22 research outputs found
The inference of gray whale (Eschrichtius robustus) historical population attributes from whole-genome sequences
Commercial whaling caused extensive demographic declines in many great whale species, including gray whales that were extirpated from the Atlantic Ocean and dramatically reduced in the Pacific Ocean. The Eastern Pacific gray whale has recovered since the 1982 ban on commercial whaling, but the Western Pacific gray whale-once considered possibly extinct-consists of only about 200 individuals and is considered critically endangered by some international authorities. Herein, we use whole-genome sequencing to investigate the demographic history of gray whales from the Pacific and use environmental niche modelling to make predictions about future gene flow.Our sequencing efforts and habitat niche modelling indicate that: i) western gray whale effective population sizes have declined since the last glacial maximum; ii) contemporary gray whale genomes, both eastern and western, harbor less autosomal nucleotide diversity than most other marine mammals and megafauna; iii) the extent of inbreeding, as measured by autozygosity, is greater in the Western Pacific than in the Eastern Pacific populations; and iv) future climate change is expected to open new migratory routes for gray whales.Our results indicate that gray whale genomes contain low nucleotide diversity and have been subject to both historical and recent inbreeding. Population sizes over the last million years likely peaked about 25,000Â years before present and have declined since then. Our niche modelling suggests that novel migratory routes may develop within the next century and if so this could help retain overall genetic diversity, which is essential for adaption and successful recovery in light of global environmental change and past exploitation
The Russian consensus on the diagnosis and treatment of chronic pancreatitis: Enzyme replacement therapy
The Russian consensus on the diagnosis and treatment of chronic pancreatitis has been prepared on the initiative of the Russian Pancreatology Club to clarify and consolidate the opinions of Russian specialists (gastroenterologists, surgeons, and pediatricians) on the most significant problems of diagnosis and treatment of chronic pancreatitis. This article continues a series of publications explaining the most significant interdisciplinary consensus statements and deals with enzyme replacement therapy
Data from: Age specific survival rates of Steller sea lions at rookeries with divergent population trends in the Russian Far East
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
Age Specific Survival Rates of Steller Sea Lions at Rookeries with Divergent Population Trends in the Russian Far East
<div><p>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.</p></div
Resight history of Steller sea lions in the Russian Far East
Data file contains annual resight history of Steller sea lions branded as pups between 1989 and 2008 and resighted between 1996 and 2011 at 6 major rookeries in the Russian Far East. Detailed information on data structure provided in read me file
Age specific cumulative survival for females and males until age 15 in the Commander Islands, Eastern Kamchatka and Kuril Islands.
<p>Age specific cumulative survival for females and males until age 15 in the Commander Islands, Eastern Kamchatka and Kuril Islands.</p
Annual and cumulative age and sex specific survival for the Kuril Islands, through 22 years of age (error bars = 2 SE).
<p>Note that the survival estimates are plotted at the maximum age of each age class, e.g. the survival of age 0 sea lions to age 1 is plotted at 1.</p
Survival model candidate selection list.
<p>Note: Ab = basis spline on Age with df = 4, Sx = sex covariate, Pp = pup covariate, Ad = adult (1+) covariate (opposite to the pup covariate), Rg = region covariate, Ns = site (natal site), time = time (year) factor covariate, age = age factor covariate. To allow models with multiple additive interaction terms we have removed the intercept.</p><p>Survival model candidate selection list.</p
Selection list of survival and resight parameters model combinations.
<p>Note: Ab = basis spline on Age with df = 4, Sx = sex covariate, Pp = pup covariate, Ad = adult (1+) covariate (opposite to the pup covariate), Rg = region covariate, Ns = site (natal site), HE = effort on haulouts, H# = number of haulouts surveyed, RE = effort on the natal rookery, time = time (year) factor covariate. To allow models with multiple additive interaction terms we have removed the intercept.</p><p>Selection list of survival and resight parameters model combinations.</p
Apparent annual survival in different time periods and geographic regions.
<p>(i) pre-decline in central Gulf of Alaska [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127292#pone.0127292.ref054" target="_blank">54</a>]; (ii) pooled male and female survival during decline in Marmot I. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127292#pone.0127292.ref037" target="_blank">37</a>]; (iii) Central Gulf of Alaska females post-decline [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127292#pone.0127292.ref010" target="_blank">10</a>]; (iv) Eastern Stock females survival 1994—2003 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127292#pone.0127292.ref037" target="_blank">37</a>] and (v) more recently [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127292#pone.0127292.ref006" target="_blank">6</a>]; (vi) Eastern Aleutian females 2001—2011 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127292#pone.0127292.ref010" target="_blank">10</a>]; (vii, viii, ix) female survival at Russian rookeries (this study). Note that the survival estimates are plotted at the maximum age of each age class, e.g. the survival of age 0 sea lions to age 1 is plotted at 1.</p