Kamchatka Research Institute of Fisheries and Oceanography

Petropavlovsk-Kamchatskiy, Russia

Kamchatka Research Institute of Fisheries and Oceanography

Petropavlovsk-Kamchatskiy, Russia

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PubMed | University of Washington, State Nature Reserve Komandorsky, TRL Wildlife Consulting NMML retired, Russia; North Pacific Wildlife Consulting LLC and 6 more.
Type: Journal Article | Journal: PloS one | Year: 2015

After a dramatic population decline, Steller sea lions have begun to recover throughout most of their range. However, Steller sea lions in the Western Aleutians and Commander Islands are continuing to decline. Comparing survival rates between regions with different population trends may provide insights into the factors driving the dynamics, but published data on vital rates have been extremely scarce, especially in regions where the populations are still declining. Fortunately, an unprecedented dataset of marked Steller sea lions at rookeries in the Russian Far East is available, allowing us to determine age and sex specific survival in sea lions up to 22 years old. We focused on survival rates in three areas in the Russian range with differing population trends: the Commander Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery) and the Kuril Islands (four rookeries). Survival rates differed between these three regions, though not necessarily as predicted by population trends. Pup survival was higher where the populations were declining (Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island rookeries. The lowest adult (> 3 years old) female survival was found on Medny Island and this may be responsible for the continued population decline there. However, the highest adult survival was found at Kozlov Cape, not in the Kuril Islands where the population is increasing, so we suggest that differences in birth rates might be an important driver of these divergent population trends. High pup survival on the Commander Islands and Kamchatka Coast may be a consequence of less frequent (e.g. biennial) reproduction there, which may permit females that skip birth years to invest more in their offspring, leading to higher pup survival, but this hypothesis awaits measurement of birth rates in these areas.


Solovieva N.,University College London | Solovieva N.,Kazan Federal University | Klimaschewski A.,Queen's University of Belfast | Self A.E.,Natural History Museum in London | And 6 more authors.
Global and Planetary Change | Year: 2015

A radiocarbon and tephra-dated sediment core from Lifebuoy Lake, located on the north-east coast of Kamchatka Peninsula, was analysed for pollen, spores, diatoms, chironomids and tephra in order to uncover regional environmental history. The 6500-year environmental history of Lifebuoy Lake correlates with the broad regional patterns of vegetation development and climate dynamics with both diatoms and chironomids showing near-synchronous changes. Between ca. 6300 and 3900 cal. yr. BP, the lake ecosystem was naturally enriched, with several Stephanodiscus species dominating the diatom plankton. This natural eutrophication state is likely to be due to a combination of the base-rich catchment geology, the fertilisation effect of several fires in the catchment, silica input from tephra layers and, possibly, nitrogen input from seabirds. The substantial tephra deposit at about 3850 cal. yr. BP might have stopped sedimentary phosphorus from entering the lake water thus decreasing the trophic state of the lake and facilitating the shift in diatom composition to a benthic Fragiliariaceae complex. Both diatoms and chironomids showed simultaneous compositional changes, which are also reflected by statistically significant changes in their rates of change 300-400. years after the arrival of Pinus pumila in the lake catchment. The rapid increase in both total diatom concentration and the percentage abundance of the large heavy species, Aulacoseira subarctica might be a response to the change in timing and intensity of lake spring turn-over due to the changes in the patterns of North Pacific atmospheric circulation, most notably westward shift of the Aleutian Low. The two highest peaks in A. subarctica abundance at Lifebouy Lake occurred during opposite summer temperature inferences: the earlier peak (3500-2900. cal. yr. BP) coincided with warm summers and the latter peak (300. cal. yr. BP-present) occurred during the cold summer period. These imply that A. subarctica shows no direct response to the changes of summer air temperature. Instead, it appears to thrive during the periods of increased winter precipitation, thicker ice and late spring turn-over periods, i.e., shows indirect response to climate. The clearest effect of tephra deposition on the lake ecosystem is above 908 cm (ca. 3800 cal. yr. BP) where the tephra deposit might have caused the shift from Stephanodiscus-dominated planktonic assemblages to the Fragilariaceae complex of benthic species. Tephra deposits might have also contributed towards the development of eutrophic plankton from about 6300 cal. yr. BP. It is not certain if several tephra deposits influenced diatom and chironomid changes during the last 300 years. © 2015.


Ryazanova T.V.,Kamchatka Research Institute of Fisheries and Oceanography | Eliseikina M.G.,RAS A.V. Zhirmunsky Institute of Marine Biology
Russian Journal of Marine Biology | Year: 2010

Diseases caused by microsporidia were found in the red king crab Paralithodes camtschaticus and the blue king crab P. platypus that inhabit the Sea of Okhotsk. Based on the histological features of the invasion and data on the morphological structure of the parasites, the microsporidia were assigned to the genera Thelohania and Ameson. Infected crabs exhibited severe destructive changes of their internal organs along with sharply pronounced external signs of disease. During the observation period, the microsporidian invasion was only found in females and young (unmarketable size) males from August to mid-October. Later, until mid-December, no diseased crabs were found. © 2010 Pleiades Publishing, Ltd.


Lepskaya E.V.,Kamchatka Research Institute of Fisheries and Oceanography | Jewson D.H.,University of Ulster | Usoltseva M.V.,Russian Academy of Sciences
Diatom Research | Year: 2010

Kurilskoye Lake is a deep (max. depth 316 m), oligotrophic lake that has been affected by nearby volcanic eruptions and extensive fertilisation aimed at increasing primary productivity in order to support a sockeye salmon fishery. Aulacoseira subarctica has dominated the phytoplankton community since studies began in 1980. Maximum cell concentrations were relatively low (from 137 cells ml -1 in 1987 to 3,710 cells ml -1 in 1990) and, in most years, occurred between June and August. More intensive seasonal studies were started in 2000 and these showed that there was little or no net diatom cell increase in some years. Even when an increase did occur, it could take up to two months for the population to double, mainly because of limited light availability resulting from deep mixing. Phosphorus was the main limiting nutrient but silica concentrations were relatively low and limited diatom growth in one out of 19 years. Further phosphate increases are likely to cause more extensive silica limitation and a probable shift in phytoplankton community composition. The lake did not freeze every year but when it was ice covered for over 100 days A. subarctica did less well. Comparison with other A. subarctica populations showed that cell dimensions were similar but that the frequency of auxosporulation was low.


Stepanov V.G.,Russian Academy of Sciences | Morozov T.B.,Kamchatka Research Institute of Fisheries and Oceanography
Russian Journal of Marine Biology | Year: 2014

Two species of holothurians of the order Molpadiida were found on the shelf of Kamchatka and the Kurile Islands: Molpadia orientalis (Saveljeva, 1933) comb. nov. and M. roretzi (von Marenzeller, 1877). Molpadiid holothurians were not previously recorded in waters near Kamchatka and the Kurile Islands. Brief descriptions of the morphology of the two species, distribution and ecology data, as well as figures depicting calcareous rings and body skin ossicles, are provided. © 2014 Pleiades Publishing, Ltd.


Pilganchuk O.A.,Kamchatka Research Institute of Fisheries and Oceanography | Shpigalskaya N.Y.,Kamchatka Research Institute of Fisheries and Oceanography
Russian Journal of Marine Biology | Year: 2013

The interpopulation differentiation of the sockeye salmon Oncorhynchus nerka (Walbaum) from the Olyutorskiy and Karaginskiy districts and from the Kamchatka River basin was examined based on the allelic variation at eight microsatellite loci (Ots107, Oki1a, Oki1b, One104, One109, OtsG68, OtsG85, and Oki6). The genetic diversity of samples from the northern rivers was lower, compared to samples from the Kamchatka River basin. Significant heterogeneity was found in the allele-frequency distribution at microsatellite loci of sockeye salmon from the investigated localities. The degree of genetic similarity of populations corresponded to their geographic closeness. The differences between population groups greatly exceeded the level of interpopulation differentiation. The analyzed samples formed four relatively separate groups: Lake Azabachye, Kamchatka River basin, Karaginskiy area (including the Navyrinvayam River in the south of the Olyutorskiy district), and northern Olyutorskiy area. The identification likelihood estimates of eastern Kamchatkan sockeye salmon in mixed aggregations at the level of population groups were fairly high (67.2-81.8%), greatly exceeding the accuracy of identification of individual populations. © 2013 Pleiades Publishing, Ltd.


Ryazanova T.V.,Kamchatka Research Institute of Fisheries and Oceanography | Eliseikina M.G.,RAS A.V. Zhirmunsky Institute of Marine Biology | Kalabekov I.M.,Russian Academy of Agricultural Sciences | Odintsova N.A.,Far Eastern Federal University
Journal of Invertebrate Pathology | Year: 2015

A herpes-like virus was found infecting the antennal gland and bladder epithelium in the blue king crab Paralithodes platypus from the eastern area of the Sea of Okhotsk. Electron microscopic analysis of antennal gland samples from blue king crabs with histologically confirmed signs of disease revealed virus particles, which were mostly hexagonal in shape and located primarily in the nucleus; these particles were rarely observed in the cytoplasm of infected cells. Most virus particles ranged in size from 115 to 125. nm. Hemocytes of the red king crab Paralithodes camtschaticus in cell culture could be experimentally infected with virus from thawed antennal gland samples of the blue king crabs with histologically confirmed signs of viral infection. Clear signs of infection were observed in hemocyte cultures at 3-4. days post-inoculation as small foci of highly vacuolated formations. These formations included several nuclei and were surrounded by a halo of small cytoplasmic bubbles containing actin and tubulin. As demonstrated by electron microscopic studies, no virus-like particles were found in the cells 1. day post-inoculation, but particles become abundant at 7. days post-inoculation. We developed a consensus primer PCR method for amplification of a region of the herpesviral DNA-directed DNA polymerase. Primers were designed to target sequences encoding highly conserved amino acid motifs covering a region of approximately 800. bp. Thus, macroscopic, histological and ultra-structural examinations of blue king crabs infected with a virus and the molecular identification of the pathogen revealed the presence of herpesviruses. The frequency of the herpes-like viral infection in natural populations of blue king crabs in the Sea of Okhotsk ranged from 0% to 3% in different years. © 2015 Elsevier Inc.


Odintsova N.A.,Far Eastern Federal University | Eliseikina M.G.,Far Eastern Federal University | Ryazanova T.V.,Kamchatka Research Institute of Fisheries and Oceanography
Russian Journal of Marine Biology | Year: 2015

To date, herpes-like viruses have been repeatedly found in wild king crab populations. In this study, freshly collected hemocytes of the red king crab Paralithodes camtschaticus have been experimentally exposed in culture to the herpes-like virus from thawed antennal gland samples from infected blue king crabs P. platypus. After 3–4 months of cultivation, significant differences in the pigmentation were observed between control and virus-infected hemocytes. Using Raman spectroscopy, we detected two obligatory peaks, characteristic for melanin identification, in the spectra of pigmented inclusions in harvested virus-infected hemocytes. These peaks are absent in the spectra obtained from control hemocytes. The cells of virus-infected cultures were viable after 10 months, while all control uninfected hemocytes were lost. As demonstrated by electron microscopic studies, virus-like particles become abundant at 7 days post-inoculation. Our results suggest that hemocytes could be used as a suitable model system for studies of crab pathogens. The in vitro studies confirm previous findings regarding the presence of viral infection in the natural population of king crabs. © 2015, Pleiades Publishing, Ltd.


Ryazanova T.V.,Kamchatka Research Institute of Fisheries and Oceanography | Eliseikina M.G.,RAS A.V. Zhirmunsky Institute of Marine Biology | Kukhlevsky A.D.,RAS A.V. Zhirmunsky Institute of Marine Biology | Kharlamenko V.I.,RAS A.V. Zhirmunsky Institute of Marine Biology
Journal of Invertebrate Pathology | Year: 2010

A disease caused by a parasitic dinoflagellate of the genus Hematodinium was identified in red, Paralithodes camtschaticus, and blue, Paralithodes platypus, king crabs from the north-east region of the Sea of Okhotsk, Russia, during annual stock surveys. No carapace color change was observed even in heavily infected crabs, but diseased crabs possessed creamy-yellow hemolymph, which was visible through the arthrodial membranes of the abdomen and appendages. Several stages of the parasite's life history, including trophonts, plasmodia, sporonts and macrodinospores, were observed in tissues of infected king crabs. Numerous parasite cells were observed in the lumina of the myocardium, the gills, the connective tissue of antennal glands and the sinuses of nerve ganglia, eyestalks and gastrointestinal tract of king crabs with gross signs of infection. Based on sequencing of the 18S rDNA, it appears that the Hematodinium sp. found in red and blue king crabs is identical or closely related to Hematodinium sp. isolated from crabs of the genera Chionoecetes and Lithodes. Observed prevalences were 0.33% in sublegal male red king crabs, 0.18% in female red king crabs, 0.34% in sublegal male blue king crabs and 0.31% in female blue king crabs. © 2010 Elsevier Inc.


PubMed | RAS A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Federal University, Kamchatka Research Institute of Fisheries and Oceanography and Russian Academy of Agricultural Sciences
Type: | Journal: Journal of invertebrate pathology | Year: 2015

A herpes-like virus was found infecting the antennal gland and bladder epithelium in the blue king crab Paralithodes platypus from the eastern area of the Sea of Okhotsk. Electron microscopic analysis of antennal gland samples from blue king crabs with histologically confirmed signs of disease revealed virus particles, which were mostly hexagonal in shape and located primarily in the nucleus; these particles were rarely observed in the cytoplasm of infected cells. Most virus particles ranged in size from 115 to 125nm. Hemocytes of the red king crab Paralithodes camtschaticus in cell culture could be experimentally infected with virus from thawed antennal gland samples of the blue king crabs with histologically confirmed signs of viral infection. Clear signs of infection were observed in hemocyte cultures at 3-4days post-inoculation as small foci of highly vacuolated formations. These formations included several nuclei and were surrounded by a halo of small cytoplasmic bubbles containing actin and tubulin. As demonstrated by electron microscopic studies, no virus-like particles were found in the cells 1day post-inoculation, but particles become abundant at 7days post-inoculation. We developed a consensus primer PCR method for amplification of a region of the herpesviral DNA-directed DNA polymerase. Primers were designed to target sequences encoding highly conserved amino acid motifs covering a region of approximately 800bp. Thus, macroscopic, histological and ultra-structural examinations of blue king crabs infected with a virus and the molecular identification of the pathogen revealed the presence of herpesviruses. The frequency of the herpes-like viral infection in natural populations of blue king crabs in the Sea of Okhotsk ranged from 0% to 3% in different years.

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