the survey period. This is the first time belugas have been found consistently in Trading Bay since the July 1995 survey. No beluga groups were found in Knik Arm, or elsewhere in Cook Inlet. The estimated abundance for June 2012 is 312 (CV = 0.13, 95% CI: 242 to 402, Nmin = 280) with a ten-year trend (2002-2012) of -0.6% per year (SE = 1.1%). The trend since the management of the hunt began in 1999 (i.e. 1999-2012) is -1.3% per year (SE = 0.8%).

Abstract: Diesel oil is one of the most dangerous pollutions of oil resource in marine environment. During this toxicity test, juveniles of beluga were exposed to the acute doses (5, 10, 20, 40, 100, 500 and 1000 ppm) of direct infusion crude diesel oil for 0 h, 48 h and 7 days. The results showed that during 48 h exposure, except protein all biochemical indices showed significant change (p 0.05). The result also showed increased glucose and decreased triglyceride and calcium within the crude diesel oil adjacency. Furthermore, 7-day exposures show that all biochemical indices indicated significant change (p 0.01) and that glucose, calcium and protein increased and triglyceride decreased within the crude diesel oil adjacency.

Abstract: The accumulations of Cd, Pb and Zn were determined in edible and inedible tissues of Persian sturgeon (Acipenser persicus; n = 27), stellate sturgeon (Acipenser stellatus; n = 5) and beluga (Huso huso; n = 4) collected from coastal waters of the South Caspian Sea from March to April 2011. Concentrations of metals evaluated in the caviar, muscle, liver, kidney, gills, ovary and heart of the three species of sturgeons have been assessed using the flame and graphite furnace atomic absorption spectrophotometer. Concentrations of Zn, Pb and Cd in the edible and inedible tissues were apparently different among the three species of sturgeons. Especially, beluga heart showed the highest concentrations of Zn and Pb and Cd in Persian sturgeon liver. The analyzed metals were found in the caviar and muscle samples of Persian sturgeon and likewise muscle samples two other sturgeon species at mean concentrations under the permissible limits proposed by MAFF (2000).