Project description:Spotted seals (Phoca largha) is a critically endangered pinniped in China and South Korea. Captive in artificially controlled environment is a conventional method to protect and maintain the population of this species. However, little is known about the physiological differences between the wild and captive P. largha. In order to draw the preliminary protein expression profile in the P. largha, blood from the wild and captive pups were subjected to a label-free comparative proteomic analysis. According to the results, 972 proteins were identified, which performed functions related to various metabolic, immune and cellular processes. Among these identified proteins, the expression level of 51 proteins significantly changed between the wild and captive P. large pups. These differentially expressed proteins were enriched in a wide range of cellular functions, including cytoskeleton, phagocytosis. proteolysis, gene expression regulation and carbohydrate metabolism. The activities of phagocytosis and its related ubiquitin mediated proteolysis were significantly higher in the blood of wild P. largha pups than in captive individuals. In addition, a key protein associated with the differences in the wild and captive P. largha pups, heat shock protein 90-beta, were determined due to the most interactions of it with various differentially expressed proteins. Moreover, the wild P. largha pups could be more nutritionally stressed and have more powerful immune capacity. Our study provides the first data on the preliminary protein composition and gives useful information for the physiological characteristics research in this species.
Project description:Tidewater glacial fjords in Alaska provide habitat for some of the largest aggregations of harbor seals (Phoca vitulina), with calved ice serving as platforms for birthing and nursing pups, molting, and resting. These fjords have also been popular destinations for tour ships for more than a century, with dramatic increases in vessel traffic since the 1980s. Seals on ice are known to flush into the water when approached by tour ships, but estimating the exposure to disturbance across populations is difficult. Using aerial transect sampling while simultaneously tracking vessel movements, we estimated the spatial overlap between seals on ice and cruise ships in Disenchantment Bay, Alaska, USA. By integrating previously estimated rates of disturbance as a function of distance with an 'intensity surface' modeled spatially from seal locations in the surveys, we calculated probabilities of seals flushing during three separate ship visits. By combining our estimate of seals flushed with a modeled estimate of the total fjord population, we predict that up to 14% of the seals (up to 11% of pups) hauled out would have flushed into the water, depending on the route taken by ships relative to seal aggregations. Such high potential for broad-scale disturbance by single vessels (when up to 4 ships visit per day) was unexpected and underscores the need to 1) better understand long-term effects of disturbance; 2) regularly monitor populations exposed to high vessel traffic; and 3) develop conservation measures to reduce seal-ship overlap.
Project description:During the second morbillivirus epidemic (2007 to 2011) in cetaceans along the Italian coastline, dolphin morbillivirus (DMV) was detected by molecular analyses in a captive harbor seal (Phoca vitulina), with pathological findings consistent with morbillivirus infection. This report confirms interspecies DMV transmission from cetaceans to pinnipeds.
Project description:The harbour seal population in Orkney, off the north coast of Scotland, has reduced by 65% between 2001 and 2010. The cause(s) of this decline are unknown but must affect the demographic parameters of the population. Here, satellite telemetry data were used to test the hypothesis that increased pup mortality could be a primary driver of the decline in Orkney. Pup mortality and tag failure parameters were estimated from the duration of operation of satellite tags deployed on harbour seal pups from the Orkney population (n?=?24) and from another population on the west coast of Scotland (n?=?24) where abundance was stable. Survival probabilities from both populations were best represented by a common gamma distribution and were not different from one another, suggesting that increased pup mortality is unlikely to be the primary agent in the Orkney population decline. The estimated probability of surviving to 6 months was 0.390 (95% CI 0.297 - 0.648) and tag failure was represented by a Gaussian distribution, with estimated mean 270 (95% CI?=?198 - 288) and s.d. 21 (95% CI?=?1 - 66) days. These results suggest that adult survival is the most likely proximate cause of the decline. They also demonstrate a novel technique for attaining age-specific mortality rates from telemetry data.