Changes in Alaskan soft-bottom prey communities along a gradient in sea otter predation

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Kvitek, R.G.; Oliver, J.S.; DeGange, A.R.; Anderson, B.S.

1992-01-01

Sea Otter (Enhydra lutris), well documented as "keystone" predators in rocky marine communities, were found to exert a strong influence on infaunal prey communities in soft-sediment habitats. Direct and indirect effects of sea otter predation on subtidal soft-bottom prey communities were evaluated along a temporal gradient of sea otter occupancy around the Kodiak Archipelago. The results indicate that Kodiak otters forage primarily on bivalve prey and dramatically reduce infaunal bivalve and green sea urchin (Strongylocentrotus droebachiensis) prey populations. Bivalve prey abundance, biomass, and size were inversely related to duration of sea otter occupancy. The relative conditions of shells discarded by otters in shallow ( 20 m) water at the same sites indicate that otters first exploited Saxidomus in shallow-water feeding areas, and later switched to Macoma spp. in deeper water. Otter-cracked shells of the deep-burrowing clam Tresus capax were rarely found, even at otter foraging sites where the clam accounted for the majority of available prey biomass, suggesting that it has a partial depth refuge from otter predation. The indirect effects of otter predation included substratum disturbance and the facilitation of sea star predation on infaunal prey. Sea stars, Pycnopodia helianthoides, were attracted to experimentally dug excavations as well as natural sea otter foraging pits, where the sea stars foraged on smaller size classes of infaunal bivalves than those eaten by otters. Otters also discard clam shells on the sediment surface and expose old, buried shells during excavation. Surface shells were found to provide attachment sites for large anemones and kelp. Our study shows that sea otters can affect soft-sediment communities, not only through predation, as in rocky habitats, but also through disturbance, and thus retain a high degree of influence in two very different habitat types.

Variations of transcript profiles between sea otters Enhydra lutris from Prince William Sound, Alaska, and clinically normal reference otters

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Miles, A. Keith; Bowen, Lizabeth; Ballachey, Brenda E.; Bodkin, James L.; Murray, M.; Estes, J.L.; Keister, Robin A.; Stott, J.L.

2012-01-01

Development of blood leukocyte gene transcript profiles has the potential to expand condition assessments beyond those currently available to evaluate wildlife health, including sea otters Enhydra lutris, both individually and as populations. The 10 genes targeted in our study represent multiple physiological systems that play a role in immuno-modulation, inflammation, cell protection, tumor suppression, cellular stress-response, xenobiotic metabolizing enzymes, and antioxidant enzymes. These genes can be modified by biological, physical, or anthropogenic impacts and consequently provide information on the general type of stressors present in a given environment. We compared gene transcript profiles of sea otters sampled in 2008 among areas within Prince William Sound impacted to varying degrees by the 1989 ‘Exxon Valdez’ oil spill with those of captive and wild reference sea otters. Profiles of sea otters from Prince William Sound showed elevated transcription in genes associated with tumor formation, cell death, organic exposure, inflammation, and viral exposure when compared to the reference sea otter group, indicating possible recent and chronic exposure to organic contaminants. Sea otters from historically designated oiled areas within Prince William Sound 19 yr after the oil spill had higher transcription of genes associated with tumor formation, cell death, heat shock, and inflammation than those from areas designated as less impacted by the spill.

Dramatic increase in sea otter mortality from white sharks in California

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Tinker, M. Tim; Hatfield, Brian B.; Harris, Michael D.; Ames, Jack A.

2016-01-01

Although southern sea otters (Enhydra lutris nereis) are not considered prey for white sharks (Carcharodon carcharias), sharks do nonetheless bite sea otters. We analyzed spatial and temporal trends in shark bites on sea otters in California, assessing the frequency of shark bite wounds in 1,870 carcasses collected since 1985. The proportion of stranded sea otters having shark bites has increased sharply since 2003, and white shark bites now account for >50% of recovered carcasses. The trend was most pronounced in the southern part of the range, from Estero Bay to Point Conception, where shark bite frequency has increased eightfold. Seasonal trends were also evident: most shark-bitten carcasses are recovered in late summer and fall; however, the period of elevated shark bite frequency has lengthened. The causes of these trends are unclear, but possible contributing factors include increased white shark abundance and/or changes in white shark behavior and distribution. In particular, the spatiotemporal patterns of shark-bitten sea otters match increases in pinniped populations, and the increased availability of marine mammal prey for white sharks may have led to more sharks spending more time in nearshore waters utilized by both sea otters and pinnipeds.

Refining aging criteria for northern sea otters in Washington State

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Schuler, Krysten L.; Baker, Bridget B.; Mayer, Karl A.; Perez-Heydrich, Carolina; Holahan, Paula M.; Thomas, Nancy J.; White, C. LeAnn

2018-01-01

Measurement of skull ossification patterns is a standard method for aging various mammalian species and has been used to age Russian, Californian, and Alaskan sea otter populations. Cementum annuli counts have also been verified as an accurate aging method for the Alaskan sea otter population. In this study, cementum annuli count results and skull ossification patterns were compared as methods for aging the northern sea otter (Enhydra lutris kenyoni) population in Washington State. Significant agreement was found between the two methods suggesting that either method could be used to age the Washington population of otters. This study also found that ossification of the squamosal-jugal suture at the ventral glenoid fossa can be used to differentiate male subadults from adults. To assist field biologists or others without access to cementum annuli or skull ossification analysis techniques, a suite of morphologic, physiologic, and developmental characteristics were analyzed to assess whether a set of these more easily accessible parameters could also predict age class for the Washington population of otters. Tooth condition score, evidence of reproductive activity in females, and tooth eruption pattern were identified as the most useful criteria for classifying Washington sea otters as pups, juveniles, subadults, or adults/aged adults. A simple decision tree based on characteristics accessible in the field or at necropsy was created that can be used to reliably predict age class of Washington sea otters as determined by cementum annuli.

Evaluation of sea otter capture after the Exxon Valdez oil spill, Prince William Sound, Alaska

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Bodkin, James L.; Weltz, F.; Bayha, Keith; Kormendy, Jennifer

1990-01-01

After the T/V Exxon Valdez oil spill into Prince William Sound, the U.S. Fish and Wildlife Service and Exxon Company, U.S.A., began rescuing sea otters (Enhydra lutris). The primary objective of this operation was to capture live, oiled sea otters for cleaning and rehabilitation. Between 30 March and 29 May 1989, 139 live sea otters were captured in the sound and transported to rehabilitation centers in Valdez, Alaska. Within the first 15 days of capture operations, 122 (88%) otters were captured. Most sea otters were captured near Knight, Green, and Evans islands in the western sound. The primary capture method consisted of dipnetting otters out of water and off beaches. While capture rates declined over time, survival of captured otters increased as the interval from spill date to capture date increased. The relative degree of oiling observed for each otter captured declined over time. Declining capture rates led to the use of tangle nets. The evidence suggests the greatest threat to sea otters in Prince William Sound occurred within the first 3 weeks after the spill. Thus, in the future, the authors believe rescue efforts should begin as soon as possible after an oil spill in sea otter habitat. Further, preemptive capture and relocation of sea otters in Prince William Sound may have increased the number of otters that could have survived this event.

Innervation Patterns of Sea Otter (Enhydra lutris Mystacial Follicle-Sinus Complexes

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Christopher Douglas Marshall

2014-10-01

Full Text Available Sea otters (Enhydra lutris are the most recent group of mammals to return to the sea, and may exemplify divergent somatosensory tactile systems among mammals. Therefore, we quantified the mystacial vibrissal array of sea otters and histologically processed follicle-sinus complexes (F-SCs to test the hypotheses that the number of myelinated axons per F-SC is greater than that found for terrestrial mammalian vibrissae and that their organization and microstructure converge with those of pinniped vibrissae. A mean of 120.5 vibrissae were arranged rostrally on a broad, blunt muzzle in 7-8 rows and 9-13 columns. The F-SCs of sea otters are tripartite in their organization and similar in microstructure to pinnipeds rather than terrestrial species. Each F-SC was innervated by a mean 1339±408.3 axons. Innervation to the entire mystacial vibrissal array was estimated at 161,313 axons. Our data support the hypothesis that the disproportionate expansion of the coronal gyrus in somatosensory cortex of sea otters is related to the high innervation investment of the mystacial vibrissal array, and that quantifying innervation investment is a good proxy for tactile sensitivity. We predict that the tactile performance of sea otter mystacial vibrissae is comparable to that of harbor seals, sea lions and walruses¬.

Otters, Marine

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Estes, James A.; Bodkin, James L.; Ben-David, M.; Perrin, William F.; Würsing, Bernd; Thewissen, J.G.M.

2009-01-01

The otters (Mustelidae; Lutrinae) provide an exceptional perspective into the evolution of marine living by mammals. Most extant marine mammals (e.g. the cetaceans, pinnipeds, and sirenians) have been so highly modified by long periods of selection for life in the sea that they bear little resemblance to their terrestrial ancestors. Marine otters, in contrast, are more recent expatriates from freshwater habitats and some species still live in both environments. Contrasts among species within the otters, and among the otters, terrestrial mammals, and the more highly adapted pinnipeds and cetaceans provide powerful insights into mammalian adaptations to life in the sea (Estes, 1989). Among the marine mammals, sea otters (Enhydra lutris, Fig. 1) provide the clearest understanding of consumer-induced effects on ecosystem function. This is due in part to opportunities provided by history and in part to the relative ease with which shallow coastal systems where sea otters live can be observed and studied. Although more difficult to study than sea otters, other otter species reveal the connectivity among the marine, freshwater, and terrestrial systems. These three qualities of the otters – their comparative biology, their role as predators, and their role as agents of ecosystem connectivity – are what make them interesting to marine mammalogy.The following account provides a broad overview of the comparative biology and ecology of the otters, with particular emphasis on those species or populations that live in the sea. Sea otters are features prominently, in part because they live exclusively in the sea whereas other otters have obligate associations with freshwater and terrestrial environments (Kenyon, 1969; Riedman and Estes, 1990).

Translocated sea otter populations off the coasts of Oregon and Washington

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Jameson, Ronald J.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

1998-01-01

The historical distribution of sea otters extended from the northern islands of Japan north and east across the Aleutian chain to the mainland of North America then south along the west coast to central Baja California, Mexico (Riedman and Estes 1990). By the beginning of the twentieth century, after 150 years of being intensively hunted for their valuable fur, sea otters had been extirpated from most of their range (Kenyon 1969). In 1911 sea otters were protected by the passage of the International Fur Seal Treaty. Unfortunately, only 13 remnant populations survived the fur-hunting period, and two of those, British Columbia and Mexico, would also ultimately disappear, leaving only a small group of sea otters south of Alaska, along the rugged Big Sur coast of California (Kenyon 1969).The earliest attempts to reestablish sea otters to unoccupied habitat were begun in the early 1950’s by R. D. (Sea Otter) Jones, then manager of the Aleutian National Wildlife Refuge (Kenyon 1969). These early efforts were experimental, and all failed to establish populations. However, the knowledge gained from Jones’s efforts and the seminal work of Kenyon (1969) and others during the 1950’s and early 1960’s ultimately led to the successful efforts to come.During the mid-1960’s the Alaska Department of Fish and Game began translocating sea otters to sites where the species had occurred before the fur-trade period. The first translocations were restricted to Alaska, but beginning in 1969 and continuing through 1972, the effort expanded beyond Alaska. During this period, 241 sea otters were translocated to sites in British Columbia, Washington, and Oregon (Jameson et al. 1982). The work was done cooperatively between state and provincial conservation agencies, with much of the financial support for the Oregon and Washington efforts coming from the Atomic Energy Commission (now ERDA). Followup studies of the Oregon population began in 1971 and continued through 1975. After 1975

Comparison of anesthetic agents in the sea otter

Energy Technology Data Exchange (ETDEWEB)

Williams, T.D.; Kocher, F.H.

1978-01-01

Five anesthetic agents (CI744, etorphine, fentanyl, ketamine hydrochloride, and halothane) were tested to establish the dosage of a safe, effective, short-acting anesthetic for use in the sea otter. Etorphine, at a dosage of 0.75 mg per adult otter and used in conjunction with diazepam, at a dosage of 1.25 mg per adult otter, met most of the requirements for use under field conditions. Halothane, administered through an anesthetic machine, proved to be effective for use in a veterinary hospital.

Protozoal meningoencephalitis in sea otters (Enhydra lutris): A histopathological and immunohistochemical study of naturally occurring cases

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Thomas, N.J.; Dubey, J.P.; Lindsay, D.S.; Cole, Rebecca A.; Meteyer, C.U.

2007-01-01

Protozoal meningoencephalitis is considered to be an important cause of mortality in the California sea otter (Enhydra lutris). Thirty nine of 344 (11.3%) California (CA) and Washington state (WA) sea otters examined from 1985 to 2004 had histopathological evidence of significant protozoal meningoencephalitis. The aetiological agents and histopathological changes associated with these protozoal infections are described. The morphology of the actively multiplicative life stages of the organisms (tachyzoites for Toxoplasma gondii and merozoites for Sarcocystis neurona) and immunohistochemical labelling were used to identify infection with S. neurona (n=22, 56.4%), T. gondii (n=5, 12.8%) or dual infection with both organisms (n=12, 30.8%). Active S. neurona was present in all dual infections, while most had only the latent form of T. gondii. In S. neuronameningoencephalitis, multifocal to diffuse gliosis was widespread in grey matter and consistently present in the molecular layer of the cerebellum. In T. gondiimeningoencephalitis, discrete foci of gliosis and malacia were more widely separated, sometimes incorporated pigment-laden macrophages and mineral, and were found predominantly in the cerebral cortex. Quiescent tissue cysts of T. gondii were considered to be incidental and not a cause of clinical disease and mortality. Protozoal meningoencephalitis was diagnosed more frequently in the expanding population of WA sea otters (10 of 31, 32.3%) than in the declining CA population (29 of 313, 9.3%). Among sea otters with protozoal meningoencephalitis, those that had displayed neurological signs prior to death had active S. neurona encephalitis, supporting the conclusion that S. neurona is the most significant protozoal pathogen in the central nervous system of sea otters.

Sea otters homogenize mussel beds and reduce habitat provisioning in a rocky intertidal ecosystem.

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Gerald G Singh

Full Text Available Sea otters (Enhydra lutris are keystone predators that consume a variety of benthic invertebrates, including the intertidal mussel, Mytilus californianus. By virtue of their competitive dominance, large size, and longevity, M. californianus are ecosystem engineers that form structurally complex beds that provide habitat for diverse invertebrate communities. We investigated whether otters affect mussel bed characteristics (i.e. mussel length distributions, mussel bed depth, and biomass and associated community structure (i.e. biomass, alpha and beta diversity by comparing four regions that varied in their histories of sea otter occupancy on the west coast of British Columbia and northern Washington. Mussel bed depth and average mussel lengths were 1.5 times lower in regions occupied by otters for >20 years than those occupied for <5 yrs. Diversity of mussel bed associated communities did not differ between regions; however, the total biomass of species associated with mussel beds was more than three-times higher where sea otters were absent. We examined alternative explanations for differences in mussel bed community structure, including among-region variation in oceanographic conditions and abundance of the predatory sea star Pisaster ochraceus. We cannot discount multiple drivers shaping mussel beds, but our findings indicate the sea otters are an important one. We conclude that, similar to their effects on subtidal benthic invertebrates, sea otters reduce the size distributions of intertidal mussels and, thereby, habitat available to support associated communities. Our study indicates that by reducing populations of habitat-providing intertidal mussels, sea otters may have substantial indirect effects on associated communities.

California sea otter (Enhydra lutris nereis) census results, Spring 2017

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Tinker, M. Tim; Hatfield, Brian B.

2017-09-29

The 2017 census of southern sea otters (Enhydra lutris nereis) was conducted between late April and early July along the mainland coast of central California and in April at San Nicolas Island in southern California. The 3-year average of combined counts from the mainland range and San Nicolas Island was 3,186, down by 86 sea otters from the previous year. This is the second year that the official index has exceeded 3,090, the Endangered Species Act delisting threshold identified in the U.S. Fish and Wildlife Service’s Southern Sea Otter Recovery Plan (the threshold would need to be exceeded for 3 consecutive years before delisting consideration). The 5-year average trend in abundance, including both the mainland range and San Nicolas Island populations, remains positive at 2.3 percent per year. Continuing lack of growth in the range peripheries likely explains the cessation of range expansion.

Hearing in the sea otter (Enhydra lutris): auditory profiles for an amphibious marine carnivore.

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Ghoul, Asila; Reichmuth, Colleen

2014-11-01

In this study we examine the auditory capabilities of the sea otter (Enhydra lutris), an amphibious marine mammal that remains virtually unstudied with respect to its sensory biology. We trained an adult male sea otter to perform a psychophysical task in an acoustic chamber and at an underwater apparatus. Aerial and underwater audiograms were constructed from detection thresholds for narrowband signals measured in quiet conditions at frequencies from 0.125-40 kHz. Aerial hearing thresholds were also measured in the presence of octave-band masking noise centered at eight signal frequencies (0.25-22.6 kHz) so that critical ratios could be determined. The aerial audiogram of the sea otter resembled that of sea lions and showed a reduction in low-frequency sensitivity relative to terrestrial mustelids. Best sensitivity was -1 dB re 20 µPa at 8 kHz. Under water, hearing sensitivity was significantly reduced when compared to sea lions and other pinniped species, demonstrating that sea otter hearing is primarily adapted to receive airborne sounds. Critical ratios were more than 10 dB higher than those measured for pinnipeds, suggesting that sea otters are less efficient than other marine carnivores at extracting acoustic signals from background noise, especially at frequencies below 2 kHz.

Activity patterns and time budgets of the declining sea otter population at Amchitka Island, Alaska

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Gelatt, Thomas S.; Siniff, Donald B.; Estes, James A.

2002-01-01

Time budgets of predators may reflect population status if time spent foraging varies with local prey abun- dance. We assumed that the sea otter (Enhydra lutris) population at Amchitka Island, Alaska, USA, had been at equilibrium since the early 1960s and collected time budgets of otters to be used to represent future conditions of currently expanding sea otter populations. We used radiotelemetry to monitor activity-time budgets of otters from August 1992 to March 1994. Sea otter activity was directly linked to sex, age, weather condition, season, and time of day. Sea otters differed in percent time foraging among cohorts but not within cohorts. Percent time foraging ranged from 21% for females with very young (≤ 3weeks of age) dependent pups to 52% for females with old (≥10 weeks of age) pups. Otters foraged more and hauled out more as local sea conditions worsened. Adult males spent less time foraging during winter and spring, consistent with seasonal changes in prey selection. Time spent for- aging was similar to that reported for otters in California and an established population in Prince William Sound, Alaska, but greater than that of otters in recently established populations in Oregon and Alaska. Despite current evidence indicating that the population was in decline during our study, we were unable to recognize this change using time budgets. Our results illustrate the importance of stratifying analyses of activity patterns by age and sex cohorts and the complexity inherent in comparisons of behavioral data between different populations relying on distinct prey bases.

Butyltin residues in southern sea otters (Enhydra lutris nereis) found dead along California coastal waters

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Kannan, K.; Guruge, K.S.; Thomas, N.J.; Tanabe, S.; Giesy, J.P.

1998-01-01

Tributyltin (TBT) and its degradation products, mono- (MBT) and dibutyltin (DBT), were determined in liver, kidney, and brain tissues of adult southern sea otters (Enhydra lutris nereis) found dead along the coast of California during 1992a??1996. Hepatic concentrations of butyltin compounds (BTs = MBT + DBT + TBT) ranged from 40 to 9200 ng/g wet wt, which varied depending on the sampling location and gender. Concentrations of BTs in sea otters were comparable to those reported in stranded bottlenose dolphins from the U.S. Atlantic Coast during 1989a??1994. Greater accumulation of butyltins in sea otters was explained by their bottom-feeding habit and the diet that consists exclusively of invertebrates such as mollusks and gastropods. Livers of female sea otters contained approximately 2-fold greater concentrations of BTs than did those of males. The composition of butyltin compounds in sea otter tissues was predominated by TBT in most cases and suggestive of recent exposure. Large harbors such as Monterey Harbor that handle ships legally painted with TBT-containing antifouling paints continued to experience ecotoxicologically significant butyltin contamination. Sea otters, which were affected by infectious diseases, contained greater concentrations of BTs in their tissues than those that died from trauma and other unknown causes.

Ecological drivers of variation in tool-use frequency across sea otter populations

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Fujii, Jessica; Ralls, Katherine; Tinker, M. Tim

2015-01-01

Sea otters are well-known tool users, employing objects such as rocks or shells to break open hard-shelled invertebrate prey. However, little is known about how the frequency of tool use varies among sea otter populations and the factors that drive these differences. We examined 17 years of observational data on prey capture and tool use from 8 sea otter populations ranging from southern California to the Aleutian Islands in Alaska. There were significant differences in the diets of these populations as well as variation in the frequency of tool use. Sea otters at Amchitka Island, Alaska, used tools on less than 1% of dives that resulted in the capture of prey compared with approximately 16% in Monterey, California. The percentage of individuals in the population that used tools ranged from 10% to 93%. In all populations, marine snails and thick-shelled bivalves were most likely to be associated with tool use, whereas soft-bodied prey items such as worms and sea stars were the least likely. The probability that a tool would be used on a given prey type varied across populations. The morphology of the prey item being handled and the prevalence of various types of prey in local diets were major ecological drivers of tool use: together they accounted for about 64% of the variation in tool-use frequency among populations. The remaining variation may be related to changes in the relative costs and benefits to an individual otter of learning to use tools effectively under differing ecological circumstances.

Food abundance, prey morphology, and diet specialization influence individual sea otter tool use

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Fujii, Jessica A.; Ralls, Katherine; Tinker, M. Tim

2017-01-01

Sea otters are well-known tool users, employing objects such as rocks or shells to break open invertebrate prey. We used a series of generalized linear mixed effect models to examine observational data on prey capture and tool use from 211 tagged individuals from 5 geographically defined study areas throughout the sea otter’s range in California. Our best supported model was able to explain 75% of the variation in the frequency of tool use by individual sea otters with only ecological and demographic variables. In one study area, where sea otter food resources were abundant, all individuals had similar diets focusing on preferred prey items and used tools at low to moderate frequencies (4–38% of prey captures). In the remaining areas, where sea otters were food-limited, individuals specialized on different subsets of the available prey and had a wider range of average tool-use frequency (0–98% of prey captures). The prevalence of difficult-to-access prey in individual diets was a major predictor of tool use and increased the likelihood of using tools on prey that were not difficult to access as well. Age, sex, and feeding habitat also contributed to the probability of tool use but to a smaller extent. We developed a conceptual model illustrating how food abundance, the prevalence of difficult-to-access prey, and individual diet specialization interacted to determine the likelihood that individual sea otters would use tools and considered the model’s relevance to other tool-using species.

Sarcocysts of an unidentified species of Sarcocystis in the sea otter (Enhydra lutris)

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Dubey, J.P.; Lindsay, D.S.; Rosenthal, B.M.; Thomas, N.J.

2003-01-01

The number of Sarcocystis species that infect sea otters (Enhydra lutris) is unknown. Sea otter tissues were recently shown to harbor sarcocysts of S. neurona and of unidentified species of Sarcocystis. Whereas sarcocysts of S. neurona have walls 1a??3 I?m thick with type 9 villar protrusions, ultrastructure of a distinct thin-walled sarcocyst (0.5a??0.7 I?m thick) lacking villar protrusions, but instead exhibiting minute type 1 undulations on the sarcocyst wall, is described in this report. Parasites characterized from a sea otter infection were inferred to be related to, but distinct from, other species belonging to Sarcocystis, based on sequencing and phylogenetic analysis of a portion of the beta subunit of the plastid-encoded RNA polymerase gene.

PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill

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Ricca, Mark A.; Miles, A. Keith; Ballachey, Brenda E.; Bodkin, James L.; Esler, Daniel N.; Trust, Kimberly A.

2010-01-01

Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the unoiled area, whereas concentrations were similar among harlequin ducks from the oiled and unoiled area. Blood enzymes often elevated by xenobiotics were not related to PCB concentrations in sea otters. Only sea otters from the unoiled area had estimated risk from PCBs, and PCB composition or concentrations did not correspond to reported lower measures of population performance in sea otters or harlequin ducks from the oiled area. PCBs probably did not influence limited sea otter or harlequin duck recovery in the oiled area a decade after the spill.

Evaluating potential conservation conflicts between two listed species: sea otters and black abalone.

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Raimondi, Peter; Jurgens, Laura J; Tinker, M Tim

2015-11-01

Population consequences of endangered species interacting as predators and prey have been considered theoretically and legally, but rarely investigated in the field. We examined relationships between spatially variable populations of a predator, the California sea otter, Enhydra lutris nereis, and a prey species, the black abalone, Haliotis cracherodii. Both species are federally listed under the Endangered Species Act and co-occur along the coast of California. We compared the local abundance and habitat distribution of black abalone at 12 sites with varying densities of sea otters. All of the populations of abalone we examined were in the geographic area currently unaffected by withering disease, which has decimated populations south of the study area. Surprisingly, our findings indicate that sea otter density is positively associated with increased black abalone density. The presence of sea otters also correlated with a shift in black abalone to habitat conferring greater refuge, which could decrease illegal human harvest. These results highlight the need for a multi-species approach to conservation management of the two species, and demonstrate the importance of using field-collected data rather than simple trophic assumptions to understand relationships between jointly vulnerable predator and prey populations.

Monitoring population status of sea otters (Enhydra lutris) in Glacier Bay National Park and Preserve, Alaska: options and considerations

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Esslinger, George G.; Esler, Daniel N.; Howlin, S.; Starcevich, L.A.

2015-06-25

After many decades of absence from southeast Alaska, sea otters (Enhydra lutris) are recolonizing parts of their former range, including Glacier Bay, Alaska. Sea otters are well known for structuring nearshore ecosystems and causing community-level changes such as increases in kelp abundance and changes in the size and number of other consumers. Monitoring population status of sea otters in Glacier Bay will help park researchers and managers understand and interpret sea otter-induced ecosystem changes relative to other sources of variation, including potential human-induced impacts such as ocean acidification, vessel disturbance, and oil spills. This report was prepared for the National Park Service (NPS), Southeast Alaska Inventory and Monitoring Network following a request for evaluation of options for monitoring sea otter population status in Glacier Bay National Park and Preserve. To meet this request, we provide a detailed consideration of the primary method of assessment of abundance and distribution, aerial surveys, including analyses of power to detect interannual trends and designs to reduce variation around annual abundance estimates. We also describe two alternate techniques for evaluating sea otter population status—(1) quantifying sea otter diets and energy intake rates, and (2) detecting change in ages at death. In addition, we provide a brief section on directed research to identify studies that would further our understanding of sea otter population dynamics and effects on the Glacier Bay ecosystem, and provide context for interpreting results of monitoring activities.

Determining the pattern of cementum annuli and relationship to reproduction in male sea otters

Science.gov (United States)

Proper, Josh; von Biela, Vanessa R.; Burns, Jennifer M.

2007-01-01

Since the early 1990s, the southwestern Alaskan sea otter (Enhydra lutris) population has declined dramatically and the cause has yet to be determined. Population trajectories of large mammals are determined by three factors: survival rate, reproduction rate, and age of first reproduction (AFR). Of these three, AFR should respond first to environmental change. Life history theory predicts that AFR will be older with bottom-up causes (ie, food limitation) and younger when the cause of the decline is top-down (ie, predation), as there is usually abundant resources in this scenario. Traditionally, determining AFR required lethal sampling, which may not always be possible. Work on many mammalian species suggests that the width of annual cementum layers in teeth may decline when breeding begins. If so, examining teeth annuli may provide a nonlethal alternative for determining AFR. Ongoing research has shown this relationship in female sea otters, but male sea otters have not been tested. Sea otter testes and premolar teeth slides were collected by subsistence hunters working with the US Fish and Wildlife Service and the Alaska Sea Otter and Steller Sea Lion Commission from Alaska (1994– 2005). We determined the pattern in cementum annuli thickness for male sea otters across age by measuring annuli at three sites on each of the two slide sections available. We found that cementum annuli layers decreased with age, but found no correlation between cementum annuli and sexual maturity in male sea otters. This lack of correlation may be due to sampling error or different energy expenditures during reproduction for each sex. Since females expend large amounts of energy through gestation and lactation, we hypothesize that the width of female cementum annuli decreases at a much sharper rate when they reach AFR.The southwest Alaskan sea otter population has plummeted up to 90% since the early 1990s and the reason is unknown.1 Declines may be due to a bottom-up source caused by

76 FR 53381 - Endangered and Threatened Wildlife and Plants; Termination of the Southern Sea Otter...

Science.gov (United States)

2011-08-26

..., the plan was required to include: (1) The number, age, and sex of southern sea otters proposed to be... status of the species under the ESA and determinations under section 7 of the ESA. The purposes of the... a self- sustaining southern sea otter population (experimental population) that would provide a...

Dual congenital transmission of Toxoplasma gondii and Sarcocystis neurona in a late-term aborted pup from a chronically infected southern sea otter (Enhydra lutris nereis).

Science.gov (United States)

Shapiro, Karen; Miller, Melissa A; Packham, Andrea E; Aguilar, Beatriz; Conrad, Patricia A; Vanwormer, Elizabeth; Murray, Michael J

2016-03-01

Toxoplasma gondii and Sarcocystis neurona are protozoan parasites with terrestrial definitive hosts, and both pathogens can cause fatal disease in a wide range of marine animals. Close monitoring of threatened southern sea otters (Enhydra lutris nereis) in California allowed for the diagnosis of dual transplacental transmission of T. gondii and S. neurona in a wild female otter that was chronically infected with both parasites. Congenital infection resulted in late-term abortion due to disseminated toxoplasmosis. Toxoplasma gondii and S. neurona DNA was amplified from placental tissue culture, as well as from fetal lung tissue. Molecular characterization of T. gondii revealed a Type X genotype in isolates derived from placenta and fetal brain, as well as in all tested fetal organs (brain, lung, spleen, liver and thymus). This report provides the first evidence for transplacental transmission of T. gondii in a chronically infected wild sea otter, and the first molecular and immunohistochemical confirmation of concurrent transplacental transmission of T. gondii and S. neurona in any species. Repeated fetal and/or neonatal losses in the sea otter dam also suggested that T. gondii has the potential to reduce fecundity in chronically infected marine mammals through parasite recrudescence and repeated fetal infection.

Modeling the Effects of Mortality on Sea Otter Populations

Science.gov (United States)

Bodkin, James L.; Ballachey, Brenda E.

2010-01-01

Conservation and management of sea otters can benefit from managing the magnitude and sex composition of human related mortality, including harvesting within sustainable levels. Using age and sex-specific reproduction and survival rates from field studies, we created matrix population models representing sea otter populations with growth rates of 1.005, 1.072, and 1.145, corresponding to stable, moderate, and rapid rates of change. In each modeled population, we incrementally imposed additional annual mortality over a 20-year period and calculated average annual rates of change (lambda). Additional mortality was applied to (1) males only, (2) at a 1:1 ratio of male to female, and (3) at a 3:1 ratio of male to female. Dependent pups (age 0-0.5) were excluded from the mortality. Maintaining a stable or slightly increasing population was largely dependent on (1) the magnitude of additional mortality, (2) the underlying rate of change in the population during the period of additional mortality, and (3) the extent that females were included in the additional mortality (due to a polygnous reproductive system where one male may breed with more than one female). In stable populations, additional mortality as high as 2.4 percent was sustainable if limited to males only, but was reduced to 1.2 percent when males and females were removed at ratios of 3:1 or 0.5 percent at ratios of 1:1. In moderate growth populations, additional mortality of 9.8 percent (male-only) and 15.0 percent (3:1 male to female) maximized the sustainable mortality about 3-10 ten-fold over the stable population levels. However, if additional mortality consists of males and females at equal proportions, the sustainable rate is 7.7 percent. In rapid growth populations, maximum sustainable levels of mortality as high as 27.3 percent were achieved when the ratio of additional mortality was 3:1 male to female. Although male-only mortality maximized annual harvest in stable populations, high male biased

2013 update on sea otter studies to assess recovery from the 1989 Exxon Valdez oil spill, Prince William Sound, Alaska

Science.gov (United States)

Ballachey, Brenda E.; Monson, Daniel H.; Esslinger, George G.; Kloecker, Kimberly; Bodkin, James L.; Bowen, Lizabeth; Miles, A. Keith

2014-01-01

On March 24, 1989, the tanker vessel Exxon Valdez ran aground in Prince William Sound, Alaska, spilling an estimated 42 million liters of Prudhoe Bay crude oil. Oil spread in a southwesterly direction and was deposited on shores and waters in western Prince William Sound (WPWS). The sea otter (Enhydra lutris) was one of more than 20 nearshore species considered to have been injured by the spill. Since 1989, the U.S. Geological Survey has led a research program to evaluate effects of the spill on sea otters and assess progress toward recovery, as defined by demographic and biochemical indicators. Here, we provide an update on the status of sea otter populations in WPWS, presenting findings through 2013. To assess recovery based on demographic indicators, we used aerial surveys to estimate abundance and annual collections of sea otter carcasses to evaluate patterns in ages-at-death. To assess recovery based on biochemical indicators, we quantified transcription rates for a suite of genes selected as potential indicators of oil exposure in sea otters based on laboratory studies of a related species, the mink (Mustela vison). In our most recent assessment of sea otter recovery, which incorporated results from a subset of studies through 2009, we concluded that recovery of sea otters in WPWS was underway. This conclusion was based on increasing abundance throughout WPWS, including increasing numbers at northern Knight Island, an area that was heavily oiled in 1989 and where the local sea otter population had previously shown protracted injury and lack of recovery. However, we did not conclude that the WPWS sea otter population had fully recovered, due to indications of continuing reduced survival and exposure to lingering oil in sea otters at Knight Island, at least through 2009. Based on data available through 2013, we now conclude that the status of sea otters—at all spatial scales within WPWS—is consistent with the designation of recovery from the spill as

Using stable isotopes to investigate individual diet specialization in California sea otters (Enhydra lutris nereis)

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Newsome, S.D.; Tinker, M.T.; Monson, Daniel H.; Oftedal, O.T.; Ralls, K.; Staedler, M.M.; Fogel, M.L.; Estes, J.A.

2009-01-01

Differences in diet composition among conspecifics (dietary specialization) have been documented across a broad range of taxonomic groups and habitats, and such variation at the individual level is increasingly recognized as an important component of diversity in trophic interactions. Accurate identification of individual dietary specialization, however, requires longitudinal dietary records that are labor-intensive and cost-prohibitive to obtain for many species. Here we explore the use of stable isotopes (δ13C and δ15N) as a promising technique for detecting and quantifying patterns of individual dietary specialization. Southern sea otters (Enhydra lutris nereis) offer a unique opportunity for testing this approach because (1) they consume a wide variety of prey that span multiple trophic levels, habitats, and ecologically defined functional groups; and (2) individual diet specialization can be validated with existing observational data. We analyzed the isotopic composition of sea otter vibrissae (n = 31) in order to characterize inter- and intra-individual variation in sea otter diets at Monterey Bay, California, USA. At the population level, sea otters showed substantial variation in both δ13C and δ15N values, occupying nearly all of the “isotopic space” created by the diversity of isotopic signatures of potential prey taxa. Most of the variation in sea otter vibrissae was accounted for by differences between individuals, with much less contributed by within-individual variation. A majority of sea otters (∼80%) showed relatively little temporal variability in isotopic composition, suggesting that the proportional composition of most individuals' diets is relatively constant over time; a few individuals (∼20%) exhibited a high degree of intra-vibrissa isotopic variability, suggesting seasonal shifts in diet composition. These results and our interpretation of them were supported by long-term observational data on the diets of radio-tagged sea otters

Setting realistic recovery targets for two interacting endangered species, sea otter and northern abalone.

Science.gov (United States)

Chadès, Iadine; Curtis, Janelle M R; Martin, Tara G

2012-12-01

Failure to account for interactions between endangered species may lead to unexpected population dynamics, inefficient management strategies, waste of scarce resources, and, at worst, increased extinction risk. The importance of species interactions is undisputed, yet recovery targets generally do not account for such interactions. This shortcoming is a consequence of species-centered legislation, but also of uncertainty surrounding the dynamics of species interactions and the complexity of modeling such interactions. The northern sea otter (Enhydra lutris kenyoni) and one of its preferred prey, northern abalone (Haliotis kamtschatkana), are endangered species for which recovery strategies have been developed without consideration of their strong predator-prey interactions. Using simulation-based optimization procedures from artificial intelligence, namely reinforcement learning and stochastic dynamic programming, we combined sea otter and northern abalone population models with functional-response models and examined how different management actions affect population dynamics and the likelihood of achieving recovery targets for each species through time. Recovery targets for these interacting species were difficult to achieve simultaneously in the absence of management. Although sea otters were predicted to recover, achieving abalone recovery targets failed even when threats to abalone such as predation and poaching were reduced. A management strategy entailing a 50% reduction in the poaching of northern abalone was a minimum requirement to reach short-term recovery goals for northern abalone when sea otters were present. Removing sea otters had a marginally positive effect on the abalone population but only when we assumed a functional response with strong predation pressure. Our optimization method could be applied more generally to any interacting threatened or invasive species for which there are multiple conservation objectives. © 2012 Society for

Sediment-associated aliphatic and aromatic hydrocarbons in coastal British Columbia, Canada: Concentrations, composition, and associated risks to protected sea otters

International Nuclear Information System (INIS)

Harris, Kate A.; Yunker, Mark B.; Dangerfield, Neil; Ross, Peter S.

2011-01-01

Sediment-associated hydrocarbons can pose a risk to wildlife that rely on benthic marine food webs. We measured hydrocarbons in sediments from the habitat of protected sea otters in coastal British Columbia, Canada. Alkane concentrations were dominated by higher odd-chain n-alkanes at all sites, indicating terrestrial plant inputs. While remote sites were dominated by petrogenic polycyclic aromatic hydrocarbons (PAHs), small harbour sites within sea otter habitat and sites from an urban reference area reflected weathered petroleum and biomass and fossil fuel combustion. The partitioning of hydrocarbons between sediments and adjacent food webs provides an important exposure route for sea otters, as they consume ∼25% of their body weight per day in benthic invertebrates. Thus, exceedences of PAH sediment quality guidelines designed to protect aquatic biota at 20% of the sites in sea otter habitat suggest that sea otters are vulnerable to hydrocarbon contamination even in the absence of catastrophic oil spills. - Highlights: → Sediment hydrocarbon signatures differed between remote and impacted coastal sites. → A natural background comprised terrestrial plant alkanes and petrogenic PAHs. → Impacted sites reflected a history of petrogenic and pyrogenic hydrocarbon inputs. → Hydrocarbons at some sites exceeded guidelines for the protection of aquatic life. → Protected sea otters may thus be at risk as they rely primarily on benthic prey. - Anthropogenically-derived hydrocarbons in coastal sediments in British Columbia may pose a risk to protected sea otters.

Pathogenesis of Streptococcus infantarius subspecies coli Isolated from Sea Otters with Infective Endocarditis.

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Counihan, Katrina L; Gill, Verena A; Miller, Melissa A; Burek-Huntington, Kathleen A; LeFebvre, Rance B; Byrne, Barbara A

2015-06-01

The Gram positive bacterial coccus Streptococcus infantarius subspecies coli is increasingly linked with development of fatal vegetative infective endocarditis and septicemia in humans, sea otters (Enhydra lutris) and other animals. However, the pathogenesis of these infections is poorly understood. Using S. infantarius subsp. coli strains isolated from sea otters with infective endocarditis, this study evaluated adherence and invasion of epithelial and endothelial cells, adherence to extracellular matrix components, and macrophage survival. Significant adherence to endothelial-derived cells was observed for 62% of isolates, 24% adhered to epithelial cell lines, and 95% invaded one or both cell types in vitro. The importance of the hyaluronic acid capsule in host cell adherence and invasion was also evaluated. Capsule removal significantly reduced epithelial adherence and invasion for most S. infantarius subsp. coli isolates, suggesting that the capsule facilitates attachment to and invasion of epithelium. Enzyme-linked immunosorbent assay testing revealed that all isolates adhered significantly to the extracellular matrix components collagen IV, fibronectin, laminin and hyaluronic acid. Finally, significant bacterial survival following phagocytosis by macrophages was apparent for 81% of isolates at one or more time points. Taken collectively these findings indicate that S. infantarius subsp. coli has multiple pathogenic properties that may be important to host colonization, invasion and disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pathological studies of sea otters. Marine mammal study 6-11. Exxon Valdez oil spill state/federal natural resource damage assessment final report

Energy Technology Data Exchange (ETDEWEB)

Lipscomb, T.P.; Harris, R.K.; Rebar, A.H.; Ballachey, B.E.; Haebler, R.J.

1996-06-01

Following the Exxon Valdez oil spill, sea otters were captured and taken to rehabilitaion centers. Oil exposure was assessed by visual examination on arrival at the centers. Records of 21 oiled otters that died within 10 days of arrival at the centers were reviewed to define the laboratory abnormalities and clinical syndromes associated with these deaths. Tissues from 51 oiled and 6 unoiled sea otters that died in the centers were examined histologically. Histologic examinations were performed on tissues from 5 oiled otters found dead shortly after the spill. Nucropsies were performed on 214 sea otters that were collected and frozen following the oil spill. Pulmonary interstitial emphysema and gastric erosion and hemorrhage were common in oiled animals, and were less frequent in unoiled animals. Tissues from 6 sea otters collected from a nonoiled area were examined, and none of these lesions were found. We conclude that pulmonary interstitial emphysema, gastric erosion and hemorrhage, centrilobular hepatic necrosis, and hepatic and renal lipidosis were associated with exposure to crude oil in sea otters.

Inter-decadal patterns of population and dietary change in sea otters at Amchitka Island, Alaska

Science.gov (United States)

Watt, J.; Siniff, D.B.; Estes, J.A.

2000-01-01

After having been hunted to near-extinction in the Pacific maritime fur trade, the sea otter population at Amchitka Island, Alaska increased from very low numbers in the early 1900s to near equilibrium density by the 1940s. The population persisted at or near equilibrium through the 1980s, but declined sharply in the 1990s in apparent response to increased killer whale predation. Sea otter diet and foraging behavior were studied at Amchitka from August 1992 to March 1994 and the data compared with similar information obtained during several earlier periods. In contrast with dietary patterns in the 1960s and 1970s, when the sea otter population was at or near equilibrium density and kelp-forest fishes were the dietary mainstay, these fishes were rarely eaten in the 1990s. Benthic invertebrates, particularly sea urchins, dominated the otter's diet from early summer to midwinter, then decreased in importance during late winter and spring when numerous Pacific smooth lumpsuckers (a large and easily captured oceanic fish) were eaten. The occurrence of spawning lumpsuckers in coastal waters apparently is episodic on a scale of years to decades. The otters' recent dietary shift away from kelp-forest fishes is probably a response to the increased availability of lumpsuckers and sea urchins (both high-preference prey). Additionally, increased urchin densities have reduced kelp beds, thus further reducing the availability of kelp-forest fishes. Our findings suggest that dietary patterns reflect changes in population status and show how an ecosystem normally under top-down control and limited by coastal zone processes can be significantly perturbed by exogenous events.

Brucella Infection in Asian Sea Otters (Enhydra lutris lutris) on Bering Island, Russia.

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Burgess, Tristan L; Johnson, Christine Kreuder; Burdin, Alexander; Gill, Verena A; Doroff, Angela M; Tuomi, Pamela; Smith, Woutrina A; Goldstein, Tracey

2017-10-01

Infection with Brucella spp., long known as a cause of abortion, infertility, and reproductive loss in domestic livestock, has increasingly been documented in marine mammals over the past two decades. We report molecular evidence of Brucella infection in Asian sea otters (Enhydra lutris lutris). Brucella DNA was detected in 3 of 78 (4%) rectal swab samples collected between 2004 and 2006 on Bering Island, Russia. These 78 animals had previously been documented to have a Brucella seroprevalence of 28%, markedly higher than the prevalence documented in sea otters (Enhydra lutris) in North America. All of the DNA sequences amplified were identical to one or more previously isolated Brucella spp. including strains from both terrestrial and marine hosts. Phylogenetic analysis of this sequence suggested that one animal was shedding Brucella spp. DNA with a sequence matching a Brucella abortus strain, whereas two animals yielded a sequence matching a group of strains including isolates classified as Brucella pinnipedialis and Brucella melitensis. Our results highlight the diversity of Brucella spp. within a single sea otter population.

Trade-offs between energy maximization and parental care in a central place forager, the sea otter

Science.gov (United States)

Thometz, N M; Staedler, M.M.; Tomoleoni, Joseph; Bodkin, James L.; Bentall, G.B.; Tinker, M. Tim

2016-01-01

Between 1999 and 2014, 126 archival time–depth recorders (TDRs) were used to examine the foraging behavior of southern sea otters (Enhydra lutris nereis) off the coast of California, in both resource-abundant (recently occupied, low sea otter density) and resource-limited (long-occupied, high sea otter density) locations. Following predictions of foraging theory, sea otters generally behaved as energy rate maximizers. Males and females without pups employed similar foraging strategies to optimize rates of energy intake in resource-limited habitats, with some exceptions. Both groups increased overall foraging effort and made deeper, longer and more energetically costly dives as resources became limited, but males were more likely than females without pups to utilize extreme dive profiles. In contrast, females caring for young pups (≤10 weeks) prioritized parental care over energy optimization. The relative importance of parental care versus energy optimization for adult females with pups appeared to reflect developmental changes as dependent young matured. Indeed, contrary to females during the initial stages of lactation, females with large pups approaching weaning once again prioritized optimizing energy intake. The increasing prioritization of energy optimization over the course of lactation was possible due to the physiological development of pups and likely driven by the energetic deficit incurred by females early in lactation. Our results suggest that regardless of resource availability, females at the end of lactation approach a species-specific ceiling for percent time foraging and that reproductive females in the central portion of the current southern sea otter range are disproportionately affected by resource limitation.

Human Impacts on Seals, Sea Lions, and Sea Otters: Integrating Archaeology and Ecology of the Northeast Pacific

Directory of Open Access Journals (Sweden)

Ray Pierotti

2013-03-01

Full Text Available Review of Human Impacts on Seals, Sea Lions, and Sea Otters: Integrating Archaeology and Ecology of the Northeast Pacific. Todd J. Braje and Torben C. Rick, editors. 2011. University of California Press, Berkeley. Pp. 328. $65.00 (hardcover. ISBN 9780520267268.

Could residual oil from the Exxon Valdez spill create a long-term population "sink" for sea otters in Alaska?

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Monson, Daniel H.; Doak, Daniel F.; Ballachey, Brenda E.; Bodkin, James L.

2011-01-01

Over 20 years ago, the Exxon Valdez oil tanker spilled 42 million L of crude oil into the waters of Prince William Sound, Alaska, USA. At the time of the spill, the sea otter (Enhydra lutris) population inhabiting the spill area suffered substantial acute injuries and loss. Subsequent research has resulted in one of the best-studied species responses to an oil spill in history. However, the question remains: Is the spill still influencing the Prince William Sound sea otter population? Here we fit time-varying population models to data for the sea otter population of western Prince William Sound to quantify the duration and extent of mortality effects from the spill. We hypothesize that the patchy nature of residual oil left in the environment has created a source-sink population dynamic. We fit models using the age distributions of both living and dying animals and estimates of sea otter population size to predict the number of sea otters in the hypothesized sink population and the number lost to this sink due to chronic exposure to residual oil. Our results suggest that the sink population has remained at just over 900 individuals (95% CI: 606-960) between 1990 and 2009, during which time prime-age survival remained 2-6% below pre-spill levels. This reduced survival led to chronic losses of ???900 animals over the past two decades, which is similar in magnitude to the number of sea otter deaths documented in western Prince William Sound during the acute phase of the spill. However, the unaffected source population appears to be counterbalancing these losses, with the model indicating that the sea otter population increased from ???2150 individuals in 1990 to nearly 3000 in 2009. The most optimistic interpretation of our results suggests that mortality effects dissipated between 2005 and 2007. Our results suggest that residual oil can affect wildlife populations on time scales much longer than previously believed and that cumulative chronic effects can be as

ISOLATION AND CHARACTERIZATION OF A NOVEL MARINE BRUCELLA FROM A SOUTHERN SEA OTTER (ENHYDRA LUTRIS NEREIS), CALIFORNIA, USA.

Science.gov (United States)

Miller, Melissa A; Burgess, Tristan L; Dodd, Erin M; Rhyan, Jack C; Jang, Spencer S; Byrne, Barbara A; Gulland, Frances M D; Murray, Michael J; Toy-Choutka, Sharon; Conrad, Patricia A; Field, Cara L; Sidor, Inga F; Smith, Woutrina A

2017-04-01

We characterize Brucella infection in a wild southern sea otter ( Enhydra lutris nereis) with osteolytic lesions similar to those reported in other marine mammals and humans. This otter stranded twice along the central California coast, US over a 1-yr period and was handled extensively at two wildlife rehabilitation facilities, undergoing multiple surgeries and months of postsurgical care. Ultimately the otter was euthanized due to severe, progressive neurologic disease. Necropsy and postmortem radiographs revealed chronic, severe osteoarthritis spanning the proximal interphalangeal joint of the left hind fifth digit. Numerous coccobacilli within the joint were strongly positive on Brucella immunohistochemical labelling, and Brucella sp. was isolated in pure culture from this lesion. Sparse Brucella-immunopositive bacteria were also observed in the cytoplasm of a pulmonary vascular monocyte, and multifocal granulomas were observed in the spinal cord and liver on histopathology. Findings from biochemical characterization, 16S ribosomal DNA, and bp26 gene sequencing of the bacterial isolate were identical to those from marine-origin brucellae isolated from cetaceans and phocids. Although omp2a gene sequencing revealed 100% homology with marine Brucella spp. infecting pinnipeds, whales, and humans, omp2b gene sequences were identical only to pinniped-origin isolates. Multilocus sequence typing classified the sea otter isolate as ST26, a sequence type previously associated only with cetaceans. Our data suggest that the sea otter Brucella strain represents a novel marine lineage that is distinct from both Brucella pinnipedialis and Brucella ceti. Prior reports document the zoonotic potential of the marine brucellae. Isolation of Brucella sp. from a stranded sea otter highlights the importance of wearing personal protective equipment when handling sea otters and other marine mammals as part of wildlife conservation and rehabilitation efforts.

Dual Sarcocystis neurona and Toxoplasma gondii infection in a northern sea otter from Washington state, USA

Science.gov (United States)

Lindsay, D.S.; Thomas, N.J.; Rosypal, A.C.; Dubey, J.P.

2001-01-01

Dual Sarcocystis neurona and Toxoplasma gondii infection was observed in a Northern sea otter from Washington, USA. The animal was found stranded, convulsed, and died shortly thereafter. Encephalitis caused by both S. neurona and T. gondii was demonstrated in histological sections of brain. Immunohistochemical examination of sections with S. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. PCR of brain tissue from the sea otter using primer pairs JNB33/JNB54 resulted in amplification of a 1100 bp product. This PCR product was cut in to 884 and 216 bp products by Dra I but was not cut by Hinf I indicating that it was S. neurona [J. Parasitol. 85 (1999) 221]. No PCR product was detected in the brain of a sea otter which had no lesions of encephalitis. Examination of brain sections using T. gondii specific antisera demonstrated tachyzoites and tissue cysts of T. gondii. The lesions induced by T. gondii suggested that the sea otter was suffering from reactivated toxoplasmosis. T. gondii was isolated in mice inoculated with brain tissue. A cat that was fed infected mouse brain tissue excreted T. gondii oocysts which were infective for mice. This is apparently the first report of dual S. neurona and T. gondii in a marine mammal.

Histopathologic lesions associated with crude oil exposure in sea otters. Marine mammal study 6-10. Exxon Valdez oil spill state/federal natural resources damage assessment final report

Energy Technology Data Exchange (ETDEWEB)

Lipscomb, T.P.; Harris, R.K.; Moeller, R.B.; Pletcher, J.M.; Haebler, R.J.

1996-06-01

Following the Exxon Valdez oil spill in Prince William Sound, Alaska, sea otters (Enhydra lutris) that appeared oiled, were in danger of becoming oiled, or were behaving abnormally were captured and taken to rehabilitation centers. Oil exposure was assessed by visual examination on arrival at the centers. Tissues from 51 oiled sea otters and from 6 unoiled sea otters that died in rehabilitation centers were examined histologically. Histologic examinations were performed on tissues from 5 sea otters found dead with external oil present shortly after the spill. Necropsies were performed on 214 sea otters that had been collected and frozen in the period following the oil spill. Tissues from 6 apparently normal sea otters collected from an area not affected by the oil spill were examined histologically, and none of these lesions were found. We conclude that pulmonary interstitial emphysema, gastric erosion and hemorrhage, centrilobular hepatic necrosis, and hepatic and renal lipidosis were associated with exposure to crude oil in sea otters.

The cost of reproduction: differential resource specialization in female and male California sea otters.

Science.gov (United States)

Smith, Emma A Elliott; Newsome, Seth D; Estes, James A; Tinker, M Tim

2015-05-01

Intraspecific variation in behavior and diet can have important consequences for population and ecosystem dynamics. Here, we examine how differences in reproductive investment and spatial ecology influence individual diet specialization in male and female southern sea otters (Enhydra lutris nereis). We hypothesize that greater reproductive constraints and smaller home ranges of females lead to more pronounced intraspecific competition and increased specialization. We integrate stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope analysis of sea otter vibrissae with long-term observational studies of five subpopulations in California. We define individual diet specialization as low ratios of within-individual variation (WIC) to total population niche width (TNW). We compare isotopic and observational based metrics of WIC/TNW for males and females to data on population densities, and movement patterns using both general linear and linear mixed-effects models. Consistent with our hypothesis, increasing population density is associated with increased individual diet specialization by females but not by males. Additionally, we find the amount of coastline in a sea otter's home range positively related with individual dietary variability, with increased range span resulting in weaker specialization for both males and females. We attribute our results to sex-based differences in movement, with females needing to specialize in their small ranges to maximize energy gain, and posit that the paradigm of individual prey specialization in sea otters with increased intraspecific competition may be a pattern driven largely by females. Our work highlights a potentially broader role of sex in the mechanistic pressures promoting and maintaining diet specialization.

Evidence for a novel marine harmful algal bloom: cyanotoxin (microcystin transfer from land to sea otters.

Directory of Open Access Journals (Sweden)

Melissa A Miller

Full Text Available "Super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine

Evidence for a novel marine harmful algal bloom: Cyanotoxin (Microcystin) transfer from land to sea otters

Science.gov (United States)

Miller, Melissa A.; Kudela, Raphael M.; Mekebri, Abdu; Crane, Dave; Oates, Stori C.; Tinker, M. Timothy; Staedler, Michelle; Miller, Woutrina A.; Toy-Choutka, Sharon; Dominik, Clare; Hardin, Dane; Langlois, Gregg; Murray, Michael; Ward, Kim; Jessup, David A.

2010-01-01

"Super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb) were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels) and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine "harmful algal

Using ecological function to develop recovery criteria for depleted species: Sea otters and kelp forests in the Aleutian archipelago

Science.gov (United States)

Estes, James A.; Tinker, M. Tim; Bodkin, James L.

2010-01-01

Recovery criteria for depleted species or populations normally are based on demographic measures, the goal being to maintain enough individuals over a sufficiently large area to assure a socially tolerable risk of future extinction. Such demographically based recovery criteria may be insufficient to restore the functional roles of strongly interacting species. We explored the idea of developing a recovery criterion for sea otters (Enhydra lutris) in the Aleutian archipelago on the basis of their keystone role in kelp forest ecosystems. We surveyed sea otters and rocky reef habitats at 34 island-time combinations. The system nearly always existed in either a kelp-dominated or deforested phase state, which was predictable from sea otter density. We used a resampling analysis of these data to show that the phase state at any particular island can be determined at 95% probability of correct classification with information from as few as six sites. When sea otter population status (and thus the phase state of the kelp forest) was allowed to vary randomly among islands, just 15 islands had to be sampled to estimate the true proportion that were kelp dominated (within 10%) with 90% confidence. We conclude that kelp forest phase state is a more appropriate, sensitive, and cost-effective measure of sea otter recovery than the more traditional demographically based metrics, and we suggest that similar approaches have broad potential utility in establishing recovery criteria for depleted populations of other functionally important species.

An otter tragedy

International Nuclear Information System (INIS)

Raloff, J.

1993-01-01

Otters appear to be the most vulnerable of all marine mammals to oil; oil reduces the insulating value of their fur by as much as 70% and otters are extremely vulnerable to oil poisoning through inhalation of hydrocarbon fumes, ingestion of petroleum, and absorption through the skin. After the Exxon Valdez accident in Alaska's Prince William Sound, dramatic efforts were made to rescue and rehabilitate otters and other sea animals. One hundred ninety seven of the treated otters were released back into the wild. However, soon after the release, wildlife biologist Lisa Rotterman reported an unprecidented die-off of never-oiled otters. Many of the treated otters may have carried a potentially novel herpesvirus, but whether this caused the die-off is controversial. It is also hard to separate symptoms of sickness, stress, and fear from oil toxicity. Overall the findings suggest a generic regimen for all oiled otters: antibiotics, vitamin and mineral supplements, and prompt administration of fluids. Assessing which animals need care is an urgent need. Strict quarantine, short captivity time, and protected handling of oiled animals are further suggestions

Accumulation pattern of organochlorine pesticides and polychlorinated biphenyls in sourthern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA

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Nakata, H.; Kannan, K.; Jing, L.; Thomas, N.J.; Tanabe, S.; Giesy, J.P.

1998-01-01

Concentrations of PCBs, DDTs (p,p'-DDE, p,p'-DDD and p,p'-DDT), HCHs (α-, β-, γ-isomers), chlordanes (trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane) and HCB (hexachlorobenzene were measured in liver, kidney and brain tissues of adult southern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA, during 1992–96. The contamination pattern of organochlorines in sea otters from several locations was in the order of DDTs > PCBs > > CHLs > HCHs > > HCB, whereas those from Monterey Harbor contained greater concentrations of PCBs than of DDTs. Hepatic concentrations of PCBs and DDTs were in the ranges of 58–8700 and 280–5900 ng/g, wet weight, respectively, which varied depending on the geographic location. Sea otters collected from Monterey Harbor contained the greatest concentrations of PCBs and DDTs. In general, accumulation of DDTs, CHLs and PCBs was greater in kidney than in liver, whereas that of HCHs was similar in both the tissues. The gender difference in organochlorine concentrations was less than those reported in cetaceans. The composition of DDTs, HCHs and CHLs compounds in sea otter tissues indicated no recent inputs of these compounds in coastal California. Sea otters that died from infectious diseases, neoplasia and emaciation contained higher concentrations of DDTs than those that died from trauma.

Sarcocystis neurona retinochoroiditis in a sea otter (Enhydra lutris kenyoni).

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Dubey, J P; Thomas, N J

2011-12-29

Sarcocystis neurona is an important cause of fatal disease in sea otters in the USA. Encephalitis is the predominant lesion and parasites are confined to the central nervous system and muscles. Here we report retinochoroiditis in a sea otter (Enhydra lutris kenyoni) found dead on Copalis Beach, WA, USA. Salient lesions were confined to the brain and eye. Multifocal nonsuppurative meningoencephalitis was present in the cerebrum and cerebellum associated with S. neurona schizonts. The retina of one eye had a focus of inflammation that contained numerous S. neurona schizonts and merozoites. The focus extended from the retinal pigment epithelium inward through all layers of the retina, but inflammation was most concentrated at the inner surface of the tapetum and the outer retina. The inner and outer nuclear layers of the retina were disorganized and irregular at the site of inflammation. There was severe congestion and mild hemorrhage in the choroid, and mild hemorrhage into the vitreous body. Immunohistochemistry with S. neurona-specific polyclonal rabbit antibodies stained schizonts and merozoites. To our knowledge this is the first report of S. neurona-associated retinochoroiditis in any naturally infected animal. Copyright © 2011 Elsevier B.V. All rights reserved.

Persistent organic pollutants in the blood of free-ranging sea otters (Enhydra lutris ssp.) in Alaska and California

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Jessup, David A.; Johnson, Christine K.; Estes, James A.; Carlson-Bremer, Daphne; Jarman, Walter M.; Reese, Stacey; Dodd, Erin; Tinker, M. Tim; Ziccardi, Michael H.

2010-01-01

As part of tagging and ecologic research efforts in 1997 and 1998, apparently healthy sea otters of four age-sex classes in six locations in Alaska and three in California were sampled for persistent organic pollutants (POPs) and other chemicals of ecologic or environmental concern (COECs). Published techniques for the detection of POPs (specifically Σpolychlorinated biphenyls [PCBs], ΣDDTs, Σhexachlorocyclohexanes [HCHs], Σpolycyclic aromatic hydrocarbons [PAHs], Σchlordanes [CHLs], hexachlorobenzene [HCB], dieldrin, and mirex) in the tissue of dead otters were modified for use with serum from live sea otters. Toxic equivalencies (TEQs) were calculated for POPs with proven bioactivity. Strong location effects were seen for most POPs and COECs; sea otters in California generally showed higher mean concentrations than those in Alaska. Differences in contaminant concentrations were detected among age and sex classes, with high levels frequently observed in subadults. Very high levels of ΣDDT were detected in male sea otters in Elkhorn Slough, California, where strong freshwater outflow from agricultural areas occurs seasonally. All contaminants except mirex differed among Alaskan locations; only ΣDDT, HCB, and chlorpyrifos differed within California. High levels of ΣPCB (particularly larger, more persistent congeners) were detected at two locations in Alaska where associations between elevated PCBs and military activity have been established, while higher PCB levels were found at all three locations in California where no point source of PCBs has been identified. Although POP and COEC concentrations in blood may be less likely to reflect total body burden, concentrations in blood of healthy animals may be more biologically relevant and less influenced by state of nutrition or perimortem factors than other tissues routinely sampled.

Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana)

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Dubey, J.P.; Rosypal, A.C.; Rosenthal, B.M.; Thomas, N.J.; Lindsay, D.S.; Stanek, J.F.; Reed, S.M.; Saville, W.J.A.

2001-01-01

Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 I?m long, and the villar protrusions on the sarcocyst wall were up to 1.3 I?m long and up to 0.25 I?m wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana).

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Dubey, J R; Rosypal, A C; Rosenthal, B M; Thomas, N J; Lindsay, D S; Stanek, J F; Reed, S M; Saville, W J

2001-12-01

Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 microm long, and the villar protrusions on the sarcocyst wall were up to 1.3 microm long and up to 0.25 microm wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

77 FR 75265 - Endangered and Threatened Wildlife and Plants; Termination of the Southern Sea Otter...

Science.gov (United States)

2012-12-19

... (USFWS 2003), the recovery team recommends that we declare the translocation program a failure and... be in the best interest of southern sea otter recovery to declare the translocation program a failure... Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; Termination of the Southern Sea...

Social organization of sea otters in Prince William Sound, Alaska

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Garshelis, David L.; Johnson, Ancel M.; Garshelis, Judith A.

1984-01-01

Sea otters in Prince William Sound. Alaska, were spatially segregated into predominantly (97%) male areas at the front of the expanding population and breeding areas with fewer (up to 33%) males. From 1975 to 1984 we captured and marked 267 otters with tags and (or) radio transmitters and investigated their reproductive strategies, social relationships, and patterns of sexual segregation. Mating occurred year-round, but peaked in September and October. Females first bred at 4 years of age and were capable of pupping annually; they generally separated from their pup before mating. Males established breeding territories that enabled prolonged precopulatory interactions that may have prompted female–pup separation and post-copulatory interactions that precluded females from mating with other males. Male mating success was related to age, weight, territory quality, and the length of time they maintained their territory. After the breeding season, territorial males returned to male areas where food was more abundant. Young, dispersing males also entered male areas and remained there until attaining breeding age. In male areas, otters commonly rested in groups of >50 individuals. Gregariousness promoted social interactions and likely enhanced food finding and (historically) predator protection. As food diminished, males moved into adjacent, unoccupied regions; females then occupied former male areas.

Genotypic Characterization of Streptococcus infantarius subsp. coli Isolates from Sea Otters with Infective Endocarditis and/or Septicemia and from Environmental Mussel Samples

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Counihan-Edgar, Katrina L.; Gill, Verena A.; Doroff, Angela M.; Burek, Kathleen A.; Miller, Woutrina A.; Shewmaker, Patricia L.; Jang, Spencer; Goertz, Caroline E. C.; Tuomi, Pamela A.; Miller, Melissa A.; Jessup, David A.

2012-01-01

Pulsed-field gel electrophoresis (PFGE) was used to type 128 Streptococcus infantarius subsp. coli isolates from sea otters and mussels. Six SmaI PFGE groups were detected, with one predominant group representing 57% of the isolates collected over a wide geographic region. Several sea otter and mussel isolates were highly related, suggesting that an environmental infection source is possible. PMID:23052307

The effects of oil contamination and cleaning on sea otters (Enhydra lutris); II. Metabolism, thermoregulation, and behavior

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Davis, R W; Williams, T M; Thomas, J A; DasSelein, R A; Cornell, L H [Hubbs marine Research Center, San Diego, CA (USA)

1988-12-01

The purpose of this study was to develop a method to clean and rehabilitate sea otters that might become contaminated during an oil spill and to determine which physiological and behavioral factors were important in restoring the insulation provided by the fur. Tests were conducted on 12 sea otters; measurements of average metabolic rate, core body temperature, behavior, and squalene concentration on the fur were made before oiling 1-3 days after 20% of the body surface area was covered with fresh crude oil, and after cleaning. Under base-line conditions in water at 13{degrees}C, average metabolic rate was 8.0 W/kg, core body temperature was 38.9{degrees}C, and whole body thermal conductance was 10.7 W/(m2/{degrees}C). The squalene concentration on the fur averaged 3.7 mg/g fur. Oiling increased thermal conductance 1.8 times. To compensate for the loss of insulation and maintain a normal core body temperature (39{degrees}C), the otters increased average metabolic rate (1.9 times) through voluntary activity and shivering; the time spent grooming and swimming increased 1.7 times. Using detergent, the oiled fur could be cleaned during 40 min. of washing and rinsing. Grooming activity by the otters was essential for restoring the water-repellent quality of the fur. Core body temperature, average metabolic rate, and thermal conductance returned to base-line levels 3-6 days after cleaning. Squalene was removed by cleaning and did not return to normal levels in the oiled area after 7 days. Veterinary care was important to keep the otters healthy. At least 1-2 weeks should be allowed for otters to restore the insulation of their fur and for recovery from the stress of oiling and cleaning. 29 ref., 5 figs., 6 tabs.

Phocine Distemper Virus in Northern Sea Otters in the Pacific Ocean, Alaska, USA

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Mazet, Jonna A.K.; Gill, Verena A.; Doroff, Angela M.; Burek, Kathy A.; Hammond, John A.

2009-01-01

Phocine distemper virus (PDV) has caused 2 epidemics in harbor seals in the Atlantic Ocean but had never been identified in any Pacific Ocean species. We found that northern sea otters in Alaska are infected with PDV, which has created a disease threat to several sympatric and decreasing Pacific marine mammals. PMID:19523293

Kelp Forests versus Urchin Barrens: Alternate Stable States and Their Effect on Sea Otter Prey Quality in the Aleutian Islands

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Nathan L. Stewart

2012-01-01

Full Text Available Macroalgal and urchin barren communities are alternately stable and persist in the Aleutians due to sea otter presence and absence. In the early 1990s a rapid otter population decline released urchins from predation and caused a shift to the urchin-dominated state. Despite increases in urchin abundance, otter numbers continued to decline. Although debated, prey quality changes have been implicated in current otter population status. This study examined otter prey abundance, size, biomass, and potential energy density in remnant kelp forest and urchin-dominated communities to determine if alternate stable states affect prey quality. Findings suggest that although urchin barrens provide more abundant urchin prey, individual urchins are smaller and provide lower biomass and potential energy density compared to kelp forests. Shifts to urchin barrens do affect prey quality but changes are likely compensated by increased prey densities and are insufficient in explaining current otter population status in the Aleutians.

High-altitude diving in river otters: coping with combined hypoxic stresses.

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Crait, Jamie R; Prange, Henry D; Marshall, Noah A; Harlow, Henry J; Cotton, Clark J; Ben-David, Merav

2012-01-15

River otters (Lontra canadensis) are highly active, semi-aquatic mammals indigenous to a range of elevations and represent an appropriate model for assessing the physiological responses to diving at altitude. In this study, we performed blood gas analyses and compared blood chemistry of river otters from a high-elevation (2357 m) population at Yellowstone Lake with a sea-level population along the Pacific coast. Comparisons of oxygen dissociation curves (ODC) revealed no significant difference in hemoglobin-oxygen (Hb-O(2)) binding affinity between the two populations - potentially because of demands for tissue oxygenation. Instead, high-elevation otters had greater Hb concentrations (18.7 g dl(-1)) than sea-level otters (15.6 g dl(-1)). Yellowstone otters displayed higher levels of the vasodilator nitric oxide (NO), and half the concentration of the serum protein albumin, possibly to compensate for increased blood viscosity. Despite compensation in several hematological and serological parameters, theoretical aerobic dive limits (ADL) were similar between high-elevation and sea-level otters because of the lower availability of O(2) at altitude. Our results suggest that recent disruptions to the Yellowstone Lake food web could be detrimental to otters because at this high elevation, constraints on diving may limit their ability to switch to prey in a deep-water environment.

Trends in sea otter population abundance in western Prince William Sound, Alaska: Progress toward recovery following the 1989 Exxon Valdez oil spill

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Bodkin, James L.; Ballachey, Brenda E.; Esslinger, George G.

2011-01-01

Sea otters in western Prince William Sound (WPWS) and elsewhere in the Gulf of Alaska suffered widespread mortality as a result of oiling following the 1989 T/V Exxon Valdez oil spill. Following the spill, extensive efforts have been directed toward identifying and understanding long-term consequences of the spill and the process of recovery. We conducted annual aerial surveys of sea otter abundance from 1993 to 2009 (except for 2001 and 2006) in WPWS. We observed an increasing trend in population abundance at the scale of WPWS through 2000 at an average annual rate of 4 percent: however, at northern Knight Island where oiling was heaviest and sea otter mortality highest, no increase in abundance was evident by 2000. We continued to see significant increase in abundance at the scale of WPWS between 2001 and 2009, with an average annual rate of increase from 1993 to 2009 of 2.6 percent. We estimated the 2009 population size of WPWS to be 3,958 animals (standard error=653), nearly 2,000 animals more than the first post-spill estimate in 1993. Surveys since 2003 also have identified a significant increasing trend at the heavily oiled site in northern Knight Island, averaging about 25 percent annually and resulting in a 2009 estimated population size of 116 animals (standard error=19). Although the 2009 estimate for northern Knight Island remains about 30 percent less than the pre-spill estimate of 165 animals, we interpret this trend as strong evidence of a trajectory toward recovery of spill-affected sea otter populations in WPWS.

Biological characterisation of Sarcocystis neurona isolated from a Southern sea otter (Enhydra lutris nereis)

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Lindsay, D.S.; Thomas, N.J.; Dubey, J.P.

2000-01-01

Sarcocystis neurona was isolated from the brain of a juvenile, male southern sea otter (Enhydra lutris nereis) suffering from CNS disease. Schizonts and merozoites in tissue sections of the otter's brain reacted with anti-S. neurona antiserum immunohistochemically. Development in cell culture was by endopolyogeny and mature schizonts were first observed at 3 days postinoculation. PCR of merozoite DNA using primer pairs JNB33/JNB54 and restriction enzyme digestion of the 1100 bp product with Dra I indicated the organism was S. neurona. Four of four interferon-γ gene knockout mice inoculated with merozoites developed S. neurona-associated encephalitis. Antibodies to S. neurona but not Sarcocystis falcatula, Toxoplasma gondii, or Neospora caninum were present in the serum of inoculated mice. This is the first isolation of S. neurona from the brain of a non-equine host.

Structure and mechanism of diet specialisation: testing models of individual variation in resource use with sea otters

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Tinker, M. Tim; Guimarães, Paulo R.; Novak, Mark; Marquitti, Flavia Maria Darcie; Bodkin, James L.; Staedler, Michelle; Bentall, Gena B.; Estes, James A.

2012-01-01

Studies of consumer-resource interactions suggest that individual diet specialisation is empirically widespread and theoretically important to the organisation and dynamics of populations and communities. We used weighted networks to analyze the resource use by sea otters, testing three alternative models for how individual diet specialisation may arise. As expected, individual specialisation was absent when otter density was low, but increased at high-otter density. A high-density emergence of nested resource-use networks was consistent with the model assuming individuals share preference ranks. However, a density-dependent emergence of a non-nested modular network for ‘core’ resources was more consistent with the ‘competitive refuge’ model. Individuals from different diet modules showed predictable variation in rank-order prey preferences and handling times of core resources, further supporting the competitive refuge model. Our findings support a hierarchical organisation of diet specialisation and suggest individual use of core and marginal resources may be driven by different selective pressures.

Comparative functional anatomy of hindlimb muscles and bones with reference to aquatic adaptation of the sea otter.

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Mori, Kent; Suzuki, Satoshi; Koyabu, Daisuke; Kimura, Junpei; Han, Sung-Yong; Endo, Hideki

2015-05-01

Although the sea otter (Enhydra lutris) is a complete aquatic species, spending its entire life in the ocean, it has been considered morphologically to be a semi-aquatic animal. This study aimed to clarify the unique hindlimb morphology and functional adaptations of E. lutris in comparison to other Mustelidae species. We compared muscle mass and bone measurements of five Mustelidae species: the sea otter, Eurasian river otter (Lutra lutra), American mink (Neovison vison), Japanese weasel (Mustela itatsi) and Siberian weasel (M. sibirica). In comparison with the other 4 species, E. lutris possessed significantly larger gluteus, popliteus and peroneus muscles, but smaller adductor and ischiopubic muscles. The popliteus muscle may act as a medial rotator of the crus, and the peroneus muscle may act as an abductor of the fifth toe and/or the pronator of the foot. The bundles of the gluteus superficialis muscle of E. lutris were fused with those of the tensor fasciae latae muscle and gluteofemoralis muscles, and they may play a role in femur abduction. These results suggest that E. lutris uses the abducted femur, medially rotated crus, eversion of the ankle and abducted fifth digit or extended interdigital web as a powerful propulsion generator. Therefore, we conclude that E. lutris is a complete aquatic animal, possessing differences in the proportions of the hindlimb muscles compared with those in other semi-aquatic and terrestrial mustelids.

A protozoal-associated epizootic impacting marine wildlife: mass-mortality of southern sea otters (Enhydra lutris nereis) due to Sarcocystis neurona infection.

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Miller, Melissa A; Conrad, Patricia A; Harris, Michael; Hatfield, Brian; Langlois, Gregg; Jessup, David A; Magargal, Spencer L; Packham, Andrea E; Toy-Choutka, Sharon; Melli, Ann C; Murray, Michael A; Gulland, Frances M; Grigg, Michael E

2010-09-20

During April 2004, 40 sick and dead southern sea otters (Enhydra lutris nereis) were recovered over 18km of coastline near Morro Bay, California. This event represented the single largest monthly spike in mortality ever recorded during 30 years of southern sea otter stranding data collection. Because of the point-source nature of the event and clinical signs consistent with severe, acute neurological disease, exposure to a chemical or marine toxin was initially considered. However, detailed postmortem examinations revealed lesions consistent with an infectious etiology, and further investigation confirmed the protozoan parasite Sarcocystis neurona as the underlying cause. Tissues from 94% of examined otters were PCR-positive for S. neurona, based on DNA amplification and sequencing at the ITS-1 locus, and 100% of tested animals (n=14) had elevated IgM and IgG titers to S. neurona. Evidence to support the point-source character of this event include the striking spatial and temporal clustering of cases and detection of high concentrations of anti-S. neurona IgM in serum of stranded animals. Concurrent exposure to the marine biotoxin domoic acid may have enhanced susceptibility of affected otters to S. neurona and exacerbated the neurological signs exhibited by stranded animals. Other factors that may have contributed to the severity of this epizootic include a large rainstorm that preceded the event and an abundance of razor clams near local beaches, attracting numerous otters close to shore within the affected area. This is the first report of a localized epizootic in marine wildlife caused by apicomplexan protozoa.

ENDEMIC INFECTION OF STRANDED SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS) WITH NOVEL PARVOVIRUS, POLYOMAVIRUS, AND ADENOVIRUS.

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Siqueira, Juliana D; Ng, Terry F; Miller, Melissa; Li, Linlin; Deng, Xutao; Dodd, Erin; Batac, Francesca; Delwart, Eric

2017-07-01

Over the past century, the southern sea otter (SSO; Enhydra lutris nereis) population has been slowly recovering from near extinction due to overharvest. The SSO is a threatened subspecies under federal law and a fully protected species under California law, US. Through a multiagency collaborative program, stranded animals are rehabilitated and released, while deceased animals are necropsied and tissues are cryopreserved to facilitate scientific study. Here, we processed archival tissues to enrich particle-associated viral nucleic acids, which we randomly amplified and deeply sequenced to identify viral genomes through sequence similarities. Anelloviruses and endogenous retroviral sequences made up over 50% of observed viral sequences. Polyomavirus, parvovirus, and adenovirus sequences made up most of the remaining reads. We characterized and phylogenetically analyzed the full genome of sea otter polyomavirus 1 and the complete coding sequence of sea otter parvovirus 1 and found that the closest known viruses infect primates and domestic pigs ( Sus scrofa domesticus), respectively. We tested archived tissues from 69 stranded SSO necropsied over 14 yr (2000-13) by PCR. Polyomavirus, parvovirus, and adenovirus infections were detected in 51, 61, and 29% of examined animals, respectively, with no significant increase in frequency over time, suggesting endemic infection. We found that 80% of tested SSO were infected with at least one of the three DNA viruses, whose tissue distribution we determined in 261 tissue samples. Parvovirus DNA was most frequently detected in mesenteric lymph node, polyomavirus DNA in spleen, and adenovirus DNA in multiple tissues (spleen, retropharyngeal and mesenteric lymph node, lung, and liver). This study describes the virome in tissues of a threatened species and shows that stranded SSO are frequently infected with multiple viruses, warranting future research to investigate associations between these infections and observed lesions.

Synthesis of nearshore recovery following the 1989 Exxon Valdez oil spill: sea otter liver pathology and survival in Western Prince William Sound, 2001 – 2008

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Ballachey, Brenda E.; Monson, Daniel H.; Kloecker, K.A.; Esslinger, George G.; Mohr, F.C.; Lipscomb, T.P.; Murray, M.J.; Howlin, S.

2014-01-01

We examined livers and liver biopsies collected from captured sea otters in WPWS, 2001–2008, to determine whether indicators of liver health correlated with history of oil contamination from the 1989 Exxon Valdez oil spill. Sea otters captured in oiled areas had a significantly higher proportion of livers with gross pathological change, based on visual inspection at the time of capture, than those from unoiled areas. Of the 10 histopathology variables scored on liver biopsies, only two (vacuolar change and pigment) differed between animals from oiled and unoiled areas, and neither correlated with gross pathology scores. Vacuolar change indicates physiological disturbance, which is consistent with potential effects from oil exposure but also could be influenced by a number of other factors. We concluded that, as of 2008, some differences in liver health were evident between sea otters from oiled and unoiled areas; these differences were consistent with, but not specific to, effects that might be expected with sublethal exposure to lingering Exxon Valdez oil. We also quantified variation in survival of radiomarked sea otters within oiled areas of WPWS in relation to age, sex, body condition, selected blood serum chemistry variables, and histological scores indicative of liver health. Of the variables considered, only the serum enzyme aspartate aminotransferase (AST) and the ratio of serum proteins albumin and globulin (A/G) were correlated with survival, with higher levels of AST and lower levels of A/G associated with increased likelihood of mortality. High AST and low A/G both may be indicative of liver disease. Taken together, results reported here suggest that liver health of sea otters in oiled areas was slightly poorer than those from unoiled areas and, ifurther, that this may have translated to poorer survival through 2008, nearly 2 decades after the spill. More recently collected information indicated that mortality patterns and abundance had returned to

Permissible Home Range Estimation (PHRE in Restricted Habitats: A New Algorithm and an Evaluation for Sea Otters.

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L Max Tarjan

Full Text Available Parametric and nonparametric kernel methods dominate studies of animal home ranges and space use. Most existing methods are unable to incorporate information about the underlying physical environment, leading to poor performance in excluding areas that are not used. Using radio-telemetry data from sea otters, we developed and evaluated a new algorithm for estimating home ranges (hereafter Permissible Home Range Estimation, or "PHRE" that reflects habitat suitability. We began by transforming sighting locations into relevant landscape features (for sea otters, coastal position and distance from shore. Then, we generated a bivariate kernel probability density function in landscape space and back-transformed this to geographic space in order to define a permissible home range. Compared to two commonly used home range estimation methods, kernel densities and local convex hulls, PHRE better excluded unused areas and required a smaller sample size. Our PHRE method is applicable to species whose ranges are restricted by complex physical boundaries or environmental gradients and will improve understanding of habitat-use requirements and, ultimately, aid in conservation efforts.

Improved reproductive success in otters (Lutra lutra), grey seals (Halichoerus grypus) and sea eagles (Haliaeetus albicilla) from Sweden in relation to concentrations of organochlorine contaminants

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Roos, Anna M.; Bäcklin, Britt-Marie V.M.; Helander, Björn O.; Rigét, Frank F.; Eriksson, Ulla C.

2012-01-01

We studied indices of reproductive outcome in three aquatic species in relation to organochlorine concentrations during four decades. In female otters, the frequency of signs of reproduction increased after 1990. In grey seals, pregnancy rate increased 1990–2010 and uterine obstructions ceased after 1993. The frequency of uterine tumours was highest 1980–2000. The number of sea eagle nestlings per checked nest increased 1985–2000, while the frequency of desiccated eggs decreased. Organochlorine concentrations decreased at annual rates between 3.5 and 10.2%. The estimated mean concentration (mg/kg lw) for total-PCB decreased from 70 to 8 (otters), from 110 to 15 (seals) and from 955 to 275 (eagles). The corresponding concentrations for ΣDDT decreased from 3.4 to 0.2 (otters), from 192 to 2.8 (seals) and from 865 to 65 (eagles). This study adds evidence to support the hypothesis that PCBs and DDTs have had strong negative effects on the reproduction and population levels of these species. - Highlights: ► We compared trends of reproductive success in three aquatic top predators in Sweden. ► The study period covers four decades. ► Similar, increasing trends are seen from the end of the 1980s for otters, grey seals and sea eagles. ► Concentrations of total-PCB and DDTs have decreased in these species at similar rates. ► PCBs and DDTs have severely affected reproductive success in these species. - The reproductive success in otters, grey seals and white-tailed sea eagles has increased as the concentrations of PCBs and ΣDDT have decreased supporting a causative relationship.

Osteosarcoma of the maxilla with concurrent osteoma in a southern sea otter (Enhydra lutris nereis)

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Fernandez, J. Rodriguez-Ramos; Thomas, N.J.; Dubielzig, R.R.; Drees, R.

2012-01-01

Southern sea otters (Enhydra lutris nereis) are threatened marine mammals that belong to the family Mustelidae and are native to the coast of Central California. Neoplasia is reported infrequently in seaotters. An adult female free-ranging southern sea otter was found alive at Pebble Beach, Monterey County, California, on January 1st, 1994 and died soon after capture. The carcass was submitted to the US Geological Survey – National Wildlife Health Center for necropsy examination. Grossly, a mass with rubbery texture was firmly attached to the left maxillary region of the skull and the nasopharynx was occluded by soft neoplastic tissue. Post-mortem skull radiographs showed an oval, smoothly marginated mineralized opaque mass centered on the left maxilla, extending from the canine tooth to caudal to the molar and replacing portions of the zygomatic arch and palatine and temporal bones. The majority of the mass protruded laterally from the maxilla and was characterized by central homogeneous mineral opacity. Microscopically, the mass was characterized by fully differentiated lamellar non-osteonal bone that expanded beyond the margins of the adjacent normal osteonal bone. Sections of the nasopharyngeal mass were comprised of moderately pleomorphic cells with bony stroma. Gross, microscopical and radiological findings were compatible with maxillary osteosarcoma with concurrent osteoma.

Toxoplasma gondii, source to sea: higher contribution of domestic felids to terrestrial parasite loading despite lower infection prevalence.

Science.gov (United States)

Vanwormer, Elizabeth; Conrad, Patricia A; Miller, Melissa A; Melli, Ann C; Carpenter, Tim E; Mazet, Jonna A K

2013-09-01

Environmental transmission of Toxoplasma gondii, a global zoonotic parasite, adversely impacts human and animal health. Toxoplasma is a significant cause of mortality in threatened Southern sea otters, which serve as sentinels for disease threats to people and animals in coastal environments. As wild and domestic felids are the only recognized hosts capable of shedding Toxoplasma oocysts into the environment, otter infection suggests land-to-sea pathogen transmission. To assess relative contributions to terrestrial parasite loading, we evaluated infection and shedding among managed and unmanaged feral domestic cats, mountain lions, and bobcats in coastal California, USA. Infection prevalence differed among sympatric felids, with a significantly lower prevalence for managed feral cats (17%) than mountain lions, bobcats, or unmanaged feral cats subsisting on wild prey (73-81%). A geographic hotspot of infection in felids was identified near Monterey Bay, bordering a high-risk site for otter infection. Increased odds of oocyst shedding were detected in bobcats and unmanaged feral cats. Due to their large populations, pet and feral domestic cats likely contribute more oocysts to lands bordering the sea otter range than native wild felids. Continued coastal development may influence felid numbers and distribution, increase terrestrial pathogens in freshwater runoff, and alter disease dynamics at the human-animal-environment interface.

Quantifying population-level risks using an individual-based model: sea otters, Harlequin Ducks, and the Exxon Valdez oil spill.

Science.gov (United States)

Harwell, Mark A; Gentile, John H; Parker, Keith R

2012-07-01

Ecological risk assessments need to advance beyond evaluating risks to individuals that are largely based on toxicity studies conducted on a few species under laboratory conditions, to assessing population-level risks to the environment, including considerations of variability and uncertainty. Two individual-based models (IBMs), recently developed to assess current risks to sea otters and seaducks in Prince William Sound more than 2 decades after the Exxon Valdez oil spill (EVOS), are used to explore population-level risks. In each case, the models had previously shown that there were essentially no remaining risks to individuals from polycyclic aromatic hydrocarbons (PAHs) derived from the EVOS. New sensitivity analyses are reported here in which hypothetical environmental exposures to PAHs were heuristically increased until assimilated doses reached toxicity reference values (TRVs) derived at the no-observed-adverse-effects and lowest-observed-adverse-effects levels (NOAEL and LOAEL, respectively). For the sea otters, this was accomplished by artificially increasing the number of sea otter pits that would intersect remaining patches of subsurface oil residues by orders of magnitude over actual estimated rates. Similarly, in the seaduck assessment, the PAH concentrations in the constituents of diet, sediments, and seawater were increased in proportion to their relative contributions to the assimilated doses by orders of magnitude over measured environmental concentrations, to reach the NOAEL and LOAEL thresholds. The stochastic IBMs simulated millions of individuals. From these outputs, frequency distributions were derived of assimilated doses for populations of 500,000 sea otters or seaducks in each of 7 or 8 classes, respectively. Doses to several selected quantiles were analyzed, ranging from the 1-in-1000th most-exposed individuals (99.9% quantile) to the median-exposed individuals (50% quantile). The resulting families of quantile curves provide the basis for

Causes of mortality in California sea otters during periods of population growth and decline

Science.gov (United States)

Estes, J.A.; Hatfield, B.B.; Ralls, K.; Ames, J.

2003-01-01

Elevated mortality appears to be the main reason for both sluggish growth and periods of decline in the threatened California sea otter population. We assessed causes of mortality from salvage records of 3,105 beach-cast carcasses recovered from 1968 through 1999, contrasting two periods of growth with two periods of decline. Overall, an estimated 40%-60% of the deaths were not recovered and 70% of the recovered carcasses died from unknown causes. Nonetheless, several common patterns were evident in the salvage records during the periods of population decline. These included greater percentages of (1) prime age animals (3-10 yr), (2) carcasses killed by great white shark attacks, (3) carcasses recovered in spring and summer, and (4) carcasses for which the cause of death was unknown. Neither sex composition nor the proportion of carcasses dying of infectious disease varied consistently between periods of population increase and decline. The population decline from 1976 to 1984 was likely due to incidental mortality in a set-net fishery, and the decline from 1995 to 1999 may be related to a developing live-fish fishery. Long-term trends unrelated to periods of growth and decline included a decrease in per capita pup production and mass/length ratios of adult carcasses over the 31-yr study. The generally high proportion of deaths from infectious disease suggests that this factor has contributed to the chronically sluggish growth rate of the California sea otter population.

Sea otter dental enamel is highly resistant to chipping due to its microstructure.

Science.gov (United States)

Ziscovici, Charles; Lucas, Peter W; Constantino, Paul J; Bromage, Timothy G; van Casteren, Adam

2014-10-01

Dental enamel is prone to damage by chipping with large hard objects at forces that depend on chip size and enamel toughness. Experiments on modern human teeth have suggested that some ante-mortem chips on fossil hominin enamel were produced by bite forces near physiological maxima. Here, we show that equivalent chips in sea otter enamel require even higher forces than human enamel. Increased fracture resistance correlates with more intense enamel prism decussation, often seen also in some fossil hominins. It is possible therefore that enamel chips in such hominins may have formed at even greater forces than currently envisaged. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Hematology and clinical chemistry of sea otters vaptured in Prince William Sound, Alaska following the Exxon Valdez Oil Spill

Science.gov (United States)

Rebar, A.H.; Ballachey, Brenda E.; Bruden, D.L.; Kloecker, K.A.

1996-01-01

Hematologic and serum chemical analyses were performed on sea otter blood samples collected from 31 adult males, 63 adult females, and 42 pups captured in western Prince William Sound (oiled area), and 12 adult males, 40 adult females, and 15 pups captured in eastern Prince William Sound (unoiled area) in 1989 and 1990. Hematologic differences between eastern and western adult males were minimal. Both hematocrits and hemoglobins were higher in western than eastern otters but the biological significance of this is equivocal. Western males had higher absolute eosinophil counts, suggesting possible systemic hypersensitivity reactions. Western males had higher serum protein and serum globulin levels than eastern males, suggesting greater antigenic stimulation (more inflammatory and/or infectious conditions). There were no differences in hematologic parameters between eastern and western female otters. Some chemistry changes were present, but the degree of difference was small. Total protein and serum globulin levels were slightly higher in western females, a finding also seen in adult males. Mean levels of liver enzymes for western females were somewhat higher than for the eastern otters, suggesting the possibility of subclinical liver disease. As a group, western pup hematocrits, hemoglobins, and red cell counts were significantly lower than those of eastern pups. From a biological perspective, these reductions were minimal but supported by individual animal data. The red cell data suggest a mild anemia in western pups; however, the degree of anemia was minimal, so that biological significance was equivocal. Other hematologic and clinical chemical differences between eastern and western pups were not striking and were also of equivocal biological significance.

SPORULATION AND SURVIVAL OF TOXOPLASMA GONDII OOCYSTS IN SEA WATER

Science.gov (United States)

Since 1992, we have been collaborating in studies on southern sea otters (Enhdyra lutris nereis) as part of a program to define factors which may be responsible for limiting the growth of the southern sea otter population. We previously demonstrated Toxoplasma gondii in sea otter...

Ultrastructural and molecular confirmation of the development of Sarcocystis neurona tissue cysts in the central nervous system of southern sea otters (Enhydra lutris nereis).

Science.gov (United States)

Miller, M A; Barr, B C; Nordhausen, R; James, E R; Magargal, S L; Murray, M; Conrad, P A; Toy-Choutka, S; Jessup, D A; Grigg, M E

2009-10-01

In 2004, three wild sea otters were diagnosed with putative Sarcocystis neurona-associated meningoencephalitis by histopathology and immunohistochemistry. Schizonts, free merozoites and tissue cysts were observed in the brains of all three infected animals. Tissue cysts walls from sea otter 1 (SO1) stained positively using anti-S. neurona polyclonal antiserum. However, positive staining does not preclude infection by closely related or cross-reactive tissue cyst-forming coccidian parasites. Two immature tissue cysts in the brain of SO1 were examined using transmission electron microscopy. Ultrastructural features included cyst walls with thin villous projections up to 1 microm long with tapered ends and a distinctive, electron-dense outer lining layer composed of linearly-arranged, semi-circular structures with a "hobnailed" surface contour. Small numbers of microtubules extended down through the villi into the underlying granular layer. Metrocytes were short and plump with an anterior apical complex, 22 sub-pellicular microtubules, numerous free ribosomes and no rhoptries. Some metrocytes appeared to be dividing, with two adjacent nuclear profiles. Collectively these ultrastructural features were compatible with developing protozoal cysts and were similar to prior descriptions of S. neurona tissue cysts. Panspecific 18S rDNA primers were utilized to identify protozoa infecting the brains of these otters and DNA amplification and additional sequencing at the ITS1 locus confirmed that all three otters were infected with S. neurona. No other Sarcocystis spp. were detected in the brains or skeletal muscles of these animals by immunohistochemistry or PCR. We believe this is the first ultrastructural and molecular confirmation of the development of S. neurona tissue cysts in the CNS of any animal.

Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline

Science.gov (United States)

Laidre, K.L.; Estes, J.A.; Tinker, M.T.; Bodkin, James L.; Monson, Daniel H.; Schneider, K.

2006-01-01

1. Growth models for body mass and length were fitted to data collected from 1842 sea otters Enhydra lutris shot or live-captured throughout south-west Alaska between 1967 and 2004. Growth curves were constructed for each of two main year groups: 1967–71 when the population was at or near carrying capacity and 1992–97 when the population was in steep decline. Analyses of data collected from animals caught during 2004, when the population density was very low, were precluded by a small sample size and consequently only examined incidentally to the main growth curves.2. Growth curves demonstrated a significant increase in body mass and body length at age in the 1990s. Asymptotic values of body mass were 12–18% higher in the 1990s than in the 1960s/70s, and asymptotic values for body length were 10–11% higher between the same periods. Data collected in 2004 suggest a continued increase in body size, with nearly all data points for mass and length falling significantly above the 1990s growth curves.3. In addition to larger asymptotic values for mass and length, the rate of growth towards asymptotic values was more rapid in the 1990s than in the 1960s/70s: sea otters reached 95% of asymptotic body mass and body length 1–2 years earlier in the 1990s.4. Body condition (as measured by the log mass/log length ratio) was significantly greater in males than in females. There was also an increasing trend from the 1960s/70s through 2004 despite much year-to-year variation.5. Population age structures differed significantly between the 1960s/70s and the 1990s with the latter distribution skewed toward younger age classes (indicating an altered lxfunction) suggesting almost complete relaxation of age-dependent mortality patterns (i.e. those typical of food-limited populations).6. This study spanned a period of time over which the population status of sea otters in the Aleutian archipelago declined precipitously from levels at or near equilibrium densities at

Marine Fish and Shellfish Survey data from otter trawls in the Chukchi Sea from the OCEAN HOPE 3 and OSHORO MARU from 16 August 1990 to 31 July 1992 (NODC Accession 9400061)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Marine Fish and Shellfish Survey data were collected from otter trawls in the Chukchi Sea from the OCEAN HOPE. Data were collected by the University of Alaska from...

Patterns of otter (Lutra Lutra) distribution and man-otter conflicts in river Sado basin : conservation implications

OpenAIRE

Pedroso, Teresa Marta Pacheco de Sales Luís Sampaio, 1974-

2011-01-01

Tese de doutoramento, Biologia (Ecologia), Universidade de Lisboa, Faculdade de Ciências, 2012 The Eurasian otter (Lutra lutra), a protected predator, competes with man for water, in drier regions, and for fish in important fish rearing areas. This thesis addresses man-otter conflicts, by examining: i) otter distribution and persistence in a waterscape facing natural water shortage, yet aggravated by human activities; and ii) otter damages in fish rearing areas, to further understand the l...

Otter trawls in Greece: Landing profiles and potential mιtiers

Directory of Open Access Journals (Sweden)

S. KATSANEVAKIS

2010-02-01

Full Text Available A fleet of 326 bottom trawlers operate in Greek Seas and their landings represent approximately 30% of the total fish production in Greece. In this study, otter trawl landings data were analyzed in order to identify potential métiers. Landings data between 2002 and 2006 were used, collected from 42 ports in the Aegean and East Ionian Sea. A three-step procedure was applied to identify potential métiers: the first step involved a factorial analysis of the log-transformed landings profiles, the second step a classification of the factorial coordinates, and the third step a further aggregation of clusters based on expert knowledge. In all, six potential métiers were identified in the Aegean Sea, and five in the Ionian Sea. The most important target species were European hake (Merluccius merluccius, deepwater pink shrimp (Parapenaeus longirostris, red mullet (Mullus barbatus, caramote prawn (Melicertus kerathurus, picarel (Spicara smaris, cephalopods, bogue (Boops boops, anglers (Lophiusspp., and Norway lobster (Nephrops norvegicus. Otter trawls in Greece use more or less the same gear with minor modification, and métier selection is basically reflected as a choice of geographical sub-area and hauling depth. The limitations of using landings profiles to identify métiers and the need for further verification are discussed.

OTTER, Resolution Style Theorem Prover

International Nuclear Information System (INIS)

McCune, W.W.

2001-01-01

1 - Description of program or function: OTTER (Other Techniques for Theorem-proving and Effective Research) is a resolution-style theorem-proving program for first-order logic with equality. OTTER includes the inference rules binary resolution, hyper-resolution, UR-resolution, and binary para-modulation. These inference rules take as small set of clauses and infer a clause. If the inferred clause is new and useful, it is stored and may become available for subsequent inferences. Other capabilities are conversion from first-order formulas to clauses, forward and back subsumption, factoring, weighting, answer literals, term ordering, forward and back demodulation, and evaluable functions and predicates. 2 - Method of solution: For its inference process OTTER uses the given-clause algorithm, which can be viewed as a simple implementation of the set of support strategy. OTTER maintains three lists of clauses: axioms, sos (set of support), and demodulators. OTTER is not automatic. Even after the user has encoded a problem into first-order logic or into clauses, the user must choose inference rules, set options to control the processing of inferred clauses, and decide which input formulae or clauses are to be in the initial set of support and which, if any, equalities are to be demodulators. If OTTER fails to find a proof, the user may try again different initial conditions. 3 - Restrictions on the complexity of the problem - Maxima of: 5000 characters in an input string, 64 distinct variables in a clause, 51 characters in any symbol. The maxima can be changed by finding the appropriate definition in the header.h file, increasing the limit, and recompiling OTTER. There are a few constraints on the order of commands

Giant Otters in Peru

OpenAIRE

Schenk C.; Staib E.

1992-01-01

We are in the second year of fieldwork surveying for Giant Otters in the southeastern rainforest of Peru, in three areas with differing levels of legal protection. While there is some illegal hunting still happening outside the protected areas, the main threat to the otters is badly-conducted tourism. Well-organised tourism can be a promising argument for establishing protected areas like national parks.

Characterization of the putatively introduced red alga Acrochaetium secundatum (Acrochaetiales, Rhodophyta) growing epizoically on the pelage of southern sea otters (Enhydra lutris nereis)

Science.gov (United States)

Bentall, Gena B.; Rosen, Barry H.; Kunz, Jessica M.; Miller, Melissa A.; Saunders, Gary W.; LaRoche, Nicole L.

2016-01-01

Ecological associations between epibionts (organisms that live on the surface of another living organism) and vertebrates have been documented in both marine and terrestrial environments, and may be opportunistic, commensal, or symbiotic (Lewin et al. 1981, Holmes 1985, Allen et al. 1993, Bledsoe et al. 2006, Pfaller et al. 2008, Suutari et al. 2010). Although epibiont proliferation is frequently reported on slow-moving, sparsely haired organisms such as manatees and sloths, reports from densely furred, highly mobile mammals are much less common. There are reports of epizoic algae for several species of pinnipeds (Kenyon and Rice 1959, Scheffer 1962, Baldridge 1977, Allen et al. 1993), which rely to varying degrees on both pelage and blubber for thermoregulation, but the phenomenon has not been widely described. Scheffer (1962) noted that red algae was fairly common on the pelage of northern fur seals (Callorhinus ursinus), pinnipeds for which fur likely makes a comparatively high contribution to thermoregulation (Donohue et al. 2000). For species with pelage that plays a critical role of thermal insulation, it seems implausible that an epibiont would persist on healthy individuals that devote significant energy resources toward grooming and actively maintaining their coat. Biological characteristics of epibiont settlement and attachment, and physiological requirements of epizoic species play key roles in their successful colonization and potential host impacts. To investigate this relationship, we explore a novel discovery of an epizoic alga from southern sea otters, including describing algal development on sea otter hair and molecular identification of the algae.

Detection and characterization of diverse coccidian protozoa shed by California sea lions

OpenAIRE

Girard, Yvette A.; Johnson, Christine K.; Fritz, Heather M.; Shapiro, Karen; Packham, Andrea E.; Melli, Ann C.; Carlson-Bremer, Daphne; Gulland, Frances M.; Rejmanek, Daniel; Conrad, Patricia A.

2015-01-01

© 2015 The Authors. Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris). California sea lions (Zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated wi...

Canopy Chemistry (OTTER)

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: Canopy characteristics: leaf chemistry, specific leaf area, LAI, PAR, IPAR, NPP, standing biomass--see also: Meteorology (OTTER) for associated...

OTTER 3.3 Reference Manual

OpenAIRE

McCune, William

2003-01-01

OTTER is a resolution-style theorem-proving program for first-order logic with equality. OTTER includes the inference rules binary resolution, hyperresolution, UR-resolution, and binary paramodulation. Some of its other abilities and features are conversion from first-order formulas to clauses, forward and back subsumption, factoring, weighting, answer literals, term ordering, forward and back demodulation, evaluable functions and predicates, Knuth-Bendix completion, and the hints strategy. O...

Effects of potential surface coal mining on dissolved solids in Otter Creek and in the Otter Creek alluvial aquifer, southeastern Montana

Science.gov (United States)

Cannon, M.R.

1985-01-01

Otter Creek drains an area of 709 square miles in the coal-rich Powder River structural basin of southeastern Montana. The Knobloch coal beds in the Tongue River Member of the Paleocene Fort Union Formation is a shallow aquifer and a target for future surface mining in the downstream part of the Otter Creek basin. A mass-balance model was used to estimate the effects of potential mining on the dissolved solids concentration in Otter Creek and in the alluvial aquifer in the Otter Creek valley. With extensive mining of the Knobloch coal beds, the annual load of dissolved solids to Otter Creek at Ashland at median streamflow could increase by 2,873 tons, or a 32-percent increase compared to the annual pre-mining load. Increased monthly loads of Otter Creek, at the median streamflow, could range from 15 percent in February to 208 percent in August. The post-mining dissolved solids load to the subirrigated part of the alluvial valley could increase by 71 percent. The median dissolved solids concentration in the subirrigated part of the valley could be 4,430 milligrams per liter, compared to the pre-mining median concentration of 2,590 milligrams per liter. Post-mining loads from the potentially mined landscape were calculated using saturated-paste-extract data from 506 overburdened samples collected from 26 wells and test holes. Post-mining loads to the Otter Creek valley likely would continue at increased rates for hundreds of years after mining. If the actual area of Knobloch coal disturbed by mining were less than that used in the model, post-mining loads to the Otter Creek valley would be proportionally smaller. (USGS)

OTTER 3.0 reference manual and guide

Energy Technology Data Exchange (ETDEWEB)

McCune, W.W.

1994-01-01

OTTER (Organized Techniques for Theorem-proving and Effective Research) is a resolution-style theorem-proving program for first-order logic with equality. OTTER includes the inference rules binary resolution, hyperresolution, UR-resolution, and binary paramodulation. Some of its other abilities and features are conversion from first-order formulas to clauses, forward and back subsumption, factoring, weighting, answer literals, term ordering, forward and back demodulation, evaluable functions and predicates, and Knuth-Bendix completion. OTTER is coded in C, is free, and is portable to many different kinds of computer.

Habitat quality, water quality and otter distribution

Directory of Open Access Journals (Sweden)

Christopher Mason

1995-12-01

Full Text Available Abstract In recent decades the otter (Lutra lutra has declined over much of Europe. Good habitat has been shown to be essential to otters. Specific elements of cover have been identified in some studies but the minimum cover requirements to support otter populations are not known. These are likely to vary in relation to other factors, such as disturbance. Habitat destruction has been severe in many areas of Europe. Water quantity is important to otters, especially where low flows destroy the food base, namely fish. However the minimum food requirements to support populations are not known. The main cause of the decline in otter populations is almost certainly bioaccumulating pollutants, especially PCBs. These are likely to be inhibiting recolonization in many areas. In Britain, catchment distribution of otters within regions is negatively correlated to mean PCB levels in otter spraints, and these are indicative of tissue levels. PCBs have been found in all samples studied. Current EC statutory monitoring is inadequate to protect otter populations from bioaccumulating contaminants. Standards are presented here for otter protection. More fundamental research is required to refine our understanding of the requirements of the otter. Riassunto Qualità ambientale, qualità dell'acqua e distribuzione della lontra - Negli ultimi decenni la lontra (Lutra lutra è diminuita su buona parte del suo areale europeo, dove particolarmente pesante è stata la distruzione di ambienti favorevoli. Habitat qualitativamente idonei sono essenziali per la sopravvivenza della specie. In alcuni studi, specifici parametri di copertura vegetale dei corpi idrici sono stati ritenuti importanti per la specie, ma quale sia il valore minimo di copertura riparia in grado di supportare una popolazione resta sconosciuto. I parametri di copertura variano probabilmente in relazione ad altri fattori, quali, ad

Biological characteristics and pathogenicity of a highly pathogenic Shewanella marisflavi infected sea cucumber (Apostichopus uaponicus)

Science.gov (United States)

Shewanella marisflavi isolate AP629 was characterized as a novel pathogen of sea cucumber. The LD50 values (14 days) in sea cucumber and swordtail fish were 3.89 × 106 and 4.85 × 104 CFU g-1 body weight, respectively. Studies on S. marisflavi had been conducted, including morphology, physiological a...

Airborne gravity survey of Lincoln Sea and Wandel Sea, north Greenland

DEFF Research Database (Denmark)

Olesen, Arne Vestergaard; Forsberg, René; Keller, K.

2000-01-01

In June 1998 National Survey and Cadastre Denmark (KMS) carried out an airborne gravity survey over the Polar Sea to the north of Greenland. A Twin Otter from Greenlandair, equipped with autopilot and additional fuel tanks, was employed for the survey. A modified marine LaCoste & Romberg gravimet...

Discovery of the fossil otter Enhydritherium terraenovae (Carnivora, Mammalia) in Mexico reconciles a palaeozoogeographic mystery.

Science.gov (United States)

Tseng, Z Jack; Pacheco-Castro, Adolfo; Carranza-Castañeda, Oscar; Aranda-Gómez, José Jorge; Wang, Xiaoming; Troncoso, Hilda

2017-06-01

The North American fossil otter Enhydritherium terraenovae is thought to be partially convergent in ecological niche with the living sea otter Enhydra lutris , both having low-crowned crushing teeth and a close association with marine environments. Fossil records of Enhydritherium are found in mostly marginal marine deposits in California and Florida; despite presence of very rich records of fossil terrestrial mammals in contemporaneous localities inland, no Enhydritherium fossils are hitherto known in interior North America. Here we report the first occurrence of Enhydritherium outside of Florida and California, in a land-locked terrestrial mammal fauna of the upper Miocene deposits of Juchipila Basin, Zacatecas State, Mexico. This new occurrence of Enhydritherium is at least 200 km from the modern Pacific coastline, and nearly 600 km from the Gulf of Mexico. Besides providing further evidence that Enhydritherium was not dependent on coastal marine environments as originally interpreted, this discovery leads us to propose a new east-to-west dispersal route between the Florida and California Enhydritherium populations through central Mexico. The proximity of the fossil locality to nearby populations of modern neotropical otters Lontra longicaudis suggests that trans-Mexican freshwater corridors for vertebrate species in riparian habitats may have persisted for a prolonged period of time, pre-dating the Great American Biotic Interchange. © 2017 The Author(s).

Monitoring and assessment of conservation status of the Eurasian Otter (Lutra lutra) in Denmark

DEFF Research Database (Denmark)

Søgaard, Bjarne; Madsen, Aksel Bo; Elmeros, Morten

Monitoring and assessment of conservation status of the Eurasian Otter Lutra lutra in Denmark Søgaard B. ¹, Madsen A.B.¹, Elmeros M.¹ ¹Institute of Bioscience - Kaloe, Aarhus University. Keywords: Eurasian Otter; Monitoring; Conservation status According to the EU Habitats Directive Denmark has...... of the otter inside Denmark, DNA analysis of dead found otters in Schleswig-Holstein (North Germany) shows that “Danish” otter have crossed the border to Germany connecting the Danish population to the East German population, which spreads into Schleswig-Holstein from Mecklenburg-Vorpommern....

Global distribution of two fungal pathogens threatening endangered sea turtles.

Science.gov (United States)

Sarmiento-Ramírez, Jullie M; Abella-Pérez, Elena; Phillott, Andrea D; Sim, Jolene; van West, Pieter; Martín, María P; Marco, Adolfo; Diéguez-Uribeondo, Javier

2014-01-01

Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are implicated in low hatch success. These two fungi possess key biological features that are similar to emerging pathogens leading to host extinction, e.g., high virulence, and a broad host range style of life. Their optimal growth temperature overlap with the optimal incubation temperature for eggs, and they are able to kill up to 90% of the embryos. Environmental forcing, e.g., tidal inundation and clay/silt content of nests, were correlated to disease development. Thus, these Fusarium species constitute a major threat to sea turtle nests, especially to those experiencing environmental stressors. These findings have serious implications for the survival of endangered sea turtle populations and the success of conservation programs worldwide.

Global distribution of two fungal pathogens threatening endangered sea turtles.

Directory of Open Access Journals (Sweden)

Jullie M Sarmiento-Ramírez

Full Text Available Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are implicated in low hatch success. These two fungi possess key biological features that are similar to emerging pathogens leading to host extinction, e.g., high virulence, and a broad host range style of life. Their optimal growth temperature overlap with the optimal incubation temperature for eggs, and they are able to kill up to 90% of the embryos. Environmental forcing, e.g., tidal inundation and clay/silt content of nests, were correlated to disease development. Thus, these Fusarium species constitute a major threat to sea turtle nests, especially to those experiencing environmental stressors. These findings have serious implications for the survival of endangered sea turtle populations and the success of conservation programs worldwide.

A Distribution Survey for Otters along a River in Central Bhutan

OpenAIRE

Prakash Chettri; Melissa Savage

2014-01-01

We report the findings of a survey for otters along a major river in central Bhutan. The river bears various names in different stretches along its run, including Mochhu, Phochhu, Punatsangchhu and Sunkosh. We report: 1) the distribution and density of otter sign, including tracks, scats, latrines and dens, 2) the correlation between sign abundance and vegetation and substrate characteristics, and 3) the correlation of otter sign with human disturbance. Five of the six 5.5 km transects sample...

Modelling the extinction of Steller's sea cow

OpenAIRE

Turvey, S.T; Risley, C.L

2005-01-01

Steller's sea cow, a giant sirenian discovered in 1741 and extinct by 1768, is one of the few megafaunal mammal species to have died out during the historical period. The species is traditionally considered to have been exterminated by ‘blitzkrieg’-style direct overharvesting for food, but it has also been proposed that its extinction resulted from a sea urchin population explosion triggered by extirpation of local sea otter populations that eliminated the shallow-water kelps on which sea cow...

Otter Lutra lutra L. mortality and marine oil pollution

Energy Technology Data Exchange (ETDEWEB)

Baker, J R [Veterinary Field Station, Cheshire, England; Jones, A M; Jones, T P; Watson, H C

1981-01-01

Following an oil spill at Sullom Voe Oil Terminal, Shetland, at least 13 otters died. Post-mortems on five corpses showed that they had died of haemorrhagic gastroenteropathy, associated with ingested oil. The primary cause of oil ingestion seems to have been grooming of the fur. A survey of the polluted coasts revealed that otters were still present throughout most of the area.

Global Distribution of Two Fungal Pathogens Threatening Endangered Sea Turtles

OpenAIRE

Sarmiento-Ramírez, Jullie M.; Abella-Pérez, Elena; Phillott, Andrea D.; Sim, Jolene; van West, Pieter; Martín, María P.; Marco, Adolfo; Diéguez-Uribeondo, Javier

2014-01-01

Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are i...

Otter ( Lutra lutra ) predation on stocked brown trout ( Salmo trutta ) in two Danish lowland rivers

DEFF Research Database (Denmark)

Jacobsen, Lene

2005-01-01

This study aimed to evaluate otter predation on stocked trout. Large hatchery-reared trout (16-30 cm) were stocked into two Danish rivers with different fish populations. Otter diet before and after trout stocking was determined by analysing 685 spraints, collected regularly during the 35-day study...... period. Fish composition in the rivers before stocking was assessed by electrofishing. In River Trend, a typical trout river, the proportion of trout in the otter diet increased from 8% before stocking to 33% a few days after stocking. Moreover, trout lengths in the diet changed significantly towards...... the lengths of stocked trout, indicating that newly stocked trout were preferred to wild trout. In River Skals, dominated by cyprinids, there was no change in otter diet after stocking of hatchery trout, i.e., these were ignored by otter. Otter predation should be taken into account together with fish...

The use of genetic methods to study Eurasian otters

Czech Academy of Sciences Publication Activity Database

Hájková, Petra; Gettová, Lenka; Sládkovičová, V.; Zemanová, Barbora

Supp., - (2011), s. 102 ISSN 0394-1914. [International Otter Colloquium /11./. 30.08.2011-04.09.2011, Pavia] R&D Projects: GA AV ČR KJB600930804; GA MŽP SP/2D4/16/08; GA ČR GA206/03/0757 Institutional research plan: CEZ:AV0Z60930519 Keywords : Eurasian otter * genetic analyses Subject RIV: EG - Zoology http://www.internationalottercolloquium2010.eu/files/proceedings_iucn_xi_ioc_2011.pdf

Using demography and movement behavior to predict range expansion of the southern sea otter.

Science.gov (United States)

Tinker, M.T.; Doak, D.F.; Estes, J.A.

2008-01-01

In addition to forecasting population growth, basic demographic data combined with movement data provide a means for predicting rates of range expansion. Quantitative models of range expansion have rarely been applied to large vertebrates, although such tools could be useful for restoration and management of many threatened but recovering populations. Using the southern sea otter (Enhydra lutris nereis) as a case study, we utilized integro-difference equations in combination with a stage-structured projection matrix that incorporated spatial variation in dispersal and demography to make forecasts of population recovery and range recolonization. In addition to these basic predictions, we emphasize how to make these modeling predictions useful in a management context through the inclusion of parameter uncertainty and sensitivity analysis. Our models resulted in hind-cast (1989–2003) predictions of net population growth and range expansion that closely matched observed patterns. We next made projections of future range expansion and population growth, incorporating uncertainty in all model parameters, and explored the sensitivity of model predictions to variation in spatially explicit survival and dispersal rates. The predicted rate of southward range expansion (median = 5.2 km/yr) was sensitive to both dispersal and survival rates; elasticity analysis indicated that changes in adult survival would have the greatest potential effect on the rate of range expansion, while perturbation analysis showed that variation in subadult dispersal contributed most to variance in model predictions. Variation in survival and dispersal of females at the south end of the range contributed most of the variance in predicted southward range expansion. Our approach provides guidance for the acquisition of further data and a means of forecasting the consequence of specific management actions. Similar methods could aid in the management of other recovering populations.

Data management for support of the Oregon Transect Ecosystem Research (OTTER) project

Science.gov (United States)

Skiles, J. W.; Angelici, Gary L.

1993-01-01

Management of data collected during projects that involve large numbers of scientists is an often overlooked aspect of the experimental plan. Ecosystem science projects like the Oregon Transect Ecosystem Research (OTTER) Project that involve many investigators from many institutions and that run for multiple years, collect and archive large amounts of data. These data range in size from a few kilobytes of information for such measurements as canopy chemistry and meteorological variables, to hundreds of megabytes of information for such items as views from multi-band spectrometers flown on aircraft and scenes from imaging radiometers aboard satellites. Organizing and storing data from the OTTER Project, certifying those data, correcting errors in data sets, validating the data, and distributing those data to other OTTER investigators is a major undertaking. Using the National Aeronautics and Space Administration's (NASA) Pilot Land Data System (PLDS), a Support mechanism was established for the OTTER Project which accomplished all of the above. At the onset of the interaction between PLDS and OTTER, it was not certain that PLDS could accomplish these tasks in a manner that would aid researchers in the OTTER Project. This paper documents the data types that were collected under the auspices of the OTTER Project and the procedures implemented to store, catalog, validate, and certify those data. The issues of the compliance of investigators with data-management requirements, data use and certification, and the ease of retrieving data are discussed. We advance the hypothesis that formal data management is necessary in ecological investigations involving multiple investigators using many data gathering instruments and experimental procedures. The issues and experience gained in this exercise give an indication of the needs for data management systems that must be addressed in the coming decades when other large data-gathering endeavors are undertaken by the ecological

Limited genetic diversity among Sarcocystis neurona strains infecting southern sea otters precludes distinction between marine and terrestrial isolates.

Science.gov (United States)

Wendte, J M; Miller, M A; Nandra, A K; Peat, S M; Crosbie, P R; Conrad, P A; Grigg, M E

2010-04-19

Sarcocystis neurona is an apicomplexan parasite identified as a cause of fatal neurological disease in the threatened southern sea otter (Enhydra lutris nereis). In an effort to characterize virulent S. neurona strains circulating in the marine ecosystem, this study developed a range of markers relevant for molecular genotyping. Highly conserved sequences within the 18S ribosomal gene array, the plastid-encoded RNA polymerase (RPOb) and the cytochrome c oxidase subunit 1 mitochondrial gene (CO1) were assessed for their ability to distinguish isolates at the genus and species level. For within-species comparisons, five surface antigens (SnSAG1-SnSAG5) and one high resolution microsatellite marker (Sn9) were developed as genotyping markers to evaluate intra-strain diversity. Molecular analysis at multiple loci revealed insufficient genetic diversity to distinguish terrestrial isolates from strains infecting marine mammals. Furthermore, SnSAG specific primers applied against DNA from the closely related species, Sarcocystis falcatula, lead to the discovery of highly similar orthologs to SnSAG2, 3, and 4, calling into question the specificity of diagnostic tests based on these antigens. The results of this study suggest a population genetic structure for S. neurona similar to that reported for the related parasite, Toxoplasma gondii, dominated by a limited number of successful genotypes. Published by Elsevier B.V.

76 FR 62605 - Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes With Supplemental Type...

Science.gov (United States)

2011-10-11

... Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes With Supplemental Type Certificate.... That AD applies to Viking Air Limited Model DHC-3 (Otter) airplanes equipped with a Honeywell TPE331... limitations and marking the airspeed indicator accordingly for Viking Air Limited Model DHC-3 (Otter...

From deep-sea volcanoes to human pathogens: a conserved quorum-sensing signal in Epsilonproteobacteria.

Science.gov (United States)

Pérez-Rodríguez, Ileana; Bolognini, Marie; Ricci, Jessica; Bini, Elisabetta; Vetriani, Costantino

2015-05-01

Chemosynthetic Epsilonproteobacteria from deep-sea hydrothermal vents colonize substrates exposed to steep thermal and redox gradients. In many bacteria, substrate attachment, biofilm formation, expression of virulence genes and host colonization are partly controlled via a cell density-dependent mechanism involving signal molecules, known as quorum sensing. Within the Epsilonproteobacteria, quorum sensing has been investigated only in human pathogens that use the luxS/autoinducer-2 (AI-2) mechanism to control the expression of some of these functions. In this study we showed that luxS is conserved in Epsilonproteobacteria and that pathogenic and mesophilic members of this class inherited this gene from a thermophilic ancestor. Furthermore, we provide evidence that the luxS gene is expressed--and a quorum-sensing signal is produced--during growth of Sulfurovum lithotrophicum and Caminibacter mediatlanticus, two Epsilonproteobacteria from deep-sea hydrothermal vents. Finally, we detected luxS transcripts in Epsilonproteobacteria-dominated biofilm communities collected from deep-sea hydrothermal vents. Taken together, our findings indicate that the epsiloproteobacterial lineage of the LuxS enzyme originated in high-temperature geothermal environments and that, in vent Epsilonproteobacteria, luxS expression is linked to the production of AI-2 signals, which are likely produced in situ at deep-sea vents. We conclude that the luxS gene is part of the ancestral epsilonproteobacterial genome and represents an evolutionary link that connects thermophiles to human pathogens.

76 FR 31800 - Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes

Science.gov (United States)

2011-06-02

... Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes AGENCY: Federal Aviation... INFORMATION: Discussion Recent analysis by the FAA on the Viking Air Limited Model DHC-3 (Otter) airplanes... new airworthiness directive (AD): 2011-12-02 Viking Aircraft Limited: Amendment 39-16709; Docket No...

Estimating Otter Numbers Using Spraints: Is It Possible?

Directory of Open Access Journals (Sweden)

Paul Yoxon

2014-01-01

Full Text Available Spraints have been used to survey otters in the UK since 1979 and a standard methodology has been set up which has been used in Britain and Europe for most survey work. At present data from these surveys is being used to give an estimation of actual population numbers. However, for this to be possible, there must be a correlation between sprainting numbers, active spraint sites, and otter numbers. This paper investigates whether such a correlation exists. There is evidence from previous work that there is seasonal variation in sprainting and this study confirms this. Therefore spraint surveys should be undertaken in the same months for each repeat survey.

Late Cenozoic Arctic Ocean sea ice and terrestrial paleoclimate.

Science.gov (United States)

Carter, L.D.; Brigham-Grette, J.; Marincovich, L.; Pease, V.L.; Hillhouse, J.W.

1986-01-01

Sea otter remains found in deposits of two marine transgressions (Bigbendian and Fishcreekian) of the Alaskan Arctic Coastal Plain which occurred between 2.4 and 3 Ma suggest that during these two events the southern limit of seasonal sea ice was at least 1600 km farther north than at present in Alaskan waters. Perennial sea ice must have been severely restricted or absent, and winters were warmer than at present during these two sea-level highstands. Paleomagnetic, faunal, and palynological data indicate that the later transgression (Fishcreekian) occurred during the early part of the Matuyama Reversed-Polarity Chron. -from Authors

The Inhibitor Pathogen Bacteria’s of Sea Grape Caulerpa lentillifera Applies on Fresh Fish

Directory of Open Access Journals (Sweden)

Alfonsina M.Tapotubun

2016-12-01

Full Text Available Contamination of pathogen bacteries at the fresh fish may occur during the post harvesting to the consuming period, and endanger human health. One of simple and safe way to protect secureness of fresh fish food is the use of Caulerpa lentillifera to push down pathogen bacteries activity. The aims of this research to investigate lability of sea grape (Caulerpa lentillifera against the activity of pathogen bacteries Escherichia coli, Vibrio cholerae and Salmonella sp., in fresh fish, during storage phase, at ambient and ice temperatures. Method used in this research is experimental laboratories method, that is, 10%, 20% and 30% blended sea grapes applied on fresh fishes, Selar crumenopthalmus during storage of 1, 2 and 3 days at ambient and ice temperatures. All the applied of blended of Caulerpa lentillifera, shows the ability to obstruct the activity of bactery group coliform and Escherichia coli on fresh fish Selar crumenopthalmus up to 2x 24 hours, at ambient temperature, and 3x24 hours at ice temperature. During storage period, the occurance and grows of Salmonella sp. and Vibrio cholerae bacteries is undetected. Fresh sea grapes concentration of 10% is sufficient to be applied on fresh fish to obstruct the activity of pathogen bacteries Escherichia coli during storage time of 2 x 24 hours at room temperature, and 3 x 24 hours at ice temperature, and to block the occurance of Vibrio cholerae and Salmonella sp. during storage period. .

Bilateral uric acid nephrolithiasis and ureteral hypertrophy in a free-ranging river otter (Lontra canadensis)

Science.gov (United States)

Grove, Robert A.; Bildfell, Rob; Henny, Charles J.; Buhler, D.R.

2003-01-01

We report the first case of uric acid nephrolithiasis in a free-ranging river otter (Lontra canadensis). A 7 yr old male river otter collected from the Skagit River of western Washington (USA) had bilateral nephrolithiasis and severely enlarged ureters (one of 305 examined [0.33%]). The uroliths were 97% uric acid and 3% protein. Microscopic changes in the kidney were confined to expansion of renal calyces, minor loss of medullary tissue, and multifocal atrophy of the cortical tubules. No inflammation was observed in either kidney or the ureters. The ureters were enlarged due to marked hypertrophy of smooth muscle plus dilation of the lumen. Fusion of the major calyces into a single ureteral lumen was several cm distal to that of two adult male otters used as histopathologic control specimens. This case report is part of a large contaminant study of river otters collected from Oregon and Washington. It is important to understand diseases and lesions of the otter as part of our overall evaluation of this population.

Changes in diets of river otters in Prince William Sound, Alaska: Effects of the Exxon Valdez oil spill

International Nuclear Information System (INIS)

Bowyer, R.T.; Testa, J.W.; Faro, J.B.; Schwartz, C.C.; Browning, J.B.

1994-01-01

The effects of the Exxon Valdez oil spill on the diets of river otters (Lutra canadensis) from oiled and nonoiled areas of Prince William Sound, Alaska, were examined in 1989 and 1990. On the basis of identification of prey remains in their feces, otters fed principally on marine, bottom-dwelling fishes. Marine gastropods, bivalves, and crustaceans composed most of the invertebrates in the diet of otters; freshwater and terrestrial food items seldom occurred in their feces. The diets of otters included 149 different taxa, most of which rarely occurred in their feces. Sixty-five taxa occurred ≥5 times in the combined data set. Species richness and diversity of prey remains in otter feces were similar on oiled and nonoiled study areas in late winter 1989 (before the oil spill) and during summer 1989 following the spill. By summer 1990, however, there were significant declines in the richness and diversity of species (mostly bony fish, molluscs, and bivalves) in otter diets on the oiled area. Likewise, the relative abundance of prey remains in otter feces showed strong differences between areas and years, and an area by year interaction. Members of the Perciformes and Archaeogastropoda declined from 1989 to 1990 on the oiled area while they increased on the nonoiled site; Malacostraca exhibited the opposite pattern. These outcomes, when considered with other data on body mass and blood chemistry, strongly suggest that some effects of the oil spill on otters were delayed. 14 refs., 6 figs., 1 tab

Surgical implantation of intra-abdominal radiotransmitters in marine otters (Lontra felina) in central Chile.

Science.gov (United States)

Soto-Azat, Claudio; Boher, Francisca; Fabry, Mauricio; Pascual, Paulo; Medina-Vogel, Gonzalo

2008-10-01

Six free-ranging marine otters (Lontra felina) were livetrapped on the central coast of Chile and implanted with specially designed radiotransmitters as part of a spatial ecology study. Marine otters frequent the rocky seashore, often squeezing their narrow bodies through cracks and crevices and grooming themselves on the rocks. They are also among the smallest of the otter species, weighing between 3.4 kg and 4.5 kg. For these reasons, the transmitter used was small, rectangular, and flat, measuring 3.5 x 3.2 x 1.0 cm. They were implanted using a ventral midline approach to minimize contact between the skin incision and sharp-edged rocks. Surgical incisions healed within 2 wk. The transmitters functioned well, but the duration varied from 62 days to 143 days instead of the 240 days predicted by the manufacturer. All six marine otters reestablished in their home ranges, and survey results suggest they survived well beyond the life of the transmitters.

Hydrodynamic characteristics of the oval cambered double slotted otter board in bottom trawl fisheries

Science.gov (United States)

Liu, J.; Huang, H. L.; Li, L. Z.; Qu, T. C.; Wu, Y.; Chen, S.; Yang, J. L.; Rao, X.

2017-07-01

The otter board is one of the main components of single boat trawl fisheries. An oval cambered double slotted otter board was developed for improving the expansion performance of trawl net in bottom trawl fisheries. A flume model experiment was conducted to measure the lift coefficient (C L), drag coefficient (C D), and lift to drag ratio (K) in different angles of attack (α). The experimental results are as follows : (1) The C L and K value show a trend of increasing at the beginning and then decreasing with the increase of angle of attack, the C D value reflects an upward trend as the angle of attack increases; (2) The D3 otter board (front flow deflector angle at 29°) showed a better hydrodynamic performance. When α=30°, the max lift coefficient (C Lmax) was 1.464, in this case C D = 0.554 and K=2.643. When α=15°, the max lift to drag ratio (K max) was 4.165, C L =0.633, and C D = 0.152. This suggests that the best working scope for the angle of attack is between 15°~30°, in which case, C L>0.633 and K>2.643. The mean value of the lift coefficient was 1.071 and the mean of the lift to drag ratio was 3.482. Comparative analysis of the hydrodynamic performance of different types of otter boards showed that the D3 otter board both had good expansion performance and efficiency, which can provide a reference basis for further optimization of the bottom trawl otter board.

Review of the systematics, biology and ecology of lice from pinnipeds and river otters (Insecta: Phthiraptera: Anoplura: Echinophthiriidae).

Science.gov (United States)

Soledad Leonardi, Maria; Palma, Ricardo Luis

2013-01-01

We present a literature review of the sucking louse family Echinophthiriidae, its five genera and twelve species parasitic on pinnipeds (fur seals, sea lions, walruses, true seals) and the North American river otter. We give detailed synonymies and published records for all taxonomic hierarchies, as well as hosts, type localities and repositories of type material; we highlight significant references and include comments on the current taxonomic status of the species. We provide a summary of present knowledge of the biology and ecology for eight species. Also, we give a host-louse list, and a bibliography to the family as complete as possible.

Bacterial and viral pathogens detected in sea turtles stranded along the coast of Tuscany, Italy.

Science.gov (United States)

Fichi, G; Cardeti, G; Cersini, A; Mancusi, C; Guarducci, M; Di Guardo, G; Terracciano, G

2016-03-15

During 2014, six loggerhead turtles, Caretta caretta and one green turtle, Chelonia mydas, found stranded on the Tuscany coast of Italy, were examined for the presence of specific bacterial and viral agents, along with their role as carriers of fish and human pathogens. Thirteen different species of bacteria, 10 Gram negative and 3 Gram positive, were identified. Among them, two strains of Vibrio parahaemolyticus and one strain of Lactococcus garviae were recovered and confirmed by specific PCR protocols. No trh and tdh genes were detected in V. parahaemolyticus. The first isolation of L. garviae and the first detection of Betanodavirus in sea turtles indicate the possibility for sea turtles to act as carriers of fish pathogens. Furthermore, the isolation of two strains of V. parahaemolyticus highlights the possible role of these animals in human pathogens' diffusion. Copyright © 2016 Elsevier B.V. All rights reserved.

The occurrence of pathogenic bacteria in some ships' ballast water incoming from various marine regions to the Sea of Marmara, Turkey.

Science.gov (United States)

Altug, Gulsen; Gurun, Sevan; Cardak, Mine; Ciftci, Pelin S; Kalkan, Samet

2012-10-01

The composition and frequency of antibiotic resistance of pathogenic bacteria, the abundance of heterotrophic aerobic bacteria (HPC) and possible in-situ use of chromogenic agar were investigated in the ships' ballast water coming from different regions of the world to the Sea of Marmara, Turkey for the first time. The samples that were taken from 21 unit ships coming from various marine environments of the Southern China Sea, the Atlantic Ocean, the Mediterranean and the Black Sea to the Sea of Marmara, Turkey in 2009 and 2010 were tested. 38 bacteria species, 27 of them pathogenic bacteria belonging to 17 familia, were detected. Vibrio cholera was not detected in the samples. However, the presence of a high number of HPC, including a cocktail of pathogenic bacteria showed that the ships carry a potential risk for the Sea of Marmara. Copyright © 2012 Elsevier Ltd. All rights reserved.

78 FR 62361 - Green Mountain Power Corporation; Vermont; Otter Creek Hydroelectric Project; Notice of Proposed...

Science.gov (United States)

2013-10-21

... Power Corporation; Vermont; Otter Creek Hydroelectric Project; Notice of Proposed Restricted Service... issuance of a new license for the Otter Creek Hydroelectric Project No. 2558. The programmatic agreement... Agreement would be incorporated into any Order issuing a license. Green Mountain Power Corporation, as...

Feeding habits of giant otters Pteronura brasiliensis (Carnivora: Mustelidae in the Balbina hydroelectric reservoir, Central Brazilian Amazon

Directory of Open Access Journals (Sweden)

Márcia M. M. Cabral

2010-02-01

Full Text Available This study aimed to identify the diet of giant otters, Pteronura brasiliensis (Zimmermann, 1780 in the Balbina reservoir (01º55'S, 59º29'W, to compare it with literature data on the diet of giant otters from non-dammed areas, and to verify the effects of the seasonal changes in water levels on the feeding habits of Balbina otters. A total of 254 feces samples were collected and identified according to the lowest possible taxonomic level. Teleostei fish were present in 100% of the samples; two samples also presented monkey fur (n = 1 and sloth fur (n = 1, suggesting that the diet of P. brasiliensis, in the reservoir, is almost exclusively based on fish. Ten fish families were identified in our samples, six of which were exclusive to the Balbina Lake (not present in the diet of giant otters from non-dammed areas. These six fish families, however, were present in less than 3% of the samples. The fish families with highest representation in the diet of giant otters from non-dammed areas also appeared with higher frequencies in the Balbina Lake, suggesting that the otters have not changed their diet substantially after the implementation of the reservoir. During the high-water period, when the fish are dispersed into the flooded forest and are not very easy to catch, the otters seem to have an opportunistic feeding habit. By contrast, during the low-water period, when prey items are widely available and easier to catch in the reservoir, their feeding habits are more selective.

Presence of Aspergillus sydowii, a pathogen of gorgonian sea fans in the marine sponge Spongia obscura.

Science.gov (United States)

Ein-Gil, Neta; Ilan, Micha; Carmeli, Shmuel; Smith, Garriet W; Pawlik, Joseph R; Yarden, Oded

2009-06-01

The fungus Aspergillus sydowii is the causative agent of epidemics that affect gorgonian corals (sea fans) and has significantly affected their populations in the Caribbean Sea. We have isolated a strain of A. sydowii from healthy marine sponges (Spongia obscura) collected in Bahamian inshore waters. After its identification on the basis of morphology, molecular markers and chemical profiling followed by pathogenicity tests, we found this strain to be highly similar to a strain isolated from diseased coral, and have shown the capacity of this fungus to persist in sponge environment. Our findings suggest that sponges have the possibility of being reservoirs of a potential marine pathogen.

Proposals for the conservation of otters Lutra lutra L. on Corfu island (Ionian Sea, Greece

Directory of Open Access Journals (Sweden)

Xavier Grémillet

1995-12-01

Full Text Available Abstract Suggested measures for the conservation of otters (Lutra lutra on Corfu include: 1 a nature sanctuary ("Otter Haven" for some little remote lagoons near Aghios Stephanos in the north-east; 2 a lagoon restoration scheme including restoration of traditional fishing with joint nature tourism for the large reedbeds and lagoons: Antinioti (100 ha in the north, Chalkiopoulou (380 ha in the suburbs of Kerkyra, Korission (500 ha in the south-west; 3 the stopping of raw sewage discharge, illegal infilling, building and waste dumping in the wetlands; 4 the limitation of intensive fish farming schemes. Such a policy is reconcilable with economic activities (tourism, fishing, trade or administration. Riassunto Proposte per la conservazione della lontra Lutra lutra L. nell'isola di Corfù (Mare Jonio, Grecia - Per la conservazione della lontra (Lutra lutra nell'Isola di Corfù sono suggeriti i seguenti interventi: 1 creazione di "santuari naturali" per la specie comprendenti le piccole lagune vicino a Aghios Stephanos nella parte nord-est dell'isola; 2 riqualificazione degli ambienti a canneto e delle lagune, abbinata a1 ripristino della pesca tradizionale e allo sviluppo del turismo ecologico: Antinioti (100 ha nella parte settentrionale, Chalkiopoulou (380 ha nell'area suburbana di Kerkyra, Korission (500 ha nella parte sud-ovest; 3 divieto di scarichi fognari e abusivi, divieto di costruzione di insediamenti abitativi e eliminazione di discariche nelle zone umide; 4 limitazioni allo sviluppo degli allevamenti ittici intensivi. Gli interventi prospettati si inquadrano in una politica di gestione ambientale compatibile con le attività economiche presenti (turismo, pesca, commercio.

Congener-specific model for polychlorinated biphenyl effect on otter (Lutra lutra) and associated sediment quality criteria

NARCIS (Netherlands)

Traas, T.P.; Luttik, R.; Klepper, O.; Beurskens, J.E.M.; Smit, M.D.; Leonards, P.E.G.; Hattum, van A.G.M.; Aldenberg, T.

2001-01-01

A model for risk assessment was built for simultaneous, congener-specific PCB bioaccumulation from sediment to fish to otters (Lutra lutra). Toxic equivalence factors (TEFs) were used to sum individual congeners in otters to a toxic equivalent concentration (TEQ) relative to

Determination of Hg and diet identification in otter (Lontra longicaudis) feces

Energy Technology Data Exchange (ETDEWEB)

Ferreira Josef, Carla [Centro de Energia Nuclear na Agricultura - CENA-USP, Universidade de Sao Paulo, Av. Centenario 303, 13400-970 Piracicaba, Sao Paulo (Brazil)], E-mail: carlajosef@hotmail.com; Ramos Adriano, Leonardo; Franca, Elvis Joacir de; Gustinelli Arantes de Carvalho, Gabriel [Centro de Energia Nuclear na Agricultura - CENA-USP, Universidade de Sao Paulo, Av. Centenario 303, 13400-970 Piracicaba, Sao Paulo (Brazil); Ferreira, Jose Roberto [Centro de Energia Nuclear na Agricultura - CENA-USP, Universidade de Sao Paulo, Av. Centenario 303, 13400-970 Piracicaba, Sao Paulo (Brazil); Polo de Pesquisa e Desenvolvimento Regional do Centro Sul - APTA, Agencia Paulista de Tecnologia dos Agronegocios. Rua Alberto Coral 1500, 13400-000 Piracicaba, Sao Paulo (Brazil)

2008-04-15

An analytical procedure for the determination of Hg in otter (Lontra longicaudis) feces was developed, to separate fish scales for the identification of the animal diet. Samples were washed with ultra-pure water and the suspension was sampled and transferred for digestion. The solubilization was performed with nitric-perchloric acid mixture, and detection carried out by the atomic fluorescence spectrometry (AFS). The quality of the analytical procedure was assessed by analyzing in-house standard solutions and certified reference materials. Total Hg concentrations were in the range of 7.6-156 ng g{sup -1} (July 2004), 25.6-277 ng g{sup -1} (January 2005) and 14.6-744 ng g{sup -1} (May 2005) that is approximately the same order of magnitude for all samples collected in two reservoirs at the Tiete River, Brazil. Although Hg concentrations varied with sampling periods and diet, high levels were correlated to the percentage of carnivorous fish scales present in the otter feces. - The importance of otter feces preparation for Hg analysis, focusing the food web.

Determination of Hg and diet identification in otter (Lontra longicaudis) feces

International Nuclear Information System (INIS)

Ferreira Josef, Carla; Ramos Adriano, Leonardo; Franca, Elvis Joacir de; Gustinelli Arantes de Carvalho, Gabriel; Ferreira, Jose Roberto

2008-01-01

An analytical procedure for the determination of Hg in otter (Lontra longicaudis) feces was developed, to separate fish scales for the identification of the animal diet. Samples were washed with ultra-pure water and the suspension was sampled and transferred for digestion. The solubilization was performed with nitric-perchloric acid mixture, and detection carried out by the atomic fluorescence spectrometry (AFS). The quality of the analytical procedure was assessed by analyzing in-house standard solutions and certified reference materials. Total Hg concentrations were in the range of 7.6-156 ng g -1 (July 2004), 25.6-277 ng g -1 (January 2005) and 14.6-744 ng g -1 (May 2005) that is approximately the same order of magnitude for all samples collected in two reservoirs at the Tiete River, Brazil. Although Hg concentrations varied with sampling periods and diet, high levels were correlated to the percentage of carnivorous fish scales present in the otter feces. - The importance of otter feces preparation for Hg analysis, focusing the food web

Cellular responses in sea fan corals: granular amoebocytes react to pathogen and climate stressors.

Directory of Open Access Journals (Sweden)

Laura D Mydlarz

Full Text Available BACKGROUND: Climate warming is causing environmental change making both marine and terrestrial organisms, and even humans, more susceptible to emerging diseases. Coral reefs are among the most impacted ecosystems by climate stress, and immunity of corals, the most ancient of metazoans, is poorly known. Although coral mortality due to infectious diseases and temperature-related stress is on the rise, the immune effector mechanisms that contribute to the resistance of corals to such events remain elusive. In the Caribbean sea fan corals (Anthozoa, Alcyonacea: Gorgoniidae, the cell-based immune defenses are granular acidophilic amoebocytes, which are known to be involved in wound repair and histocompatibility. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate for the first time in corals that these cells are involved in the organismal response to pathogenic and temperature stress. In sea fans with both naturally occurring infections and experimental inoculations with the fungal pathogen Aspergillus sydowii, an inflammatory response, characterized by a massive increase of amoebocytes, was evident near infections. Melanosomes were detected in amoebocytes adjacent to protective melanin bands in infected sea fans; neither was present in uninfected fans. In naturally infected sea fans a concurrent increase in prophenoloxidase activity was detected in infected tissues with dense amoebocytes. Sea fans sampled in the field during the 2005 Caribbean Bleaching Event (a once-in-hundred-year climate event responded to heat stress with a systemic increase in amoebocytes and amoebocyte densities were also increased by elevated temperature stress in lab experiments. CONCLUSIONS/SIGNIFICANCE: The observed amoebocyte responses indicate that sea fan corals use cellular defenses to combat fungal infection and temperature stress. The ability to mount an inflammatory response may be a contributing factor that allowed the survival of even infected sea fan corals during a

Tourists’ willingness to pay to view otters along the Wild Coast, South Africa: a potential for increased ecotourism

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Lihle Dumalisile

2005-05-01

Full Text Available This article reports on tourists’ willingness to pay to view Cape clawless otters Aonyx capensis along the Eastern Cape Wild Coast, South Africa. We collected data from a survey carried out using a structured, selfadministered questionnaire. We analyzed 67 completed questionnaires, of which 60 respondents (89.5% indicated that they would be interested in viewing otters and would be prepared to pay an extra fee, over and above the normal entrance fees, for a trained guide to show them otters. The remaining 7 (10.4% respondents indicated that they would reconsider and pay if this would create jobs for members of the local community. Most (98.4% and 91.8% of the respondents also indicated that they would still pay even if there was only a 50% or 25% chance of seeing otters. Most of the respondents were willing to pay either less than R50.00 (ca US$8.00 or R50.00-R100.00 to view otters regardless of the chances of seeing them. We conclude from our results that otters do have the potential to increase ecotourism in the area, and also to contribute financially to the poverty stricken local Dwesa community.

Distribution and observations on the population of marine otters Lontra felina(Molina 1782 in Peru

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Manuel Apaza

2013-06-01

Full Text Available We analyzed the distribution of marine otter Lontra felinaon the Peruvian coast, from Punta Aguja (05°47'S to the boundary with Chile (18°21'S. We performed a comprehensive analysis of the literature on L. felinato elucidate a northern boundary of its geographic distribution, concluding that there is no solid evidence of a possible northern limit at 6°S. For the same reasons, the affirmation of a "historic distribution" to the Lobos de Tierra island was discarded. It is also presented information of 272 otters from 130 locations between the years 2000 and 2010. The distribution of these records no has spatial autocorrelation, suggesting a homogeneous distribution. Considering the morphostructure and geomorphology of the Peruvian coast we can see similarities with the division into three zones: north, central and south, the last two add all records of otters, which could provide habitat characteristics that, allow a continuous distribution of L. felina. Finally there is an increase in the number of otters in the Peruvian coast to compare the current values with those of 40 years ago, but we show the lack of traceability of the latest information. We suggest undertaking research linking abundances and densities of otters with the characterization and distribution of their habitats, and behavioral studies that reveal the processes or intrinsic characteristics of the species to move into its geographic range.

The Fetal Membranes of the Otter Shrews and a Synapomorphy for Afrotheria

DEFF Research Database (Denmark)

Carter, Anthony M.; Blankenship, T.N.; Enders, A.C.

2006-01-01

The otter shrews of mainland Africa are the closest relatives of the Madagascar tenrecs. We sought for similarities in placentation between the two groups and, in a wider context, with other mammals of the Afrotheria clade. Specimens of the Nimba otter shrew (Micropotamogale lamottei) were obtain...... by two pairs of septal folds. A similar arrangement has been described for representatives of each of the remaining five orders within Afrotheria. This is significant because previous anatomical studies have failed to establish a single synapomorphy in support of Afrotheria....

Development of a real-time PCR for the detection of pathogenic Leptospira spp. in California sea lions.

Science.gov (United States)

Wu, Qingzhong; Prager, Katherine C; Goldstein, Tracey; Alt, David P; Galloway, Renee L; Zuerner, Richard L; Lloyd-Smith, James O; Schwacke, Lori

2014-08-11

Several real-time PCR assays are currently used for detection of pathogenic Leptospira spp.; however, few methods have been described for the successful evaluation of clinical urine samples. This study reports a rapid assay for the detection of pathogenic Leptospira spp. in California sea lions Zalophus californianus using real-time PCR with primers and a probe targeting the lipL32 gene. The PCR assay had high analytic sensitivity-the limit of detection was 3 genome copies per PCR volume using L. interrogans serovar Pomona DNA and 100% analytic specificity; it detected all pathogenic leptospiral serovars tested and none of the non-pathogenic Leptospira species (L. biflexa and L. meyeri serovar Semaranga), the intermediate species L. inadai, or the non-Leptospira pathogens tested. Our assay had an amplification efficiency of 1.00. Comparisons between the real-time PCR assay and culture isolation for detection of pathogenic Leptospira spp. in urine and kidney tissue samples from California sea lions showed that samples were more often positive by real-time PCR than by culture methods. Inclusion of an internal amplification control in the real-time PCR assay showed no inhibitory effects in PCR negative samples. These studies indicated that our real-time PCR assay has high analytic sensitivity and specificity for the rapid detection of pathogenic Leptospira species in urine and kidney tissue samples.

Habitat and food resources of otters (Mustelidae) in Peninsular Malaysia

Science.gov (United States)

Abdul-Patah, P.; Nur-Syuhada, N.; Md-Nor, S.; Sasaki, H.; Md-Zain, B. M.

2014-09-01

Habitat and food resources of otters were studied in several locations in Peninsular Malaysia. A total of 210 fecal samples were collected from April 2010 to March 2011 believed to be of otter's were analyzed for their diet composition and their habitat preferences. The DNA testing conducted revealed that only 126 samples were identified as Lultrogale perspicillata and Aonyx cinereus with 105 and 21 samples, respectively. Habitat analyses revealed that these two species preferred paddy fields and mangroves as their main habitats but L. perspicillata preferred to hunt near habitat with large water bodies, such as mangroves, rivers, ponds, and lakes. A. cinereus on the other hand, were mainly found near land-based habitat, such as paddy fields, casuarinas forest and oil palms near mangroves. Habitats chosen were influenced by their food preferences where L. perspicillata consumed a variety of fish species with a supplementary diet of prawns, small mammals, and amphibians, compared to A. cinereus which consumed less fish and more non-fish food items, such as insects, crabs, and snails. Since, the most of the otter habitats in this study are not located within the protected areas, conservation effort involving administrations, landowners, private organizations and public are necessary.

Habitat networking: a new chance for the otter in Europe?

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Claus Reuther

1995-12-01

Full Text Available Abstract One of the main problems for otter protection in Germany as well as in Europe is the fragmentation and isolation of populations. In Germany a thriving population exists in the eastern parts of the country while in the central parts only isolated populations remain, and in the western parts the species is extirpated. On the basis of this situation a habitat network program is in progress with the aim to protect and restore not only those habitats where the otter still remains but also those habitats which can function as a network to connect the thriving with the isolated populations. This network focuses on existing protected wetlands or rivers and restoration activities in wetlands or rivers. The situation of the otter in Europe (excluding Scandinavia and the British Isles is comparable to that in Germany. There are stable or thriving populations in the eastern and western parts while in Central Europe only isolated populations remain. Following the German otter habitat network program possibilities are shown and discussed to establish a habitat network program for the otter on a European level. Riassunto Ripristino di una rete di ambienti favorevoli alla lontra: una nuova possibilità per la specie in Europa? - Uno dei principali problemi riguardanti la conservazione della lontra (Lutra lutra in Germania, come del resto in Europa, è la frammentazione e l'isolamento delle popolazioni. In Germania, una cospicua popolazione esiste nella parte orientale, mentre in quella centrale sono presenti nuclei isolati; nella porzione occidentale del paese la specie è invece praticamente estinta. Tenendo presente questa situazione, è stato avviato un programma di ricostruzione di una rete di ambienti favorevoli alla lontra con l'obiettivo di proteggere e ripristinare non solo gli ambienti in cui la specie è attualmente presente, ma anche quelli che possono funzionare come rete di

Detection and characterization of diverse coccidian protozoa shed by California sea lions

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Yvette A. Girard

2016-04-01

Full Text Available Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris. California sea lions (Zalophus californianus, whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina. In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi diagnosed with protozoal disease in Oregon (USA. Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near

Detection and characterization of diverse coccidian protozoa shed by California sea lions

Science.gov (United States)

Girard, Yvette A.; Johnson, Christine K.; Fritz, Heather M.; Shapiro, Karen; Packham, Andrea E.; Melli, Ann C.; Carlson-Bremer, Daphne; Gulland, Frances M.; Rejmanek, Daniel; Conrad, Patricia A.

2015-01-01

Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris). California sea lions (Zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina). In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi) diagnosed with protozoal disease in Oregon (USA). Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near-shore marine

Detection and characterization of diverse coccidian protozoa shed by California sea lions.

Science.gov (United States)

Girard, Yvette A; Johnson, Christine K; Fritz, Heather M; Shapiro, Karen; Packham, Andrea E; Melli, Ann C; Carlson-Bremer, Daphne; Gulland, Frances M; Rejmanek, Daniel; Conrad, Patricia A

2016-04-01

Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris). California sea lions (Zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina). In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi) diagnosed with protozoal disease in Oregon (USA). Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near-shore marine

Eagles, Otters, and Unicorns: An Anatomy of Innovation.

Science.gov (United States)

Grossman, Stephen R.; King, Margaret J.

1990-01-01

This article describes three archetypal workers: eagles who innovate by improvements, otters who innovate by extension, and unicorns who innovate by paradigm. Each of these innovators is discussed in terms of domain-relevant skills, manipulative skills, and motivation. Needs of each type in terms of business culture are discussed. (PB)

Differential resilience of Amazonian otters along the Rio Negro in the aftermath of the 20th century international fur trade.

Science.gov (United States)

Pimenta, Natalia C; Antunes, André P; Barnett, Adrian A; Macedo, Valêncio W; Shepard, Glenn H

2018-01-01

Commercial hunting for the international trade in animal hides in the 20th century decimated many populations of aquatic wildlife in Amazonia. However, impacts varied significantly between different species and regions, depending upon hunting intensity, accessibility of habitat, and the inherent resilience of various species and their habitats. We investigated the differential responses of two Amazonian Mustelid species, the neotropical otter and giant otter, to commercial hunting pressure along the upper Rio Negro in Brazil, and examined historical factors that influenced spatial and temporal variation in commercial exploitation. We analyzed previously unanalyzed data from historical records of hide shipments to track changes in hide sales and prices for the two species in the late 20th century. We also gathered oral histories from older Baniwa people who had witnessed or participated in commercial otter hunting. These complimentary data sources reveal how intrinsic biological and social characteristics of the two otter species interacted with market forces and regional history. Whereas giant otter populations were driven to local or regional extinction during the late 20th century by commercial hunting, neotropical otters persisted. In recent decades, giant otter populations have returned to some parts of the upper Rio Negro, a development which local people welcome as part of a generalized recovery of the ecosystems in their territory as a result of the banning of animal pelt exports and indigenous land demarcation. This paper expands the scope of the field historical ecology and reflects on the role of local knowledge in biodiversity conservation.

Application of biomarkers for exposure and effect of polyhalogenated aromatic hydrocarbons in naturally exposed european otters (Lutra lutra)

NARCIS (Netherlands)

Murk, A.J.; Leonards, P.E.G.; van Hattum, A.G.M.; Luit, R.; Vanderweiden, M.E.J.; Smit, M.

1998-01-01

In the serious decline of European otters (Lutra lutra) over the last decades, polychlorinated biphenyls (PCBs) are considered to be one of the major factors. As no experiments can be conducted with otters, an eco-epidemiological study was performed to derive no observed effect concentrations

Management and Level of Asian small-clawed otter (Aonyx cinereus Illinger, 1815 as Display Animal in Indonesia Conservation Institution

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Ulfa Hansyari Ar-Rasyid

2017-09-01

Full Text Available Education and breeding become main reasons for asian small-clawed otter placement as display animal in zoo. Proper management is needed to maintain asian small-clawed otter welfare. This research objectives were to examine and assess asian small-clawed otter welfare in three Indonesia zoos. The study was conducted from December 2016 to February 2017 in Bandung Zoo, Ragunan Zoo and Ocean Dream Samudra Ancol. The methods of this research were literature review, interview and field observation. Data were analyzed using the suitability of management and animal welfare assessment. The result showed that there were three main management activities conducted at the three study locations, i.e., nutrition, housing, and health management. Bandung Zoo achieved the lowest score of asian small-clawed otter welfare (45,24% compared to Ragunan Zoo (62,24% and Ocean Dream Samudra (65,90%. Asian small-clawed otter welfare in three institutions were relatively low to fair category, this was due to the unfilled quality of food and water i.e.,  the type, amount, feeding frequency, diet and preparing of food; the unavailability of suitable and favorable environmental conditions; the care facilities provided could not ensure the health of animal; the appearance of abnormal behavior that affected the growth and breeding of animal; and animal had no freedom to behave as in their natural habitat. Keywords: animal display, animal welfare, Asian small-clawed otter, zoo 

Genetic consequences of population decline in Eurasian otter (Lutra lutra) populations in the Czech and Slovak Republics

Czech Academy of Sciences Publication Activity Database

Gettová, Lenka; Hájková, Petra

Supp., - (2011), s. 102 ISSN 0394-1914. [International Otter Colloquium /11./. 30.08.2011-04.09.2011, Pavia] R&D Projects: GA AV ČR KJB600930804 Institutional research plan: CEZ:AV0Z60930519 Keywords : Eurasian otter * population size Subject RIV: EG - Zoology http://www.internationalottercolloquium2010.eu/files/proceedings_iucn_xi_ioc_2011.pdf

75 FR 63850 - Proposed Information Collection; OMB Control Number 1018-0066; Marine Mammal Tagging, Marking...

Science.gov (United States)

2010-10-18

... bears. Type of take (live killed or beach found) for walrus. Number of otters present in and number of... Oceans may harvest polar bears, northern sea otters, and Pacific walrus for subsistence or handicraft... bear, northern sea otter, and Pacific walrus. These regulations enable us to gather data on the Alaska...

Eurasian otters, Lutra lutra, have a dominant mtDNA haplotype from the Iberian Peninsula to Scandinavia.

Science.gov (United States)

Ferrando, Ainhoa; Ponsà, Montserrat; Marmi, Josep; Domingo-Roura, Xavier

2004-01-01

The Eurasian otter, Lutra lutra, has a Palaearctic distribution and has suffered a severe decline throughout Europe during the last century. Previous studies in this and other mustelids have shown reduced levels of variability in mitochondrial DNA, although otter phylogeographic studies were restricted to central-western Europe. In this work we have sequenced 361 bp of the mtDNA control region in 73 individuals from eight countries and added our results to eight sequences available from GenBank and the literature. The range of distribution has been expanded in relation to previous works north towards Scandinavia, east to Russia and Belarus, and south to the Iberian Peninsula. We found a single dominant haplotype in 91.78% of the samples, and six more haplotypes deviating a maximum of two mutations from the dominant haplotype restricted to a single country. Variability was extremely low in western Europe but higher in eastern countries. This, together with the lack of phylogeographical structuring, supports the postglacial recolonization of Europe from a single refugium. The Eurasian otter mtDNA control region has a 220-bp variable minisatellite in Domain III that we sequenced in 29 otters. We found a total of 19 minisatellite haplotypes, but they showed no phylogenetic information.

Autumn-winter diet of three carnivores, European mink (Mustela lutreola, Eurasian otter (Lutra lutra and small-spotted genet (Genetta genetta, in northern Spain

Directory of Open Access Journals (Sweden)

Palazón, S.

2008-12-01

Full Text Available This study describes the autumn-winter diet of three carnivores (Mustela lutreola, Lutra lutra and Genetta genetta in northern Spain. Diet composition was analysed from 85 European mink, 156 otter and 564 spotted genet fecal samples The European mink diet was based on small mammals (relative frequency of occurrences 38.1%, fish (30.9% and birds (16.7%. Spotted genet consumed mainly small mammals, birds and fruits, whilst otter predated practically only fish (95%. Using Levins’ index, trophic-niche widths in European mink, small-spotted genet and Eurasian otter were 3.76, 3.77 and 1.10, respectively. The trophic niche overlap by Pianka index for autumn-winter was 0.77 for European mink vs. Small-spotted genet, and 0.60 for European mink vs. otter. The average size of brown trout taken by otter was larger than those consumed by European mink.

Genetic structure and evidence for recent population decline in Eurasian otter populations in the Czech and Slovak Republics: implications for conservation

DEFF Research Database (Denmark)

Hájková, P.; Pertoldi, C.; Ukendt, Zemanová

2007-01-01

Over the latter part of the 20th century, Eurasian otter Lutra lutra populations suffered dramatic declines, resulting in extinction or fragmentation of populations in many western and central European countries. Part of the Czech otter population became totally isolated while the Slovak populati...... that they remain a strongly protected species in both countries. The spreading and re-connection of otter populations observed recently is essential for the future health of the populations, and should be supported through habitat conservation......., suggesting that the strongest decline probably occurred between the 1970s and the mid-1990s. The results of this study confirm that otter populations remain vulnerable to any violent demographic change and, despite the claims of fish-farmers and anglers for legal culls, it is highly desirable...

Marine Mammals as Models for Cost Efficient AUVs: Specifications of Oscillating Hydrofoils

National Research Council Canada - National Science Library

Williams, Terrie

2004-01-01

...), California sea lions (Zalophus californianus), river otters (Lontra canadensis), and sea otters (Enhydra lutris) to assess the mechanical operation and energetic cost of oscillating hydrofoils performing in controlled environments...

First characterization of bacterial pathogen, Vibrio alginolyticus, for Porites andrewsi White syndrome in the South China Sea.

Science.gov (United States)

Zhenyu, Xie; Shaowen, Ke; Chaoqun, Hu; Zhixiong, Zhu; Shifeng, Wang; Yongcan, Zhou

2013-01-01

White syndrome, a term for scleractinian coral disease with progressive tissue loss, is known to cause depressed growth and increased morality of coral reefs in the major oceans around the world, and the occurrence of this disease has been frequently reported in the past few decades. Investigations during April to September in both 2010 and 2011 identified widespread Porites andrewsi White syndrome (PAWS) in Xisha Archipelago, South China Sea. However, the causes and etiology of PAWS have been unknown. A transmission experiment was performed on P. andrewsi in the Qilianyu Subgroup (QLY). The results showed that there was a significant (P ≤ 0.05) difference between test and control groups after 28 days if the invalid replicates were excluded. Rates of tissue loss ranged from 0.90-10.76 cm(2) d(-1) with a mean of 5.40 ± 3.34 cm(2) d(-1) (mean ± SD). Bacterial strains were isolated from the PAWS corals at the disease outbreak sites in QLY of the Xisha Archipelago, South China Sea, and included in laboratory-based infection trials to satisfy Koch's postulates for establishing causality. Following exposure to bacterial concentrations of 10(5) cells mL(-1), the infected colonies exhibited similar signs to those observed in the field. Using phylogenetic 16S rRNA gene analysis, classical phenotypic trait comparison, Biolog automatic identification system, MALDI-TOF mass spectrometry and MALDI Biotyper method, two pathogenic strains were identified as Vibrio alginolyticus . This is the first report of V. alginolyticus as a pathogenic agent of PAWS in the South China Sea. Our results point out an urgent need to develop sensitive detection methods for V. alginolyticus virulence strains and robust diagnostics for coral disease caused by this and Vibrio pathogenic bacterium in the South China Sea.

Habitat quality assessment for the Eurasian otter (Lutra lutra on the river Jajrood, Iran

Directory of Open Access Journals (Sweden)

Roohallah Mirzaei

2010-06-01

Full Text Available Abstract There is little information about the status and ecology of the Eurasian otter (Lutra lutra in Iran. We assessed the habitat suitability for otters of the River Jajrood, Tehran province, measuring, or visually estimating, 12 environmental parameters along 16 600 m long river stretches (sampling sites. The downstream stretches of the river were found to be more suitable for otters with respect to the upper part of its course. Although the assessments of habitat suitability for the otter may be affected by several limits, the current distribution of the species on the river agrees with the results of this study. The preservation of the otter in Tehran province should involve the restoration of the ecosystem of the River Jajrood in order to improve the length of suitable river stretches.
Riassunto Stima dell’idoneità ambientale per la lontra (Lutra lutra del fiume Jajrood, Iran. Le informazioni relative alla lontra (Lutra lutra in Iran sono scarse. L’idoneità ambientale per la specie del fiume Jajrood, provincia di Tehran, è stata valutata, misurando o stimando 12 parametri ambientali lungo 16 stazioni di campionamento, coincidenti con tratti di fiume della lunghezza di 600 m. I tratti più a valle sono risultati più idonei rispetto al corso superiore del fiume. Malgrado i numerosi limiti del metodo di stima dell’idoneità ambientale adottato, i risultati sono in accordo con l’attuale distribuzione della lontra lungo il fiume Jajrood. La conservazione della lontra nella provincia di Tehran dovrebbe prevedere miglioramenti ambientali volti a incrementare lo sviluppo lineare degli habitat idonei lungo il fiume Jajrood.

doi:10.4404/hystrix-20.2-4447

Spatial and Temporal Changes in Air Pollution Along the Gulf Coast Observed During BRACE: A Case Study of the Land-Sea Breeze

Science.gov (United States)

Wellman, D.; Luke, W.; Arnold, J.; Watson, T.; Gunter, L.

2003-12-01

NOAA's Air Resources Laboratory conducted airborne measurements of trace gases and aerosols in the Bay Region Atmospheric Chemistry Experiment (BRACE) using the NOAA Twin Otter. The Twin Otter flew more than 90 hours in 21 flights in and around the Tampa metropolitan region in May, 2002, at altitudes of 60-3000 m MSL. Flights were conducted over rural and suburban areas, over the centers of Tampa and St. Petersburg, and over Tampa Bay and the Gulf of Mexico. One objective of the aircraft flights was to investigate the role of the sea breeze circulation in determining patterns of nutrient deposition and pollutant loads in the Tampa Bay watershed. Results will be presented from a May 8 flight designed to investigate the effect of the sea breeze recirculation upon Tampa's air quality. The Twin Otter took off at 1425 UTC and after performing a spiral ascent over the Sydney ground site, proceeded to fly north, at 200 feet above mean sea level (MSL) just off the Gulf coast, west of St. Petersburg. Back trajectory analysis suggested the dominance of a northerly rotation in the sea breeze; thus, air sampled over the Gulf passed some hours earlier to the south of the Tampa metropolitan area, in an area largely devoid of major pollution sources, before being advected eastward in the afternoon return flow. Ozone levels in this air mass ranged from 40 to 50 ppbv. Farther north the Twin Otter encountered the advected urban plume from Tampa, displaced to the north by the combination of southeasterly sea breeze flow and westerly return flow, and tracked this plume inland. Ozone levels quickly jumped to 60 ppbv, and increased to as high as 90 ppbv as photochemical processing continued in the advected plume. Nitric acid levels, which approached 4 ppbv in the aged urban air at the coast, dropped rapidly to as low as 1 ppbv inland. A final flight leg to the east of downtown Tampa encountered fresh anthropogenic pollution from the afternoon rush hour; ozone was rapidly produced in the

Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems

Science.gov (United States)

Krusor, Colin; Smith, Woutrina A.; Tinker, M. Tim; Silver, Mary; Conrad, Patricia A.; Shapiro, Karen

2015-01-01

The parasite Toxoplasma gondii is an environmentally persistent pathogen that can cause fatal disease in humans, terrestrial warm-blooded animals and aquatic mammals. Although an association between T. gondii exposure and prey specialization on marine snails was identified in threatened California sea otters, the ability of kelp-dwelling snails to transmit terrestrially derived pathogens has not been previously investigated. The objective of this study was to measure concentration and retention of T. gondii by marine snails in laboratory aquaria, and to test for natural T. gondii contamination in field-collected snails. Following exposure to T. gondii-containing seawater, oocysts were detected by microscopy in snail faeces and tissues for 10 and 3 days respectively. Nested polymerase chain reaction was also applied as a method for confirming putative T. gondii oocysts detected in snail faeces and tissues by microscopy. Toxoplasma gondiiwas not detected in field-collected snails. Results suggest that turban snails are competent transport hosts for T. gondii. By concentrating oocysts in faecal pellets, snails may facilitate entry of T. gondii into the nearshore marine food web. This novel mechanism also represents a general pathway by which marine transmission of terrestrially derived microorganisms can be mediated via pathogen concentration and retention by benthic invertebrates.

Using molecular epidemiology to track Toxoplasma gondii from terrestrial carnivores to marine hosts: implications for public health and conservation.

Science.gov (United States)

VanWormer, Elizabeth; Miller, Melissa A; Conrad, Patricia A; Grigg, Michael E; Rejmanek, Daniel; Carpenter, Tim E; Mazet, Jonna A K

2014-01-01

Environmental transmission of the zoonotic parasite Toxoplasma gondii, which is shed only by felids, poses risks to human and animal health in temperate and tropical ecosystems. Atypical T. gondii genotypes have been linked to severe disease in people and the threatened population of California sea otters. To investigate land-to-sea parasite transmission, we screened 373 carnivores (feral domestic cats, mountain lions, bobcats, foxes, and coyotes) for T. gondii infection and examined the distribution of genotypes in 85 infected animals sampled near the sea otter range. Nested PCR-RFLP analyses and direct DNA sequencing at six independent polymorphic genetic loci (B1, SAG1, SAG3, GRA6, L358, and Apico) were used to characterize T. gondii strains in infected animals. Strains consistent with Type X, a novel genotype previously identified in over 70% of infected sea otters and four terrestrial wild carnivores along the California coast, were detected in all sampled species, including domestic cats. However, odds of Type X infection were 14 times higher (95% CI: 1.3-148.6) for wild felids than feral domestic cats. Type X infection was also linked to undeveloped lands (OR = 22, 95% CI: 2.3-250.7). A spatial cluster of terrestrial Type II infection (P = 0.04) was identified in developed lands bordering an area of increased risk for sea otter Type II infection. Two spatial clusters of animals infected with strains consistent with Type X (P ≤ 0.01) were detected in less developed landscapes. Differences in T. gondii genotype prevalence among domestic and wild felids, as well as the spatial distribution of genotypes, suggest co-existing domestic and wild T. gondii transmission cycles that likely overlap at the interface of developed and undeveloped lands. Anthropogenic development driving contact between these cycles may increase atypical T. gondii genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans, domestic animals

Using molecular epidemiology to track Toxoplasma gondii from terrestrial carnivores to marine hosts: implications for public health and conservation.

Directory of Open Access Journals (Sweden)

Elizabeth VanWormer

Full Text Available Environmental transmission of the zoonotic parasite Toxoplasma gondii, which is shed only by felids, poses risks to human and animal health in temperate and tropical ecosystems. Atypical T. gondii genotypes have been linked to severe disease in people and the threatened population of California sea otters. To investigate land-to-sea parasite transmission, we screened 373 carnivores (feral domestic cats, mountain lions, bobcats, foxes, and coyotes for T. gondii infection and examined the distribution of genotypes in 85 infected animals sampled near the sea otter range.Nested PCR-RFLP analyses and direct DNA sequencing at six independent polymorphic genetic loci (B1, SAG1, SAG3, GRA6, L358, and Apico were used to characterize T. gondii strains in infected animals. Strains consistent with Type X, a novel genotype previously identified in over 70% of infected sea otters and four terrestrial wild carnivores along the California coast, were detected in all sampled species, including domestic cats. However, odds of Type X infection were 14 times higher (95% CI: 1.3-148.6 for wild felids than feral domestic cats. Type X infection was also linked to undeveloped lands (OR = 22, 95% CI: 2.3-250.7. A spatial cluster of terrestrial Type II infection (P = 0.04 was identified in developed lands bordering an area of increased risk for sea otter Type II infection. Two spatial clusters of animals infected with strains consistent with Type X (P ≤ 0.01 were detected in less developed landscapes.Differences in T. gondii genotype prevalence among domestic and wild felids, as well as the spatial distribution of genotypes, suggest co-existing domestic and wild T. gondii transmission cycles that likely overlap at the interface of developed and undeveloped lands. Anthropogenic development driving contact between these cycles may increase atypical T. gondii genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans

Buoyancy Regulation and the Energetics of Diving in Dolphins Seals, Sea Lions and Sea Otters

National Research Council Canada - National Science Library

Costa, Daniel

1998-01-01

We examined swim speed and ascent descent rates in sea lions and elephant seals in order to make comparisons in their diving strategies and how these may be effected by different strategies of buoyancy regulation...

Trophic interactions of the endangered Southern river otter ( Lontra provocax) in a Chilean Ramsar wetland inferred from prey sampling, fecal analysis, and stable isotopes

Science.gov (United States)

Franco, Marcela; Guevara, Giovany; Correa, Loreto; Soto-Gamboa, Mauricio

2013-04-01

Non-invasive methodological approaches are highly recommended and commonly used to study the feeding ecology of elusive and threatened mammals. In this study, we use multiple lines of evidence to assess the feeding strategies of the endangered Southern river otter, by determining seasonal prey availability (electrofishing), analysis of undigested prey remains (spraints), and the use of stable isotopes (δ15N and δ13C) in otter spraints ( n = 262) and prey in a wetland ecosystem of southern Chile (39°49'S, 73°15'W). Fecal and isotopic analyses suggest that the otter diet is restricted to a few prey items, particularly the less-mobile, bottom-living, and larger prey such as crayfish ( Samastacus spinifrons, 86.11 %) and crabs ( Aegla spp., 32.45 %), supplemented opportunistically by cyprinids ( Cyprinus carpio, 9.55 %) and catfish ( Diplomystes camposensis, 5.66 %). The results suggest that the river otter is highly specialized in bottom foraging. Isotopic signatures of food sources and feces revealed a mid-upper trophic position for the Southern river otter, with either higher or lower δ15N values than their potential prey items. δ13C values for river otters were less enriched than their potential food resources. We suggest that due to their narrow trophic niche and possible dependence on only a few food items, this species may be highly vulnerable to the reduction in its prey populations. Finally, maintaining the ecological interactions between Southern river otters and their prey is considered a central priority for the survival of this endangered carnivore mammal.

Climate change and the potential spreading of marine mucilage and microbial pathogens in the Mediterranean Sea.

Directory of Open Access Journals (Sweden)

Roberto Danovaro

2009-09-01

Full Text Available Marine snow (small amorphous aggregates with colloidal properties is present in all oceans of the world. Surface water warming and the consequent increase of water column stability can favour the coalescence of marine snow into marine mucilage, large marine aggregates representing an ephemeral and extreme habitat. Marine mucilage characterize aquatic systems with altered environmental conditions.We investigated, by means of molecular techniques, viruses and prokaryotes within the mucilage and in surrounding seawater to examine the potential of mucilage to host new microbial diversity and/or spread marine diseases. We found that marine mucilage contained a large and unexpectedly exclusive microbial biodiversity and hosted pathogenic species that were absent in surrounding seawater. We also investigated the relationship between climate change and the frequency of mucilage in the Mediterranean Sea over the last 200 years and found that the number of mucilage outbreaks increased almost exponentially in the last 20 years. The increasing frequency of mucilage outbreaks is closely associated with the temperature anomalies.We conclude that the spreading of mucilage in the Mediterranean Sea is linked to climate-driven sea surface warming. The mucilage can act as a controlling factor of microbial diversity across wide oceanic regions and could have the potential to act as a carrier of specific microorganisms, thereby increasing the spread of pathogenic bacteria.

Dietary specifications reflect the feeding behaviour of the European otter (Lutra lutra in “Strandzha” Natural Park (Bulgaria

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Natchev Nikolay

2015-12-01

Full Text Available Within the scope of the present study a field survey in the area of “Strandzha” Natural Park in south-east Bulgaria was carried out. The main goal of the investigation was to gain more detailed information on the diet of the European otters (Lutra lutra that inhabit the park. As indicators for the presence of the mustelids a set of standard procedures, such as footprints tracking and inspecting the terrain for otter spraints were used. A total of 204 excrements were found, measured, documented and then disintegrated in water. The food rests in the faeces were investigated and the diet of the local population was documented. On the base of the results we separated the excrements into six groups and analysed the relations between the contents of the spraints and the characteristics of the habitat where they were found. We discovered a clear tendency toward piscivory in the middle and down streams of the studied rivers in the Natural Park. In the upper streams, otters relied almost exclusively on invertebrates like bivalves and crayfish as food source. The fact, that even suboptimal habitats, which offered invariable menu, were exploited by the otters is an indication for the stability of the local population.

Contamination of community water sources by potentially pathogenic vibrios following sea water inundation.

Science.gov (United States)

Kanungo, Reba; Shashikala; Karunasagar, I; Srinivasan, S; Sheela, Devi; Venkatesh, K; Anitha, P

2007-12-01

Potentially pathogenic members of the Vibrionaceae family including Vibrio cholerae and Vibrio parahemolyticus were isolated from domestic sources of drinking water in coastal villages following sea water inundation during the tsunami in Southern India. Phenotypic and genotypic studies were done to confirm the identity and detection of toxins. Vibrio-gyr (gyrase B gene) was detected in all sixteen vibrio isolates. Toxin regulating genes i.e.: ctx gene, tdh gene, and trh gene, however were not detected in any of the strains, thereby ruling out presence of toxins which could endanger human life. Other potentially pathogenic bacteria Aeromonas and Plesiomonas were also isolated from hand pumps and wells, in a few localities. There was no immediate danger in the form of an outbreak or sporadic gastroenteritis at the time of the study. Timely chlorination and restoration of potable water supply to the flood affected population by governmental and nongovernmental agencies averted waterborne gastroenteritis. Assessment of quality of water and detection of potential virulent organisms is an important public health activity following natural disasters. This work highlights the importance of screening water sources for potentially pathogenic microorganisms after natural disasters to avert outbreaks of gastroenteritis and other infectious diseases.

Modeling Behavior by Coastal River Otter (Lontra Canadensis in Response to Prey Availability in Prince William Sound, Alaska: A Spatially-Explicit Individual-Based Approach.

Directory of Open Access Journals (Sweden)

Shannon E Albeke

Full Text Available Effects of climate change on animal behavior and cascading ecosystem responses are rarely evaluated. In coastal Alaska, social river otters (Lontra Canadensis, largely males, cooperatively forage on schooling fish and use latrine sites to communicate group associations and dominance. Conversely, solitary otters, mainly females, feed on intertidal-demersal fish and display mutual avoidance via scent marking. This behavioral variability creates "hotspots" of nutrient deposition and affects plant productivity and diversity on the terrestrial landscape. Because the abundance of schooling pelagic fish is predicted to decline with climate change, we developed a spatially-explicit individual-based model (IBM of otter behavior and tested six scenarios based on potential shifts to distribution patterns of schooling fish. Emergent patterns from the IBM closely mimicked observed otter behavior and landscape use in the absence of explicit rules of intraspecific attraction or repulsion. Model results were most sensitive to rules regarding spatial memory and activity state following an encounter with a fish school. With declining availability of schooling fish, the number of social groups and the time simulated otters spent in the company of conspecifics declined. Concurrently, model results suggested an elevation of defecation rate, a 25% increase in nitrogen transport to the terrestrial landscape, and significant changes to the spatial distribution of "hotspots" with declines in schooling fish availability. However, reductions in availability of schooling fish could lead to declines in otter density over time.

Interactions between the tropical sea anemone Aiptasia pallida and Serratia marcescens, an opportunistic pathogen of corals.

Science.gov (United States)

Krediet, Cory J; Meyer, Julie L; Gimbrone, Nicholas; Yanong, Roy; Berzins, Ilze; Alagely, Ali; Castro, Herman; Ritchie, Kim B; Paul, Valerie J; Teplitski, Max

2014-06-01

Coral reefs are under increasing stress caused by global and local environmental changes, which are thought to increase the susceptibility of corals to opportunistic pathogens. In the absence of an easily culturable model animal, the understanding of the mechanisms of disease progression in corals remains fairly limited. In the present study, we tested the susceptibility of the tropical sea anemone Aiptasia pallida to an opportunistic coral pathogen (Serratia marcescens). A. pallida was susceptible to S. marcescens PDL100 and responded to this opportunistic coral pathogen with darkening of the tissues and retraction of tentacles, followed by complete disintegration of polyp tissues. Histological observations revealed loss of zooxanthellae and structural changes in eosinophilic granular cells in response to pathogen infection. A screen of S. marcescens mutants identified a motility and tetrathionate reductase mutants as defective in virulence in the A. pallida infection model. In co-infections with the wild-type strain, the tetrathionate reductase mutant was less fit within the surface mucopolysaccharide layer of the host coral Acropora palmata. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

Unravelling the microbiome of eggs of the endangered sea turtle Eretmochelys imbricata identifies bacteria with activity against the emerging pathogen Fusarium falciforme.

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Jullie M Sarmiento-Ramírez

Full Text Available Habitat bioaugmentation and introduction of protective microbiota have been proposed as potential conservation strategies to rescue endangered mammals and amphibians from emerging diseases. For both strategies, insight into the microbiomes of the endangered species and their habitats is essential. Here, we sampled nests of the endangered sea turtle species Eretmochelys imbricata that were infected with the fungal pathogen Fusarium falciforme. Metagenomic analysis of the bacterial communities associated with the shells of the sea turtle eggs revealed approximately 16,664 operational taxonomic units, with Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes as the most dominant phyla. Subsequent isolation of Actinobacteria from the eggshells led to the identification of several genera (Streptomyces, Amycolaptosis, Micromomospora Plantactinospora and Solwaraspora that inhibit hyphal growth of the pathogen F. falciforme. These bacterial genera constitute a first set of microbial indicators to evaluate the potential role of microbiota in conservation of endangered sea turtle species.

Unravelling the microbiome of eggs of the endangered sea turtle Eretmochelys imbricata identifies bacteria with activity against the emerging pathogen Fusarium falciforme.

Science.gov (United States)

Sarmiento-Ramírez, Jullie M; van der Voort, Menno; Raaijmakers, Jos M; Diéguez-Uribeondo, Javier

2014-01-01

Habitat bioaugmentation and introduction of protective microbiota have been proposed as potential conservation strategies to rescue endangered mammals and amphibians from emerging diseases. For both strategies, insight into the microbiomes of the endangered species and their habitats is essential. Here, we sampled nests of the endangered sea turtle species Eretmochelys imbricata that were infected with the fungal pathogen Fusarium falciforme. Metagenomic analysis of the bacterial communities associated with the shells of the sea turtle eggs revealed approximately 16,664 operational taxonomic units, with Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes as the most dominant phyla. Subsequent isolation of Actinobacteria from the eggshells led to the identification of several genera (Streptomyces, Amycolaptosis, Micromomospora Plantactinospora and Solwaraspora) that inhibit hyphal growth of the pathogen F. falciforme. These bacterial genera constitute a first set of microbial indicators to evaluate the potential role of microbiota in conservation of endangered sea turtle species.

Otter Lutra lutra movements assessed by genotyped spraints in southern Italy

Directory of Open Access Journals (Sweden)

Claudio Prigioni

2006-09-01

Full Text Available Abstract
This paper analyses some otter (Lutra lutra spatial data, obtained by the location of genetically typed spraints in the Pollino national park and surrounding areas (southern Italy. A sample of 214 otter spraints was collected (27 faeces in 2001-02 and 187 in 2004 along 10 streams of the park, and their location was digitalized by a Geographic Information System (Arcview 3.1 for spatial analysis. DNA was extracted using the GuSCN/silica method and each faecal sample was genotyped by PCR amplification of twelve microsatellite loci. Finally, 103 (48.1% spraints yielded a reliable genotype, providing the identification of 31 otters. The maximum distance, measured along watercourses between the genotyped faecal samples of each individual identified by at least two faeces, varied from 0.02 to 34.8 km. On the whole, our results outlined a ranging pattern based on the occupation by one otter of a long stretch of watercourse (21.6 and 34.8 km, including 4-6 partially overlapped short stretches (from 0.02 to 14.1 km occupied by as many animals. RIASSUNTO – Spostamenti della Lontra Lutra lutra valutati mediante analisi genetica delle feci in Italia meridionale. Tramite l’estrazione del DNA da feci “fresche” e la succes- siva amplificazione di 12 loci microsatellite, da un campione di 214 feci di Lontra raccolto lungo 10 corsi idrici del Parco Nazionale del Pollino e aree limitrofe (27 feci nel 2001-02 e 187 nel 2004 sono stati ottenuti 103 genotipi affidabili (48,1%, consentendo l’identifi- cazione di 31 individui. La localizzazione delle feci genotipizzate è stata stabilita mediante GPS (Global Positioning System e trasferita su una mappa digitalizzata (scala 1:10000 tramite GIS (Geographic Information System. La distanza massima, misurata lungo i corsi idrici investigati, tra i campioni fecali tipizzati di ciascun individuo è variata da 0,02 a 34,8 km. Nel complesso, i risultati ottenuti hanno

Organochlorine pesticides and polychlorinated biphenyls in California sea lions

Energy Technology Data Exchange (ETDEWEB)

Kannan, K.; Kajiwara, N.; Le Boeuf, B.J.; Tanabe, S

2004-10-01

Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few {mu}g/g to several hundreds of {mu}g/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several {mu}g/g on a lipid weight basis.

Organochlorine pesticides and polychlorinated biphenyls in California sea lions

International Nuclear Information System (INIS)

Kannan, K.; Kajiwara, N.; Le Boeuf, B.J.; Tanabe, S.

2004-01-01

Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few μg/g to several hundreds of μg/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several μg/g on a lipid weight basis

Evolutionary history and identification of conservation units in the giant otter, Pteronura brasiliensis.

Science.gov (United States)

Pickles, R S A; Groombridge, J J; Zambrana Rojas, V D; Van Damme, P; Gottelli, D; Kundu, S; Bodmer, R; Ariani, C V; Iyengar, A; Jordan, W C

2011-12-01

The giant otter, Pteronura brasiliensis, occupies a range including the major drainage basins of South America, yet the degree of structure that exists within and among populations inhabiting these drainages is unknown. We sequenced portions of the mitochondrial DNA (mtDNA) cytochrome b (612bp) and control region (383 bp) genes in order to determine patterns of genetic variation within the species. We found high levels of mtDNA haplotype diversity (h = 0.93 overall) and support for subdivision into four distinct groups of populations, representing important centers of genetic diversity and useful units for prioritizing conservation within the giant otter. We tested these results against the predictions of three hypotheses of Amazonian diversification (Pleistocene Refugia, Paleogeography, and Hydrogeology). While the phylogeographic pattern conformed to the predictions of the Refugia Hypothesis, molecular dating using a relaxed clock revealed the phylogroups diverged from one another between 1.69 and 0.84 Ma, ruling out the influence of Late Pleistocene glacial refugia. However, the role of Plio-Pleistocene climate change could not be rejected. While the molecular dating also makes the influence of geological arches according to the Paleogeography Hypothesis extremely unlikely, the recent Pliocene formation of the Fitzcarrald Arch and its effect of subsequently altering drainage pattern could not be rejected. The data presented here support the interactions of both climatic and hydrological changes resulting from geological activity in the Plio-Pleistocene, in shaping the phylogeographic structure of the giant otter. Copyright © 2011 Elsevier Inc. All rights reserved.

Mercury concentrations in wild mink (Mustela vison) and river otters (Lontra canadensis) collected from eastern and Atlantic Canada: Relationship to age and parasitism

Energy Technology Data Exchange (ETDEWEB)

Klenavic, Katherine [Environmental and Resource Studies, Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada); Champoux, Louise [Service Canadien de la Faune Environnement Canada, 1141 Route de l' Eglise, c.p. 10100, Sainte-Foy, QC G1V 4H5 (Canada)], E-mail: louise.champoux@ec.gc.ca; Mike, O' Brien [Furbearers and Upland Game, Department of Natural Resources, Kentville, NS B4N 4E5 (Canada)], E-mail: obrienms@gov.ns.ca; Daoust, Pierre-Y. [Department of Pathology and Microbiology, Atlantic Veterinary College, University of P.E.I., 550 University Avenue, Charlottetown, PEI C1A 4P3 (Canada)], E-mail: daoust@upei.ca; Evans, R. Douglas [Environmental and Resource Studies, Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada); Evans, Hayla E. [Environmental and Resource Studies, Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada)], E-mail: hevans@trentu.ca

2008-11-15

Total mercury (Hg) concentrations were measured in the fur, brain and liver of wild mink (Mustela vison) and river otters (Lontra canadensis) collected from eastern and Atlantic Canada. Total Hg concentrations in fur were strongly correlated with levels in the brain and liver. There was no difference in tissue concentrations between male and female mink; however, female otters had significantly higher fur, brain and liver Hg levels than males. Similarly, there was not a significant relationship between Hg concentration and age of mink, whereas in otters, Hg concentrations in all three tissues decreased significantly with age. In both species, only a very small percentage of the variability in Hg concentration was explained by age. After adjusting the data for site-to-site differences in Hg levels, Hg concentrations in the fur of mink infected by the parasite, Dioctophyma renale, were found to be significantly higher than Hg levels in uninfected mink. - Mercury (Hg) concentrations in liver, brain and fur are correlated in mink (Mustela vison) and otters (Lontra canadensis), allowing the use of fur as an indicator of internal tissue concentrations.

Mercury concentrations in wild mink (Mustela vison) and river otters (Lontra canadensis) collected from eastern and Atlantic Canada: Relationship to age and parasitism

International Nuclear Information System (INIS)

Klenavic, Katherine; Champoux, Louise; Mike, O'Brien; Daoust, Pierre-Y.; Evans, R. Douglas; Evans, Hayla E.

2008-01-01

Total mercury (Hg) concentrations were measured in the fur, brain and liver of wild mink (Mustela vison) and river otters (Lontra canadensis) collected from eastern and Atlantic Canada. Total Hg concentrations in fur were strongly correlated with levels in the brain and liver. There was no difference in tissue concentrations between male and female mink; however, female otters had significantly higher fur, brain and liver Hg levels than males. Similarly, there was not a significant relationship between Hg concentration and age of mink, whereas in otters, Hg concentrations in all three tissues decreased significantly with age. In both species, only a very small percentage of the variability in Hg concentration was explained by age. After adjusting the data for site-to-site differences in Hg levels, Hg concentrations in the fur of mink infected by the parasite, Dioctophyma renale, were found to be significantly higher than Hg levels in uninfected mink. - Mercury (Hg) concentrations in liver, brain and fur are correlated in mink (Mustela vison) and otters (Lontra canadensis), allowing the use of fur as an indicator of internal tissue concentrations

77 FR 27246 - Marine Mammal Protection Act; Stock Assessment Report

Science.gov (United States)

2012-05-09

... contaminants in sea otters among populations in California and Alaska. M.S. thesis, University of California... Island. Master's Thesis, University of California, Santa Cruz, unpublished. Bryant, H.C. 1915. Sea otters near Point Sur. California Department of Fish and Game Bull. 1:134-135. Cameron, G.A., and K.A. Forney...

Distribution of Bottom Trawling Effort in the Yellow Sea and East China Sea.

Directory of Open Access Journals (Sweden)

Shengmao Zhang

Full Text Available Bottom trawling is one of the most efficient fishing activities, but serious and persistent ecological issues have been observed by fishers, scientists and fishery managers. Although China has applied the Beidou fishing vessel position monitoring system (VMS to manage trawlers since 2006, little is known regarding the impacts of trawling on the sea bottom environments. In this study, continuous VMS data of the 1403 single-rig otter trawlers registered in the Xiangshan Port, 3.9% of the total trawlers in China, were used to map the trawling effort in 2013. We used the accumulated distance (AD, accumulated power distance (APD, and trawling intensity as indexes to express the trawling efforts in the Yellow Sea (YS and East China Sea (ECS. Our results show that all three indexes had similar patterns in the YS and ECS, and indicated a higher fishing effort of fishing grounds that were near the port. On average, the seabed was trawled 0.73 times in 2013 over the entire fishing region, and 51.38% of the total fishing grounds were with no fishing activities. Because of VMS data from only a small proportion of Chinese trawlers was calculated fishing intensity, more VMS data is required to illustrate the overall trawling effort in China seas. Our results enable fishery managers to identify the distribution of bottom trawling activities in the YS and ECS, and hence to make effective fishery policy.

Virulence Profiles of Vibrio vulnificus in German Coastal Waters, a Comparison of North Sea and Baltic Sea Isolates

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Nadja Bier

2015-12-01

Full Text Available Vibrio vulnificus is a halophilic bacterium of coastal environments known for sporadically causing severe foodborne or wound infections. Global warming is expected to lead to a rising occurrence of V. vulnificus and an increasing incidence of human infections in Northern Europe. So far, infections in Germany were exclusively documented for the Baltic Sea coast, while no cases from the North Sea region have been reported. Regional variations in the prevalence of infections may be influenced by differences in the pathogenicity of V. vulnificus populations in both areas. This study aimed to compare the distribution of virulence-associated traits and genotypes among 101 V. vulnificus isolates from the Baltic Sea and North Sea in order to assess their pathogenicity potential. Furthermore, genetic relationships were examined by multilocus sequence typing (MLST. A high diversity of MLST sequences (74 sequence types and differences regarding the presence of six potential pathogenicity markers were observed in the V. vulnificus populations of both areas. Strains with genotypes and markers associated with pathogenicity are not restricted to a particular geographic region. This indicates that lack of reported cases in the North Sea region is not caused by the absence of potentially pathogenic strains.

PATHOGENIC LEPTOSPIRA SEROVARS IN FREE-LIVING SEA LIONS IN THE GULF OF CALIFORNIA AND ALONG THE BAJA CALIFORNIA COAST OF MEXICO.

Science.gov (United States)

Avalos-Téllez, Rosalía; Carrillo-Casas, Erika M; Atilano-López, Daniel; Godínez-Reyes, Carlos R; Díaz-Aparicio, Efrén; Ramírez-Delgado, David; Ramírez-Echenique, María F; Leyva-Leyva, Margarita; Suzán, Gerardo; Suárez-Güemes, Francisco

2016-04-28

The California sea lion ( Zalophus californianus ), a permanent inhabitant of the Gulf of California in Mexico, is susceptible to pathogenic Leptospira spp. infection, which can result in hepatic and renal damage and may lead to renal failure and death. During summer 2013, we used the microscopic agglutination test (MAT) to investigate the prevalence of anti-Leptospira antibodies in blood of clinically healthy sea lion pups from seven rookery islands on the Pacific Coast of Baja California (Pacific Ocean) and in the Gulf of California. We also used PCR to examine blood for Leptospira DNA. Isolation of Leptospira in liquid media was unsuccessful. We found higher antibody prevalence in sea lions from the rookery islands in the gulf than in those from the Pacific Coast. Antibodies against 11 serovars were identified in the Gulf of California population; the most frequent reactions were against serovars Bataviae (90%), Pyrogenes (86%), Wolffi (86%), Celledoni (71%), and Pomona (65%). In the Pacific Ocean population, MAT was positive against eight serovars, where Wolffi (88%), Pomona (75%), and Bataviae (70%) were the most frequent. Serum samples agglutinated with more than one Leptospira serovar. The maximum titer was 3,200. Each island had a different serology profile, and islands combined showed a distinct profile for each region. We detected pathogenic Leptospira DNA in 63% of blood samples, but we found no saprophytic Leptospira. Positive PCR results were obtained in blood samples with high and low MAT titers. Together, these two methods enhance the diagnosis and interpretation of sea lion leptospirosis. Our results may be related to human activities or the presence of other reservoirs with which sea lions interact, and they may also be related to sea lion stranding.

Biodiversity of deep-sea demersal megafauna in western and central Mediterranean basins

Directory of Open Access Journals (Sweden)

Samuele Tecchio

2011-06-01

Full Text Available Abundance, biomass and diversity patterns of bathyal and abyssal Mediterranean megafauna (fishes and invertebrates were analyzed in the western Balearic Sea, the western Ionian Sea and the eastern Ionian Sea. Sampling was conducted with a Otter-trawl Maireta System (OTMS at depths ranging from 600 to 4000 m. A series of ecological indicators were computed: total abundance and biomass, Margalef species richness, Shannon-Wiener diversity and Pielou’s index of evenness. A multidimensional scaling was applied, indicating that the megafauna communities were grouped by depth, while geographic area had a less defined influence. Margalef richness declined with depth in all three areas, but more steeply in the western Ionian Sea. Pielou’s evenness behaved differently in the three zones, showing a V-shaped curve in the eastern Ionian while showing a decreasing pattern in the other two areas. At lower slope depths, massive presence of the fishes Alepocephalus rostratus in the western basin and Bathypterois mediterraneus in the central basin caused a sharp reduction in evenness.

Conservation genetics of otters: Review about the use of non-invasive samples

OpenAIRE

Aristizábal Duque, Sandra L.; Orozco-Jiménez, Luz Y.; Zapata-Escobar, Carolina; Palacio-Baena, Jaime A.

2018-01-01

Abstract: Wild population management programs require determining some fundamental aspects for conservation, including population structure, flow between populations, evolutionary history and kinship, among others. Since sample collection from wild mammals for DNA extraction is a complex task, conservation genetics has developed non-invasive sampling techniques, which allow obtaining DNA without the need to capture individuals. For the genetic characterization of otter populations, stools are...

Genetic consequences of population decline in the European otter ( Lutra lutra ) : an assessment of microsatellite DNA variation in Danish otters from 1883 to 1993

DEFF Research Database (Denmark)

Pertoldi, C.; Hansen, Michael Møller; Loeschcke, V.

2001-01-01

alleles, suggested that a drastic long-term population decline has taken place, which could have started more than 2000 years ago, possibly due to ancient anthropogenic pressure. Finally, assignment tests and pairwise F-ST values suggested weak but statistically significant genetic differentiation between......The European otter (Lutra lutra) was common in Denmark until the 1960s, but its present distribution encompasses only a minor part of the country. The aim of this study was to assess whether the recent population decline has resulted in loss of genetic variability and to gain further insight...

Mercury concentrations in wild mink (Mustela vison) and river otters (Lontra canadensis) collected from eastern and Atlantic Canada: relationship to age and parasitism.

Science.gov (United States)

Klenavic, Katherine; Champoux, Louise; Mike, O'Brien; Daoust, Pierre-Y; Evans, R Douglas; Evans, Hayla E

2008-11-01

Total mercury (Hg) concentrations were measured in the fur, brain and liver of wild mink (Mustela vison) and river otters (Lontra canadensis) collected from eastern and Atlantic Canada. Total Hg concentrations in fur were strongly correlated with levels in the brain and liver. There was no difference in tissue concentrations between male and female mink; however, female otters had significantly higher fur, brain and liver Hg levels than males. Similarly, there was not a significant relationship between Hg concentration and age of mink, whereas in otters, Hg concentrations in all three tissues decreased significantly with age. In both species, only a very small percentage of the variability in Hg concentration was explained by age. After adjusting the data for site-to-site differences in Hg levels, Hg concentrations in the fur of mink infected by the parasite, Dioctophyma renale, were found to be significantly higher than Hg levels in uninfected mink.

Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California.

Science.gov (United States)

Rejmanek, Daniel; Miller, Melissa A; Grigg, Michael E; Crosbie, Paul R; Conrad, Patricia A

2010-05-28

Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums. (c) 2010 Elsevier B.V. All rights reserved.

Sprainting activity of captive otters: its relationship with breeding cycle and number of animals

Directory of Open Access Journals (Sweden)

Claudio Prigioni

1995-12-01

Full Text Available Abstract The marking activity of captive otters (Lutra lutra was studied from April 1989 to August 1993 in an enclosure of 1.64 ha in size, located in the Ticino Valley Natural Park (Piemonte region, northern Italy. The number of otters in the enclosure varied from 1 to 6 and three litters of 1, 2 and 2 cubs were recorded in October 1990, 1991 and 1992. The sprainting activity, expressed as number of signs (spraints and anal secretions per day was associated to the breeding cycle and increased in relation to the number of animals present in the enclosure. These data are of particular importance in order to explain the annual variation of the marking level in wild otter populations. Riassunto Attività di marcamento di 1ontre in cattività in relazione a1 ciclo riproduttivo e a1 numero degli animali - L'attività di marcamento della lontra (Lutra lutra è stata rilevata dall'aprile 1989 all'agosto 1993 in un recinto di 1,64 ha, situato nel Parco Naturale della Valle del Ticino (regione Piemonte, provincia di Novara. I1 numero di animali presenti in tale recinto variava da 1 a 6, e la nascita di tre cucciolate, composte da 1, 2 e 2 piccoli, è stata registrata in ottobre negli anni 1990, 1991 e 1992. L'intensità di marcamento, espressa come numero di segni (feci e secrezioni anali per giorno era associata a1 ciclo riproduttivo della specie e incrementava in relazione al numero di animali presenti nel recinto. I dati acquisiti rivestono particolare importanza per interpretare le variazioni nell'arco dell'anno del livello di marcamento di popolazioni selvatiche.

The diet of otters ( Lutra lutra L.) in Danish freshwater habitats : comparisons of prey fish populations

DEFF Research Database (Denmark)

Taastrom, H.M.; Jacobsen, Lene

1999-01-01

Otter spraints from five Danish freshwater localities were analysed. In all localities fish was the main prey (76-99% of estimated bulk), especially in winter. Depending on locality, the prey fish mainly consisted of cyprinids (Cyprinidae), percids (Percidae) or salmonids (Salmonidae). Seasonal v...

Detection of Total and Pathogenic Vibrio parahaemolyticus in Shellfish Growing along the South Yellow Sea and the East China Sea.

Science.gov (United States)

Han, Feng; Gu, Run-Run; Shen, Xiao-Sheng; Chen, Yuan-Ge; Tian, Liang-Liang; Zhou, Wei-Feng; Cai, You-Qiong

2017-10-17

This study was conducted to monitor the densities of total and pathogenic Vibrio parahaemolyticus in 300 samples of nine shellfish species harvested from the coasts of the South Yellow Sea and the East China Sea (N 23° to 34°, E 116° to 124°), People's Republic of China, between May and October 2015. Total V. parahaemolyticus densities were measured, and V. parahaemolyticus isolates were biochemically identified with probes for the thermostable direct hemolysin gene (tdh) and the thermostable direct hemolysin-related hemolysin gene (trh). We found that 202 of the 300 samples were positive for V. parahaemolyticus from all the sites: 58 of the 100 samples from the Fujian province, 71 of the 100 samples from the Zhejiang province, and 73 of the 100 samples from the Jiangsu province. In most (170) of the 300 samples, V. parahaemolyticus densities were 0.3 to 10 most probable number (MPN)/g; five lots exceeded 110 MPN/g, and two lots were estimated at 110 MPN/g. Among the 202 V. parahaemolyticus strains, only one was trh positive. Densities of V. parahaemolyticus in these shellfish were temperature dependent, with highest densities in June and July. Among the nine mollusk species, V. parahaemolyticus was most abundant in the agemaki clam (Sinonovacula constricta). The highest and lowest V. parahaemolyticus prevalences were found in oriental cyclina (Cyclina sinensis, 93.8%) and mussels (Mytilus edulis, 28.1%), respectively. Overall, although V. parahaemolyticus is widely distributed in marine environments, the density of V. parahaemolyticus was low and the prevalence of the main virulence factor was very low in shellfish along the coasts of the South Yellow Sea and East China Sea, which is important from a public health perspective. Data presented here will be useful for correlational research and can be utilized for developing risk management plans that establish food safety guidelines for V. parahaemolyticus in Chinese shellfish.

Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

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Britton J. Robert

2017-01-01

Full Text Available The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish Pacifastacus leniusculus only being prominent prey items in warmer months and amphibians in winter, revealing that non-fish resources were seasonally important dietary components. Reconstructed body lengths of prey revealed the only species present in diet >350 mm was pike Esox lucius. These dietary data thus provide important information for informing conservation conflicts between otters and fishery interests.

Winter predation by otter, Lutra lutra on carp pond system in South Bohemia (Czech Republic)

Czech Academy of Sciences Publication Activity Database

Kortan, D.; Adámek, Zdeněk; Poláková, S.

2007-01-01

Roč. 56, č. 4 (2007), s. 416-428 ISSN 0139-7893 Institutional research plan: CEZ:AV0Z60930519 Keywords : otter diet * spraint analysis * excessive hunting * fish remains Subject RIV: EH - Ecology, Behaviour Impact factor: 0.376, year: 2007 http://www.ivb.cz/folia/56/4/416-428_MS1301.pdf

Environmental Assessment: Proposed U.S. Air Force Military Family Housing Privatization Initiative Patrick Air Force Base, Florida

Science.gov (United States)

2008-11-03

mockingbird , other songbirds, and white ibis (Eudocimus albus). Cormorants (Phalacrocorax auritus) were observed resting on old dock pilings in the...surfacing, nursing, breeding, feeding or sheltering), hunting, capturing, or killing of polar bears, sea otters, marine otters, whales, porpoises, walruses

Deep Trawl Dataset

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Otter trawl (36' Yankee and 4-seam net deepwater gear) catches from mid-Atlantic slope and canyons at 200 - 800 m depth. Deep-sea (200-800 m depth) flat otter trawls...

Complex trophic interactions in kelp forest ecosystems

Science.gov (United States)

Estes, J.A.; Danner, E.M.; Doak, D.F.; Konar, B.; Springer, A.M.; Steinberg, P.D.; Tinker, M. Tim; Williams, T.M.

2004-01-01

The distributions and abundances of species and populations change almost continuously. Understanding the processes responsible is perhaps ecology’s most fundamental challenge. Kelp-forest ecosystems in southwest Alaska have undergone several phase shifts between alga- and herbivore-dominated states in recent decades. Overhunting and recovery of sea otters caused the earlier shifts. Studies focusing on these changes demonstrate the importance of top-down forcing processes, a variety of indirect food-web interactions associated with the otter-urchin-kelp trophic cascade, and the role of food-chain length in the coevolution of defense and resistance in plants and their herbivores. This system unexpectedly shifted back to an herbivore-dominated state during the 1990s, because of a sea-otter population collapse that apparently was driven by increased predation by killer whales. Reasons for this change remain uncertain but seem to be linked to the whole-sale collapse of marine mammals in the North Pacific Ocean and southern Bering Sea. We hypothesize that killer whales sequentially "fished down" pinniped and sea-otter populations after their earlier prey, the great whales, were decimated by commercial whaling. The dynamics of kelp forests in southwest Alaska thus appears to have been influenced by an ecological chain reaction that encompassed numerous species and large scales of space and time.

Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California

OpenAIRE

Rejmanek, Daniel; Miller, Melissa A.; Grigg, Michael E.; Crosbie, Paul R.; Conrad, Patricia A.

2010-01-01

Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was an...

Isolation of TDA-producing Phaeobacter strains from sea bass larval rearing units and their probiotic effect against pathogenic Vibrio spp. in Artemia cultures

DEFF Research Database (Denmark)

Grotkjær, Torben; Bentzon-Tilia, Mikkel; D'Alvise, Paul

2016-01-01

V. harveyi, which is the major bacterial pathogen in crustaceans and Mediterranean sea bass larvae cultures. Concomitantly, they significantly improved survival of V. harveyi-infected brine shrimp. 16S rRNA gene sequence homology identified the antagonists as Phaeobacter sp., and in silico DNA...... Vibrio anguillarum and reduce mortality in V. anguillarum-infected cod and turbot larvae. In this study, it was demonstrated that antagonistic Roseobacter-clade bacteria could be isolated from sea bass larval rearing units. In addition, it was shown that they not only antagonized V. anguillarum but also......-producing Phaeobacter isolated from Mediterranean marine larviculture are promising probiotic bacteria against pathogenic Vibrio in crustacean live-feed cultures for marine fish larvae....

Demodex lutrae n. sp. (Acari) in European otter Lutra lutra (Carnivora: Mustelidae) with data from other demodecid mites in carnivores.

Science.gov (United States)

Izdebska, Joanna N; Rolbiecki, Leszek

2014-12-01

This article describes morphological characteristics and occurrence of Demodex lutrae n. sp., which was found on European otter Lutra lutra (Linnaeus, 1758) in Poland. The new species was found in hairy regions of otter skin, mainly in the head area. With respect to morphological features, D. lutrae is most similar to D. canis (Leydig, 1859) from the domestic dog Canis familiaris Linnaeus, 1758. The new species is a medium-sized demodecid mite (adult stages average 200 μm in length); characteristic features of these mites are hammer-shaped supracoxal spines (setae elc.p) on dorsal side of gnathosoma and palps with 3 conical spines. Demodex lutrae is the first representative of the family Demodecidae described in a host from the subfamily Lutrinae. This paper also contains a checklist of demodecid mites known from carnivores.

A predictive model of the effect of environmental factors on the occurrence of otters (Lutra lutra L. in Hungary

Directory of Open Access Journals (Sweden)

Ildikó Kemenes

1995-12-01

Full Text Available Abstract A survey of the distribution of otters (Lutra lutra L. in Hungary revealed that this species is common in most parts of the country where there appear to be suitable aquatic habitats. However, there were a large number of apparently "good" habitats where no otters were found. On the other hand, in some places where, based on a qualitative assessment, otters should not have been present, we still found signs of them. The only strictly and consistently limiting factor was heavy chemical pollution of the water which could not be assayed during the survey but was analysed based on data provided by the water authorities. These observations led us to employ a quantitative method which takes into account 3 scalable and 5 non-scalable variables of the environment and their relationships which might influence the occurrence of otters. The technique was based on a non-parametric multiple regression method specifically developed for use on PCs. This so called logistic regression model is useful for investigating the relationships between a binary dependent variable and a set of categorical independent variables. We recorded the presence (1 or absence (0 of signs of otters as well as the water depth, steepness of the bank, density of the bank vegetation and the presence or absence of various disturbance factors, such as agricultural use of the water bank, obvious signs of pollution of the water, etc., at 369 sites in Hungary. The three former environmental variables were scaled, whereas the disturbance factors were each assigned a value of either 0 or 1 (0 = absent, 1 = present. The analysis has shown that this method can be used to characterise particular combinations of factors at which otters were most likely to occur and even predictions can be made on the probability of finding otters at particular places with a known combination of these environmental factors. Besides its theoretical importance, this method is a very

Diverse deep-sea fungi from the South China Sea and their antimicrobial activity.

Science.gov (United States)

Zhang, Xiao-Yong; Zhang, Yun; Xu, Xin-Ya; Qi, Shu-Hua

2013-11-01

We investigated the diversity of fungal communities in nine different deep-sea sediment samples of the South China Sea by culture-dependent methods followed by analysis of fungal internal transcribed spacer (ITS) sequences. Although 14 out of 27 identified species were reported in a previous study, 13 species were isolated from sediments of deep-sea environments for the first report. Moreover, these ITS sequences of six isolates shared 84-92 % similarity with their closest matches in GenBank, which suggested that they might be novel phylotypes of genera Ajellomyces, Podosordaria, Torula, and Xylaria. The antimicrobial activities of these fungal isolates were explored using a double-layer technique. A relatively high proportion (56 %) of fungal isolates exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among four marine pathogenic microbes (Micrococcus luteus, Pseudoaltermonas piscida, Aspergerillus versicolor, and A. sydowii). Out of these antimicrobial fungi, the genera Arthrinium, Aspergillus, and Penicillium exhibited antibacterial and antifungal activities, while genus Aureobasidium displayed only antibacterial activity, and genera Acremonium, Cladosporium, Geomyces, and Phaeosphaeriopsis displayed only antifungal activity. To our knowledge, this is the first report to investigate the diversity and antimicrobial activity of culturable deep-sea-derived fungi in the South China Sea. These results suggest that diverse deep-sea fungi from the South China Sea are a potential source for antibiotics' discovery and further increase the pool of fungi available for natural bioactive product screening.

An eDNA assay for river otter detection: A tool for surveying a semi-aquatic mammal

Science.gov (United States)

Ticha M. Padgett-Stewart; Taylor M. Wilcox; Kellie J. Carim; Kevin S. McKelvey; Michael K. Young; Michael K. Schwartz

2016-01-01

Environmental DNA (eDNA) is an effective tool for the detection of elusive or low-density aquatic organisms. However, it has infrequently been applied to mammalian species. North American river otters (Lontra canadensis) are both broad ranging and semi-aquatic, making them an ideal candidate for examining the uses of eDNA for detection of mammals. We developed...

Nicho trófico de la nutria neotropical (Lontra longicaudis en un ambiente modificado, Temascaltepec, México Food niche of the neotropical river otter (Lontra longicaudis in a modified environment, Temascaltepec, México

Directory of Open Access Journals (Sweden)

Octavio Monroy-Vilchis

2009-12-01

Full Text Available Se analizaron los cambios en espacio y tiempo de dieta de la nutria en Temascaltepec, Estado de México, en 2 ríos que presentan importante intervención humana causada por el establecimiento de criaderos de peces comerciales. Se recolectaron 157 excrementos, identificandose la trucha (Oncorhynchus mykiss como la presa más consumida (92.4%, seguida por invertebrados (3.5%, anfibios (2.9% y plantas (1.8%. La dieta de la nutria no varía significativamente entre estaciones climáticas, mientras que entre ríos, la variación fue significativa. En la zona de estudio, la nutria muestra tendencia a especializarse en el consumo de trucha. Las granjas de trucha influyen en la dieta de la nutria y se presentan como clave para la permanencia de la nutria en la zona de estudio.Spatial and temporal changes in the diet of the river otter in Temascaltepec, Mexico were analyzed on 2 rivers that present important human disturbance caused by aquaculture of commercial fish. 157 scats were collected, the principal prey was trout Oncorhynchus mykiss (92.4% followed by invertebrates (3.5%, amphibians (2.9% and plants (1.8%. Between climatic stations the diet of the river otter did not vary significantly, whereas between rivers it presented significant variation. The river otter showed specialization in the consumption of trout. The trout farms have influenced the diet of the river otter, and appear as key for the permanence of the otter in the study zone.

A review of the immune molecules in the sea cucumber.

Science.gov (United States)

Xue, Zhuang; Li, Hui; Wang, Xiuli; Li, Xia; Liu, Yang; Sun, Jing; Liu, Cenjie

2015-05-01

It is very important to identify and characterize the immune-related genes that respond to pathogens. Until recently, only some of the immune-related genes in sea cucumbers had been characterized. Their expression patterns after pathogen challenges have been analyzed via expressed sequence tag libraries, microarray studies and proteomic approaches. These genes include lectins, antimicrobial peptides, lysozyme, enzymes, clotting protein, pattern recognition proteins, Toll receptors, complement C3 and other humoral factors that might participate in the innate immune system of sea cucumbers. Although the participation of some of these immune molecules in the sea cucumber's innate immune defense against invading pathogens has been demonstrated, the functions of many of the molecules remain unclear. This review focuses on the discovery and functional characterization of the immune-related molecules from the sea cucumber for the first time and provides new insights into the immune mechanisms of the sea cucumber, which opens new possibilities for developing drugs for novel anti-bacterial and antiviral applications in fisheries. Copyright © 2015 Elsevier Ltd. All rights reserved.

Polychlorinated biphenyls, organochlorinated pesticides, and polybrominated diphenyl ethers in the cerebral cortex of wild river otters (Lontra canadensis)

International Nuclear Information System (INIS)

Basu, Niladri; Scheuhammer, Anton M.; O'Brien, Mike

2007-01-01

We measured the levels of ortho-substituted polychlorinated biphenyls (PCB), organochlorinated pesticides (OCP), and polybrominated diphenyl ethers (PBDE) in the cerebral cortex of river otters (Lontra canadensis) trapped from Ontario and Nova Scotia between 2002 and 2004. The mean concentration of total PCBs was 70.9 ± 12.1 ng/g l.w., and congeners 153, 180 and 138 accounted for nearly 60% of the sum. The mean concentration of total OCPs was 21.2 ± 3.7 ng/g l.w., and hexachlorobenzene (32.6% of total) and DDE (28.1%) accounted for the majority. The mean concentration of total PBDEs was 3.2 ± 0.6 ng/g l.w., and congeners 99 (44.9%), 153 (30.5%), and 100 (24.7%) were measured at the indicated percentages. There was no relationship between these residue data and concentrations of brain mercury or neurochemical receptors and enzymes as determined in earlier studies on these same animals. - River otters accumulated PCBs, OCPs, and PBDEs, but at levels below thresholds for neurotoxic effects

Polychlorinated biphenyls, organochlorinated pesticides, and polybrominated diphenyl ethers in the cerebral cortex of wild river otters (Lontra canadensis)

Energy Technology Data Exchange (ETDEWEB)

Basu, Niladri [National Wildlife Research Center, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, K1A 0H3 (Canada)]. E-mail: nbasu@uottawa.ca; Scheuhammer, Anton M. [National Wildlife Research Center, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, K1A 0H3 (Canada); O' Brien, Mike [Furbearers and Upland Game, Nova Scotia Department of Natural Resources, Kentville, Nova Scotia, B4N 4E5 (Canada)

2007-09-15

We measured the levels of ortho-substituted polychlorinated biphenyls (PCB), organochlorinated pesticides (OCP), and polybrominated diphenyl ethers (PBDE) in the cerebral cortex of river otters (Lontra canadensis) trapped from Ontario and Nova Scotia between 2002 and 2004. The mean concentration of total PCBs was 70.9 {+-} 12.1 ng/g l.w., and congeners 153, 180 and 138 accounted for nearly 60% of the sum. The mean concentration of total OCPs was 21.2 {+-} 3.7 ng/g l.w., and hexachlorobenzene (32.6% of total) and DDE (28.1%) accounted for the majority. The mean concentration of total PBDEs was 3.2 {+-} 0.6 ng/g l.w., and congeners 99 (44.9%), 153 (30.5%), and 100 (24.7%) were measured at the indicated percentages. There was no relationship between these residue data and concentrations of brain mercury or neurochemical receptors and enzymes as determined in earlier studies on these same animals. - River otters accumulated PCBs, OCPs, and PBDEs, but at levels below thresholds for neurotoxic effects.

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northern California: M_MAMMAL (Marine Mammal Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seals, whales, dolphins, porpoises, sea otters, and sea lions in Northern California. Vector polygons...

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Southern California: M_MAMMAL (Marine Mammal Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seals, sea lions, whales, dolphins, porpoises, and sea otters in Southern California. Vector polygons...

Genetic diversity and landscape genetic structure of otter (Lutra lutra) populations in Europe

DEFF Research Database (Denmark)

Mucci, Nadia; Arrendal, Johanna; Ansorge, Hermann

2010-01-01

Eurasian otter populations strongly declined and partially disappeared due to global and local causes (habitat destruction, water pollution, human persecution) in parts of their continental range. Conservation strategies, based on reintroduction projects or restoration of dispersal corridors...... and landscape genetic analyses however indicate that local populations are genetically differentiated, perhaps as consequence of post-glacial demographic fluctuations and recent isolation. These results delineate a framework that should be used for implementing conservation programs in Europe, particularly...

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: M_MAMMAL (Marine Mammal Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for dolphins, porpoises, whales, seals, sea lions, and sea otters in Central California. Vector polygons in...

Epidemiology and pathology of Toxoplasma gondii in free-ranging California sea lions (Zalophus californianus).

Science.gov (United States)

Carlson-Bremer, Daphne; Colegrove, Kathleen M; Gulland, Frances M D; Conrad, Patricia A; Mazet, Jonna A K; Johnson, Christine K

2015-04-01

The coccidian parasite Toxoplasma gondii infects humans and warm-blooded animals worldwide. The ecology of this parasite in marine systems is poorly understood, although many marine mammals are infected and susceptible to clinical toxoplasmosis. We summarized the lesions associated with T. gondii infection in the California sea lion (Zalophus californianus) population and investigated the prevalence of and risk factors associated with T. gondii exposure, as indicated by antibody. Five confirmed and four suspected cases of T. gondii infection were identified by analysis of 1,152 medical records of necropsied sea lions from 1975-2009. One suspected and two confirmed cases were identified in aborted fetuses from a sea lion rookery. Toxoplasmosis was the primary cause of death in five cases, including the two fetuses. Gross and histopathologic findings in T. gondii-infected sea lions were similar to those reported in other marine mammals. The most common lesions were encephalitis, meningitis, and myocarditis. The antibody prevalence in stranded, free-ranging sea lions for 1998-2009 was 2.5% (±0.03%; IgG titer 640). There was an increase in odds of exposure in sea lions with increasing age, suggesting cumulative risk of exposure and persistent antibody over time. The occurrence of disseminated T. gondii infection in aborted fetuses confirms vertical transmission in sea lions, and the increasing odds of exposure with age is consistent with additional opportunities for horizontal transmission in free-ranging sea lions over time. These data suggest that T. gondii may have two modes of transmission in the sea lion population. Overall, clinical disease was uncommon in our study which, along with low prevalence of T. gondii antibody, suggests substantially less-frequent exposure and lower susceptibility to clinical disease in California sea lions as compared to sympatric southern sea otters (Enhydra lutris nereis).

Bristol Bay, Alaska Subarea ESI: M_MAMMAL (Marine Mammal Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seals, whales, porpoises, walruses, sea otters, and Steller sea lions in the Bristol Bay Subarea. The...

Materials on the diet of the Otter (Lutra lutra L. in the West Rhodopes Mountain, South Bulgaria

Directory of Open Access Journals (Sweden)

Dilian G. Georgiev

2013-06-01

Full Text Available Otter spraints were collected from the West Rhodopes from Batak Dam, Chaya and Parvenetska River areas during 2005-2007. Main food resources in Batak Dam during autumn were the frogs dominated by representatives of the family Ranidae, followed by different fish species. In both rivers the main food was the fish with predominance of Barbus cyclolepis, the frogs, and the crabs.

Isolation and characterization of pathogenic Vibrio alginolyticus from sea cage cultured cobia (Rachycentron canadum (Linnaeus 1766)) in India.

Science.gov (United States)

Rameshkumar, P; Nazar, A K A; Pradeep, M A; Kalidas, C; Jayakumar, R; Tamilmani, G; Sakthivel, M; Samal, A K; Sirajudeen, S; Venkatesan, V; Nazeera, B M

2017-11-01

Mass mortalities of cobia, Rachycentron canadum, sub-adults occurred during August 2013 in cage culture in the Gulf of Mannar, Mandapam Tamil Nadu, India. The epizootic of disease was started with typical classical clinical signs followed by acute mortality. Grossly, severe haemorrhage and congestion were observed in the gastric mucosa. The abdomen was distended with peritoneal fluid. The heart revealed haemopericardium and fibrinous pericardium. Histologically, the gastric mucosa showed severe erosion and necrosis. Haemorrhagic pericarditis and an increased size of the melano macrophage centre (MMC) in the tail kidney were other histopathological changes. Vibrio sp. was isolated from the gastric lesions and heart blood swab of moribund fishes and it was found to be virulent to the cobia fingerlings. After the challenge, the same bacterium could be re-isolated from moribund fingerlings. The 16S ribosomal RNA of the isolate was amplified and blast analysis of the sequence confirmed that the pathogen was Vibrio alginolyticus. The confirmation was also correlated with its cultural, biochemical and pathomorphological changes. This is the second report and the first incidence of epizootics with severe pathological lesions in cultured cobia in India. The study throws light on the pathology of vibriosis. By practising cage farm management measures, occurrences of infection may be prevented. The epizootics of vibriosis caused serious economic losses to farmers. Natural blooms of the pathogen can be prevented by sea cage management measures such as, changing the inner net of the cages, changing the location of the cages to relatively clean water (about 50 m apart) from the affected site and providing shade over the cages while the water temperature rises. Supplementation of the feed with immunostimulants and mineral mixture may be practised to improve the immune response against infection. Early diagnosis and sea cage management measures may prevent occurrences of the

Evaluarea şi conservarea efectivelor de vidră (Lutra lutra L.: un studiu de caz în aria naturală protejată ”Moldova superioară” [Assessment and conservation of otter (Lutra lutra L. populations: A case study in natural protected area ”Moldova superioară”

Directory of Open Access Journals (Sweden)

Dănilă Gabriel

2014-08-01

Full Text Available According to the international legislation, the otter is a protected species. The main purpose of this paper is the analysis of the otter population in a protected area from north of Romania, the estimation of populations and the quantification of existent and potential threats, together with conservation measures. The research was conducted in the natural area ”Superior Moldova” (north of Romanian Eastern Carpathians, between Câmpulung Moldovenesc and Breaza localities, in March and June 2014. To assess the otter population, the track analysis and registration methods were used. Both of the Moldova river banks were checked up and in certain parts, and the presence of the otter was recorded. The den places were registered with GPS coordinates. There were identified three zones where the otters lived within an area of 5-7 km, with a nucleus of intense activity of 2-4 km. The presence of 2-3 otter families, respectively 2-3 adults and 4-6 youngsters was confirmed. These results corespond to a density of about 0.6 individuals/km2 or 1.6 individuals reported to approximately 10 km water course length. The data collected are comparable to that obtained in other areas in Romania. We conclude that the monitoring can be done by track analysis/registration method or by direct observation if the conditions allow it. For the otter population conservation, an important step is the human being awareness, the checking of the aquaculture farm owners and the strict application of the legislation.

First record of the neotropical otter Lontra longicaudis annectens (Carnivora, Mustelidae in the estuary Boca Negra, Jalisco, Mexico: an approach to understanding its diet.

Directory of Open Access Journals (Sweden)

Rodríguez-Uribe, M.C.

2015-01-01

Full Text Available The first record of the neotropical otter Lontra longicaudis annectens in the estuary Boca Negra, Jalisco, Mexico is presented. It includes relevant information about its diet and a photograph in its natural habitat is showed.

Chronic fuel oil toxicity in American mink (Mustela vison): systemic and hematological effects of ingestion of a low-concentration of bunker C fuel oil

International Nuclear Information System (INIS)

Schwartz, Julie A.; Aldridge, Brian M.; Lasley, Bill L.; Snyder, Paul W.; Stott, Jeff L.; Mohr, F. Charles

2004-01-01

Petroleum oil enters the coastal marine environment through various sources; marine mammals such as sea otters that inhabit this environment may be exposed to low concentrations of petroleum hydrocarbons through ingestion of contaminated prey. The inability to perform controlled studies in free-ranging animals hinders investigations of the effects of chronic petroleum oil exposure on sea otter morbidity and mortality, necessitating the development of a reliable laboratory model. We examined the effects of oral exposure to 500 ppm bunker C fuel oil over 113-118 days on American mink, a species phylogenetically related to the sea otter. Hematological parameters and organs were examined for fuel oil-associated changes. Hepatic cytochrome P4501A1 mRNA expression and fecal cortisol concentrations were also measured. Ingestion of fuel oil was associated with a decrease in erythrocyte count, hemoglobin concentration (Hgb), hematocrit (HCT), and an increase in mean corpuscular volume (MCV). Total leukocytes were elevated in the fuel oil group from increases in neutrophils, lymphocytes, and monocytes. Significant interactions between fuel oil and antigen challenge were found for erythrocyte parameters, monocyte and lymphocyte counts. Liver and adrenal weights were increased although mesenteric lymph node weights were decreased in the fuel oil group. Hepatic cytochrome P4501A1 mRNA was elevated in the fuel oil group. Fecal cortisol concentration did not vary between the two groups. Our findings show that fuel oil exposure alters circulating leukocyte numbers, erythrocyte homeostasis, hepatic metabolism and adrenal physiology and establish a framework to use mink as a model for sea otters in studying the systemic effects of marine contaminants

Infectious diseases of fishes in the Salish Sea

Science.gov (United States)

Hershberger, Paul; Rhodes, Linda; Kurath, Gael; Winton, James

2013-01-01

As in marine regions throughout other areas of the world, fishes in the Salish Sea serve as hosts for many pathogens, including nematodes, trematodes, protozoans, protists, bacteria, viruses, and crustaceans. Here, we review some of the better-documented infectious diseases that likely contribute to significant losses among free-ranging fishes in the Salish Sea and discuss the environmental and ecological factors that may affect the population-level impacts of disease. Demonstration of these diseases and their impacts to critical and endangered resources provides justification to expand pathogen surveillance efforts and to incorporate disease forecasting and mitigation tools into ecosystem restoration efforts.

Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

OpenAIRE

Britton, J.R.; Berry, M.; Sewell, S.; Lees, C.; Reading, P.

2017-01-01

The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish...

Amnesic Shellfish Poisoning

Science.gov (United States)

... Since then, the death or stranding of other marine animals, including whales, has been suspected or confirmed to ... sickened or die due to domoic acid poisoning. Animals poisoned by domoic acid include seabirds and marine mammals, including sea lions, sea otters, whales. Domoic- ...

Coastal wetlands, sea level, and the dimensions of geomorphic resilience

Science.gov (United States)

Phillips, Jonathan D.

2018-03-01

Geomorphic system resilience is often perceived as an intrinsic property of system structure and interactions but is also related to idiosyncratic place and history factors. The importance of geographical and historical circumstances makes it difficult to generate categorical statements about geomorphic resilience. However, network-based analyses of system structure can be used to determine the dynamical stability (= resilience) based on generally applicable relationships and to determine scenarios of stability or instability. These provide guidelines for assessing place and history factors to assess resilience. A model of coastal wetlands is analyzed, based on interactions among relative sea level, wetland surface elevation, hydroperiod, vegetation, and sedimentation. The system is generally (but not always) dynamically unstable and non-resilient. Because of gradients of environmental factors and patchy distributions of microtopography and vegetation, a coastal wetland landscape may have extensive local variations in stability/resilience and in the key relationships that trigger instabilities. This is illustrated by a case study where dynamically unstable fragmentation is found in two nearby coastal wetlands in North Carolina's Neuse River estuary-Otter Creek Mouth and Anderson Creek. Neither is keeping pace with relative sea level rise, and both show unstable state transitions within the wetland system; but locally stable relationships exist within the wetland systems.

Non–invasive sampling of endangered neotropical river otters reveals high levels of dispersion in the Lacantun River System of Chiapas, Mexico

Directory of Open Access Journals (Sweden)

Ortega, J.

2012-01-01

Full Text Available Patterns of genetic dispersion, levels of population genetic structure, and movement of the neotropical river otter (Lontra longicaudis were investigated by screening eight polymorphic microsatellites from DNA extracted from fecal samples, collected in a hydrologic system of the Lacandon rainforest in Chiapas, Mexico. A total of 34 unique genotypes were detected from our surveys along six different rivers, and the effect of landscape genetic structure was studied. We recovered 16 of the 34 individuals in multiple rivers at multiple times. We found high levels of dispersion and low levels of genetic differentiation among otters from the six surveyed rivers (P > 0.05, except for the pairwise comparison among the Lacantún and José rivers (P < 0.05. We recommend that conservation management plans for the species consider the entire Lacantún River System and its tributaries as a single management unit to ensure the maintenance of current levels of population genetic diversity, because the population analyzed seems to follow a source–sink dynamic mainly determined by the existence of the major river.

Investigations of Antibacterial Activity of Methanol and Aqueous Ex-tracts of the Body Wall of Sea Cucumber Holothuria leucospilota on some Human Pathogenic Bacteria

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M. Nazemi

2016-04-01

Full Text Available Introduction & Objective: Holothuria leucospilota, sea cucumber, is a species of the Phylum Echinodermata. Sea cucumbers have the most natural products with biological activity. In this study we investigated the antibacterial activity of aqueous and methanol extract of H. leucospilota used against gram positive and gram negative human pathogenic bacteria. Materials & Methods: 9 Samples of H. leucospilota were harvested from the Hengam Island,. The methanol extract was prepared from the powder of sea cucumber. The antibacterial activity of the extracts was determined by broth dilution methods against clinical Gram-negative bacteria to identify MIC and MBC. Results: Aqueous extract of H. leucospilota was inactive on the bacteria. Methanol extract was active on Gram-negetive bacteria; E. coli, Salmonella typhi and Serratia marcescens. But it killed only Salmonella typhi and Serratia marcescens. The MBC of H. leucospilota methanol extract was 10 mg/ml. Methanol extract was active on all Gram-positive bacteria; B. pumilus, B. cereus and S. aureus but it killed only S. aureus. The MBC of H. leucospilota methanol extract was 40 mg/ml. Conclusion: Based on our results, H. leucospilota methanol extract. can be considered as a source of novel antibiotic. Contrary to many marine organisms, sea cucumbers are active against gram-negative bacteria. (Sci J Hamadan Univ Med Sci 2016; 23 (1:75-82

Interactions of microorganisms isolated from gilthead sea bream, Sparus aurata L., on Vibrio harveyi, a pathogen of farmed Senegalese sole, Solea senegalensis (Kaup).

Science.gov (United States)

Chabrillón, M; Rico, R M; Arijo, S; Díaz-Rosales, P; Balebona, M C; Moriñigo, M A

2005-09-01

Four bacterial isolates from farmed gilthead sea bream, Sparus aurata, included in a previous study as members of the Vibrionaceae and Pseudomonodaceae and the genus Micrococcus, have been evaluated for their adhesive ability to skin and intestinal mucus of farmed Senegalese sole, Solea senegalensis, and their antagonistic effect on Vibrio harveyi, a pathogen of sole. These isolates showed higher adhesion to sole mucus than the pathogenic strains of V. harveyi assayed. Only two of the isolates showed antagonistic activity to V. harveyi. Interactions of the four isolates with V. harveyi in respect of adhesion to skin and intestinal mucus under exclusion, competition and displacement conditions were studied. Three isolates were able to reduce the attachment to skin and intestinal sole mucus of a pathogenic strain of V. harveyi under displacement and exclusion conditions, but not under competition conditions. The in vivo probiotic potential of isolate Pdp11 was assessed by oral administration followed by challenge with the pathogenic V. harveyi strain Lg14/00. A group of 50 Senegalese sole received a commercial diet supplemented with 10(8) cfu g(-1) of lyophilized Lg14/00 for 15 days. A second group of fish received a non-supplemented commercial diet. After challenge the mortality of the fish receiving the diet supplemented with the potential probiotic isolate was significantly lower than that in the fish receiving the non-supplemented commercial diet. This study has shown that the ability to interfere with attachment of pathogens, as well as the adhesion to host surfaces, are suitable criteria for selection of candidate probiotics for use in the culture of Senegalese sole.

Health implications associated with exposure to farmed and wild sea turtles.

Science.gov (United States)

Warwick, Clifford; Arena, Phillip C; Steedman, Catrina

2013-01-01

Exposure to sea turtles may be increasing with expanding tourism, although reports of problems arising from interaction with free-living animals appear of negligible human health and safety concern. Exposure both to wild-caught and captive-housed sea turtles, including consumption of turtle products, raises several health concerns for the public, including: microbiological (bacteria, viruses, parasites and fungi), macrobiological (macroparasites), and organic and inorganic toxic contaminants (biotoxins, organochlorines and heavy metals). We conducted a review of sea turtle associated human disease and its causative agents as well as a case study of the commercial sea turtle facility known as the Cayman Turtle Farm (which receives approximately 240,000 visitors annually) including the use of water sampling and laboratory microbial analysis which identified Pseudomonas aeruginosa, Aeromonas spp., Vibrio spp. and Salmonella spp. Our assessment is that pathogens and toxic contaminants may be loosely categorized to represent the following levels of potential risk: viruses and fungi = very low; protozoan parasites = very low to low; metazoan parasites, bacteria and environmental toxic contaminants = low or moderate to high; and biotoxin contaminant = moderate to very high. Farmed turtles and their consumable products may constitute a significant reservoir of potential human pathogen and toxin contamination. Greater awareness among health-care professionals regarding both potential pathogens and toxic contaminants from sea turtles, as well as key signs and symptoms of sea turtle-related human disease, is important for the prevention and control of salient disease.

Environmental and behavioral changes may influence the exposure of an Arctic apex predator to pathogens and contaminants

Science.gov (United States)

Atwood, Todd C.; Duncan, Colleen G.; Patyk, Kelly A.; Nol, Pauline; Rhyan, Jack; McCollum, Matthew; McKinney, Melissa A.; Ramey, Andy M.; Cerqueira-Cezar, Camila; Kwok, Oliver C H; Dubey, Jitender P; Hennager, S.G.

2017-01-01

Recent decline of sea ice habitat has coincided with increased use of land by polar bears (Ursus maritimus) from the southern Beaufort Sea (SB), which may alter the risks of exposure to pathogens and contaminants. We assayed blood samples from SB polar bears to assess prior exposure to the pathogens Brucella spp., Toxoplasma gondii, Coxiella burnetii, Francisella tularensis, and Neospora caninum, estimate concentrations of persistent organic pollutants (POPs), and evaluate risk factors associated with exposure to pathogens and POPs. We found that seroprevalence of Brucella spp. and T. gondii antibodies likely increased through time, and provide the first evidence of exposure of polar bears to C. burnetii, N. caninum, and F. tularensis. Additionally, the odds of exposure to T. gondii were greater for bears that used land than for bears that remained on the sea ice during summer and fall, while mean concentrations of the POP chlordane (ΣCHL) were lower for land-based bears. Changes in polar bear behavior brought about by climate-induced modifications to the Arctic marine ecosystem may increase exposure risk to certain pathogens and alter contaminant exposure pathways.

78 FR 8577 - Final Environmental Impact Statement; Izembek National Wildlife Refuge Proposed Land Exchange...

Science.gov (United States)

2013-02-06

... the threatened Steller's eider, threatened sea otter, threatened Steller sea lion, tundra swan, black... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R7-R-2012-N206; FXRS12650700000-134.... SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce the availability of a final...

Vertebrate behavior and ecology. Progress report, 1 July 1978--30 June 1979

Energy Technology Data Exchange (ETDEWEB)

Tester, J.R.; Siniff, D.B.

1979-07-01

Efforts in engineering design and development this year emphasized improvement in the quality and versatility of radio transmitters, use of microprocessors in an automated fish tracking system, and construction of an automated system to monitor movements and activities of aquatic mammals in response to water temperature. Improved radio transmitters were used on a variety of species including sea otters, manatees, and wall-eyed pike. The fish tracking system, installed at Monticello, Minnesota, will next be modified for monitoring marine mammal movements. The temperature data logging system was tested on manatees in the St. John River near Blue Springs, Florida. The long-term goal in the subproject on evaluation of census methods is to utilize the extensive experience, technology, and equipment developed over the years in radio telemetry to resolve basic problems in animal census and population study methods. During the past year, efforts have resulted in information on activity patterns and the behavioral repertoire of sea otters and on the response of otters to contamination by Alaskan crude oil. Three preliminary manuscripts presented as part of this report describe these aspects in detail.

A Low-Cost GPS GSM/GPRS Telemetry System: Performance in Stationary Field Tests and Preliminary Data on Wild Otters (Lutra lutra)

Science.gov (United States)

Quaglietta, Lorenzo; Martins, Bruno Herlander; de Jongh, Addy; Mira, António; Boitani, Luigi

2012-01-01

Background Despite the increasing worldwide use of global positioning system (GPS) telemetry in wildlife research, it has never been tested on any freshwater diving animal or in the peculiar conditions of the riparian habitat, despite this latter being one of the most important habitat types for many animal taxa. Moreover, in most cases, the GPS devices used have been commercial and expensive, limiting their use in low-budget projects. Methodology/Principal Findings We have developed a low-cost, easily constructed GPS GSM/GPRS (Global System for Mobile Communications/General Packet Radio Service) and examined its performance in stationary tests, by assessing the influence of different habitat types, including the riparian, as well as water submersion and certain climatic and environmental variables on GPS fix-success rate and accuracy. We then tested the GPS on wild diving animals, applying it, for the first time, to an otter species (Lutra lutra). The rate of locations acquired during the stationary tests reached 63.2%, with an average location error of 8.94 m (SD = 8.55). GPS performance in riparian habitats was principally affected by water submersion and secondarily by GPS inclination and position within the riverbed. Temporal and spatial correlations of location estimates accounted for some variation in the data sets. GPS-tagged otters also provided accurate locations and an even higher GPS fix-success rate (68.2%). Conclusions/Significance Our results suggest that GPS telemetry is reliably applicable to riparian and even diving freshwater animals. They also highlight the need, in GPS wildlife studies, for performing site-specific pilot studies on GPS functioning as well as for taking into account eventual spatial and temporal correlation of location estimates. The limited price, small dimensions, and high performance of the device presented here make it a useful and cost-effective tool for studies on otters and other aquatic or terrestrial medium

A low-cost GPS GSM/GPRS telemetry system: performance in stationary field tests and preliminary data on wild otters (Lutra lutra.

Directory of Open Access Journals (Sweden)

Lorenzo Quaglietta

Full Text Available BACKGROUND: Despite the increasing worldwide use of global positioning system (GPS telemetry in wildlife research, it has never been tested on any freshwater diving animal or in the peculiar conditions of the riparian habitat, despite this latter being one of the most important habitat types for many animal taxa. Moreover, in most cases, the GPS devices used have been commercial and expensive, limiting their use in low-budget projects. METHODOLOGY/PRINCIPAL FINDINGS: We have developed a low-cost, easily constructed GPS GSM/GPRS (Global System for Mobile Communications/General Packet Radio Service and examined its performance in stationary tests, by assessing the influence of different habitat types, including the riparian, as well as water submersion and certain climatic and environmental variables on GPS fix-success rate and accuracy. We then tested the GPS on wild diving animals, applying it, for the first time, to an otter species (Lutra lutra. The rate of locations acquired during the stationary tests reached 63.2%, with an average location error of 8.94 m (SD = 8.55. GPS performance in riparian habitats was principally affected by water submersion and secondarily by GPS inclination and position within the riverbed. Temporal and spatial correlations of location estimates accounted for some variation in the data sets. GPS-tagged otters also provided accurate locations and an even higher GPS fix-success rate (68.2%. CONCLUSIONS/SIGNIFICANCE: Our results suggest that GPS telemetry is reliably applicable to riparian and even diving freshwater animals. They also highlight the need, in GPS wildlife studies, for performing site-specific pilot studies on GPS functioning as well as for taking into account eventual spatial and temporal correlation of location estimates. The limited price, small dimensions, and high performance of the device presented here make it a useful and cost-effective tool for studies on otters and other aquatic or

Dioxin compounds in the deep-sea rose shrimp Aristeus antennatus (Risso, 1816) throughout the Mediterranean Sea

Science.gov (United States)

Rotllant, Guiomar; Abad, Esteban; Sardà, Francisco; Ábalos, Manuela; Company, Joan B.; Rivera, Josep

2006-12-01

Polychlorodibenzo- p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) are among the more toxic anthropogenic contaminants. They are fat-soluble and accumulate in animal tissues. Exposure to PCDD/Fs can cause several endocrine, reproductive and developmental problems in animals, including human beings. Several studies have demonstrated that fish and invertebrates living in association with sediments are exposed to and accumulate contaminants, but to date there have been no studies of PCDD/Fs contamination in deep-sea regions. Specimens of Aristeus antennatus (Risso, 1816) were collected from depths of 600-2500 m at different points in the Mediterranean Sea, from the western basin off the coast of Barcelona to the central basin off the Peloponnesian Peninsula, with otter trawl gear. Amounts of PCDD/Fs were measured in different animal tissues by high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC-HRMS). This is the first study to report the presence of PCDD/Fs in deep-sea organisms dwelling at depths below 600 m. A. antennatus presented levels of PCDD/Fs of the same order of magnitude, or slightly higher, as those found in shallow-water species ( Melicertus kerathurus) with respect to land-generated contamination. This highlights the widespread distribution of these pollutants and the potential threat posed to the biodiversity of fragile and vulnerable ecosystems such as the deep-sea. PCDD/F levels detected in the edible parts (muscle) of the commercial shrimp A. antennatus were clearly below the toxic limit value established by European legislation. Levels followed the trend muscle

Anti-dog IgG secondary antibody successfully detects IgG in a variety of aquatic mammals

Science.gov (United States)

Roehl, Katherine; Jankowski, Mark D.; Hofmeister, Erik K.

2016-01-01

Serological tests play an important role in the detection of wildlife diseases. However, while there are many commercial assays and reagents available for domestic species, there is a need to develop efficient serological assays for wildlife. In recent years, marine mammals have represented a wildlife group with emerging infectious diseases, such as influenza, brucellosis, and leptospirosis. However, with the exception of disease-agent-specific assays or functional assays, few reports describe the use of antibody detection assays in marine mammals. In an indirect enzyme-linked immunoassay (EIA) or an immunofluorescence assay, antibody is detected using an antitarget species secondary conjugated antibody. The sensitivity of the assay depends on the avidity of the binding reaction between the bound antibody and the detection antibody. A commercial polyclonal antidog IgG conjugated antibody was tested in an EIA for its ability to sensitively detect the IgG of seven marine mammals including sea otter (Enhydra lutris), polar bear (Ursus maritimus), grey seal (Halichoerus grypus), harbor seal (Phoca vitulina), northern elephant seal (Mirounga angustirostris), California sea lion (Zalophus californianus), Pacific walrus (Odobenus rosmarus) and one freshwater mammal: Asian small-clawed otter (Aonyx cinerea). With the exception of Asian small-clawed sea otters, the detection of IgG in these marine mammals either exceeded or was nearly equal to detection of dog IgG. The use of the tested commercial antidog IgG antibody may be a valid approach to the detection of antibody response to disease in sea mammals.

Search Results | Page 69 | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

Results 681 - 690 of 8531 ... Sea otter tourism in British Columbia : the effects of ... Despite concerns over negative impacts, one of the anticipated benefits to wildlife ... Role of the sea kayak tour guide : mixed methods exploration into the guides' perspective ... Integrated education intervention to improve infant and young child ...

76 FR 18725 - Marine Mammals; File Nos. 14330 and 14335

Science.gov (United States)

2011-04-05

... (Phoca vitulina) on St. Paul, St. George, Otter, and Walrus Islands, and Sea Lion Rock, all of the... marine mammals in Alaska: (File No. 14330) the Aleut Community of St. Paul Island, Tribal Government, Ecosystem Conservation Office, St. Paul Island, AK; and (File No. 14335) the Alaska SeaLife Center, Seward...

Discovery of three novel coccidian parasites infecting California sea lions (Zalophus californianus), with evidence of sexual replication and interspecies pathogenicity.

Science.gov (United States)

Colegrove, Kathleen M; Grigg, Michael E; Carlson-Bremer, Daphne; Miller, Robin H; Gulland, Frances M D; Ferguson, David J P; Rejmanek, Daniel; Barr, Bradd C; Nordhausen, Robert; Melli, Ann C; Conrad, Patricia A

2011-10-01

Enteric protozoal infection was identified in 5 stranded California sea lions (Zalophus californianus). Microscopically, the apical cytoplasm of distal jejunal enterocytes contained multiple stages of coccidian parasites, including schizonts with merozoites and spherical gametocytes, which were morphologically similar to coccidians. By histopathology, organisms appeared to be confined to the intestine and accompanied by only mild enteritis. Using electron microscopy, both sexual (microgametocytes, macrogamonts) and asexual (schizonts, merozoites) coccidian stages were identified in enterocytes within parasitophorous vacuoles, consistent with apicomplexan development in a definitive host. Serology was negative for tissue cyst-forming coccidians, and immunohistochemistry for Toxoplasma gondii was inconclusive and negative for Neospora caninum and Sarcocystis neurona. Analysis of ITS-1 gene sequences amplified from frozen or formalin-fixed paraffin-embedded intestinal sections identified DNA sequences with closest homology to Neospora sp. (80%); these novel sequences were referred to as belonging to coccidian parasites "A," "B," and "C." Subsequent molecular analyses completed on a neonatal harbor seal (Phoca vitulina) with protozoal lymphadenitis, hepatitis, myocarditis, and encephalitis showed that it was infected with a coccidian parasite bearing the "C" sequence type. Our results indicate that sea lions likely serve as definitive hosts for 3 newly described coccidian parasites, at least 1 of which is pathogenic in a marine mammal intermediate host species.

50 CFR 82.5 - Definitions.

Science.gov (United States)

2010-10-01

... not limited to, any raw, dressed, or dyed fur or skin: Scientific name Common name Ursus maritimus Polar bear. Enhydra lutris Sea Otter. Odobenus rosmarus Walrus. Dugong dugong Dugong. Trichechus...

Egypt's Red Sea coast: phylogenetic analysis of cultured microbial consortia in industrialized sites.

Science.gov (United States)

Mustafa, Ghada A; Abd-Elgawad, Amr; Abdel-Haleem, Alyaa M; Siam, Rania

2014-01-01

The Red Sea possesses a unique geography, and its shores are rich in mangrove, macro-algal and coral reef ecosystems. Various sources of pollution affect Red Sea biota, including microbial life. We assessed the effects of industrialization on microbes along the Egyptian Red Sea coast at eight coastal sites and two lakes. The bacterial communities of sediment samples were analyzed using bacterial 16S rDNA pyrosequencing of V6-V4 hypervariable regions. The taxonomic assignment of 131,402 significant reads to major bacterial taxa revealed five main bacterial phyla dominating the sampled sites: Proteobacteria (68%), Firmicutes (13%), Fusobacteria (12%), Bacteriodetes (6%), and Spirochetes (0.03%). Further analysis revealed distinct bacterial consortia that primarily included (1) marine Vibrio spp.-suggesting a "marine Vibrio phenomenon"; (2) potential human pathogens; and (3) oil-degrading bacteria. We discuss two divergent microbial consortia that were sampled from Solar Lake West near Taba/Eilat and Saline Lake in Ras Muhammad; these consortia contained the highest abundance of human pathogens and no pathogens, respectively. Our results draw attention to the effects of industrialization on the Red Sea and suggest the need for further analysis to overcome the hazardous effects observed at the impacted sites.

Search Results | Page 66 | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

2010-01-01

Results 651 - 660 of 8487 ... ... Apply International Partnerships for Sustainable Societies filter ... Developing a predictive GIS model of sea level rise for a ... January 1, 2010 ... Establishing a recovery orientation in first line mental health teams in Québec : perspectives from ... Sea otter tourism in British Columbia : the effects of ...

Egypt’s Red Sea Coast: Phylogenetic analysis of cultured microbial consortia in industrialized sites

Directory of Open Access Journals (Sweden)

Ghada A. Mustafa

2014-08-01

Full Text Available The Red Sea has a unique geography and ecosystem and its shores are very rich in mangrove, macro-algae and coral reefs. Different sources of pollution are affecting the Red Sea shores and waters which impacts biological life including microbial life. We assessed the effects of industrialization, along the Egyptian Red Sea coast in eight coastal sites and two lakes, on microbial life. The bacterial community in sediment samples was analyzed using bacterial 16S rDNApyrosequencing of V6-V4 hypervariable regions. Taxonomical assignment of 131,402 significant reads to major bacterial taxa revealed five main bacterial phyla dominating the sampled Red Sea sites. This includes Proteobacteria (68%, Firmicutes (13%, Fusobacteria (12%, Bacteriodetes (6% and Spirochetes (0.03%. Further analysis revealed distinct bacterial consortium formed mainly of: 1 marine Vibrio’s- suggesting a Marine Vibrio phenomenon 2 potential human pathogens and 3 oil-degrading bacteria. We discuss a distinct microbial consortium in Solar Lake West near Taba/Eilat and Saline Lake in Ras Muhammad; revealing the highest abundance of human pathogens versus no pathogens, respectively. Our results draw attention to the affects of industrialization on the Red Sea, and suggest further analysis to overcome hazardous affects on the impacted sites.

Data management for interdisciplinary field experiments: OTTER project support

Science.gov (United States)

Angelici, Gary; Popovici, Lidia; Skiles, J. W.

1993-01-01

The ability of investigators of an interdisciplinary science project to properly manage the data that are collected during the experiment is critical to the effective conduct of science. When the project becomes large, possibly including several scenes of large-format remotely sensed imagery shared by many investigators requiring several services, the data management effort can involve extensive staff and computerized data inventories. The OTTER (Oregon Transect Ecosystem Research) project was supported by the PLDS (Pilot Land Data System) with several data management services, such as data inventory, certification, and publication. After a brief description of these services, experiences in providing them are compared with earlier data management efforts and some conclusions regarding data management in support of interdisciplinary science are discussed. In addition to providing these services, a major goal of this data management capability was to adopt characteristics of a pro-active attitude, such as flexibility and responsiveness, believed to be crucial for the effective conduct of active, interdisciplinary science. These are also itemized and compared with previous data management support activities. Identifying and improving these services and characteristics can lead to the design and implementation of optimal data management support capabilities, which can result in higher quality science and data products from future interdisciplinary field experiments.

Effect of sunlight on the survival of pathogenic E. coli in freshwater and sea water

DEFF Research Database (Denmark)

Surendraraj, Alagarsamy; Farvin, Sabeena; Thampuran, N.

2011-01-01

An enteropathogenic group of E. coli are the emerging category of pathogen of public health significance. Several recent pathogenic E. coli outbreaks are associated with drinking water. Aquaculture, the fast emerging food production sector also poses a pathogenic EHEC outbreak risk, as it regularly...... uses cow dung, a reservoir of this organism. Hence, a experiment was set up to study the duration of survival of pathogenic E. coli under sunlight and darkness. Eight pathogenic E. coli isolates from clinical (EPEC, ETEC, EHEC, EAEC), veterinary (CTE3, CTE4) and environmental sources (ASHE3, Rao II......) were studied for their survival under sunlight and darkness in fresh water and seawater. Effect of direct sunlight on the viable but nonculturable (VBNC) state of cultures was also studied. The results of the study indicated a distinct pattern between freshwater system and seawater system. Pathogenic E...

DISCOVERY OF THREE NOVEL COCCIDIAN PARASITES INFECTING CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS), WITH EVIDENCE OF SEXUAL REPLICATION AND INTERSPECIES PATHOGENICITY

Science.gov (United States)

Colegrove, Kathleen M.; Grigg, Michael E.; Carlson-Bremer, Daphne; Miller, Robin H.; Gulland, Frances M. D.; Ferguson, David J. P.; Rejmanek, Daniel; Barr, Bradd C.; Nordhausen, Robert; Melli, Ann C.; Conrad, Patricia A.

2016-01-01

Enteric protozoal infection was identified in 5 stranded California sea lions (Zalophus californianus). Microscopically, the apical cytoplasm of distal jejunal enterocytes contained multiple stages of coccidian parasites, including schizonts with merozoites and spherical gametocytes, which were morphologically similar to coccidians. By histopathology, organisms appeared to be confined to the intestine and accompanied by only mild enteritis. Using electron microscopy, both sexual (microgametocytes, macrogamonts) and asexual (schizonts, merozoites) coccidian stages were identified in enterocytes within parasitophorous vacuoles, consistent with apicomplexan development in a definitive host. Serology was negative for tissue cyst-forming coccidians, and immunohistochemistry for Toxoplasma gondii was inconclusive and negative for Neospora caninum and Sarcocystis neurona. Analysis of ITS-1 gene sequences amplified from frozen or formalin-fixed paraffin-embedded intestinal sections identified DNA sequences with closest homology to Neospora sp. (80%); these novel sequences were referred to as belonging to coccidian parasites ‘‘A,’’ ‘‘B,’’ and ‘‘C.’’ Subsequent molecular analyses completed on a neonatal harbor seal (Phoca vitulina) with protozoal lymphadenitis, hepatitis, myocarditis, and encephalitis showed that it was infected with a coccidian parasite bearing the ‘‘C’’ sequence type. Our results indicate that sea lions likely serve as definitive hosts for 3 newly described coccidian parasites, at least 1 of which is pathogenic in a marine mammal intermediate host species. PMID:21495828

50 CFR 18.3 - Definitions.

Science.gov (United States)

2010-10-01

... to, any raw, dressed, or dyed fur or skin: Scientific name Common name Date listed Ursus maritimus Polar bear Dec. 21, 1972. Enhydra lutris Sea otter Do. Odobenus rosmarus Walrus Do. Dugong dugon Dugong...

Antifungal potential of marine sponge extract against plant and fish pathogenic fungi

Digital Repository Service at National Institute of Oceanography (India)

PrabhaDevi; Ravichandran, S.; Ribeiro, M.; Ciavatta, M.L.

scope for rediscovering compounds with antimicrobial activity. This study screens extracts (Diethyl Ether and Butanol) of a marine red-Sea sponge Negombata magnifica for invitro fungicidal activity against 10 plant and 3 fish pathogens. Fungicidal...

Bioactive Compounds from Omani Sea Cucumbers

Directory of Open Access Journals (Sweden)

Sergey Dobretsov

2009-01-01

Full Text Available Antimicrobial, anti-diatom and anti-larval activities of both water soluble (water  extracts and non-water soluble metabolites (methanol: chlorophorm, 1:1 extracts of the sea cucumbers Holothuria atra and Holothuria edulis  from Bander AL-Khiran region, Oman were tested in this study. There was no significant effect of  the extracts from sea cucumbers on bacterial (3 reference bacteria from seawater and pathogens  Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa,  Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus epidermidis and the diatom  Chaetoceros sp. growth. Both water extracts and methanol: chlorophorm extracts caused significant mortality of Artemia salina nauplia. This study suggests that Omani sea cucumbers might be a good  source of toxic anti-larval compounds.

The olive compound 4-hydroxytyrosol inactivates Staphyloccoccus aureus bacteria and Staphylococcal enterotoxin A (SEA)

Science.gov (United States)

The foodborne pathogen Staphylococcus aureus produces the virulent staphylococcal enterotoxin A (SEA), a single chain protein which consists of 233 amino acid residues with a molecular weight of 27,078 Da. SEA is a superantigen that is reported to contribute to animal (mastitis) and human (emesis, ...

Economic valuation of flood mitigation services: A case study from the Otter Creek, VT.

Science.gov (United States)

Galford, G. L.; Ricketts, T.; Bryan, K. L.; ONeil-Dunne, J.; Polasky, S.

2014-12-01

The ecosystem services provided by wetlands are widely recognized but difficult to quantify. In particular, estimating the effect of landcover and land use on downstream flood outcomes remains challenging, but is increasingly important in light of climate change predictions of increased precipitation in many areas. Economic valuation can help incorporate ecosystem services into decisions and enable communities to plan for climate and flood resiliency. Here we estimate the economic value of Otter Creek wetlands for Middlebury, VT in mitigating the flood that followed Tropical Storm Irene, as well as for ten historic floods. Observationally, hydrographs above and below the wetlands in the case of each storm indicated the wetlands functioned as a temporary reservoir, slowing the delivery of water to Middlebury. We compare observed floods, based on Middlebury's hydrograph, with simulated floods for scenarios without wetlands. To simulate these "without wetlands" scenarios, we assume the same volume of water was delivered to Middlebury, but in a shorter time pulse similar to a hydrograph upstream of the wetlands. For scenarios with and without wetlands, we map the spatial extent of flooding using LiDAR digital elevation data. We then estimate flood depth at each affected building, and calculate monetary losses as a function of the flood depth and house value using established depth damage relationships. For example, we expect damages equal to 20% of the houses value for a flood depth of two feet in a two-story home with a basement. We define the value of flood mitigation services as the difference in damages between the with and without wetlands scenario, and find that the Otter Creek wetlands reduced flood damage in Middlebury by 88% following Hurricane Irene. Using the 10 additional historic floods, we estimate an ongoing mean value of $400,000 in avoided damages per year. Economic impacts of this magnitude stress the importance of wetland conservation and warrant the

Inhibition of Biological Activity of Staphylococcal Enterotoxin A (SEA) by Apple Juice and Apple Polyphenols

Science.gov (United States)

The foodborne pathogen Staphylococcus aureus produces the virulent staphylococcal entertoxin A (SEA), a single-chain protein that consists of 233 amino acid residues with a molecular weight of 27 078 Da. SEA is a superantigen that is reported to contribute to animal (mastitis) and human (emesis, dia...

Diet of otters (Lutra lutra in various habitat types in the Pannonian biogeographical region compared to other regions of Europe

Directory of Open Access Journals (Sweden)

József Lanszki

2016-08-01

Full Text Available Knowledge of the effect of habitat type and region on diet and feeding behaviours of a species facilitates a better understanding of factors impacting populations, which contributes to effective conservation management. Using spraint analysis and relative frequency of occurrence data from the literature, we described the dietary patterns of Eurasian otters (Lutra lutra in 23 study sites within the Pannonian biogeographical region in Hungary. Our results indicated that diet composition varied by habitat type and is therefore context dependant. The differences among habitat types were however lower than expected. We noticed a decline in the fish consumption with a concomitant increase in trophic niche breadth and amphibian consumption in rivers, ponds (fish farms, backwaters, marshes and small watercourses. The main differences in diet were not attributed to the consumption of primary and secondary food types (fish and amphibians, but rather to differences in other, less important food types (mammals, birds. Using hierarchical cluster analysis, rivers and ponds could clearly be separated from other habitat types. We found the main fish diet of otters in most of these areas consisted of small (<100 g, eurytopic, littoral and non-native, mostly invasive species. Dietary studies from 91 sites in six European biogeographical regions showed that fish are consumed most frequently in the Atlantic and Boreal, less in the Continental and Pannonian, and least in the Alpine and Mediterranean regions. Comparative analysis indicated that the Mediterranean region (with frequent crayfish consumption and Alpine region (frequent amphibian consumption cluster separate from the other regions.

Uptake and transmission of Toxoplasma gondii oocysts by migratory filter-feeding fish

Science.gov (United States)

Toxoplasma gondii is a ubiquitous parasitic protozoan known to cause disease and death in warm-blooded animals. Bottlenose dolphins, walruses, sea otters, and other marine animals worldwide have died from toxoplasmosis, but the source of this parasite in the marine environment h...

Depredación de aves acuáticas por la nutria neotropical (Lontra longicaudis annectens, en el río Yaqui, Sonora, México Aquatic bird predation by neotropical river otter (Lontra longicaudis annectens, at Rio Yaqui, Sonora, Mexico

Directory of Open Access Journals (Sweden)

Juan Pablo Gallo-Reynoso

2008-06-01

Full Text Available Se registra la depredación de aves acuáticas por la nutria neotropical (L. longicaudis annectens en el río Yaqui, Sonora. Se colectaron e identificaron 25 cráneos, porciones de esqueleto postcraneal y plumas de aves encontrados en los comederos de las nutrias; las especies identificadas fueron el cormorán neotropical (Phalacrocorax brasilianus con 16 individuos, el pato de collar (Anas platyrhynchos diazi, 4 individuos; la garza blanca (Ardea alba, 3 individuos; el huaco de corona amarilla (Nyctanassa violacea y el pelícano café (Pelecanus occidentalis, ambos con 1 individuo. En los peces se encontró la tilapia del género Oreochromis. Probablemente los hábitos alimenticios de esta especie responden a la estacionalidad y al consumo de presas más disponibles en el hábitat. Estos registros confirman que las nutrias de río son depredadores oportunistas cuya dieta tiene una amplio rango de uso de especies de los ambientes riparios, además dichos registros son una razón más para considerar la nutria neotropical como especie sombrilla para la conservación de ecosistemas completos, ya que su presencia es un indicador de alta disponibilidad energética y de alta biodiversidad.We report the predation of aquatic birds by neotropical river otters (L. longicaudis annectens at Río Yaqui, Sonora. As many as 25 skulls, post-cranial skeletons and feathers were found at river otter feeding sites. The neotropical cormorant (Phalacrocorax brasilianus was the most predated bird with 16 individuals, followed by Mexican mallard (Anas platyrhynchos diazi with 4 individuals, great egret (Ardea alba with 3 individuals, yellow-crowned night-heron (Nyctanassa violacea, and brown pelican (Pelecanus occidentalis, both with 1 individual. With respect to fish, the tilapia Oreochromis, was the only species found in scats. Neotropical river otter feeding habits were associated with food availability at different seasons of the year. These records show that

Foraging behaviour and feeding ecology of the otter Lutra lutra: a selective review

Directory of Open Access Journals (Sweden)

David Carss

1995-12-01

Full Text Available Abstract This paper reviews literature on food, foraging behaviour and feeding ecology of Lutra lutra and on the behaviour of their prey species. Otters have a diverse diet, forage in a wide variety of different habitats and have a relatively complex social system. Similarly, their strategies for obtaining food are complex and varied. Three aspects of foraging behaviour (i, ii, iii and two of feeding ecology (iv, v are discussed: i adaptations and ontogeny, ii energetics and food-limitation, iii human disturbance, and periods of prey vulnerability, iv assessing diet, and v changes in prey vulnerability and selection. The review has three main aims: (a to summarize some recent advances in research, (b to highlight gaps in current knowledge, and (c to suggest some areas of future research. The need for such a review arises from a necessity to direct further research effort towards carnivore predator-prey relationships in general, and those of otters in particular, and also to meet demands for conservation management. Riassunto Foraggiamento ed ecologia alimentare della lontra Lutra lutra: un'analisi selettiva della letteratura disponibile - Questo lavoro prende in esame la letteratura riguardante dieta, foraggiamento ed ecologia alimentare della lontra Lutra lutra e il comportamento delle sue prede. La lontra ha una dieta varia, ricerca il cibo in un'ampia gamma di ambienti e ha un'organizzazione sociale relativamentc complessa. Similarmente, le sue strategie di ricerca del cibo sono complesse e varie. Tre aspetti del foraggiamento (i, ii, iii e due di ecologia alimentare (iv, v sono qui discussi: i adattamenti e ontogenesi, ii richiesta energetica e fattori limitanti la disponibilità di cibo, iii disturbo antropico e periodi di vulnerabilità delle prede, iv analisi della dieta, e v cambiamenti nella vulnerabilità delle prede e selezione. Il presente lavoro ha tre

Effects of aerial pollutants on cereal growth. [Hordeum vulgare var. Maris Otter

Energy Technology Data Exchange (ETDEWEB)

1975-01-01

Winter barley, var. Maris Otter, was grown at Woburn Experimental Farm in three closed plastic chambers with either filtered, ambient or sulfur dioxide-polluted air. The mean sulfur dioxide levels were 7.2 ..mu..g m/sup -3/, 37 ..mu..g m/sup -3/ for the filtered and ambient chambers respectively. In the field the mean value was 51.5 ..mu..g m/sup -3/ . Temperature and relative humidity in these closed houses differed from the outside. No visible damage occurred on any of the plants grown in the filtered or ambient air. In the fumigated chamber a high dose of sulfur dioxide was given for one week (19-25 April 1975), producing a mean concentration of 951 ..mu..g m/sup -3/, at the four-leaf stage. It caused severe necrosis of the leaves. The plants subsequently recovered and no further fumigations were given. At final harvest these plants were not significantly lower in total dry weight and grain weight from the ambient plants. The dry matter yield of the plants grown in filtered air was higher than that of plants in ambient air.

Aircraft measurements to characterize polluted winter boundary layers: Overview of twin otter flights during the Utah Winter Fine Particulate Matter Study

Science.gov (United States)

Brown, S. S.; Baasandorj, M.; Franchin, A.; Middlebrook, A. M.; Goldberger, L.; Thornton, J. A.; Dube, W. P.; McDuffie, E. E.; Womack, C.; Fibiger, D. L.; Moravek, A.; Clark, J. C.; Murphy, J. G.; Mitchell, R.

2017-12-01

Winter air pollution is a significant public health concern. In many regions of the U.S., Europe and Asia, wintertime particulate matter concentrations exceed national and / or international air quality standards. Winter air pollution also represents a scientific challenge because these events occur during stagnation events in shallow, vertically stratified boundary layers whose composition is difficult to probe from surface level measurements. Chemical processes responsible for the conversion of primary emissions to secondary pollutants such as ammonium nitrate aerosol vary with height above ground level. Sources of oxidants are poorly understood and may result from both local chemical production and mixing between shallow inversion layers and background air. During the Utah Winter Fine Particulate Study (UWFPS) in January - February 2017, the NOAA twin otter executed 23 research flights with a payload designed to characterize the formation of ammonium nitrate aerosol in three mountain valleys of northern Utah (Salt Lake, Cache, and Utah). These valleys are subject to periodic episodes of winter aerosol pollution well in excess of U.S. national ambient air quality standards. This presentation will describe the measurement strategy of the twin otter flights to address the specific features of aerosol pollution within winter boundary layer of this region. This strategy is relevant to understanding the broader issue of winter air pollution in other regions and potentially to the design of future studies. The presentation will summarize findings from UWFPS related to boundary layer structure, emissions and chemical processes responsible for ammonium nitrate aerosol in this region.

Whole-Body Microbiota of Sea Cucumber (Apostichopus japonicus) from South Korea for Improved Seafood Management.

Science.gov (United States)

Kim, Tae-Yoon; Lee, Jin-Jae; Kim, Bong-Soo; Choi, Sang Ho

2017-10-28

Sea cucumber ( Apostichopus japonicus ) is a popular seafood source in Asia, including South Korea, and its consumption has recently increased with recognition of its medicinal properties. However, because raw sea cucumber contains various microbes, its ingestion can cause foodborne illness. Therefore, analysis of the microbiota in the whole body of sea cucumber can extend our understanding of foodborne illness caused by microorganisms and help to better manage products. We collected 40 sea cucumbers from four different sites in August and November, which are known as the maximum production areas in Korea. The microbiota was analyzed by an Illumina MiSeq system, and bacterial amounts were quantified by real-time PCR. The diversity and bacterial amounts in sea cucumber were higher in August than in November. Alpha-, Beta-, and Gammaproteobacteria were common dominant classes in all samples. However, the microbiota composition differed according to sampling time and site. Staphylococcus warneri and Propionibacterium acnes were commonly detected potential pathogens in August and November samples, respectively. The effect of experimental Vibrio parahaemolyticus infection on the indigenous microbiota of sea cucumber was analyzed at different temperatures, revealing clear alterations of Psychrobacter and Moraxella ; thus, these shifts can be used as indicators for monitoring infection of sea cucumber. Although further studies are needed to clarify and understand the virulence and mechanisms of the identified pathogens of sea cucumber, our study provides a valuable reference for determining the potential of foodborne illness caused by sea cucumber ingestion and to develop monitoring strategies of products using microbiota information.

A New Subspecies Identification and Population Study of the Asian Small-Clawed Otter (Aonyx cinereus in Malay Peninsula and Southern Thailand Based on Fecal DNA Method

Directory of Open Access Journals (Sweden)

M. K. A. Rosli

2014-01-01

Full Text Available Three species of otter can be found throughout Malay Peninsula: Aonyx cinereus, Lutra sumatrana, and Lutrogale perspicillata. In this study, we focused on the A. cinereus population that ranges from the southern and the east coast to the northern regions of Malay Peninsula up to southern Thailand to review the relationships between the populations based on the mitochondrial D-loop region. Forty-eight samples from six populations were recognized as Johor, Perak, Terengganu, Kelantan, Ranong, and Thale Noi. Among the 48 samples, 33 were identified as A. cinereus, seven as L. sumatrana, and eight as L. perspicillata. Phylogenetically, two subclades formed for A. cinereus. The first subclade grouped all Malay Peninsula samples except for samples from Kelantan, and the second subclade grouped Kelantan samples with Thai sample. Genetic distance analysis supported the close relationships between Thai and Kelantan samples compared to the samples from Terengganu and the other Malaysian states. A minimum-spanning network showed that Kelantan and Thailand formed a haplogroup distinct from the other populations. Our results show that Thai subspecies A. cinereus may have migrated to Kelantan from Thai mainland. We also suggest the classification of a new subspecies from Malay Peninsula, the small-clawed otter named A. cinereus kecilensis.

A new subspecies identification and population study of the Asian small-clawed otter (Aonyx cinereus) in Malay Peninsula and southern Thailand based on fecal DNA method.

Science.gov (United States)

Rosli, M K A; Syed-Shabthar, S M F; Abdul-Patah, P; Abdul-Samad, Z; Abdul, S N; Burhanuddin, M N; Zulkifli, N A; Shukor, M N; Budsabong, K; Changtragoon, S; Sekiguchi, T; Sasaki, H; Md-Zain, B M

2014-01-01

Three species of otter can be found throughout Malay Peninsula: Aonyx cinereus, Lutra sumatrana, and Lutrogale perspicillata. In this study, we focused on the A. cinereus population that ranges from the southern and the east coast to the northern regions of Malay Peninsula up to southern Thailand to review the relationships between the populations based on the mitochondrial D-loop region. Forty-eight samples from six populations were recognized as Johor, Perak, Terengganu, Kelantan, Ranong, and Thale Noi. Among the 48 samples, 33 were identified as A. cinereus, seven as L. sumatrana, and eight as L. perspicillata. Phylogenetically, two subclades formed for A. cinereus. The first subclade grouped all Malay Peninsula samples except for samples from Kelantan, and the second subclade grouped Kelantan samples with Thai sample. Genetic distance analysis supported the close relationships between Thai and Kelantan samples compared to the samples from Terengganu and the other Malaysian states. A minimum-spanning network showed that Kelantan and Thailand formed a haplogroup distinct from the other populations. Our results show that Thai subspecies A. cinereus may have migrated to Kelantan from Thai mainland. We also suggest the classification of a new subspecies from Malay Peninsula, the small-clawed otter named A. cinereus kecilensis.

Bioerosion by pit-forming, temperate-reef sea urchins: History, rates and broader implications.

Directory of Open Access Journals (Sweden)

Michael P Russell

Full Text Available Sea urchins are dominant members of rocky temperate reefs around the world. They often occur in cavities within the rock, and fit so tightly, it is natural to assume they sculpted these "pits." However, there are no experimental data demonstrating they bore pits. If they do, what are the rates and consequences of bioerosion to nearshore systems? We sampled purple sea urchins, Strongylocentrotus purpuratus, from sites with four rock types, three sedimentary (two sandstones and one mudstone and one metamorphic (granite. A year-long experiment showed urchins excavated depressions on sedimentary rocks in just months. The rate of pit formation varied with rock type and ranged from 100 yr for granite. In the field, there were differences in pit size and shapes of the urchins (height:diameter ratio. The pits were shallow and urchins flatter at the granite site, and the pits were deeper and urchins taller at the sedimentary sites. Although overall pit sizes were larger on mudstone than on sandstone, urchin size accounted for this difference. A second, short-term experiment, showed the primary mechanism for bioerosion was ingestion of the substratum. This experiment eliminated potential confounding factors of the year-long experiment and yielded higher bioerosion rates. Given the high densities of urchins, large amounts of rock can be converted to sediment over short time periods. Urchins on sandstone can excavate as much as 11.4 kg m-2 yr-1. On a broader geographic scale, sediment production can exceed 100 t ha-1 yr-1, and across their range, their combined bioerosion is comparable to the sediment load of many rivers. The phase shift between urchin barrens and kelp bed habitats in the North Pacific is controlled by the trophic cascade of sea otters. By limiting urchin populations, these apex predators also may indirectly control a substantial component of coastal rates of bioerosion.

Bioerosion by pit-forming, temperate-reef sea urchins: History, rates and broader implications

Science.gov (United States)

Gibbs, Victoria K.; Duwan, Emily

2018-01-01

Sea urchins are dominant members of rocky temperate reefs around the world. They often occur in cavities within the rock, and fit so tightly, it is natural to assume they sculpted these “pits.” However, there are no experimental data demonstrating they bore pits. If they do, what are the rates and consequences of bioerosion to nearshore systems? We sampled purple sea urchins, Strongylocentrotus purpuratus, from sites with four rock types, three sedimentary (two sandstones and one mudstone) and one metamorphic (granite). A year-long experiment showed urchins excavated depressions on sedimentary rocks in just months. The rate of pit formation varied with rock type and ranged from 100 yr for granite. In the field, there were differences in pit size and shapes of the urchins (height:diameter ratio). The pits were shallow and urchins flatter at the granite site, and the pits were deeper and urchins taller at the sedimentary sites. Although overall pit sizes were larger on mudstone than on sandstone, urchin size accounted for this difference. A second, short-term experiment, showed the primary mechanism for bioerosion was ingestion of the substratum. This experiment eliminated potential confounding factors of the year-long experiment and yielded higher bioerosion rates. Given the high densities of urchins, large amounts of rock can be converted to sediment over short time periods. Urchins on sandstone can excavate as much as 11.4 kg m-2 yr-1. On a broader geographic scale, sediment production can exceed 100 t ha-1 yr-1, and across their range, their combined bioerosion is comparable to the sediment load of many rivers. The phase shift between urchin barrens and kelp bed habitats in the North Pacific is controlled by the trophic cascade of sea otters. By limiting urchin populations, these apex predators also may indirectly control a substantial component of coastal rates of bioerosion. PMID:29466357

Spatial distribution, inter-annual variability and influence of abiotic factors on molluscan assemblages collected with otter trawl in the northen Alborán Sea

OpenAIRE

Ciércoles, C. (Cristina); García-Ruiz, C. (Cristina); González-Aguilar, M. (María); López-González, N. (Nieves); Tuite, P. (Patrick); Ortiz-de-Urbina-Gutiérrez, J.M. (José María); Rueda, J.L. (José Luis)

2016-01-01

Molluscs constitute one of the most diverse and best represented invertebrate groups in the marine environment. In the northern sectors of the Alborán Sea and Gulf of Cádiz 1200 spp. of the 1800 spp. occurring in the Mediterranean Sea, have been found so far highlighting the importance of this area for the european molluscan fauna (Gofas et al., 2011). Molluscs are also the second group in abundance and biomass in demersal fisheries and an important component of soft-bottom benthic communitie...

76 FR 18232 - Marine Mammals; Incidental Take During Specified Activities

Science.gov (United States)

2011-04-01

... Island group, located in the central Aleutian Island chain, declined by about 94 percent; aerial survey... the construction seasons. Supplies, equipment, and personnel would be routed from the proposed beach... Habitat and Marine Mammals Affected by the Activity Three monthly surveys for sea otters were conducted in...

76 FR 329 - Marine Mammals; File No. 14330

Science.gov (United States)

2011-01-04

.... Paul, St. George, Otter, and Walrus Islands, and Sea Lion Rock, all of the Pribilof Island group in the... hereby given that the Aleut Community of St. Paul Island, Tribal Government, Ecosystem Conservation..., Disentanglement, and Island Sentinel program responsibilities as established under the co-management agreement...

Modest genetic differentiation among North American populations of Sarcocystis neurona may reflect expansion in its geographic range.

Science.gov (United States)

Sundar, N; Asmundsson, I M; Thomas, N J; Samuel, M D; Dubey, J P; Rosenthal, B M

2008-03-25

Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

Modest genetic differentiation among North American populations of Sarcocystic neurona may reflect expansion in its geographic range

Science.gov (United States)

Sundar, N.; Asmundsson, I.M.; Thomas, N.J.; Samuel, M.D.; Dubey, J.P.; Rosenthal, B.M.

2008-01-01

Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

Arcanobacterium phocae infection in mink (Neovison vison), seals (Phoca vitulina, Halichoerus grypus) and otters (Lutra lutra)

DEFF Research Database (Denmark)

Nonnemann, Bettina; Chriél, Mariann; Larsen, Gitte

2017-01-01

pathological conditions, and from wild seals and otters. In 2015, A. phocae was isolated for the first time in Denmark from outbreaks of dermatitis in mink farms. The outbreaks affected at least 12 farms. Originating from these 12 farms, 23 animals cultured positive for A. phocae. The main clinical findings......Infectious skin disorders are not uncommon in mink. Such disorders are important as they have a negative impact on animal health and welfare as well as on the quality and value of the fur. This study presents the isolation of Arcanobacterium phocae from mink with severe skin lesions and other...... were necrotizing pododermatitis or dermatitis located to other body sites, such as the lumbar and cervical regions. A. phocae could be isolated from skin lesions and in nine animals also from liver, spleen and lung, indicating a systemic spread. The bacterium was also, for the first time in Denmark...

75 FR 62562 - Endangered and Threatened Wildlife and Plants; Notice of Availability of Draft Recovery Plan for...

Science.gov (United States)

2010-10-12

... plants to the point where they are again secure, self-sustaining members of their ecosystems is a primary... spills, food limitation, disturbance, bycatch in fisheries, subsistence harvest, loss of habitat, and...; (2) maintain enough sea otters to ensure that they are playing a functional role in their nearshore...

The Color of the Wind: Fables for a New Age.

Science.gov (United States)

Nottingham, Theodore J.

This book of fables from the animal kingdom contains: "The Frog Who Knew Too Much"; "Long Tail the Lizard"; "The Otter Who Went to the Bottom of the Sea"; "The Single-Wattled Cassowary and His Lethal Toe"; "The Rebel Gerbil"; "Why Hairless Monkeys Turn Out So Bad"; and "The Eagles'…

76 FR 15333 - Information Collection Sent to the Office of Management and Budget (OMB) for Approval; OMB...

Science.gov (United States)

2011-03-21

.... Amount of time (i.e., hours/days hunted) spent hunting polar bears. Type of take (live-killed or beach... Completion time per Total annual Activity respondents responses response burden hours 3-2414 (polar bear) 25... North Pacific or Arctic Oceans may harvest polar bears, northern sea otters, and Pacific walrus for...

Search Results | Page 65 | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

2011-07-01

Results 641 - 650 of 8518 ... ... Apply International Partnerships for Sustainable Societies filter ... System dynamics and GIS in the simulation of environmental ... July 1, 2011 ... Establishing a recovery orientation in first line mental health teams in Québec : perspectives from ... Sea otter tourism in British Columbia : the effects of ...

Climate-induced behavioral changes influence exposure of an Arctic apex predator to pathogens and contaminants

Science.gov (United States)

Polar bears (Ursus maritimus) may serve as sentinels for pathogens and contaminants, providing insight into changing Arctic ecosystems and health risks to wildlife and humans. Recent changes in the availability of sea ice habitat have coincided with increased use of land by polar bears from the sout...

50 CFR 14.133 - Care in transit.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Care in transit. 14.133 Section 14.133 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING..., Sea Otters, Pinnipeds, and Polar Bears) § 14.133 Care in transit. (a) Any marine mammal shall be...

50 CFR 14.132 - Food and water.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Food and water. 14.132 Section 14.132 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING..., Sea Otters, Pinnipeds, and Polar Bears) § 14.132 Food and water. A marine mammal shall not be...

An Introduction to the Black Sea Ecology

Science.gov (United States)

2001-01-01

genus related to the Black Sea Cystoseira) are transported away from the Gulf of Mexico by the Gulf Stream to the northeast and are retained by the...social and economic consequences are not less harmful. It is enough to name the cases of epidemics of cholera and other gastrointestinal infections...seawater, are also found Salmonella, cholera’s vibrios , helmint’s eggs, viruses and other pathogenic organisms which are usually common in insufficiently

Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

OpenAIRE

Fernández, Araceli; Paz Villanueva, María; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

2014-01-01

Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and inv...

Vibrio lentus protects gnotobiotic sea bass (Dicentrarchus labrax L.) larvae against challenge with Vibrio harveyi.

Science.gov (United States)

Schaeck, M; Duchateau, L; Van den Broeck, W; Van Trappen, S; De Vos, P; Coulombet, C; Boon, N; Haesebrouck, F; Decostere, A

2016-03-15

Due to the mounting awareness of the risks associated with the use of antibiotics in aquaculture, treatment with probiotics has recently emerged as the preferred environmental-friendly prophylactic approach in marine larviculture. However, the presence of unknown and variable microbiota in fish larvae makes it impossible to disentangle the efficacy of treatment with probiotics. In this respect, the recent development of a germ-free culture model for European sea bass (Dicentrarchus labrax L.) larvae opened the door for more controlled studies on the use of probiotics. In the present study, 206 bacterial isolates, retrieved from sea bass larvae and adults, were screened in vitro for haemolytic activity, bile tolerance and antagonistic activity against six sea bass pathogens. Subsequently, the harmlessness and the protective effect of the putative probiotic candidates against the sea bass pathogen Vibrio harveyi were evaluated in vivo adopting the previously developed germ-free sea bass larval model. An equivalence trial clearly showed that no harmful effect on larval survival was elicited by all three selected probiotic candidates: Bacillus sp. LT3, Vibrio lentus and Vibrio proteolyticus. Survival of Vibrio harveyi challenged larvae treated with V. lentus was superior in comparison with the untreated challenged group, whereas this was not the case for the larvae supplemented with Bacillus sp. LT3 and V. proteolyticus. In this respect, our results unmistakably revealed the protective effect of V. lentus against vibriosis caused by V. harveyi in gnotobiotic sea bass larvae, rendering this study the first in its kind. Copyright © 2016. Published by Elsevier B.V.

The distribution of 4-nonylphenol in marine organisms of North American Pacific Coast estuaries.

Science.gov (United States)

Diehl, Jennifer; Johnson, Sarah E; Xia, Kang; West, Amy; Tomanek, Lars

2012-04-01

One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ(15)N and δ(13)C) to quantify trophic position. 4-NP concentrations in organisms from Morro Bay included 25000±8600 ng g(-1) lw in liver of California sea lion, 14000±5600 ng g(-1) lw in liver of harbor porpoise, 138000±55000 ng g(-1) lw in liver of sea otters, 15700±3600 ng g(-1) lw in liver of seabirds, 36100±6100 ng g(-1) lw in arrow goby fish, 62800±28400 ng g(-1) lw in oysters, and 12700±1300 ng g(-1) lw in mussels. 4-NP levels generally showed a pattern of trophic dilution among organisms in Morro Bay, with exceptions of biomagnification observed between three trophic links: mussel to sea otter (BMF 10.9), oyster to sea otter (BMF 2.2), and arrow goby to staghorn sculpin (BMF 2.7). Our examination of other west coast estuaries of USA and Canada revealed that mean 4-NP concentrations in gobies and mussels from Morro Bay were significantly higher than those from a more urbanized estuary, San Francisco Bay (goby: 11100±3800 ng g(-1) lw) and from a remote estuary, Bamfield Inlet, Canada (goby: 9000±900 ng g(-1) lw, mussel: 6100±700 ng g(-1) lw). Relative to other estuaries worldwide, 4-NP levels in seawater (0.42±0.16 μg L(-1)) and sediment (53±14 ng g(-1) dw) of Morro Bay are low, but gobies and oysters have higher 4-NP levels than comparable fauna. Copyright © 2012 Elsevier Ltd. All rights reserved.

A List of the Marine Mammals of the World. Third Edition.

Science.gov (United States)

Rice, Dale W.

This National Oceanic and Atmospheric Administration publication lists 116 species of living and recently extinct marine mammals of the world. Included are 36 species of Order Carnivora (polar bear, sea otter, and 34 pinnipeds); 5 species of Order Sirenia; 10 of Order Mysticeti (baleen whales); and 65 species of Order Odontoceti (tooth whales).…

Bacterial food-borne pathogens in Indian food

International Nuclear Information System (INIS)

Bandekar, J.R.

2015-01-01

. 50 species, their prevalence in export quality sea-foods as well as in food sold in retail markets such as poultry, fish, sprouts and salads. The isolates from Indian foods were characterized for the presence of virulence genes, antibiotic resistance pattern as well as pulse field gel electrophoresis (PFGE) patterns. A rapid method for the detection of Salmonella species from foods was also developed. The radiation doses for the elimination of these pathogens from various foods were optimized. Details of detection method, characteristics of the pathogens isolated form Indian foods and radiation processing for the elimination of these pathogens will be discussed. (author)

Transformation of the genital epithelial tract occurs early in California sea lion development

Science.gov (United States)

Barragán-Vargas, Cecilia; Montano-Frías, Jorge; Ávila Rosales, Germán; Godínez-Reyes, Carlos R.; Acevedo-Whitehouse, Karina

2016-01-01

An unusually high prevalence of metastatic urogenital carcinoma has been observed in free-ranging California sea lions stranded off the coast of California in the past two decades. No cases have been reported for sea lions in the relatively unpolluted Gulf of California. We investigated occurrence of genital epithelial transformation in 60 sea lions (n=57 pups and 3 adult females) from the Gulf of California and examined whether infection by a viral pathogen previously found to be associated with urogenital carcinoma accounted for such alterations. We also explored the contribution of MHC class II gene expression on transformation. Cellular alterations, such as squamous cell atypia (ASC), atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesions were observed in 42% of the pups and in 67% of the adult females. Normal genital epithelium was more common in male than female pups. ASC was five times more likely to occur in older pups. Epithelial alterations were unrelated to infection by the potentially oncogenic otarine type I gammaherpesvirus (OtHV-1), but ASCUS was more common in pups with marked and severe inflammation. Expression of MHC class II DRB loci (Zaca DRB-D) by peripheral antigen-presenting leucocytes showed a slightly ‘protective’ effect for ASC. We propose that transformation of the California sea lion genital epithelium is relatively common in young animals, increases with age and is probably the result of infection by an unidentified pathogen. Expression of a specific MHC class II gene, suggestive of presentation of specific antigenic peptides to immune effectors, appears to lower the risk of transformation. Our study provides the first evidence that epithelial transformation of the California sea lion genital tract is relatively common, even from an early age, and raises questions regarding differences in sea lion cancer-detection and -repair success between geographical regions. PMID:27069641

Infectious diseases, parasites, and biological toxins in sea ducks: Chapter 4

Science.gov (United States)

Hollmén, Tuula E.; Franson, J. Christian

2015-01-01

This chapter addresses disease agents in the broad sense, including viruses, bacteria, fungi, protozoan and helminth parasites, and biological toxins. Some of these agents are known to cause mortality in sea ducks, some are thought to be incidental findings, and the significance of others is yet poorly understood. Although the focus of the chapter is on free-living sea ducks, the study of disease in this taxonomic group has been relatively limited and examples from captive sea ducks and other wild waterfowl are used to illustrate the pathogenicity of certain diseases. Much of the early work in sea ducks consisted of anecdotal and descriptive reports of parasites, but it was soon recognized that diseases such as avian cholera, renal coccidiosis, and intestinal infections with acanthocephalans were causes of mortality in wild populations. More recently, adenoviruses, reoviruses, and the newly emergent Wellfleet Bay virus, for example, also have been linked to die-offs of sea ducks. Declining populations of animals are particularly vulnerable to the threats posed by disease and it is important that we improve our understanding of the significance of disease in sea ducks. To conclude, we offer our recommendations for future directions in this field.

Synoptic measurements of subsurface phytoplankton layers collected from Fish Lidar, Oceanic, Experimenta (FLOE) Light Detection and Ranging (LIDAR) from aircraft in Chukchi Sea and Beaufort Sea from 2014-07-17 to 2014-07-29 (NCEI Accession 0128217)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In July 2014, FLOE was installed in a NOAA Twin Otter to make the first synoptic measurements of subsurface phytoplankton layers associated with the retreating ice...

Toxoplasma gondii in stranded marine mammals from the North Sea and Eastern Atlantic Ocean

NARCIS (Netherlands)

Velde, van de Norbert; Devleesschauwer, Brecht; Leopold, Mardik; Begeman, Lineke; IJsseldijk, Lonneke; Hiemstra, Sjoukje; IJzer, Jooske; Brownlow, Andrew; Davison, Nicholas; Haelters, Jan

2016-01-01

The occurrence of the zoonotic protozoan parasite Toxoplasma gondii in marine mammals remains a poorly understood phenomenon. In this study, samples from 589 marine mammal species and 34 European otters (Lutra lutra), stranded on the coasts of Scotland, Belgium, France, The Netherlands and

Sea level trends in South East Asian Seas (SEAS)

Science.gov (United States)

Strassburg, M. W.; Hamlington, B. D.; Leben, R. R.; Manurung, P.; Lumban Gaol, J.; Nababan, B.; Vignudelli, S.; Kim, K.-Y.

2014-10-01

Southeast Asian Seas (SEAS) span the largest archipelago in the global ocean and provide a complex oceanic pathway connecting the Pacific and Indian Oceans. The SEAS regional sea level trends are some of the highest observed in the modern satellite altimeter record that now spans almost two decades. Initial comparisons of global sea level reconstructions find that 17 year sea level trends over the past 60 years exhibit good agreement in areas and at times of strong signal to noise associated decadal variability forced by low frequency variations in Pacific trade winds. The SEAS region exhibits sea level trends that vary dramatically over the studied time period. This historical variation suggests that the strong regional sea level trends observed during the modern satellite altimeter record will abate as trade winds fluctuate on decadal and longer time scales. Furthermore, after removing the contribution of the Pacific Decadal Oscillation (PDO) to sea level trends in the past twenty years, the rate of sea level rise is greatly reduced in the SEAS region. As a result of the influence of the PDO, the SEAS regional sea level trends during 2010s and 2020s are likely to be less than the global mean sea level (GMSL) trend if the observed oscillations in wind forcing and sea level persist. Nevertheless, long-term sea level trends in the SEAS will continue to be affected by GMSL rise occurring now and in the future.

The NRL 2011 Airborne Sea-Ice Thickness Campaign

Science.gov (United States)

Brozena, J. M.; Gardner, J. M.; Liang, R.; Ball, D.; Richter-Menge, J.

2011-12-01

In March of 2011, the US Naval Research Laboratory (NRL) performed a study focused on the estimation of sea-ice thickness from airborne radar, laser and photogrammetric sensors. The study was funded by ONR to take advantage of the Navy's ICEX2011 ice-camp /submarine exercise, and to serve as a lead-in year for NRL's five year basic research program on the measurement and modeling of sea-ice scheduled to take place from 2012-2017. Researchers from the Army Cold Regions Research and Engineering Laboratory (CRREL) and NRL worked with the Navy Arctic Submarine Lab (ASL) to emplace a 9 km-long ground-truth line near the ice-camp (see Richter-Menge et al., this session) along which ice and snow thickness were directly measured. Additionally, US Navy submarines collected ice draft measurements under the groundtruth line. Repeat passes directly over the ground-truth line were flown and a grid surrounding the line was also flown to collect altimeter, LiDAR and Photogrammetry data. Five CRYOSAT-2 satellite tracks were underflown, as well, coincident with satellite passage. Estimates of sea ice thickness are calculated assuming local hydrostatic balance, and require the densities of water, ice and snow, snow depth, and freeboard (defined as the elevation of sea ice, plus accumulated snow, above local sea level). Snow thickness is estimated from the difference between LiDAR and radar altimeter profiles, the latter of which is assumed to penetrate any snow cover. The concepts we used to estimate ice thickness are similar to those employed in NASA ICEBRIDGE sea-ice thickness estimation. Airborne sensors used for our experiment were a Reigl Q-560 scanning topographic LiDAR, a pulse-limited (2 nS), 10 GHz radar altimeter and an Applanix DSS-439 digital photogrammetric camera (for lead identification). Flights were conducted on a Twin Otter aircraft from Pt. Barrow, AK, and averaged ~ 5 hours in duration. It is challenging to directly compare results from the swath LiDAR with the

Extraordinary Diversity of Immune Response Proteins among Sea Urchins: Nickel-Isolated Sp185/333 Proteins Show Broad Variations in Size and Charge

Science.gov (United States)

Sherman, Lauren S.; Schrankel, Catherine S.; Brown, Kristy J.; Smith, L. Courtney

2015-01-01

Effective protection against pathogens requires the host to produce a wide range of immune effector proteins. The Sp185/333 gene family, which is expressed by the California purple sea urchin Strongylocentrotus purpuratus in response to bacterial infection, encodes a highly diverse repertoire of anti-pathogen proteins. A subset of these proteins can be isolated by affinity to metal ions based on multiple histidines, resulting in one to four bands of unique molecular weight on standard Western blots, which vary depending on the individual sea urchin. Two dimensional gel electrophoresis (2DE) of nickel-isolated protein samples followed by Western blot was employed to detect nickel-isolated Sp185/333 (Ni-Sp185/333) proteins and to evaluate protein diversity in animals before and after immune challenge with marine bacteria. Ni-Sp185/333 proteins of the same molecular weight on standard Western blots appear as a broad complex of variants that differ in pI on 2DE Western blots. The Ni-Sp185/333 protein repertoire is variable among animals, and shows a variety of changes among individual sea urchins in response to immune challenges with both the same and different species of bacteria. The extraordinary diversity of the Ni-Sp185/333 proteins may provide significant anti-pathogen capabilities for sea urchins that survive solely on innate immunity. PMID:26406912

Asymptomatic and chronic carriage of Leptospira interrogans serovar Pomona in California sea lions (Zalophus californianus)

Science.gov (United States)

Since 1970, periodic outbreaks of leptospirosis, caused by pathogenic spirochetes in the genus Leptospira, have caused morbidity and mortality of California sea lions (Zalophus californianus) along the Pacific coast of North America. Yearly seasonal epizootics of varying magnitude occur between the ...

First isolation of Aeromonas salmonicida subspecies salmonicida from diseased sea bass, Dicentrarchus labrax (L., cultured in Spain

Directory of Open Access Journals (Sweden)

Clara Fernández-Álvarez

2016-11-01

Full Text Available This work represents the first description of Aeromonas salmonicida subsp. salmonicida as causative agent of furunculosis in cultured sea bass, Dicentrarchus labrax (L.. Cumulative mortality in affected fish from two floating cages in the Mediterranean coast of Spain was 3.8%. Affected sea bass did not show the typical external signs of furunculosis in the first stages of the disease, however, when the disease progressed, open ulcers appeared on the skin and muscle. Internally, splenomegaly was the only pathological sign observed. Samples from diseased fish were subjected to standardized assays for pathogens screening. Negative results were obtained for parasites and fish viruses. A Gram-stain-negative rod-shaped bacterium was observed in smears from liver, kidney and spleen of all analysed fish. Pure bacterial cultures were recovered from liver, kidney and spleen of all diseased fish sampled during the two different outbreaks. Bacteriological, serological, molecular and chemotaxonomic analysis allowed the identification of the causative agent of sea bass mortalities as Aeromonas salmonicida subsp. salmonicida. The bacterial strains were susceptible to most of antimicrobial agents usually employed in aquaculture except to oxytetracycline. Pathogenicity assays demonstrated that the isolated bacteria were virulent for sea bass, turbot and rainbow trout.

MOLECULAR CHARACTERIZATION OF MICROSPORIDIA INDICATES THAT FUR-BEARING WILD MAMMALS CAN BE A SOURCE OF HUMAN PATHOGENIC ENTEROCYTOZOON BIENEUSI

Science.gov (United States)

Over 13 months, 465 beavers, foxes, muskrats, otters, and raccoons were trapped in four counties in eastern Maryland and examined by molecular methods for microsporidia. A two-step nested PCR protocol was developed to amplify a 392 bp fragment of the internal transcribed spacer (...

First Isolation of Streptococcus halichoeri and Streptococcus phocae from a Steller Sea Lion (Eumetopias jubatus) in South Korea.

Science.gov (United States)

Lee, Kichan; Kim, Ji-Yeon; Jung, Suk Chan; Lee, Hee-Soo; Her, Moon; Chae, Chanhee

2016-01-01

Streptococcus species are emerging potential pathogens in marine mammals. We report the isolation and identification of Streptococcus halichoeri and Streptococcus phocae in a Steller sea lion (Eumetopias jubatus) in South Korea.

Adhesive and invasive capacities of Edwardsiella tarda isolated from South American sea lion.

Science.gov (United States)

Fernández, Araceli; Villanueva, María Paz; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

2014-01-01

Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds.

Agglutinating antibodies against pathogenic Leptospira in healthy dogs and horses indicate common exposure and regular occurrence of subclinical infections

NARCIS (Netherlands)

D.J. Houwers; M.G.A. Goris (Marga); T.H. Abdoel (Theresia); J.A. Kas (Jeroen); S.S. Knobbe (Sandra); A.M. van Dongen (Astrid); F.E. Westerduin (Fenna); W.R. Klein (Wim); R.A. Hartskeerl (Rudy)

2011-01-01

textabstractIn order to get insight in the level of exposure to pathogenic Leptospira under the moderate sea climate conditions in the Netherlands, healthy dogs and horses were tested for antibodies using the Microscopic Agglutination Test (MAT). 55% of 198 dogs tested had agglutinating antibodies

Epidemiology of Rhodotorula: An Emerging Pathogen

Science.gov (United States)

Wirth, Fernanda; Goldani, Luciano Z.

2012-01-01

This is an updated paper focusing on the general epidemiological aspects of Rhodotorula in humans, animals, and the environment. Previously considered nonpathogenic, Rhodotorula species have emerged as opportunistic pathogens that have the ability to colonise and infect susceptible patients. Rhodotorula species are ubiquitous saprophytic yeasts that can be recovered from many environmental sources. Several authors describe the isolation of this fungus from different ecosystems, including sites with unfavourable conditions. Compared to R. mucilaginosa, R. glutinis and R. minuta are less frequently isolated from natural environments. Among the few references to the pathogenicity of Rhodotorula spp. in animals, there are several reports of an outbreak of skin infections in chickens and sea animals and lung infections and otitis in sheep and cattle. Most of the cases of infection due to Rhodotorula in humans were fungemia associated with central venous catheter (CVC) use. The most common underlying diseases included solid and haematologic malignancies in patients who were receiving corticosteroids and cytotoxic drugs, the presence of CVC, and the use of broad-spectrum antibiotics. Unlike fungemia, some of the other localised infections caused by Rhodotorula, including meningeal, skin, ocular, peritoneal, and prosthetic joint infections, are not necessarily linked to the use of CVCs or immunosuppression. PMID:23091485

Antimicrobial activity of methanolic extracts of selected marine macroalgae against some pathogenic microorganisms

Directory of Open Access Journals (Sweden)

Ehab Omer Abdalla

2016-05-01

Full Text Available Objective: To evaluate the antimicrobial activity of methanolic extracts of six marine macroalgae belonging to green algae (Chlorophyceae, brown algae (Phaeophyceae and the red algae (Rhodophyceae collected from the intertidal area of the Sudanese Red Sea coast near Port Sudan. Methods: Methanol was used for extracting the active principles of the algae and the disc diffusion method was performed to examine the activity and the minimum inhibitory concentration of the samples against four pathogenic bacteria and two fungi. Results: All tested algal extracts exhibited considerable bioactivity and inhibited the growth of all pathogenic microorganisms under investigation. The green alga Caulerpa racemosa produced the maximum inhibition zone (21 mm against Candida albicans while the red alga Laurencia papillosa showed low antimicrobial activity with the minimum inhibition zone of 10 mm against Pseudomonas aeruginosa. The tested algal extracts did not show any special antimicrobial influence on the selected microorganisms when they were considered as Grampositive and Gram-negative bacteria and fungi but the most efficient methanolic extracts in inhibiting microbial growth were those of green macroalgae followed by the brown and the red macroalgae respectively. Conclusions: The study demonstrated that the tested marine macroalgae from Sudanese Red Sea coast may represent a potential and alternative source for secondary metabolites with antimicrobial activity.

Two-Year Monitoring of Water Samples from Dam of Iskar and the Black Sea, Bulgaria, by Molecular Analysis: Focus on Mycobacterium spp.

Directory of Open Access Journals (Sweden)

Stefan Panaiotov

2015-06-01

Full Text Available The coast of the Bulgarian Black Sea is a popular summer holiday destination. The Dam of Iskar is the largest artificial dam in Bulgaria, with a capacity of 675 million m3. It is the main source of tap water for the capital Sofia and for irrigating the surrounding valley. There is a close relationship between the quality of aquatic ecosystems and human health as many infections are waterborne. Rapid molecular methods for the analysis of highly pathogenic bacteria have been developed for monitoring quality. Mycobacterial species can be isolated from waste, surface, recreational, ground and tap waters and human pathogenicity of nontuberculose mycobacteria (NTM is well recognized. The objective of our study was to perform molecular analysis for key-pathogens, with a focus on mycobacteria, in water samples collected from the Black Sea and the Dam of Iskar. In a two year period, 38 water samples were collected—24 from the Dam of Iskar and 14 from the Black Sea coastal zone. Fifty liter water samples were concentrated by ultrafiltration. Molecular analysis for 15 pathogens, including all species of genus Mycobacterium was performed. Our results showed presence of Vibrio spp. in the Black Sea. Rotavirus A was also identified in four samples from the Dam of Iskar. Toxigenic Escherichia coli was present in both locations, based on markers for stx1 and stx2 genes. No detectable amounts of Cryptosporidium were detected in either location using immunomagnetic separation and fluorescence microscopy. Furthermore, mass spectrometry analyses did not detect key cyanobacterial toxins. On the basis of the results obtained we can conclude that for the period 2012–2014 no Mycobacterium species were present in the water samples. During the study period no cases of waterborne infections were reported.

Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

Directory of Open Access Journals (Sweden)

Araceli Fernández

2014-09-01

Full Text Available Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds.

Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

Science.gov (United States)

Fernández, Araceli; Villanueva, María Paz; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

2014-01-01

Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds. PMID:25477948

Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California.

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Rejmanek, Daniel; Vanwormer, Elizabeth; Miller, Melissa A; Mazet, Jonna A K; Nichelason, Amy E; Melli, Ann C; Packham, Andrea E; Jessup, David A; Conrad, Patricia A

2009-12-03

Sarcocystis neurona, a protozoal parasite shed by opossums (Didelphis virginiana), has been shown to cause significant morbidity and mortality in horses, sea otters, and other marine mammals. Over the course of 3 years (fall 2005-summer 2008), opossums from central California were tested for infection with S. neurona. Of 288 opossums sampled, 17 (5.9%) were infected with S. neurona based on the molecular characterization of sporocysts from intestinal scrapings or feces. Risk factors evaluated for association with S. neurona infection in opossums included: age, sex, location, season, presence of pouch young in females, concomitant infection, and sampling method (live-trapped or traffic-killed). Multivariate logistic regression analysis identified that opossums in the Central Valley were 9 times more likely to be infected than those near the coast (p=0.009). Similarly, opossum infection was 5 times more likely to be detected during the reproductive season (March-July; p=0.013). This first investigation of S. neurona infection prevalence and associated risk factors in opossums in the western United States can be used to develop management strategies aimed at reducing the incidence of S. neurona infections in susceptible hosts, including horses and threatened California sea otters (Enhydra lutris neries).

Comparative proteomic analysis of pathogenic and non-pathogenic strains from the swine pathogen Mycoplasma hyopneumoniae

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Klein Cátia S

2009-12-01

Full Text Available Abstract Background Mycoplasma hyopneumoniae is a highly infectious swine pathogen and is the causative agent of enzootic pneumonia (EP. Following the previous report of a proteomic survey of the pathogenic 7448 strain of swine pathogen, Mycoplasma hyopneumoniae, we performed comparative protein profiling of three M. hyopneumoniae strains, namely the non-pathogenic J strain and the two pathogenic strains 7448 and 7422. Results In 2DE comparisons, we were able to identify differences in expression levels for 67 proteins, including the overexpression of some cytoadherence-related proteins only in the pathogenic strains. 2DE immunoblot analyses allowed the identification of differential proteolytic cleavage patterns of the P97 adhesin in the three strains. For more comprehensive protein profiling, an LC-MS/MS strategy was used. Overall, 35% of the M. hyopneumoniae genome coding capacity was covered. Partially overlapping profiles of identified proteins were observed in the strains with 81 proteins identified only in one strain and 54 proteins identified in two strains. Abundance analysis of proteins detected in more than one strain demonstrates the relative overexpression of 64 proteins, including the P97 adhesin in the pathogenic strains. Conclusions Our results indicate the physiological differences between the non-pathogenic strain, with its non-infective proliferate lifestyle, and the pathogenic strains, with its constitutive expression of adhesins, which would render the bacterium competent for adhesion and infection prior to host contact.

Airborne Mission Concept for Coastal Ocean Color and Ecosystems Research

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Guild, Liane S.; Hooker, Stanford B.; Morrow, John H.; Kudela, Raphael M.; Palacios, Sherry L.; Torres Perez, Juan L.; Hayashi, Kendra; Dunagan, Stephen E.

2016-01-01

NASA airborne missions in 2011 and 2013 over Monterey Bay, CA, demonstrated novel above- and in-water calibration and validation measurements supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The resultant airborne data characterize contemporaneous coastal atmospheric and aquatic properties plus sea-truth observations from state-of-the-art instrument systems spanning a next-generation spectral domain (320-875 nm). This airborne instrument suite for calibration, validation, and research flew at the lowest safe altitude (ca. 100 ft or 30 m) as well as higher altitudes (e.g., 6,000 ft or 1,800 m) above the sea surface covering a larger area in a single synoptic sortie than ship-based measurements at a few stations during the same sampling period. Data collection of coincident atmospheric and aquatic properties near the sea surface and at altitude allows the input of relevant variables into atmospheric correction schemes to improve the output of corrected imaging spectrometer data. Specific channels support legacy and next-generation satellite capabilities, and flights are planned to within 30 min of satellite overpass. This concept supports calibration and validation activities of ocean color phenomena (e.g., river plumes, algal blooms) and studies of water quality and coastal ecosystems. The 2011 COAST mission flew at 100 and 6,000 ft on a Twin Otter platform with flight plans accommodating the competing requirements of the sensor suite, which included the Coastal-Airborne In-situ Radiometers (C-AIR) for the first time. C-AIR (Biospherical Instruments Inc.) also flew in the 2013 OCEANIA mission at 100 and 1,000 ft on the Twin Otter below the California airborne simulation of the proposed NASA HyspIRI satellite system comprised of an imaging spectrometer and thermal infrared multispectral imager on the ER-2 at 65,000 ft (20,000 m). For both missions, the Compact-Optical Profiling System (Biospherical

Vibrio damsela as a pathogenic agent causing mortalities in cultured sea bass (Lates calcarifer)

OpenAIRE

Renault, Tristan; Haffner, Philippe; Malfondet, C.; Weppe, Maurice

1994-01-01

Vibrio anguillarum and Vibrio ordali are species frequently described as fish pathogens. Seven species of Vibrio can also be implicated in disease problems in mariculture (Toranzo 1990). sorne of Vibrios and Barja, In addition, these marine such as V. vulnificus (Tison et al.. 1982) and V. damsela (Love et al., 1981) can also cause illness homoiothermic animals

STREPTOCOCCUS PHOCAE IN MARINE MAMMALS OF NORTHEASTERN PACIFIC AND ARCTIC CANADA: A RETROSPECTIVE ANALYSIS OF 85 POSTMORTEM INVESTIGATIONS.

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Taurisano, Nicole D; Butler, Brian P; Stone, Diana; Hariharan, Harry; Fields, Paul J; Ferguson, Hugh W; Haulena, Martin; Cotrell, Paul; Nielsen, Ole; Raverty, Stephen

2018-01-01

:  Streptococcus phocae is a pathogen of marine mammals, although its pathogenicity remains poorly understood. Recovery of this bacterium from asymptomatic carriers suggests that it is an opportunistic pathogen. We investigated the role of S. phocae in naturally occurring disease and its significance as a pathogen based on postmortem investigations. Between 2007 and 2012, 1,696 whole carcasses, tissue samples, or both were submitted from the northeastern Pacific and Arctic Canada for diagnostic testing. Streptococcus phocae was cultured from phocids ( n=66), otariids ( n=12), harbor porpoises ( Phocoena phocoena; n=5), and sea otters ( Enhydra lutris; n=2). Pathologic manifestations of S. phocae-associated disease included localized, as well as systemic, inflammatory lesions with common findings of suppurative bronchopneumonia ( n=17) and bacteremia ( n=27). Lung lesions were frequently culture-positive for S. phocae, suggesting commensal colonization of the oropharynx with subsequent opportunistic infection of the respiratory tract during tissue injury, coinfection, immunosuppression, or other debilitating conditions. The presence of a positive spleen culture, and interpretations at necropsy and histopathology, were used to determine the presence of S. phocae bacteremia. Less frequent lesions that were culture positive for S. phocae included abscesses ( n=9), meningitis ( n=7), and cellulitis ( n=1). The majority of cases with S. phocae lesions featured pre-existing conditions that presumably contributed to some degree of debilitation or immunosuppression, including emaciation ( n=29), liver mercury accumulation ( n=29), trauma ( n=22), severe pulmonary or cardiovascular nematodiasis ( n=9), concurrent bacterial or viral infections ( n=8), or sarcocystosis ( n=6). These findings suggest that S. phocae could be characterized as an opportunistic pathogen, associated with debilitating conditions in stranded and rehabilitating marine mammals. Wildlife investigators

Sea level trends in Southeast Asian seas

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Strassburg, M. W.; Hamlington, B. D.; Leben, R. R.; Manurung, P.; Lumban Gaol, J.; Nababan, B.; Vignudelli, S.; Kim, K.-Y.

2015-05-01

Southeast Asian seas span the largest archipelago in the global ocean and provide a complex oceanic pathway connecting the Pacific and Indian oceans. The Southeast Asian sea regional sea level trends are some of the highest observed in the modern satellite altimeter record that now spans almost 2 decades. Initial comparisons of global sea level reconstructions find that 17-year sea level trends over the past 60 years exhibit good agreement with decadal variability associated with the Pacific Decadal Oscillation and related fluctuations of trade winds in the region. The Southeast Asian sea region exhibits sea level trends that vary dramatically over the studied time period. This historical variation suggests that the strong regional sea level trends observed during the modern satellite altimeter record will abate as trade winds fluctuate on decadal and longer timescales. Furthermore, after removing the contribution of the Pacific Decadal Oscillation (PDO) to sea level trends in the past 20 years, the rate of sea level rise is greatly reduced in the Southeast Asian sea region. As a result of the influence of the PDO, the Southeast Asian sea regional sea level trends during the 2010s and 2020s are likely to be less than the global mean sea level (GMSL) trend if the observed oscillations in wind forcing and sea level persist. Nevertheless, long-term sea level trends in the Southeast Asian seas will continue to be affected by GMSL rise occurring now and in the future.

A transnational and holistic breeding approach is needed for sustainable wheat production in the Baltic Sea region.

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Chawade, Aakash; Armoniené, Rita; Berg, Gunilla; Brazauskas, Gintaras; Frostgård, Gunilla; Geleta, Mulatu; Gorash, Andrii; Henriksson, Tina; Himanen, Kristiina; Ingver, Anne; Johansson, Eva; Jørgensen, Lise Nistrup; Koppel, Mati; Koppel, Reine; Makela, Pirjo; Ortiz, Rodomiro; Podyma, Wieslaw; Roitsch, Thomas; Ronis, Antanas; Svensson, Jan T; Vallenback, Pernilla; Weih, Martin

2018-03-14

The Baltic Sea is one of the largest brackish water bodies in the world. Eutrophication is a major concern in the Baltic Sea due to the leakage of nutrients to the sea with agriculture being the primary source. Wheat (Triticum aestivum L.) is the most widely grown crop in the countries surrounding the Baltic Sea and thus promoting sustainable agriculture practices for wheat cultivation will have a major impact on reducing pollution in the Baltic Sea. This approach requires identifying and addressing key challenges for sustainable wheat production in the region. Implementing new technologies for climate-friendly breeding and digital farming across all surrounding countries should promote sustainable intensification of agriculture in the region. In this review, we highlight major challenges for wheat cultivation in the Baltic Sea region and discuss various solutions integrating transnational collaboration for pre-breeding and technology sharing to accelerate development of low input wheat cultivars with improved host plant resistance to pathogen and enhanced adaptability to the changing climate. © 2018 The Authors. Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.

Inhibition of biological activity of staphylococcal enterotoxin A (SEA) by apple juice and apple polyphenols.

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Rasooly, Reuven; Do, Paula M; Friedman, Mendel

2010-05-12

The foodborne pathogen Staphylococcus aureus produces the virulent staphylococcal enterotoxin A (SEA), a single-chain protein that consists of 233 amino acid residues with a molecular weight of 27 078 Da. SEA is a superantigen that is reported to contribute to animal (mastitis) and human (emesis, diarrhea, atopic dermatitis, arthritis, and toxic shock) syndromes. Changes of the native structural integrity may inactivate the toxin by preventing molecular interaction with cell membrane receptor sites of their host cells. In the present study, we evaluated the ability of one commercial and two freshly prepared apple juices and a commercial apple polyphenol preparation (Apple Poly) to inhibit the biological activity of SEA. Dilutions of freshly prepared apple juices and Apple Poly inhibited the biological activity of SEA without any significant cytotoxic effect on the spleen cells. Additional studies with antibody-coated immunomagnetic beads bearing specific antibodies against the toxin revealed that SEA added to apple juice appears to be largely irreversibly bound to the juice constituents. The results suggest that food-compatible and safe anti-toxin phenolic compounds can be used to inactivate SEA in vitro and possibly also in vivo, even after induction of T-cell proliferation by long-term exposure to SEA. The significance of the results for microbial food safety and human health is discussed.

Concentration and retention of Toxoplasma gondii surrogates from seawater by red abalone (Haliotis rufescens)

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Schott, Kristen C; Krusor, Colin; Tinker, M. Tim; Moore, James G.; Conrad, Patricia A.; Shapiro, Karen

2016-01-01

Small marine snails and abalone have been identified as high- and low-risk prey items, respectively, for exposure of threatened southern sea otters to Toxoplasma gondii, a zoonotic parasite that can cause fatal encephalitis in animals and humans. While recent work has characterized snails as paratenic hosts for T. gondii, the ability of abalone to vector the parasite has not been evaluated. To further elucidate why abalone predation may be protective against T. gondii exposure, this study aimed to determine whether: (1) abalone are physiologically capable of acquiring T. gondii; and (2) abalone and snails differ in their ability to concentrate and retain the parasite. Abalone were exposed to T. gondii surrogate microspheres for 24 h, and fecal samples were examined for 2 weeks following exposure. Concentration of surrogates was 2–3 orders of magnitude greater in abalone feces than in the spiked seawater, and excretion of surrogates continued for 14 days post-exposure. These results indicate that, physiologically, abalone and snails can equally vector T. gondii as paratenic hosts. Reduced risk of T. gondii infection in abalone-specializing otters may therefore result from abalone's high nutritional value, which implies otters must consume fewer animals to meet their caloric needs.

Concentration and retention of Toxoplasma gondii surrogates from seawater by red abalone (Haliotis rufescens).

Science.gov (United States)

Schott, Kristen C; Krusor, Colin; Tinker, M Tim; Moore, James; Conrad, Patricia A; Shapiro, Karen

2016-11-01

Small marine snails and abalone have been identified as high- and low-risk prey items, respectively, for exposure of threatened southern sea otters to Toxoplasma gondii, a zoonotic parasite that can cause fatal encephalitis in animals and humans. While recent work has characterized snails as paratenic hosts for T. gondii, the ability of abalone to vector the parasite has not been evaluated. To further elucidate why abalone predation may be protective against T. gondii exposure, this study aimed to determine whether: (1) abalone are physiologically capable of acquiring T. gondii; and (2) abalone and snails differ in their ability to concentrate and retain the parasite. Abalone were exposed to T. gondii surrogate microspheres for 24 h, and fecal samples were examined for 2 weeks following exposure. Concentration of surrogates was 2-3 orders of magnitude greater in abalone feces than in the spiked seawater, and excretion of surrogates continued for 14 days post-exposure. These results indicate that, physiologically, abalone and snails can equally vector T. gondii as paratenic hosts. Reduced risk of T. gondii infection in abalone-specializing otters may therefore result from abalone's high nutritional value, which implies otters must consume fewer animals to meet their caloric needs.

Antimicrobial Potential of Bacteria Associated with Marine Sea Slugs from North Sulawesi, Indonesia

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Nils Böhringer

2017-06-01

Full Text Available Nudibranchia, marine soft-bodied organisms, developed, due to the absence of a protective shell, different strategies to protect themselves against putative predators and fouling organisms. One strategy is to use chemical weapons to distract predators, as well as pathogenic microorganisms. Hence, these gastropods take advantage of the incorporation of chemical molecules. Thereby the original source of these natural products varies; it might be the food source, de novo synthesis from the sea slug, or biosynthesis by associated bacteria. These bioactive molecules applied by the slugs can become important drug leads for future medicinal drugs. To test the potential of the associated bacteria, the latter were isolated from their hosts, brought into culture and extracts were prepared and tested for antimicrobial activities. From 49 isolated bacterial strains 35 showed antibiotic activity. The most promising extracts were chosen for further testing against relevant pathogens. In that way three strains showing activity against methicillin resistant Staphylococcus aureus and one strain with activity against enterohemorrhagic Escherichia coli, respectively, were identified. The obtained results indicate that the sea slug associated microbiome is a promising source for bacterial strains, which hold the potential for the biotechnological production of antibiotics.

AMPK in Pathogens.

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Mesquita, Inês; Moreira, Diana; Sampaio-Marques, Belém; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo

2016-01-01

During host-pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recognized to play an important role in microbial growth and persistence. Extensive studies have documented the role of AMP-activated protein kinase (AMPK) signaling, a central cellular hub involved in the regulation of energy homeostasis, in host-pathogen interactions. Here, we highlight the most recent advances detailing how pathogens hijack cellular metabolism by suppressing or increasing the activity of the host energy sensor AMPK. We also address the role of lower eukaryote AMPK orthologues in the adaptive process to the host microenvironment and their contribution for pathogen survival, differentiation, and growth. Finally, we review the effects of pharmacological or genetic AMPK modulation on pathogen growth and persistence.

Rapid evolution meets invasive species control: The potential for pesticide resistance in sea lamprey

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Dunlop, Erin S.; McLaughlin, Robert L.; Adams, Jean V.; Jones, Michael L.; Birceanu, Oana; Christie, Mark R.; Criger, Lori A.; Hinderer, Julia L.M.; Hollingworth, Robert M.; Johnson, Nicholas; Lantz, Stephen R.; Li, Weiming; Miller, James R.; Morrison, Bruce J.; Mota-Sanchez, David; Muir, Andrew M.; Sepulveda, Maria S.; Steeves, Todd B.; Walter, Lisa; Westman, Erin; Wirgin, Isaac; Wilkie, Michael P.

2018-01-01

Rapid evolution of pest, pathogen and wildlife populations can have undesirable effects; for example, when insects evolve resistance to pesticides or fishes evolve smaller body size in response to harvest. A destructive invasive species in the Laurentian Great Lakes, the sea lamprey (Petromyzon marinus) has been controlled with the pesticide 3-trifluoromethyl-4-nitrophenol (TFM) since the 1950s. We evaluated the likelihood of sea lamprey evolving resistance to TFM by (1) reviewing sea lamprey life history and control; (2) identifying physiological and behavioural resistance strategies; (3) estimating the strength of selection from TFM; (4) assessing the timeline for evolution; and (5) analyzing historical toxicity data for evidence of resistance. The number of sea lamprey generations exposed to TFM was within the range observed for fish populations where rapid evolution has occurred. Mortality from TFM was estimated as 82-90%, suggesting significant selective pressure. However, 57 years of toxicity data revealed no increase in lethal concentrations of TFM. Vigilance and the development of alternative controls are required to prevent this aquatic invasive species from evolving strategies to evade control.

Pathogen inactivation techniques.

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Pelletier, J P R; Transue, S; Snyder, E L

2006-01-01

The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area

AMPK in Pathogens

OpenAIRE

Mesquita, Inês Morais; Moreira, Diana; Marques, Belém Sampaio; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo Jorge Leal

2016-01-01

During host–pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recogn...

Arginase activity in pathogenic and non-pathogenic species of Leishmania parasites.

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Badirzadeh, Alireza; Taheri, Tahereh; Taslimi, Yasaman; Abdossamadi, Zahra; Heidari-Kharaji, Maryam; Gholami, Elham; Sedaghat, Baharehsadat; Niyyati, Maryam; Rafati, Sima

2017-07-01

Proliferation of Leishmania (L.) parasites depends on polyamine availability, which can be generated by the L-arginine catabolism and the enzymatic activity of arginase (ARG) of the parasites and of the mammalian hosts. In the present study, we characterized and compared the arginase (arg) genes from pathogenic L. major and L. tropica and from non-pathogenic L. tarentolae. We quantified the level of the ARG activity in promastigotes and macrophages infected with pathogenic L. major and L. tropica and non-pathogenic L. tarentolae amastigotes. The ARG's amino acid sequences of the pathogenic and non-pathogenic Leishmania demonstrated virtually 98.6% and 88% identities with the reference L. major Friedlin ARG. Higher ARG activity was observed in all pathogenic promastigotes as compared to non-pathogenic L. tarentolae. In vitro infection of human macrophage cell line (THP1) with pathogenic and non-pathogenic Leishmania spp. resulted in increased ARG activities in the infected macrophages. The ARG activities present in vivo were assessed in susceptible BALB/c and resistant C57BL/6 mice infected with L. major, L. tropica and L. tarentolae. We demonstrated that during the development of the infection, ARG is induced in both strains of mice infected with pathogenic Leishmania. However, in L. major infected BALB/c mice, the induction of ARG and parasite load increased simultaneously according to the time course of infection, whereas in C57BL/6 mice, the enzyme is upregulated solely during the period of footpad swelling. In L. tropica infected mice, the footpads' swellings were slow to develop and demonstrated minimal cutaneous pathology and ARG activity. In contrast, ARG activity was undetectable in mice inoculated with the non-pathogenic L. tarentolae. Our data suggest that infection by Leishmania parasites can increase ARG activity of the host and provides essential polyamines for parasite salvage and its replication. Moreover, the ARG of Leishmania is vital for parasite

Do the visual conditions at the point of escape affect European sea bass escape behavior?

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I.E. PAPADAKIS

2013-03-01

Full Text Available European sea bass (Dicentrarchus labrax, an important species for the Mediterranean aquaculture industry, has been reported to escape from sea cage installations. Fish escapes are caused mainly by operational and technical failures that eventually result into a creation of a tear. Escapees may interact with wild stocks through interbreeding, transfer of pathogens and competition for food. The aim of this study was to examine at which extent the presence of a visible obstacle close to a tear on the net have an influence on sea bass propensity to escape. Fish were initially confined into small sea cages, with a tear at one side. The escape behavior was tested under experimental conditions. It is clearly demonstrated that sea bass was able to locate a tear on the net pen, immediately after its appearance. Crossings occurred in all cages, in singles or in a series of up to seven individuals. The presence of an obstacle close to the net tear altered the escape behavior of D. labrax resulting in a delay that eventually reduced the escape rate. Concluding, it is highly recommended that sea bass cages should be kept internally the culture array. Furthermore, the placement of artificial obstacles close to the sea cages could be an efficient practice that mitigates the escape risk after severe environmental conditions.

Isolation and experimental infection with Vibrio alginolyticus in the sea horse, Hippocampus reidi Ginsburg, 1933 (Osteichthyes: Syngnathidae in Brazil

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ML. Martins

Full Text Available The aim of this study was to evaluate the pathogenicity of Vibrio alginolyticus isolated from an outbreak of sea horse Hippocampus reidi reared in the State of Santa Catarina, Brazil, by experimental infection. Sea horses with necrosis on the mouth epithelium were collected from aquaria at the Aquaculture Department, UFSC and the bacterium isolated from the mouth, liver, heart and blood in tiosulphate citrate bilesalt sucrose agar broth. The strains were identified by API 20E kit with 99.1% probability as Vibrio alginolyticus. Twelve adult sea horses (9.63 ± 2.42 g and 15.12 ± 0.87 cm were distributed in six aquaria of 10 L capacity with aerated sea water. Fish from three aquaria were submitted to an immersion bath in a solution containing 1.0 × 10(7 CFU of V. alginolyticus/mL for 15 minutes. Fish from the other three aquaria received the same procedure without bacteria. Twenty four hours after this challenge, 100% mortality was observed in the animals infected with V. alginolyticus. No mortality was observed in non-infected fish. Hyperplasia, displacement and fusion of secondary lamellae of the gills; leukocyte infiltration and necrotic foci in the kidney; hyperplasia, sinusoidal deformation and necrotic foci in the liver were observed in histopathological analysis. The V. alginolyticus isolated in this study was pathogenic to H. reidi and constitutes an important sanitary problem to its culture.

The fish and fisheries of Jones Bank and the wider Celtic Sea

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Martinez, I.; Ellis, J. R.; Scott, B.; Tidd, A.

2013-10-01

The Celtic Sea is a diverse fishing ground that supports important commercial fisheries for a range of demersal fish, large and small-bodied pelagic fish and a variety of cephalopods and other shellfish. A regional overview of the main commercial fish stocks of the Celtic Sea and of the fish that occur in the vicinity of Jones Bank are provided through analyses of landings data from English and Welsh vessels, and from scientific trawl surveys. Dedicated smaller scale sampling via trawl surveys combined with baited cameras on and around the Jones Bank were also analysed to investigate the importance of sandbank habitats with attention paid to the differences in the species occurring on the top of the bank in comparison to adjacent off-bank habitats. Official landing statistics for UK (English and Welsh) vessels indicated that the predominant commercial demersal species in ICES Divisions VIIg,h (in terms of quantities landed) were anglerfish, megrim, pollack and skates (Rajidae). There were, however, regional differences in the distribution of fish and fisheries, and the area surrounding Jones Bank (ICES Rectangles 28E1 and 28E2) supports fisheries for megrim, anglerfish, skates, hake, ling and turbot, with otter trawl, gillnet and beam trawl the main gears used. Recent survey data collected with GOV (Grande Ouverture Verticale) trawl from the Celtic Sea (ICES Divisions VIIe-h, 2007-2010) were used to highlight the broad scale distribution of the main fish assemblages in the Celtic Sea. Analyses of the fish and cephalopod catches from these surveys indicated that there were four broad assemblages in the area, including (i) a region around the Cornwall (which will also be partly influenced by the necessity to use rockhopper ground gear on these rough grounds), (ii) the shallower regions of the north-western Celtic Sea (including parts of the Bristol Channel), (iii) the deeper parts of the outer shelf and (iv) the central Celtic Sea. These data also provided

A Demo-Genetic Analysis of a Small Reintroduced Carnivore Population: The Otter (Lutra lutra in The Netherlands

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Maelle Seignobosc

2011-01-01

Full Text Available Assessing the viability of reintroduced animal populations is a complicated task. Reintroductions are usually carried out with a small number of individuals, thereby, limiting the possibilities for monitoring because of the possible negative effects of intensive monitoring on survival and reproduction. Moreover, reintroduction studies are part of a socioeconomic interplay of forces, thereby, also limiting monitoring possibilities. Also, knowledge of population demography and abundance can be incomplete or unattainable. Here, we illustrate how we combined traditional telemetry and novel non-invasive genetic methodology to construct a detailed life table of a small reintroduced otter population in The Netherlands. Combining an appropriate capture-mark-recapture framework with a matrix modelling approach provides, in general, useful insights for such populations. The data indicated that (i male survival is lower than female survival, (ii the reintroduced population is currently growing (estimated λ=1.26: range [1.06, 1.42] and seems viable, (iii increasing adult survival is currently the critical stage at which efforts of field managers should concentrate, and (iv the modelling framework allowed us to determine the boundary conditions for the vital rates under which the population would go extinct. The applied approach directs at measurements that help field managers to implement the right conservation strategy after reintroductions.

Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

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National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

Observational analysis of air-sea fluxes and sea water temperature offshore South China Sea

Science.gov (United States)

Bi, X.; Huang, J.; Gao, Z.; Liu, Y.

2017-12-01

This paper investigates the air-sea fluxes (momentum flux, sensible heat flux and latent heat flux) from eddy covariance method based on data collected at an offshore observation tower in the South China Sea from January 2009 to December 2016 and sea water temperature (SWT) on six different levels based on data collected from November 2011 to June 2013. The depth of water at the tower over the sea averages about 15 m. This study presents the in-situ measurements of continuous air-sea fluxes and SWT at different depths. Seasonal and diurnal variations in air-sea fluxes and SWT on different depths are examined. Results show that air-sea fluxes and all SWT changed seasonally; sea-land breeze circulation appears all the year round. Unlike winters where SWT on different depths are fairly consistent, the difference between sea surface temperature (SST) and sea temperature at 10 m water depth fluctuates dramatically and the maximum value reaches 7 °C during summer.

Designation of pathogenic resistant bacteria in the Sparusaurata sea collected in Tunisia coastlines: Correlation with high performance liquid chromatography-tandem mass spectrometry analysis of antibiotics.

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Zouiten, Amina; Mehri, Ines; Beltifa, Asma; Ghorbel, Asma; Sire, Olivier; Van Loco, Joris; Abdenaceur, Hassen; Reyns, Tim; Ben Mansour, Hedi

2017-05-01

Vibrio is characterized by a large number of species and some of them are human pathogens causing gastro intestinal and wound infections through the ingestion or manipulation of contaminated fishes including Vibrio parahaemolyticus and Vibrio alginolyticus. In this study, we reported the phenotypic and molecular characterization of Vibrio parahaemolyticus and Vibrio alginolyticus strains isolated from wild and farm sea bream (Sparus aurata L.) along the Tunisian coast from December 2015 to April 2016. Therefore, the antibiograms indicate a difference between farmed and wild fish. Resistance against amoxicillin antibiotic appears for the bacteria isolated from wild fish, while those from aquaculture farming presented sensitivity to amoxicillin and resistance to antibiotics colistin and fusidic acid. The chloramphenicol antibiotic exhibited a high sensitivity in all isolated bacteria. In fact, traces of amoxicillin in the organs of the fish from Hergla farm were detected by UPLC-MS/MS analysis during December 2016 to April 2016. In addition, antibiotics were detected in January 2014 with high concentration of norfloxacin 2262 ng/g in fish from Hergla coast. The results obtained in this work indicated that the use and presence of antibiotics in water impacts on the occurrence of resistant bacteria and the detection of antibiotic in fish. Copyright © 2017. Published by Elsevier Ltd.

Laboratory simulation reveals significant impacts of ocean acidification on microbial community composition and host-pathogen interactions between the blood clam and Vibrio harveyi.

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Zha, Shanjie; Liu, Saixi; Su, Wenhao; Shi, Wei; Xiao, Guoqiang; Yan, Maocang; Liu, Guangxu

2017-12-01

It has been suggested that climate change may promote the outbreaks of diseases in the sea through altering the host susceptibility, the pathogen virulence, and the host-pathogen interaction. However, the impacts of ocean acidification (OA) on the pathogen components of bacterial community and the host-pathogen interaction of marine bivalves are still poorly understood. Therefore, 16S rRNA high-throughput sequencing and host-pathogen interaction analysis between blood clam (Tegillarca granosa) and Vibrio harveyi were conducted in the present study to gain a better understanding of the ecological impacts of ocean acidification. The results obtained revealed a significant impact of ocean acidification on the composition of microbial community at laboratory scale. Notably, the abundance of Vibrio, a major group of pathogens to many marine organisms, was significantly increased under ocean acidification condition. In addition, the survival rate and haemolytic activity of V. harveyi were significantly higher in the presence of haemolymph of OA treated T. granosa, indicating a compromised immunity of the clam and enhanced virulence of V. harveyi under future ocean acidification scenarios. Conclusively, the results obtained in this study suggest that future ocean acidification may increase the risk of Vibrio pathogen infection for marine bivalve species, such as blood clams. Copyright © 2017 Elsevier Ltd. All rights reserved.

The distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea

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Woo, Sau Pinn; Yasin, Zulfigar; Ismail, Siti Hasmah; Tan, Shau Hwai

2013-11-01

A study on the distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea was carried out in July 2009. The survey was done using wandering transect underwater with SCUBA. Twelve species of sea cucumber were found from four different families and nine genera. The most dominant family was Holothuriidae (five species), followed by Stichopodidae (three species), Synaptidae (three species) and Cucumariidae with only one species. The most dominant species found around the island was Pearsonothuria graffei, which can be found abundantly on substrate of dead corals in a wide range of depth (6-15 m). The Sulawesi Sea showed a higher diversity of sea cucumber with seven different species compared to the South China Sea with only six different species and Sulu Sea with only two species. Ordination by multidimensional scaling of Bray-Curtis similarities clustered the sampling locations to three main clusters with two outgroups. Previous studies done indicated a higher diversity of sea cucumber as compared to this study. This can be indication that the population and diversity of sea cucumbers in the reef is under threat.

Identification of Vibrio harveyi as a causative bacterium for a tail rot disease of sea bream Sparus aurata from research hatchery in Malta.

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Haldar, S; Maharajan, A; Chatterjee, S; Hunter, S A; Chowdhury, N; Hinenoya, A; Asakura, M; Yamasaki, S

2010-10-20

A bacterial disease was reported from gilthead sea bream (Sparus aurata) within a hatchery environment in Malta. Symptoms included complete erosion of tail, infection in the eye, mucous secretion and frequent mortality. A total of 540 strains were initially isolated in marine agar from different infected body parts and culture water sources. Subsequently 100 isolates were randomly selected, identified biochemically and all were found to be Vibrio harveyi-related organisms; finally from 100 isolates a total of 13 numbers were randomly selected and accurately identified as V. harveyi by 16S rRNA gene sequencing and species-specific PCR. Ribotyping of these strains with HindIII revealed total of six clusters. In vivo challenge study with representative isolates from each cluster proved two clusters each were highly pathogenic, moderately pathogenic and non-pathogenic. All 13 isolates were positive for hemolysin gene, a potential virulence factor. Further analysis revealed probably a single copy of this gene was encoded in all isolates, although not in the same locus in the genome. Although V. harveyi was reported to be an important pathogen for many aquatic organisms, to our knowledge this might be the first report of disease caused by V. harveyi and their systematic study in the sea bream hatchery from Malta. Copyright © 2009 Elsevier GmbH. All rights reserved.

A novel approach for differentiating pathogenic and non-pathogenic Leptospira based on molecular fingerprinting.

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Xiao, Di; Zhang, Cuicai; Zhang, Huifang; Li, Xiuwen; Jiang, Xiugao; Zhang, Jianzhong

2015-04-24

Leptospirosis is a worldwide, deadly zoonotic disease. Pathogenic Leptospira causes leptospirosis. The rapid and accurate identification of pathogenic and non-pathogenic Leptospira strains is essential for appropriate therapeutic management and timely intervention for infection control. The molecular fingerprint is a simple and rapid alternative tool for microorganisms identification, which is based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In this study, molecular fingerprint was performed to identify pathogenic strains of Leptospira. Phylogenetic analysis based on 16S rRNA gene sequences was used as the reference method. In addition, a label-free technique was used to reveal the different proteins of pathogenic or non-pathogenic Leptospira. A reference database was constructed using 30 Leptospira strains, including 16 pathogenic strains and 14 non-pathogenic strains. Two super reference spectra that were associated with pathogenicity were established. Overall, 33 Leptospira strains were used for validation, and 32 of 33 Leptospira strains could be identified on the species level and all the 33 could be classified as pathogenic or non-pathogenic. The super reference spectra and the major spectra projection (MSP) dendrogram correctly categorized the Leptospira strains into pathogenic and non-pathogenic groups, which was consistent with the 16S rRNA reference methods. Between the pathogenic and non-pathogenic strains, 108 proteins were differentially expressed. molecular fingerprint is an alternative to conventional molecular identification and can rapidly distinguish between pathogenic and non-pathogenic Leptospira strains. Therefore, molecular fingerprint may play an important role in the clinical diagnosis, treatment, surveillance, and tracking of epidemic outbreaks of leptospirosis. Leptospirosis is a worldwide zoonosis that is caused by spirochetes of the genus Leptospira. Leptospirosis is a serious zoonotic

Oil Spills and Marine Mammals in British Columbia, Canada: Development and Application of a Risk-Based Conceptual Framework.

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Jarvela Rosenberger, Adrianne L; MacDuffee, Misty; Rosenberger, Andrew G J; Ross, Peter S

2017-07-01

Marine mammals are inherently vulnerable to oil spills. We developed a conceptual framework to evaluate the impacts of potential oil exposure on marine mammals and applied it to 21 species inhabiting coastal British Columbia (BC), Canada. Oil spill vulnerability was determined by examining both the likelihood of species-specific (individual) oil exposure and the consequent likelihood of population-level effects. Oil exposure pathways, ecology, and physiological characteristics were first used to assign species-specific vulnerability rankings. Baleen whales were found to be highly vulnerable due to blowhole breathing, surface filter feeding, and invertebrate prey. Sea otters (Enhydra lutris) were ranked as highly vulnerable due to their time spent at the ocean surface, dense pelage, and benthic feeding techniques. Species-specific vulnerabilities were considered to estimate the likelihood of population-level effects occurring after oil exposure. Killer whale (Orcinus orca) populations were deemed at highest risk due to small population sizes, complex social structure, long lives, slow reproductive turnover, and dietary specialization. Finally, we related the species-specific and population-level vulnerabilities. In BC, vulnerability was deemed highest for Northern and Southern Resident killer whales and sea otters, followed by Bigg's killer whales and Steller sea lions (Eumetopias jubatus). Our findings challenge the typical "indicator species" approach routinely used and underscore the need to examine marine mammals at a species and population level for risk-based oil spill predictions. This conceptual framework can be combined with spill probabilities and volumes to develop more robust risk assessments and may be applied elsewhere to identify vulnerability themes for marine mammals.

MHC class II DRB diversity predicts antigen recognition and is associated with disease severity in California sea lions naturally infected with Leptospira interrogans

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Acevedo-Whitehouse, Karina; Gulland, Frances; Bowen, Lizabeth

2018-01-01

We examined the associations between California sea lion MHC class II DRB (Zaca-DRB) configuration and diversity, and leptospirosis. As Zaca-DRB gene sequences are involved with antigen presentation of bacteria and other extracellular pathogens, we predicted that they would play a role in determining responses to these pathogenic spirochaetes. Specifically, we investigated whether Zaca-DRB diversity (number of genes) and configuration (presence of specific genes) explained differences in disease severity, and whether higher levels of Zaca-DRB diversity predicted the number of specific Leptospira interrogans serovars that a sea lion's serum would react against. We found that serum from diseased sea lions with more Zaca-DRB loci reacted against a wider array of serovars. Specific Zaca-DRB loci were linked to reactions with particular serovars. Interestingly, sea lions with clinical manifestation of leptospirosis that had higher numbers of Zaca-DRB loci were less likely to recover from disease than those with lower diversity, and those that harboured Zaca-DRB.C or –G were 4.5 to 5.3 times more likely to die from leptospirosis, regardless of the infective serovars. We propose that for leptospirosis, a disadvantage of having a wider range of antigen presentation might be increased disease severity due to immunopathology. Ours is the first study to examine the importance of Zaca-DRB diversity for antigen detection and disease severity following natural exposure to infective leptospires.

Regulation of growth, intestinal microbiota, non-specific immune response and disease resistance of sea cucumber Apostichopus japonicus (Selenka) in biofloc systems.

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Chen, Jinghua; Ren, Yichao; Li, Yuquan; Xia, Bin

2018-06-01

Bioflocs are not only a source of supplemental nutrition but also provide substantial probiotic bacteria and bioactive compounds, which play an important role in improving physiological health of aquatic organisms. A 60-day experiment was conducted to investigate the growth, intestinal microbiota, non-specific immune response and disease resistance of sea cucumber in biofloc systems with different carbon sources (glucose, sucrose and starch). Control (no biofloc) and three biofloc systems were set up, and each group has three replicates. The results showed that biofloc volume (BFV) and total suspended solids (TSS) increased in the sequences of glucose > sucrose > starch and green sea cucumber > white sea cucumber during the experiment. The highest specific growth rates (SGRs) were observed in biofloc system with glucose as carbon source, which also had relatively lower glucose, lactate and cortisol levels in coelomic fluid and higher glycogen content in muscle compared to other groups. There were significant increased Bacillus and Lactobacillus counts of sea cucumber intestine in biofloc systems, and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) also showed obvious ascending trends. Significant increases in total coelomocytes counts (TCC), phagocytosis, respiratory burst, complement C3 content and lysozyme (LSZ) and acid phosphatase (ACP) activities of sea cucumber were all found in biofloc system (glucose). The expression patterns of most immune-related genes (i.e. Hsp90, Hsp70, c-type lectin (CL), toll-like receptor (TLR)) were up-regulated, suggesting the promotion of pathogen recognition ability and immune signaling pathways activation by biofloc. Furthermore, green and white sea cucumber had significantly higher survival rates in biofloc systems during the 14-day challenge test. In conclusion, biofloc technology could improve growth and physiological health of A. japonicus, by optimizing intestinal

Disease resistance in Atlantic salmon (Salmo salar: coinfection of the intracellular bacterial pathogen Piscirickettsia salmonis and the sea louse Caligus rogercresseyi.

Directory of Open Access Journals (Sweden)

Jean Paul Lhorente

Full Text Available BACKGROUND: Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1 coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2 coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. METHODOLOGY: In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI of P. salmonis (primary pathogen or coinfection with C. rogercresseyi (secondary pathogen. Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish. Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. MAIN FINDINGS: C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545. Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h2SI = 0.23 ± 0.07; h2LC = 0.17 ± 0.08; h2HC = 0.24 ± 0.07. A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99 ± 0.01 but not between the single and coinfection treatments (rg SI-LC = -0.14 ± 0.33; rg SI-HC = 0.32 ± 0.34. CONCLUSIONS/SIGNIFICANCE: C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future

Disease resistance in Atlantic salmon (Salmo salar): coinfection of the intracellular bacterial pathogen Piscirickettsia salmonis and the sea louse Caligus rogercresseyi.

Science.gov (United States)

Lhorente, Jean Paul; Gallardo, José A; Villanueva, Beatriz; Carabaño, María J; Neira, Roberto

2014-01-01

Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1) coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2) coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI) of P. salmonis (primary pathogen) or coinfection with C. rogercresseyi (secondary pathogen). Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish). Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545). Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h2SI = 0.23 ± 0.07; h2LC = 0.17 ± 0.08; h2HC = 0.24 ± 0.07). A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99 ± 0.01) but not between the single and coinfection treatments (rg SI-LC = -0.14 ± 0.33; rg SI-HC = 0.32 ± 0.34). C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future research on salmon farming, selective breeding and conservation.

Exxon Valdez Oil Spill Restoration Project final report: Monitoring for evaluation of recovery and restoration of injured nearshore resources

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Ballachey, Brenda E.; Bodkin, James L.; Kloecker, Kim; Dean, Tom; Colettie, Heather A

2015-01-01

In 2012, we completed three consecutive years of full field sampling in WPWS for EVOS Restoration Project 10100750. Nearshore monitoring was conducted in collaboration with the NPS SWAN I&M program and, beginning in 2012, as part of the EVOSTC GWA program. Data collection was done in accordance with standard operating procedures set forth to monitor marine water chemistry and quality, marine intertidal invertebrates, kelps and seagrasses, marine birds, black oystercatchers, and sea otters. Summer sampling in 2012 represented the fourth year of sampling in WPWS (an initial year of sampling was done in WPWS in 2007; EVOS Restoration Project 070750). Based on our monitoring of nearshore species in WPWS, and comparisons of data from WPWS and other areas within the Gulf of Alaska, we have no evidence of continued injury to biological resources at the spatial scales we are monitoring. A key finding is that recovery of the sea otter population is no longer constrained by exposure to lingering oil; this is consistent with related EVOSTC studies on harlequin ducks (Restoration Project 12120114-Q). We anticipate continued annual nearshore monitoring in WPWS and at KATM and KEFJ under GWA, with data summaries and analyses including all three areas to provide a larger spatial and temporal context to the understanding of processes and patterns in nearshore ecosystems of the GOA which were impacted by the EVOS of 1989.

Processes for managing pathogens.

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Godfree, Alan; Farrell, Joseph

2005-01-01

Wastewater contains human, animal, and plant pathogens capable of causing viral, bacterial, or parasitic infections. There are several routes whereby sewage pathogens may affect human health, including direct contact, contamination of food crops, zoonoses, and vectors. The range and numbers of pathogens in municipal wastewater vary with the level of endemic disease in the community, discharges from commercial activities, and seasonal factors. Regulations to control pathogen risk in the United States and Europe arising from land application of biosolids are based on the concept of multiple barriers to the prevention of transmission. The barriers are (i) treatment to reduce pathogen content and vector attraction, (ii) restrictions on crops grown on land to which biosolids have been applied, and (iii) minimum intervals following application and grazing or harvesting. Wastewater treatment reduces number of pathogens in the wastewater by concentrating them with the solids in the sludge. Although some treatment processes are designed specifically to inactivate pathogens, many are not, and the actual mechanisms of microbial inactivation are not fully understood for all processes. Vector attraction is reduced by stabilization (reduction of readily biodegradable material) and/or incorporation immediately following application. Concerns about health risks have renewed interest in the effects of treatment (on pathogens) and advanced treatment methods, and work performed in the United States suggests that Class A pathogen reduction can be achieved less expensively than previously thought. Effective pathogen risk management requires control to the complete chain of sludge treatment, biosolids handling and application, and post-application activities. This may be achieved by adherence to quality management systems based on hazard analysis critical control point (HACCP) principles.

New data on Eimeria dicentrarchi (Apicomplexa: Eimeriidae), a common parasite of farmed European sea bass (Dicentrarchus labrax) from the mid-eastern Adriatic

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This study extends the original description of Eimeria dicentrarchi Daoudi and Marquès, 1987, a common coccidian parasite of European sea bass from the mid-eastern Adriatic, by providing insights into the parasite’s site of infection, development and pathogenicity. E. dicentrarchi was found in vario...

Wind-sea surface temperature-sea ice relationship in the Chukchi-Beaufort Seas during autumn

Science.gov (United States)

Zhang, Jing; Stegall, Steve T.; Zhang, Xiangdong

2018-03-01

Dramatic climate changes, especially the largest sea ice retreat during September and October, in the Chukchi-Beaufort Seas could be a consequence of, and further enhance, complex air-ice-sea interactions. To detect these interaction signals, statistical relationships between surface wind speed, sea surface temperature (SST), and sea ice concentration (SIC) were analyzed. The results show a negative correlation between wind speed and SIC. The relationships between wind speed and SST are complicated by the presence of sea ice, with a negative correlation over open water but a positive correlation in sea ice dominated areas. The examination of spatial structures indicates that wind speed tends to increase when approaching the ice edge from open water and the area fully covered by sea ice. The anomalous downward radiation and thermal advection, as well as their regional distribution, play important roles in shaping these relationships, though wind-driven sub-grid scale boundary layer processes may also have contributions. Considering the feedback loop involved in the wind-SST-SIC relationships, climate model experiments would be required to further untangle the underlying complex physical processes.

The Roles of Two miRNAs in Regulating the Immune Response of Sea Cucumber.

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Zhang, Pengjuan; Li, Chenghua; Zhang, Ran; Zhang, Weiwei; Jin, Chunhua; Wang, Lingling; Song, Linsheng

2015-12-01

MicroRNAs (miRNAs) have emerged as key regulators in many pathological processes by suppressing the transcriptional and post-transcriptional expression of target genes. MiR-2008 was previously found to be significantly up-regulated in diseased sea cucumber Apostichopus japonicus by high-through sequencing, whereas the reads of miR-137, a well-documented tumor repressor, displayed no significant change. In the present study, we found that miR-137 expression was slightly attenuated and miR-2008 was significantly enhanced after Vibrio splendidus infection or Lipopolysaccharides application. Further target screening and dual-luciferase reporter assay revealed that the two important miRNAs shared a common target gene of betaine-homocysteine S-methyltransferase (AjBHMT), which exhibited noncorrelated messenger RNA and protein expression patterns after bacterial challenge. In order to fully understand their regulatory mechanisms, we conducted the functional experiments in vitro and in vivo. The overexpression of miR-137 in sea cucumber or primary coelomocytes significantly decreased, whereas the inhibition of miR-137 increased the mRNA and protein expression levels of AjBHMT. In contrast, miR-2008 overexpression and inhibition showed no effect on AjBHMT mRNA levels, but the concentration of AjBHMT protein displayed significant changes both in vitro and in vivo. Consistently, the homocysteine (Hcy) contents were also accordingly altered in the aberrant expression analysis of both miRNAs, consistent with the results of the AjBHMT silencing assay in vitro and in vivo. More importantly, small interfering RNA mediated AjBHMT knockdown and Hcy exposure analyses both significantly increased reactive oxygen species (ROS) production and decreased the number of surviving invasive pathogen in sea cucumber coelomocytes. Taken together, these findings confirmed the differential roles of sea cucumber miR-137 and miR-2008 in regulating the common target AjBHMT to promote ROS production

Diversity and antibacterial activities of fungi derived from the Gorgonian Echinogorgia rebekka from the South China Sea.

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Wang, Ya-Nan; Shao, Chang-Lun; Zheng, Cai-Juan; Chen, Yi-Yan; Wang, Chang-Yun

2011-01-01

The diversity of symbiotic fungi associated with the gorgonian coral Echinogorgia rebekka from the Weizhou coral reef in the South China Sea was investigated. Combined with morphologic traits, ITS-rDNA sequences revealed 18 fungal strains from this gorgonian. All of the 18 fungi belonged to the phylum Ascomycota and were distributed among seven genera in five orders: Eurotiales (Aspergillus and Penicillium), Pleosporales (Alternaria), Capnodiales (Cladosporium), Trichosphaeriales (Nigrospora) and Hypocreales (Hypocrea and Nectria). Antibacterial activities of these fungal strains were investigated with five pathogenic bacteria. All of the 18 fungal strains displayed different levels of antibacterial activities, most of which exhibited moderate to high antibacterial activities to the Gram-positive pathogens Staphylococcus aureus and Micrococcus tetragenus, and showed relatively low bioactivities to other three pathogenic bacteria. Several fungal strains in the genera Penicillium and Cladosporium with strong antibacterial activities provide potential for further research on isolation of bioactive secondary metabolites.

Immune Evasion Strategies of Pathogens in Macrophages: the Potential for Limiting Pathogen Transmission.

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Ren, Yuwei; Khan, Faheem Ahmed; Pandupuspitasari, Nuruliarizki Shinta; Zhang, Shujun

2017-01-01

Preventing pathogen transmission to a new host is of major interest to the immunologist and could benefit from a detailed investigation of pathogen immune evasion strategies. The first line of defense against pathogen invasion is provided by macrophages. When they sense pathogens, macrophages initiate signals to inflammatory and pro-inflammatory cytokines through pattern recognition receptors (PRRs) subsequently mediating phagocytosis and inflammation. The macrophage immune machinery classically includes two subsets: the activated M1 and the activated M2 that respond accordingly in diverse immune challenges. The lipid and glycogen metabolic pathways work together with the lysosome to help the mature phagosome to degrade and eliminate intracellular pathogens in macrophages. The viral evasion strategies are even more complex due to the interplay between autophagy and apoptosis. However, pathogens evolve several strategies to camouflage themselves against immune responses in order to ensure their survival, replication and transmission. These strategies include the muting of PRRs initiated inflammatory responses, attenuation of M1 and/or induction of M2 macrophages, suppression of autophago-lysosomal formation, interference with lipid and glycogen metabolism, and viral mediation of autophagy and apoptosis cross-talk to enhance viral replication. This review focuses on pathogen immune evasion methods and on the strategies used by the host against camouflaged pathogens.

Comparative genome analysis of pathogenic and non-pathogenic Clavibacter strains reveals adaptations to their lifestyle.

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Załuga, Joanna; Stragier, Pieter; Baeyen, Steve; Haegeman, Annelies; Van Vaerenbergh, Johan; Maes, Martine; De Vos, Paul

2014-05-22

The genus Clavibacter harbors economically important plant pathogens infecting agricultural crops such as potato and tomato. Although the vast majority of Clavibacter strains are pathogenic, there is an increasing number of non-pathogenic isolates reported. Non-pathogenic Clavibacter strains isolated from tomato seeds are particularly problematic because they affect the current detection and identification tests for Clavibacter michiganensis subsp. michiganensis (Cmm), which is regulated with a zero tolerance in tomato seed. Their misidentification as pathogenic Cmm hampers a clear judgment on the seed quality and health. To get more insight in the genetic features linked to the lifestyle of these bacteria, a whole-genome sequence of the tomato seed-borne non-pathogenic Clavibacter LMG 26808 was determined. To gain a better understanding of the molecular determinants of pathogenicity, the genome sequence of LMG 26808 was compared with that of the pathogenic Cmm strain (NCPPB 382). The comparative analysis revealed that LMG 26808 does not contain plasmids pCM1 and pCM2 and also lacks the majority of important virulence factors described so far for pathogenic Cmm. This explains its apparent non-pathogenic nature in tomato plants. Moreover, the genome analysis of LMG 26808 detected sequences from a plasmid originating from a member of Enterobacteriaceae/Klebsiella relative. Genes received that way and coding for antibiotic resistance may provide a competitive advantage for survival of LMG 26808 in its ecological niche. Genetically, LMG 26808 was the most similar to the pathogenic Cmm NCPPB 382 but contained more mobile genetic elements. The genome of this non-pathogenic Clavibacter strain contained also a high number of transporters and regulatory genes. The genome sequence of the non-pathogenic Clavibacter strain LMG 26808 and the comparative analyses with other pathogenic Clavibacter strains provided a better understanding of the genetic bases of virulence and

Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and Sarcocystis canis-like infections in marine mammals

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Dubey, J.P.; Zarnke, R.; Thomas, N.J.; Wong, S.K.; Vanbonn, W.; Briggs, M.; Davis, J.W.; Ewing, R.; Mense, M.; Kwok, O.C.H.; Romand, S.; Thulliez, P.

2003-01-01

Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and S. canis are related protozoans that can cause mortality in many species of domestic and wild animals. Recently, T. gondii and S. neurona were recognized to cause encephalitis in marine mammals. As yet, there is no report of natural exposure of N. caninum in marine mammals. In the present study, antibodies to T. gondii and N. caninum were assayed in sera of several species of marine mammals. For T. gondii, sera were diluted 1:25, 1:50, and 1:500 and assayed in the T. gondii modified agglutination test (MAT). Antibodies (MAT a?Y1:25) to T. gondii were found in 89 of 115 (77%) dead, and 18 of 30 (60%) apparently healthy sea otters (Enhydra lutris), 51 of 311 (16%) Pacific harbor seals (Phoca vitulina), 19 of 45 (42%) sea lions (Zalophus californianus), 5 of 32 (16%) ringed seals (Phoca hispida), 4 of 8 (50%) bearded seals (Erignathus barbatus), 1 of 9 (11.1%) spotted seals (Phoca largha), 138 of 141 (98%) Atlantic bottlenose dolphins (Tursiops truncatus), and 3 of 53 (6%) walruses (Odobenus rosmarus). For N. caninum, sera were diluted 1:40, 1:80, 1:160, and 1:320 and examined with the Neospora agglutination test (NAT) using mouse-derived tachyzoites. NAT antibodies were found in 3 of 53 (6%) walruses, 28 of 145 (19%) sea otters, 11 of 311 (3.5%) harbor seals, 1 of 27 (3.7%) sea lions, 4 of 32 (12.5%) ringed seals, 1 of 8 (12.5%) bearded seals, and 43 of 47 (91%) bottlenose dolphins. To our knowledge, this is the first report of N. caninum antibodies in any marine mammal, and the first report of T. gondii antibodies in walruses and in ringed, bearded, spotted, and ribbon seals. Current information on T. gondii-like and Sarcocystis-like infections in marine mammals is reviewed. New cases of clinical S. canis and T. gondii infections are also reported in sea lions, and T. gondii infection in an Antillean manatee (Trichechus manatus manatus).

Pathogen intelligence

Directory of Open Access Journals (Sweden)

Michael eSteinert

2014-01-01

Full Text Available Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behaviour, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behaviour, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies.

Phylogeographic Diversity of Pathogenic and Non-Pathogenic Hantaviruses in Slovenia

Science.gov (United States)

Korva, Miša; Knap, Nataša; Resman Rus, Katarina; Fajs, Luka; Grubelnik, Gašper; Bremec, Matejka; Knapič, Tea; Trilar, Tomi; Avšič Županc, Tatjana

2013-01-01

Slovenia is a very diverse country from a natural geography point of view, with many different habitats within a relatively small area, in addition to major geological and climatic differences. It is therefore not surprising that several small mammal species have been confirmed to harbour hantaviruses: A. flavicollis (Dobrava virus), A. agrarius (Dobrava virus–Kurkino), M. glareolus (Puumala virus), S. areanus (Seewis virus), M. agrestis, M. arvalis and M. subterraneus (Tula virus). Three of the viruses, namely the Dobrava, Dobrava–Kurkino and Puumala viruses, cause disease in humans, with significant differences in the severity of symptoms. Due to changes in haemorrhagic fever with renal syndrome cases (HFRS) epidemiology, a detailed study on phylogenetic diversity and molecular epidemiology of pathogenic and non-pathogenic hantaviruses circulating in ecologically diverse endemic regions was performed. The study presents one of the largest collections of hantavirus L, M and S sequences obtained from hosts and patients within a single country. Several genetic lineages were determined for each hantavirus species, with higher diversity among non-pathogenic compared to pathogenic viruses. For pathogenic hantaviruses, a significant geographic clustering of human- and rodent-derived sequences was confirmed. Several geographic and ecological factors were recognized as influencing and limiting the formation of endemic areas. PMID:24335778

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

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Martin Meyer

2016-08-01

Full Text Available We here compared pathogenic (p and non-pathogenic (np isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12 derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12 derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

Science.gov (United States)

Meyer, Martin; Fehling, Helena; Matthiesen, Jenny; Lorenzen, Stephan; Schuldt, Kathrin; Bernin, Hannah; Zaruba, Mareen; Lender, Corinna; Ernst, Thomas; Ittrich, Harald; Roeder, Thomas; Tannich, Egbert; Lotter, Hannelore; Bruchhaus, Iris

2016-08-01

We here compared pathogenic (p) and non-pathogenic (np) isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA)-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12) derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12) derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP) activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

Autophagy in plant pathogenic fungi.

Science.gov (United States)

Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

2016-09-01

Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

The SpTransformer Gene Family (Formerly Sp185/333) in the Purple Sea Urchin and the Functional Diversity of the Anti-Pathogen rSpTransformer-E1 Protein

Science.gov (United States)

Smith, L. Courtney; Lun, Cheng Man

2017-01-01

multitasking activities of rSpTrf-E1 infer multiple and perhaps overlapping activities for the hundreds of native SpTrf proteins that are produced by individual sea urchins. This likely generates a flexible and highly protective immune system for the sea urchin in its marine habitat that it shares with broad arrays of microbes that may be pathogens and opportunists. PMID:28713368

Diversity and Antibacterial Activities of Fungi Derived from the Gorgonian Echinogorgia rebekka from the South China Sea

Directory of Open Access Journals (Sweden)

Chang-Yun Wang

2011-08-01

Full Text Available The diversity of symbiotic fungi associated with the gorgonian coral Echinogorgia rebekka from the Weizhou coral reef in the South China Sea was investigated. Combined with morphologic traits, ITS-rDNA sequences revealed 18 fungal strains from this gorgonian. All of the 18 fungi belonged to the phylum Ascomycota and were distributed among seven genera in five orders: Eurotiales (Aspergillus and Penicillium, Pleosporales (Alternaria, Capnodiales (Cladosporium, Trichosphaeriales (Nigrospora and Hypocreales (Hypocrea and Nectria. Antibacterial activities of these fungal strains were investigated with five pathogenic bacteria. All of the 18 fungal strains displayed different levels of antibacterial activities, most of which exhibited moderate to high antibacterial activities to the Gram-positive pathogens Staphylococcus aureus and Micrococcus tetragenus, and showed relatively low bioactivities to other three pathogenic bacteria. Several fungal strains in the genera Penicillium and Cladosporium with strong antibacterial activities provide potential for further research on isolation of bioactive secondary metabolites.

Bioactive Compounds from the Red Sea Marine Sponge Hyrtios Species

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Hani Z. Asfour

2013-03-01

Full Text Available In continuation of our search for drug leads from Red Sea sponges we have investigated the ethyl acetate fraction of the organic extract of the Red Sea sponge Hyrtios species. Bioassay-directed fractionation of the active fraction resulted into the identification of three new alkaloids, hyrtioerectines D–F (1–3. Hyrtioerectines D–F belong to the rare marine alkaloids in which the indole and β-carboline fragments of the molecule are linked through C-3/C-3 of both moieties. The structures of the isolated compounds were established based on different spectroscopic data including UV, IR, 1D and 2D NMR (COSY, HSQC, and HMBC and high-resolution mass spectral studies. The antimicrobial activity against several pathogens and the free radical scavenging activity of the compounds using DPPH reagent were evaluated. In addition, the growth inhibitory activity of the compounds against three cancer cell lines was also evaluated. Hyrtioerectines D–F (1–3 displayed variable antimicrobial, free radical scavenging and cancer growth inhibition activities. Generally, compounds 1 and 3 were more active than compound 2.

Isolation, Characterization, and Antibiotic Resistance of Vibrio spp. in Sea Turtles from Northwestern Mexico

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Alan A. eZavala-Norzagaray

2015-06-01

Full Text Available The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL, Baja California Sur, Mexico (Pacific Ocean and the lagoon system of Navachiste (LSN and Marine Area of Influence (MAI, Guasave, Sinaloa (Gulf of California. A total of 34 black turtles (Chelonia mydas agassizii were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%, V. parahaemolyticus in 17/64 (26% and V. cholerae in 6/64 (9%,. However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI. Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4% belonged to the pathogenic strains (tdh+ gene and 2/17 (11.7% had the pandemic clone (tdh+ and toxRS/new+. Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66% the accessory cholera enterotoxin gene (ace was identified but without virulence gene zot, ctxA and ctxB. Of the isolated V. parahaemolyticus, V. cholerae and V. alginolyticus strains, 94.1%, 33.4% and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin, respectively. In conclusion, the presence of several potential (toxigenic human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico.

Isolation, characterization, and antibiotic resistance of Vibrio spp. in sea turtles from Northwestern Mexico.

Science.gov (United States)

Zavala-Norzagaray, Alan A; Aguirre, A Alonso; Velazquez-Roman, Jorge; Flores-Villaseñor, Héctor; León-Sicairos, Nidia; Ley-Quiñonez, C P; Hernández-Díaz, Lucio De Jesús; Canizalez-Roman, Adrian

2015-01-01

The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL), Baja California Sur (BCS), Mexico (Pacific Ocean) and the lagoon system of Navachiste (LSN) and Marine Area of Influence (MAI), Guasave, Sinaloa (Gulf of California). A total of 34 black turtles (Chelonia mydas agassizii) were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea) were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%), V. parahaemolyticus in 17/64 (26%), and V. cholerae in 6/64 (9%). However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI). Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4%) belonged to the pathogenic strains (tdh (+) gene) and 2/17 (11.7%) had the pandemic clone (tdh (+) and toxRS/new (+)). Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66%) the accessory cholera enterotoxin gene (ace) was identified but without virulence gene zot, ctxA, and ctxB. Of the isolated V. parahaemolyticus, V. cholerae, and V. alginolyticus strains, 94.1, 33.4, and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin), respectively. In conclusion, the presence of several potential (toxigenic) human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico.

Isolation, characterization, and antibiotic resistance of Vibrio spp. in sea turtles from Northwestern Mexico

Science.gov (United States)

Zavala-Norzagaray, Alan A.; Aguirre, A. Alonso; Velazquez-Roman, Jorge; Flores-Villaseñor, Héctor; León-Sicairos, Nidia; Ley-Quiñonez, C. P.; Hernández-Díaz, Lucio De Jesús; Canizalez-Roman, Adrian

2015-01-01

The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL), Baja California Sur (BCS), Mexico (Pacific Ocean) and the lagoon system of Navachiste (LSN) and Marine Area of Influence (MAI), Guasave, Sinaloa (Gulf of California). A total of 34 black turtles (Chelonia mydas agassizii) were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea) were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%), V. parahaemolyticus in 17/64 (26%), and V. cholerae in 6/64 (9%). However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI). Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4%) belonged to the pathogenic strains (tdh+ gene) and 2/17 (11.7%) had the pandemic clone (tdh+ and toxRS/new+). Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66%) the accessory cholera enterotoxin gene (ace) was identified but without virulence gene zot, ctxA, and ctxB. Of the isolated V. parahaemolyticus, V. cholerae, and V. alginolyticus strains, 94.1, 33.4, and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin), respectively. In conclusion, the presence of several potential (toxigenic) human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico. PMID:26161078

Experimental challenge and pathology of highly pathogenic avian influenza virus H5N1 in dunlin (Calidris alpina), an intercontinental migrant shorebird species

Science.gov (United States)

Hall, Jeffrey S.; Franson, J. Christian; Gill, Robert E.; Meteyer, Carol U.; TeSlaa, Joshua L.; Nashold, Sean W.; Dusek, Robert J.; Ip, Hon S.

2011-01-01

Background Shorebirds (Charadriiformes) are considered one of the primary reservoirs of avian influenza. Because these species are highly migratory, there is concern that infected shorebirds may be a mechanism by which highly pathogenic avian influenza virus (HPAIV) H5N1 could be introduced into North America from Asia. Large numbers of dunlin (Calidris alpina) migrate from wintering areas in central and eastern Asia, where HPAIV H5N1 is endemic, across the Bering Sea to breeding areas in Alaska. Low pathogenic avian influenza virus has been previously detected in dunlin, and thus, dunlin represent a potential risk to transport HPAIV to North America. To date no experimental challenge studies have been performed in shorebirds.

Climatology of sea breezes along the Red Sea coast of Saudi Arabia

KAUST Repository

Khan, Basit

2018-04-25

Long-term near-surface observations from five coastal stations, high-resolution model data from Modern Era Retrospective-Analysis for Research and Applications (MERRA) and high-resolution daily sea surface temperature (SST) from National Ocean and Atmospheric Administration (NOAA) are used to investigate the climatology of sea breezes over the eastern side of the Red Sea region. Results show existence of separate sea breeze systems along different segments of the Red Sea coastline. Based on the physical character and synoptic influences, sea breezes in the Red Sea are broadly divided into three regions: the north and the middle Red Sea (NMRS), the Red Sea convergence zone (RSCZ) and the southern Red Sea (SRS) regions. On average, sea breezes developed on 67% of days of the 10-year study period. Although sea breezes occur almost all year, this mesoscale phenomenon is most frequent from May to October (78% of the total sea breeze days). The sea breeze frequency increases from north to south (equatorwards), and sea breeze characteristics appear to vary both temporally and spatially. In addition to land-sea thermal differential, coastline shape, latitude and topography, the prevailing northwesterly at NMRS region, the convergence of northwesterly and southeasterly wind system at RSCZ region and the northeast and southwest monsoon at SRS region play an important role in defining the sea breeze characteristics over the Red Sea.

Pathogenicity of Human ST23 Streptococcus agalactiae to Fish and Genomic Comparison of Pathogenic and Non-pathogenic Isolates

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Rui Wang

2017-10-01

Full Text Available Streptococcus agalactiae, or Group B Streptococcus (GBS, is a major pathogen causing neonatal sepsis and meningitis, bovine mastitis, and fish meningoencephalitis. CC23, including its namesake ST23, is not only the predominant GBS strain derived from human and cattle, but also can infect a variety of homeothermic and poikilothermic species. However, it has never been characterized in fish. This study aimed to determine the pathogenicity of ST23 GBS to fish and explore the mechanisms causing the difference in the pathogenicity of ST23 GBS based on the genome analysis. Infection of tilapia with 10 human-derived ST23 GBS isolates caused tissue damage and the distribution of pathogens within tissues. The mortality rate of infection was ranged from 76 to 100%, and it was shown that the mortality rate caused by only three human isolates had statistically significant difference compared with fish-derived ST7 strain (P < 0.05, whereas the mortality caused by other seven human isolates did not show significant difference compared with fish-derived ST7 strain. The genome comparison and prophage analysis showed that the major genome difference between virulent and non-virulent ST23 GBS was attributed to the different prophage sequences. The prophage in the P1 region contained about 43% GC and encoded 28–39 proteins, which can mediate the acquisition of YafQ/DinJ structure for GBS by phage recombination. YafQ/DinJ belongs to one of the bacterial toxin–antitoxin (TA systems and allows cells to cope with stress. The ST23 GBS strains carrying this prophage were not pathogenic to tilapia, but the strains without the prophage or carrying the pophage that had gene mutation or deletion, especially the deletion of YafQ/DinJ structure, were highly pathogenic to tilapia. In conclusion, human ST23 GBS is highly pathogenic to fish, which may be related to the phage recombination.

Differentiation between a pathogenic and a non-pathogenic form of Gyrodactylus salaris using PCR-RFLP

DEFF Research Database (Denmark)

Kania, Per Walther; Jørgensen, Thomas Rohde; Buchmann, Kurt

2007-01-01

A new method based on PCR-RFLP is presented. It is able to differentiate between the Danish non-pathogenic form of Gyrodactylus salaris and the Norwegian pathogenic form.......A new method based on PCR-RFLP is presented. It is able to differentiate between the Danish non-pathogenic form of Gyrodactylus salaris and the Norwegian pathogenic form....

Intraseasonal sea surface temperature variability in Indonesian seas

Science.gov (United States)

Napitu, A. M.; Gordon, A. L.; Yuan, X.

2012-12-01

The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an average SST standard deviation (STD) between 0.4-0.5°C, with strongest signature during boreal winter. What physical processes force the SST ISV variability within the Indonesian seas? Ocean process, sea-air interaction, or both? To help identify the main forcing, the satellite derived outgoing longwave radiation (OLR) and wind stress data in the region are examined. The OLR shows robust intraseasonal variations and is significantly correlated with the SST, particularly for variability with periods of 30-60 days, with OLR accounting for ~60-70% of the SST variance. The OLR is also maximum during boreal winter. Conversely, the surface wind may play insignificant role in perturbing the SST at intraseasonal timescales as shown by weak correlation between wind stress and SST. We thus suspect that the surface solar flux (suggested by the OLR) is likely more dominant than the surface turbulent heat flux (indicated by the surface wind) as the main source for the ISV in the SST in Indonesian seas. Furthermore the maximum OLR phase, coupled with a period of minimum mixed layer depth, may explain the strong SST variation during boreal winter in Indonesian seas. The influence of the Madden-Julian Oscillation (MJO) on the OLR and SST variability is currently being evaluated.

The Tick Microbiome: Why Non-pathogenic Microorganisms Matter in Tick Biology and Pathogen Transmission

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Sarah I. Bonnet

2017-06-01

Full Text Available Ticks are among the most important vectors of pathogens affecting humans and other animals worldwide. They do not only carry pathogens however, as a diverse group of commensal and symbiotic microorganisms are also present in ticks. Unlike pathogens, their biology and their effect on ticks remain largely unexplored, and are in fact often neglected. Nonetheless, they can confer multiple detrimental, neutral, or beneficial effects to their tick hosts, and can play various roles in fitness, nutritional adaptation, development, reproduction, defense against environmental stress, and immunity. Non-pathogenic microorganisms may also play a role in driving transmission of tick-borne pathogens (TBP, with many potential implications for both human and animal health. In addition, the genetic proximity of some pathogens to mutualistic symbionts hosted by ticks is evident when studying phylogenies of several bacterial genera. The best examples are found within members of the Rickettsia, Francisella, and Coxiella genera: while in medical and veterinary research these bacteria are traditionally recognized as highly virulent vertebrate pathogens, it is now clear to evolutionary ecologists that many (if not most Coxiella, Francisella, and Rickettsia bacteria are actually non-pathogenic microorganisms exhibiting alternative lifestyles as mutualistic ticks symbionts. Consequently, ticks represent a compelling yet challenging system in which to study microbiomes and microbial interactions, and to investigate the composition, functional, and ecological implications of bacterial communities. Ultimately, deciphering the relationships between tick microorganisms as well as tick symbiont interactions will garner invaluable information, which may aid in the future development of arthropod pest and vector-borne pathogen transmission control strategies.

Pathogenic agents in freshwater resources

Science.gov (United States)

Geldreich, Edwin E.

1996-02-01

Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

Sea-ice evaluation of NEMO-Nordic 1.0: a NEMO-LIM3.6-based ocean-sea-ice model setup for the North Sea and Baltic Sea

Science.gov (United States)

Pemberton, Per; Löptien, Ulrike; Hordoir, Robinson; Höglund, Anders; Schimanke, Semjon; Axell, Lars; Haapala, Jari

2017-08-01

The Baltic Sea is a seasonally ice-covered marginal sea in northern Europe with intense wintertime ship traffic and a sensitive ecosystem. Understanding and modeling the evolution of the sea-ice pack is important for climate effect studies and forecasting purposes. Here we present and evaluate the sea-ice component of a new NEMO-LIM3.6-based ocean-sea-ice setup for the North Sea and Baltic Sea region (NEMO-Nordic). The setup includes a new depth-based fast-ice parametrization for the Baltic Sea. The evaluation focuses on long-term statistics, from a 45-year long hindcast, although short-term daily performance is also briefly evaluated. We show that NEMO-Nordic is well suited for simulating the mean sea-ice extent, concentration, and thickness as compared to the best available observational data set. The variability of the annual maximum Baltic Sea ice extent is well in line with the observations, but the 1961-2006 trend is underestimated. Capturing the correct ice thickness distribution is more challenging. Based on the simulated ice thickness distribution we estimate the undeformed and deformed ice thickness and concentration in the Baltic Sea, which compares reasonably well with observations.

A Rapid and Simple Real-Time PCR Assay for Detecting Foodborne Pathogenic Bacteria in Human Feces.

Science.gov (United States)

Hanabara, Yutaro; Ueda, Yutaka

2016-11-22

A rapid, simple method for detecting foodborne pathogenic bacteria in human feces is greatly needed. Here, we examined the efficacy of a method that employs a combination of a commercial PCR master mix, which is insensitive to PCR inhibitors, and a DNA extraction method which used sodium dodecyl benzene sulfonate (SDBS), and Tween 20 to counteract the inhibitory effects of SDBS on the PCR assay. This method could detect the target genes (stx1 and stx2 of enterohemorrhagic Escherichia coli, invA of Salmonella Enteritidis, tdh of Vibrio parahaemolyticus, gyrA of Campylobacter jejuni, ceuE of Campylobacter coli, SEA of Staphylococcus aureus, ces of Bacillus cereus, and cpe of Clostridium perfringens) in a fecal suspension containing 1.0 × 10 1 to 1.0 × 10 3 CFU/ml. Furthermore, the assay was neither inhibited nor influenced by individual differences among the fecal samples of 10 subjects or fecal concentration (40-160 mg/ml in the fecal suspension). When we attempted to detect the genes of pathogenic bacteria in 4 actual clinical cases, we found that this method was more sensitive than standard culture method. These results showed that this assay is a rapid, simple detection method for foodborne pathogenic bacteria in human feces.

Sea level report

International Nuclear Information System (INIS)

Schwartz, M.L.

1979-01-01

Study of Cenozoic Era sea levels shows a continual lowering of sea level through the Tertiary Period. This overall drop in sea level accompanied the Pleistocene Epoch glacio-eustatic fluctuations. The considerable change of Pleistocene Epoch sea level is most directly attributable to the glacio-eustatic factor, with a time span of 10 5 years and an amplitude or range of approximately 200 m. The lowering of sea level since the end of the Cretaceous Period is attributed to subsidence and mid-ocean ridges. The maximum rate for sea level change is 4 cm/y. At present, mean sea level is rising at about 3 to 4 mm/y. Glacio-eustacy and tectono-eustacy are the parameters for predicting sea level changes in the next 1 my. Glacio-eustatic sea level changes may be projected on the basis of the Milankovitch Theory. Predictions about tectono-eustatic sea level changes, however, involve predictions about future tectonic activity and are therefore somewhat difficult to make. Coastal erosion and sedimentation are affected by changes in sea level. Erosion rates for soft sediments may be as much as 50 m/y. The maximum sedimentation accumulation rate is 20 m/100 y

Comparative genome analysis of pathogenic and non-pathogenic Clavibacter strains reveals adaptations to their lifestyle

OpenAIRE

Załuga, Joanna; Stragier, Pieter; Baeyen, Steve; Haegeman, Annelies; Van Vaerenbergh, Johan; Maes, Martine; De Vos, Paul

2014-01-01

Background The genus Clavibacter harbors economically important plant pathogens infecting agricultural crops such as potato and tomato. Although the vast majority of Clavibacter strains are pathogenic, there is an increasing number of non-pathogenic isolates reported. Non-pathogenic Clavibacter strains isolated from tomato seeds are particularly problematic because they affect the current detection and identification tests for Clavibacter michiganensis subsp. michiganensis (Cmm), which is reg...

Host pathogen relations: exploring animal models for fungal pathogens.

Science.gov (United States)

Harwood, Catherine G; Rao, Reeta P

2014-06-30

Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

Exploration of Sea Cucumbers Stichopus hermanii from Karimunjawa Islands as Production of Marine Biological Resources

Science.gov (United States)

Pringgenies, Delianis; Rudiyanti, Siti; Yudiati, Ervia

2018-02-01

This research aim was to study the potential of Stichopus hermanii to determine the amino acid, chondroitin, and glucosamine contents, to discover its antibacterial and anti-cancer agent. The samples were rinsed prior to separation, with only the corpus being used in the study. Sea cucumber extract was then processed using HPLC to trace contents of amino acid, chondroitin, and glucosamine contents. The samples were then put into test against several strains of pathogenic bacteria by means of diffusion for any biological activity. The anti-cancer test was performed by human ovarian cancer cell line (KOC7C) method. The study showed that the extract of Stichopus hermanii has the potency to inhibit the growth of active ovarian cancer cells. The qualitative test of the sea cucumber extract showed that it is capable of suppressing the growth of several strains of pathogenic bacteria identified as Staphylococcus aureus, Escherichia coli, Vibrio voinivica, and Pseudomonas sp. HPLC results showed that the extract contained amino acid (mg/100g), the highest being Collagen (11200), followed by Glycine (3760), Glutamic Acid (3700), Aspartic Acid (2540), Alanine (2140), Proline (2050), Arginine (2050), Tyrosine (1430), Threonine (1270), Leucine (1170), Valine (1050), Serine (971), Isoleucine (816), Phenylalanine (713), Lysine (639), Methionine (383), Cystine (263) and Histidine (208). The extract also contained Chondroitin Sulfate (4200) and Glucosamine Hydrochloride (acids, as well as chondroitin and glucosamine.

Insight of Genus Corynebacterium: Ascertaining the Role of Pathogenic and Non-pathogenic Species.

Science.gov (United States)

Oliveira, Alberto; Oliveira, Leticia C; Aburjaile, Flavia; Benevides, Leandro; Tiwari, Sandeep; Jamal, Syed B; Silva, Arthur; Figueiredo, Henrique C P; Ghosh, Preetam; Portela, Ricardo W; De Carvalho Azevedo, Vasco A; Wattam, Alice R

2017-01-01

This review gathers recent information about genomic and transcriptomic studies in the Corynebacterium genus, exploring, for example, prediction of pathogenicity islands and stress response in different pathogenic and non-pathogenic species. In addition, is described several phylogeny studies to Corynebacterium , exploring since the identification of species until biological speciation in one species belonging to the genus Corynebacterium . Important concepts associated with virulence highlighting the role of Pld protein and Tox gene. The adhesion, characteristic of virulence factor, was described using the sortase mechanism that is associated to anchorage to the cell wall. In addition, survival inside the host cell and some diseases, were too addressed for pathogenic corynebacteria, while important biochemical pathways and biotechnological applications retain the focus of this review for non-pathogenic corynebacteria. Concluding, this review broadly explores characteristics in genus Corynebacterium showing to have strong relevance inside the medical, veterinary, and biotechnology field.

Efferocytosis of Pathogen-Infected Cells

Directory of Open Access Journals (Sweden)

Niloofar Karaji

2017-12-01

Full Text Available The prompt and efficient clearance of unwanted and abnormal cells by phagocytes is termed efferocytosis and is crucial for organism development, maintenance of tissue homeostasis, and regulation of the immune system. Dying cells are recognized by phagocytes through pathways initiated via “find me” signals, recognition via “eat me” signals and down-modulation of regulatory “don’t eat me” signals. Pathogen infection may trigger cell death that drives phagocytic clearance in an immunologically silent, or pro-inflammatory manner, depending on the mode of cell death. In many cases, efferocytosis is a mechanism for eliminating pathogens and pathogen-infected cells; however, some pathogens have subverted this process and use efferocytic mechanisms to avoid innate immune detection and assist phagocyte infection. In parallel, phagocytes can integrate signals received from infected dying cells to elicit the most appropriate effector response against the infecting pathogen. This review focuses on pathogen-induced cell death signals that drive infected cell recognition and uptake by phagocytes, and the outcomes for the infected target cell, the phagocyte, the pathogen and the host.

Emerging Pathogens Initiative (EPI)

Data.gov (United States)

Department of Veterans Affairs — The Emerging Pathogens Initiative (EPI) database contains emerging pathogens information from the local Veterans Affairs Medical Centers (VAMCs). The EPI software...

California mussels (Mytilus californianus) as sentinels for marine contamination with Sarcocystis neurona.

Science.gov (United States)

Michaels, Lauren; Rejmanek, Daniel; Aguilar, Beatriz; Conrad, Patricia; Shapiro, Karen

2016-05-01

Sarcocystis neurona is a terrestrial parasite that can cause fatal encephalitis in the endangered Southern sea otter (Enhydra lutris nereis). To date, neither risk factors associated with marine contamination nor the route of S. neurona infection to marine mammals has been described. This study evaluated coastal S. neurona contamination using California mussels (Mytilus californianus) as sentinels for pathogen pollution. A field investigation was designed to test the hypotheses that (1) mussels can serve as sentinels for S. neurona contamination, and (2) S. neurona contamination in mussels would be highest during the rainy season and in mussels collected near freshwater. Initial validation of molecular assays through sporocyst spiking experiments revealed the ITS-1500 assay to be most sensitive for detection of S. neurona, consistently yielding parasite amplification at concentrations ⩾5 sporocysts/1 mL mussel haemolymph. Assays were then applied on 959 wild-caught mussels, with detection of S. neurona confirmed using sequence analysis in three mussels. Validated molecular assays for S. neurona detection in mussels provide a novel toolset for investigating marine contamination with this parasite, while confirmation of S. neurona in wild mussels suggests that uptake by invertebrates may serve as a route of transmission to susceptible marine animals.

The wind sea and swell waves climate in the Nordic seas

Science.gov (United States)

Semedo, Alvaro; Vettor, Roberto; Breivik, Øyvind; Sterl, Andreas; Reistad, Magnar; Soares, Carlos Guedes; Lima, Daniela

2015-02-01

A detailed climatology of wind sea and swell waves in the Nordic Seas (North Sea, Norwegian Sea, and Barents Sea), based on the high-resolution reanalysis NORA10, developed by the Norwegian Meteorological Institute, is presented. The higher resolution of the wind forcing fields, and the wave model (10 km in both cases), along with the inclusion of the bottom effect, allowed a better description of the wind sea and swell features, compared to previous global studies. The spatial patterns of the swell-dominated regional wave fields are shown to be different from the open ocean, due to coastal geometry, fetch dimensions, and island sheltering. Nevertheless, swell waves are still more prevalent and carry more energy in the Nordic Seas, with the exception of the North Sea. The influence of the North Atlantic Oscillation on the winter regional wind sea and swell patterns is also presented. The analysis of the decadal trends of wind sea and swell heights during the NORA10 period (1958-2001) shows that the long-term trends of the total significant wave height (SWH) in the Nordic Seas are mostly due to swell and to the wave propagation effect.

Three New Indole Diterpenoids from the Sea-Anemone-Derived Fungus Penicillium sp. AS-79.

Science.gov (United States)

Hu, Xue-Yi; Meng, Ling-Hong; Li, Xin; Yang, Sui-Qun; Li, Xiao-Ming; Wang, Bin-Gui

2017-05-12

Three new indolediterpenoids, namely, 22-hydroxylshearinine F ( 1 ), 6-hydroxylpaspalinine ( 2 ), and 7- O -acetylemindole SB ( 3 ), along with eight related known analogs ( 4 - 11 ), were isolated from the sea-anemone-derived fungus Penicillium sp. AS-79. The structures and relative configurations of these compounds were determined by a detailed interpretation of the spectroscopic data, and their absolute configurations were determined by ECD calculations ( 1 and 2 ) and single-crystal X-ray diffraction ( 3 ). Some of these compounds exhibited prominent activity against aquatic and human pathogenic microbes.

Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens

Directory of Open Access Journals (Sweden)

Catherine G. Harwood

2014-06-01

Full Text Available Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

Comparative analysis of lipopolysaccharides of pathogenic and intermediately pathogenic Leptospira species.

Science.gov (United States)

Patra, Kailash P; Choudhury, Biswa; Matthias, Michael M; Baga, Sheyenne; Bandyopadhya, Keya; Vinetz, Joseph M

2015-10-30

Lipopolysaccharides (LPS) are complex, amphipathic biomolecules that constitute the major surface component of Gram-negative bacteria. Leptospira, unlike other human-pathogenic spirochetes, produce LPS, which is fundamental to the taxonomy of the genus, involved in host-adaption and also the target of diagnostic antibodies. Despite its significance, little is known of Leptospira LPS composition and carbohydrate structure among different serovars. LPS from Leptospira interrogans serovar Copenhageni strain L1-130, a pathogenic species, and L. licerasiae serovar Varillal strain VAR 010, an intermediately pathogenic species, were studied. LPS prepared from aqueous and phenol phases were analyzed separately. L. interrogans serovar Copenhageni has additional sugars not found in L. licerasiae serovar Varillal, including fucose (2.7%), a high amount of GlcNAc (12.3%), and two different types of dideoxy HexNAc. SDS-PAGE indicated that L. interrogans serovar Copenhageni LPS had a far higher molecular weight and complexity than that of L. licerasiae serovar Varillal. Chemical composition showed that L. interrogans serovar Copenhageni LPS has an extended O-antigenic polysaccharide consisting of sugars, not present in L. licerasiae serovar Varillal. Arabinose, xylose, mannose, galactose and L-glycero-D-mannoheptose were detected in both the species. Fatty acid analysis by gas chromatography-mass spectrometry (GC-MS) showed the presence of hydroxypalmitate (3-OH-C16:0) only in L. interrogans serovar Copenhageni. Negative staining electron microscopic examination of LPS showed different filamentous morphologies in L. interrogans serovar Copenhageni vs. L. licerasiae serovar Varillal. This comparative biochemical analysis of pathogenic and intermediately pathogenic Leptospira LPS reveals important carbohydrate and lipid differences that underlie future work in understanding the mechanisms of host-adaptation, pathogenicity and vaccine development in leptospirosis.

Investigating Arctic Sea Ice Survivability in the Beaufort Sea

Directory of Open Access Journals (Sweden)

Matthew Tooth

2018-02-01

Full Text Available Arctic sea ice extent has continued to decline in recent years, and the fractional coverage of multi-year sea ice has decreased significantly during this period. The Beaufort Sea region has been the site of much of the loss of multi-year sea ice, and it continues to play a large role in the extinction of ice during the melt season. We present an analysis of the influence of satellite-derived ice surface temperature, ice thickness, albedo, and downwelling longwave/shortwave radiation as well as latitude and airborne snow depth estimates on the change in sea ice concentration in the Beaufort Sea from 2009 to 2016 using a Lagrangian tracking database. Results from this analysis indicate that parcels that melt during summer in the Beaufort Sea reside at lower latitudes and have lower ice thickness at the beginning of the melt season in most cases. The influence of sea ice thickness and snow depth observed by IceBridge offers less conclusive results, with some years exhibiting higher thicknesses/depths for melted parcels. Parcels that melted along IceBridge tracks do exhibit lower latitudes and ice thicknesses, however, which indicates that earlier melt and breakup of ice may contribute to a greater likelihood of extinction of parcels in the summer.

Sarcocyst Development in Raccoons (Procyon lotor) Inoculated with Different Strains of Sarcocystis neurona Culture-Derived Merozoites.

Science.gov (United States)

Dryburgh, E L; Marsh, A E; Dubey, J P; Howe, D K; Reed, S M; Bolten, K E; Pei, W; Saville, W J A

2015-08-01

Sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (EPM), a neurological disease in horses. Raccoon ( Procyon lotor ) is considered the most important intermediate host in the life cycle of S. neurona in the United States; S. neurona sarcocysts do mature in raccoon muscles, and raccoons also develop clinical signs simulating EPM. The focus of this study was to determine if sarcocysts would develop in raccoons experimentally inoculated with different host-derived strains of in vitro-cultivated S. neurona merozoites. Four raccoons were inoculated with strains derived from a raccoon, a sea otter, a cat, and a horse. Raccoon tissues were fed to laboratory-raised opossums ( Didelphis virginiana ), the definitive host of S. neurona . Intestinal scraping revealed sporocysts in opossums who received muscle tissue from raccoons inoculated with the raccoon-derived or the sea otter-derived isolates. These results demonstrate that sarcocysts can mature in raccoons inoculated with in vitro-derived S. neurona merozoites. In contrast, the horse and cat-derived isolates did not produce microscopically or biologically detected sarcocysts. Immunoblot analysis revealed both antigenic and antibody differences when testing the inoculated raccoons. Immunohistochemical staining indicated differences in staining between the merozoite and sarcocyst stages. The successful infections achieved in this study indicates that the life cycle can be manipulated in the laboratory without affecting subsequent stage development, thereby allowing further purification of strains and artificial maintenance of the life cycle.

Antibacterial α-pyrone derivatives from a mangrove-derived fungus Stemphylium sp. 33231 from the South China Sea.

Science.gov (United States)

Zhou, Xue-Ming; Zheng, Cai-Juan; Song, Xiao-Ping; Han, Chang-Ri; Chen, Wen-Hao; Chen, Guang-Ying

2014-05-01

Two new α-pyrone derivatives, infectopyrones A (1) and B (2), were obtained from the EtOAc extract of the endophytic fungus Stemphylium sp. 33231 isolated from the mangrove Brguiera sexangula var. rhynchopetala collected in the South China Sea. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compounds 1 and 2 were evaluated for their antibacterial activities, and they had a broad spectrum of antibacterial activity against five terrestrial pathogenic bacteria.

Ketoconazole modulates the infectivity of Ichthyophonus sp. (Mesomycetozoa) in vivo in experimentally injected European sea bass

OpenAIRE

Hontoria, Francisco; González, Mª Ángeles; Sitjà-Bobadilla, Ariadna; Palenzuela, Oswaldo

2013-01-01

In vitro studies have confirmed the inhibitory effect of the azol-derivative ketoconazole (KZ) on the growth of Ichthyophonus, an important pathogen causing epizootics in wild and cultured fish. We evaluated the effect of KZ in vivo in European sea bass Dicentrarchus labrax experimentally infected with the same Ichthyophonus isolate. Liposomes were used to vehiculate different doses of KZ to increase the effect on Ichthyophonus and lower the toxicity of the drug, and KZ toxicity was assessed ...

Sea level change

Digital Repository Service at National Institute of Oceanography (India)

Church, J.A.; Clark, P.U.; Cazenave, A.; Gregory, J.M.; Jevrejeva, S.; Levermann, A.; Merrifield, M.A.; Milne, G.A.; Nerem, R.S.; Nunn, P.D.; Payne, A.J.; Pfeffer, W.T.; Stammer, D.; Unnikrishnan, A.S.

This chapter considers changes in global mean sea level, regional sea level, sea level extremes, and waves. Confidence in projections of global mean sea level rise has increased since the Fourth Assessment Report (AR4) because of the improved...

Air-sea exchange studies at the North Sea

NARCIS (Netherlands)

Leeuw, G. de; Eijk, A.M.J. van; Kunz, G.J.; Veefkind, P.J.

1996-01-01

The North Sea can be considered as a local 'inner' sea in which many processes are quite different from these over the open ocean. The surrounding land has a major influence, being the source for man-made aerosols and gases, whereas the North Sea acts as a sink for these. At the same time the North

Sea ice dynamics across the Mid-Pleistocene transition in the Bering Sea.

Science.gov (United States)

Detlef, H; Belt, S T; Sosdian, S M; Smik, L; Lear, C H; Hall, I R; Cabedo-Sanz, P; Husum, K; Kender, S

2018-03-05

Sea ice and associated feedback mechanisms play an important role for both long- and short-term climate change. Our ability to predict future sea ice extent, however, hinges on a greater understanding of past sea ice dynamics. Here we investigate sea ice changes in the eastern Bering Sea prior to, across, and after the Mid-Pleistocene transition (MPT). The sea ice record, based on the Arctic sea ice biomarker IP 25 and related open water proxies from the International Ocean Discovery Program Site U1343, shows a substantial increase in sea ice extent across the MPT. The occurrence of late-glacial/deglacial sea ice maxima are consistent with sea ice/land ice hysteresis and land-glacier retreat via the temperature-precipitation feedback. We also identify interactions of sea ice with phytoplankton growth and ocean circulation patterns, which have important implications for glacial North Pacific Intermediate Water formation and potentially North Pacific abyssal carbon storage.

Alteration of host-pathogen interactions in the wake of climate change - Increasing risk for shellfish associated infections?

Science.gov (United States)

Hernroth, Bodil E; Baden, Susanne P

2018-02-01

The potential for climate-related spread of infectious diseases through marine systems has been highlighted in several reports. With this review we want to draw attention to less recognized mechanisms behind vector-borne transmission pathways to humans. We have focused on how the immune systems of edible marine shellfish, the blue mussels and Norway lobsters, are affected by climate related environmental stressors. Future ocean acidification (OA) and warming due to climate change constitute a gradually increasing persistent stress with negative trade-off for many organisms. In addition, the stress of recurrent hypoxia, inducing high levels of bioavailable manganese (Mn) is likely to increase in line with climate change. We summarized that OA, hypoxia and elevated levels of Mn did have an overall negative effect on immunity, in some cases also with synergistic effects. On the other hand, moderate increase in temperature seems to have a stimulating effect on antimicrobial activity and may in a future warming scenario counteract the negative effects. However, rising sea surface temperature and climate events causing high land run-off promote the abundance of naturally occurring pathogenic Vibrio and will in addition, bring enteric pathogens which are circulating in society into coastal waters. Moreover, the observed impairments of the immune defense enhance the persistence and occurrence of pathogens in shellfish. This may increase the risk for direct transmission of pathogens to consumers. It is thus essential that in the wake of climate change, sanitary control of coastal waters and seafood must recognize and adapt to the expected alteration of host-pathogen interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

ACCELERATION OF SEA LEVEL RISE OVER MALAYSIAN SEAS FROM SATELLITE ALTIMETER

Directory of Open Access Journals (Sweden)

A. I. A. Hamid

2016-09-01

Full Text Available Sea level rise becomes our concern nowadays as a result of variously contribution of climate change that cause by the anthropogenic effects. Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. Due to this change, sea level is now constantly rising and eventually will threaten many low-lying and unprotected coastal areas in many ways. This paper is proposing a significant effort to quantify the sea level trend over Malaysian seas based on the combination of multi-mission satellite altimeters over a period of 23 years. Eight altimeter missions are used to derive the absolute sea level from Radar Altimeter Database System (RADS. Data verification is then carried out to verify the satellite derived sea level rise data with tidal data. Eight selected tide gauge stations from Peninsular Malaysia, Sabah and Sarawak are chosen for this data verification. The pattern and correlation of both measurements of sea level anomalies (SLA are evaluated over the same period in each area in order to produce comparable results. Afterwards, the time series of the sea level trend is quantified using robust fit regression analysis. The findings clearly show that the absolute sea level trend is rising and varying over the Malaysian seas with the rate of sea level varies and gradually increase from east to west of Malaysia. Highly confident and correlation level of the 23 years measurement data with an astonishing root mean square difference permits the absolute sea level trend of the Malaysian seas has raised at the rate 3.14 ± 0.12 mm yr-1 to 4.81 ± 0.15 mm yr-1 for the chosen sub-areas, with an overall mean of 4.09 ± 0.12 mm yr-1. This study hopefully offers a beneficial sea level information to be applied in a wide range of related environmental and climatology issue such as flood and global warming.

Acceleration of Sea Level Rise Over Malaysian Seas from Satellite Altimeter

Science.gov (United States)

Hamid, A. I. A.; Din, A. H. M.; Khalid, N. F.; Omar, K. M.

2016-09-01

Sea level rise becomes our concern nowadays as a result of variously contribution of climate change that cause by the anthropogenic effects. Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. Due to this change, sea level is now constantly rising and eventually will threaten many low-lying and unprotected coastal areas in many ways. This paper is proposing a significant effort to quantify the sea level trend over Malaysian seas based on the combination of multi-mission satellite altimeters over a period of 23 years. Eight altimeter missions are used to derive the absolute sea level from Radar Altimeter Database System (RADS). Data verification is then carried out to verify the satellite derived sea level rise data with tidal data. Eight selected tide gauge stations from Peninsular Malaysia, Sabah and Sarawak are chosen for this data verification. The pattern and correlation of both measurements of sea level anomalies (SLA) are evaluated over the same period in each area in order to produce comparable results. Afterwards, the time series of the sea level trend is quantified using robust fit regression analysis. The findings clearly show that the absolute sea level trend is rising and varying over the Malaysian seas with the rate of sea level varies and gradually increase from east to west of Malaysia. Highly confident and correlation level of the 23 years measurement data with an astonishing root mean square difference permits the absolute sea level trend of the Malaysian seas has raised at the rate 3.14 ± 0.12 mm yr-1 to 4.81 ± 0.15 mm yr-1 for the chosen sub-areas, with an overall mean of 4.09 ± 0.12 mm yr-1. This study hopefully offers a beneficial sea level information to be applied in a wide range of related environmental and climatology issue such as flood and global warming.

Ecological niche of plant pathogens

Directory of Open Access Journals (Sweden)

Ecaterina Fodor

2011-06-01

Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread. 

Ecological niche of plant pathogens

Directory of Open Access Journals (Sweden)

Ecaterina Fodor

2011-02-01

Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.

Methods for detecting pathogens in the beef food chain: detecting particular pathogens

Science.gov (United States)

The main food-borne pathogens of concern in the beef food chain are Shiga toxin-producing Escherichia coli (STEC) and Salmonella spp.; however, the presence of other pathogens, including Listeria monocytogenes, Campylobacter spp., Clostridium spp., Bacillus cereus, and Mycobacterium avium subsp. par...

Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian Sea and White Sea from R/Vs Artemovsk, Atlantida, Okeanograf, Professor Rudovits, and ice observations, 1957 - 1995 (NODC Accession 0073674)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian...

Lipids in host-pathogen interactions: pathogens exploit the complexity of the host cell lipidome.

Science.gov (United States)

van der Meer-Janssen, Ynske P M; van Galen, Josse; Batenburg, Joseph J; Helms, J Bernd

2010-01-01

Lipids were long believed to have a structural role in biomembranes and a role in energy storage utilizing cellular lipid droplets and plasma lipoproteins. Research over the last decades has identified an additional role of lipids in cellular signaling, membrane microdomain organization and dynamics, and membrane trafficking. These properties make lipids an attractive target for pathogens to modulate host cell processes in order to allow their survival and replication. In this review we will summarize the often ingenious strategies of pathogens to modify the lipid homeostasis of host cells, allowing them to divert cellular processes. To this end pathogens take full advantage of the complexity of the lipidome. The examples are categorized in generalized and emerging principles describing the involvement of lipids in host-pathogen interactions. Several pathogens are described that simultaneously induce multiple changes in the host cell signaling and trafficking mechanisms. Elucidation of these pathogen-induced changes may have important implications for drug development. The emergence of high-throughput lipidomic techniques will allow the description of changes of the host cell lipidome at the level of individual molecular lipid species and the identification of lipid biomarkers.

Transient virulence of emerging pathogens.

Science.gov (United States)

Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

2010-05-06

Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

Food-borne pathogens

International Nuclear Information System (INIS)

Niemand, J.G.

1985-01-01

The Salmonella scare reinforced the importance of never taking chances when it comes to controlling pathogens. The issue has been resolved by radurisation. The article deals with the various pathogens that can effect food and argues the case for radurisation in dealing with them. It also looks at some of the other food products that can be treated using this process

Viral pathogen discovery

Science.gov (United States)

Chiu, Charles Y

2015-01-01

Viral pathogen discovery is of critical importance to clinical microbiology, infectious diseases, and public health. Genomic approaches for pathogen discovery, including consensus polymerase chain reaction (PCR), microarrays, and unbiased next-generation sequencing (NGS), have the capacity to comprehensively identify novel microbes present in clinical samples. Although numerous challenges remain to be addressed, including the bioinformatics analysis and interpretation of large datasets, these technologies have been successful in rapidly identifying emerging outbreak threats, screening vaccines and other biological products for microbial contamination, and discovering novel viruses associated with both acute and chronic illnesses. Downstream studies such as genome assembly, epidemiologic screening, and a culture system or animal model of infection are necessary to establish an association of a candidate pathogen with disease. PMID:23725672

Pathogenicity and Host Range of Pathogen Causing Black Raspberry (Rubus coreanus) Anthracnose in Korea

OpenAIRE

Uh Seong Jeong; Ju Hee Kim; Ki Kwon Lee; Seong Soo Cheong; Wang Hyu Lee

2013-01-01

The strains of Colletotrichum gloeosporioides, C. coccodes, C. acutatum isolated from black raspberry werepathogenic to apple and strawberry after dropping inoculation, but showed weak pathogenicity in hot-pepperand tomato. The anthracnose pathogens of C. gloeosporioides, C. orbiculare, C. acutatum isolated from apple,hot-pepper and pumpkin showed pathogenicity in black raspberry. Moreover, the anthracnose pathogensisolated from apple caused disease symptoms in non-wounded inoculation.

First biological measurements of deep-sea corals from the Red Sea.

Science.gov (United States)

Roder, C; Berumen, M L; Bouwmeester, J; Papathanassiou, E; Al-Suwailem, A; Voolstra, C R

2013-10-03

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with 'deep-sea' and 'cold-water' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

First biological measurements of deep-sea corals from the Red Sea.

KAUST Repository

Roder, Cornelia

2013-10-03

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with \\'deep-sea\\' and \\'cold-water\\' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

Phosphorus dynamics in the Black Sea and Baltic Sea

NARCIS (Netherlands)

Dijkstra, N.|info:eu-repo/dai/nl/372617034

2017-01-01

The dynamics of the key nutrient phosphorus (P) in hypoxic and anoxic marine basins are still incompletely understood. This thesis focuses on the cycling of P in two of such basins: the Baltic Sea and the Black Sea. Water column particulates and sediments from the deep basin of the Black Sea were

Future research needs involving pathogens in groundwater

Science.gov (United States)

Bradford, Scott A.; Harvey, Ronald W.

2017-01-01

Contamination of groundwater by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important prerequisites for preventing groundwater contamination. However, non-point sources of pathogen contamination are frequently difficult to identify, and existing approaches for pathogen detection are costly and only provide semi-quantitative information. Microbial indicators that are readily quantified often do not correlate with the presence of pathogens. Pathogens of emerging concern and increasing detections of antibiotic resistance among bacterial pathogens in groundwater are topics of growing concern. Adequate removal of pathogens during soil passage is therefore critical for safe groundwater extraction. Processes that enhance pathogen transport (e.g., high velocity zones and preferential flow) and diminish pathogen removal (e.g., reversible retention and enhanced survival) are of special concern because they increase the risk of groundwater contamination, but are still incompletely understood. Improved theory and modeling tools are needed to analyze experimental data, test hypotheses, understand coupled processes and controlling mechanisms, predict spatial and/or temporal variability in model parameters and uncertainty in pathogen concentrations, assess risk, and develop mitigation and best management approaches to protect groundwater.

Future research needs involving pathogens in groundwater

Science.gov (United States)

Bradford, Scott A.; Harvey, Ronald W.

2017-06-01

Contamination of groundwater by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important prerequisites for preventing groundwater contamination. However, non-point sources of pathogen contamination are frequently difficult to identify, and existing approaches for pathogen detection are costly and only provide semi-quantitative information. Microbial indicators that are readily quantified often do not correlate with the presence of pathogens. Pathogens of emerging concern and increasing detections of antibiotic resistance among bacterial pathogens in groundwater are topics of growing concern. Adequate removal of pathogens during soil passage is therefore critical for safe groundwater extraction. Processes that enhance pathogen transport (e.g., high velocity zones and preferential flow) and diminish pathogen removal (e.g., reversible retention and enhanced survival) are of special concern because they increase the risk of groundwater contamination, but are still incompletely understood. Improved theory and modeling tools are needed to analyze experimental data, test hypotheses, understand coupled processes and controlling mechanisms, predict spatial and/or temporal variability in model parameters and uncertainty in pathogen concentrations, assess risk, and develop mitigation and best management approaches to protect groundwater.

A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

Science.gov (United States)

Langhammer, Penny F; Lips, Karen R; Burrowes, Patricia A; Tunstall, Tate; Palmer, Crystal M; Collins, James P

2013-01-01

Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39), and one recently thawed from cryopreserved stock (JEL427-P9). In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity.

A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

Directory of Open Access Journals (Sweden)

Penny F Langhammer

Full Text Available Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39, and one recently thawed from cryopreserved stock (JEL427-P9. In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity.

Expression Analysis of Immune Related Genes Identified from the Coelomocytes of Sea Cucumber (Apostichopus japonicus in Response to LPS Challenge

Directory of Open Access Journals (Sweden)

Ying Dong

2014-10-01

Full Text Available The sea cucumber (Apostichopus japonicus occupies a basal position during the evolution of deuterostomes and is also an important aquaculture species. In order to identify more immune effectors, transcriptome sequencing of A. japonicus coelomocytes in response to lipopolysaccharide (LPS challenge was performed using the Illumina HiSeq™ 2000 platform. One hundred and seven differentially expressed genes were selected and divided into four functional categories including pathogen recognition (25 genes, reorganization of cytoskeleton (27 genes, inflammation (41 genes and apoptosis (14 genes. They were analyzed to elucidate the mechanisms of host-pathogen interactions and downstream signaling transduction. Quantitative real-time polymerase chain reactions (qRT-PCRs of 10 representative genes validated the accuracy and reliability of RNA sequencing results with the correlation coefficients from 0.88 to 0.98 and p-value <0.05. Expression analysis of immune-related genes after LPS challenge will be useful in understanding the immune response mechanisms of A. japonicus against pathogen invasion and developing strategies for resistant markers selection.

Impact of acute stress on antimicrobial polypeptides mRNA copy number in several tissues of marine sea bass (Dicentrarchus labrax

Directory of Open Access Journals (Sweden)

Terova Genciana

2011-12-01

Full Text Available Abstract Background In comparison to higher vertebrates, fish are thought to rely heavily on innate immune system for initial protection against pathogen invasion because their acquired immune system displays a considerably poor immunological memory, and short-lived secondary response. The endogenous antimicrobial polypeptides (AMPPs directly and rapidly killing pathogens such as bacteria, fungi, parasites, and viruses are included within the realm of innate defenses. In addition to piscidins, AMPPs that in recent years have been shown to be commonly linked to innate defense, are histones and their polypeptide fragments, and peptides derived from the respiratory protein hemoglobin. There is evidence that a number of stresses lead to significant regulation of AMPPs and thus their monitoring could be a highly sensitive measure of health status and risk of an infectious disease outbreak, which is a major impediment to the continued success of virtually all aquaculture enterprises and is often the most significant cause of economic losses. Results We firstly isolated and deposited in Genbank database the cDNA sequences encoding for hemoglobin-β-like protein (Hb-LP [GeneBank: JN410659], H2B histone-like protein 1 (HLP1 GenBank: JN410660], and HLP2 [GenBank: JN410661]. The "de novo" prediction of the three-dimensional structures for each protein is presented. Phylogenetic trees were constructed on Hb-LP, HLP1, and HLP2 sequences of sea bass and those of other teleost, avian, reptiles, amphibian and mammalian species. We then used real time RT-PCR technology to monitor for the first time in sea bass, dynamic changes in mRNA copy number of Hb-LP, HLP1, HLP2, and dicentracin in gills, skin, eyes, stomach and proximal intestine in response to acute crowding/confinement stress. We showed that acute crowding stress induces an increase in the expression levels of the aforementioned genes, in gills and skin of sea bass, but not in other tissues, and that

Monitoring sea level and sea surface temperature trends from ERS satellites

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Knudsen, Per; Beckley, B.

2002-01-01

Data from the two ESA satellites ERS-1 and ERS-2 are used in global and regional analysis of sea level and sea surface temperature trends over the last, 7.8 years. T he ERS satellites and in the future the ENVISAT satellite provide unique opportunity for monitoring both changes in sea level and sea...

PREVALENCE AND IDENTIFICATION OF VIBRIO SPP. ISOLATED ON AQUACULTURED GILTHEAD SEA BREAM

Directory of Open Access Journals (Sweden)

C. Scarano

2011-01-01

Full Text Available The aim of the study was to investigate the prevalence of Vibrio spp isolated from gilthead sea bream (Sparus aurata farmed on sea cages and to identify and characterize the pathogen by molecular techniques. Eighty fish were collected from two hatcheries located on the North-Est Sardinian Mediterranean coast, and microbiological analysis were performed on different body parts such as skin, gills, muscle and intestinal tract. Subsequently 100 pure colonies with typical morphology and phenotypic characteristics were selected and submitted to the molecular identification. The analysis on the prevalence of Vibrio spp showed the effect of the hatchery rearing system (P<0.001, of the date of sampling (P<0.001, and of the body part (P<0.001. All the strains selected were confirmed to be members of the genus Vibrio spp by the molecular method/techinique/identification, whereas the rpoA gene sequence analyses allowed to identify 89 strains belonging to the species Vibrio harveyi, 6 to V. diabolicus, 2 to V. parahaemolyticus and 1 to V. mediterranei.

Potatoes, pathogens and pests

NARCIS (Netherlands)

Lazebnik, Jenny

2017-01-01

Currently, fungicides are necessary to protect potato crops against late blight, Phytophthora infestans, one of the world’s most damaging crop pathogens. The introgression of plant resistance genes from wild potato species targeted specifically to the late blight pathogen into

Mucosal immunity to pathogenic intestinal bacteria.

Science.gov (United States)

Perez-Lopez, Araceli; Behnsen, Judith; Nuccio, Sean-Paul; Raffatellu, Manuela

2016-03-01

The intestinal mucosa is a particularly dynamic environment in which the host constantly interacts with trillions of commensal microorganisms, known as the microbiota, and periodically interacts with pathogens of diverse nature. In this Review, we discuss how mucosal immunity is controlled in response to enteric bacterial pathogens, with a focus on the species that cause morbidity and mortality in humans. We explain how the microbiota can shape the immune response to pathogenic bacteria, and we detail innate and adaptive immune mechanisms that drive protective immunity against these pathogens. The vast diversity of the microbiota, pathogens and immune responses encountered in the intestines precludes discussion of all of the relevant players in this Review. Instead, we aim to provide a representative overview of how the intestinal immune system responds to pathogenic bacteria.

An emerging cyberinfrastructure for biodefense pathogen and pathogen-host data.

Science.gov (United States)

Zhang, C; Crasta, O; Cammer, S; Will, R; Kenyon, R; Sullivan, D; Yu, Q; Sun, W; Jha, R; Liu, D; Xue, T; Zhang, Y; Moore, M; McGarvey, P; Huang, H; Chen, Y; Zhang, J; Mazumder, R; Wu, C; Sobral, B

2008-01-01

The NIAID-funded Biodefense Proteomics Resource Center (RC) provides storage, dissemination, visualization and analysis capabilities for the experimental data deposited by seven Proteomics Research Centers (PRCs). The data and its publication is to support researchers working to discover candidates for the next generation of vaccines, therapeutics and diagnostics against NIAID's Category A, B and C priority pathogens. The data includes transcriptional profiles, protein profiles, protein structural data and host-pathogen protein interactions, in the context of the pathogen life cycle in vivo and in vitro. The database has stored and supported host or pathogen data derived from Bacillus, Brucella, Cryptosporidium, Salmonella, SARS, Toxoplasma, Vibrio and Yersinia, human tissue libraries, and mouse macrophages. These publicly available data cover diverse data types such as mass spectrometry, yeast two-hybrid (Y2H), gene expression profiles, X-ray and NMR determined protein structures and protein expression clones. The growing database covers over 23 000 unique genes/proteins from different experiments and organisms. All of the genes/proteins are annotated and integrated across experiments using UniProt Knowledgebase (UniProtKB) accession numbers. The web-interface for the database enables searching, querying and downloading at the level of experiment, group and individual gene(s)/protein(s) via UniProtKB accession numbers or protein function keywords. The system is accessible at http://www.proteomicsresource.org/.

Highly pathogenic avian influenza.

Science.gov (United States)

Swayne, D E; Suarez, D L

2000-08-01

Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover and fast ice decay

Directory of Open Access Journals (Sweden)

P. Itkin

2017-10-01

Full Text Available Ice retreat in the eastern Eurasian Arctic is a consequence of atmospheric and oceanic processes and regional feedback mechanisms acting on the ice cover, both in winter and summer. A correct representation of these processes in numerical models is important, since it will improve predictions of sea ice anomalies along the Northeast Passage and beyond. In this study, we highlight the importance of winter ice dynamics for local summer sea ice anomalies in thickness, volume and extent. By means of airborne sea ice thickness surveys made over pack ice areas in the south-eastern Laptev Sea, we show that years of offshore-directed sea ice transport have a thinning effect on the late-winter sea ice cover. To confirm the preconditioning effect of enhanced offshore advection in late winter on the summer sea ice cover, we perform a sensitivity study using a numerical model. Results verify that the preconditioning effect plays a bigger role for the regional ice extent. Furthermore, they indicate an increase in volume export from the Laptev Sea as a consequence of enhanced offshore advection, which has far-reaching consequences for the entire Arctic sea ice mass balance. Moreover we show that ice dynamics in winter not only preconditions local summer ice extent, but also accelerate fast-ice decay.

Processes driving sea ice variability in the Bering Sea in an eddying ocean/sea ice model: Mean seasonal cycle

Science.gov (United States)

Li, Linghan; McClean, Julie L.; Miller, Arthur J.; Eisenman, Ian; Hendershott, Myrl C.; Papadopoulos, Caroline A.

2014-12-01

The seasonal cycle of sea ice variability in the Bering Sea, together with the thermodynamic and dynamic processes that control it, are examined in a fine resolution (1/10°) global coupled ocean/sea-ice model configured in the Community Earth System Model (CESM) framework. The ocean/sea-ice model consists of the Los Alamos National Laboratory Parallel Ocean Program (POP) and the Los Alamos Sea Ice Model (CICE). The model was forced with time-varying reanalysis atmospheric forcing for the time period 1970-1989. This study focuses on the time period 1980-1989. The simulated seasonal-mean fields of sea ice concentration strongly resemble satellite-derived observations, as quantified by root-mean-square errors and pattern correlation coefficients. The sea ice energy budget reveals that the seasonal thermodynamic ice volume changes are dominated by the surface energy flux between the atmosphere and the ice in the northern region and by heat flux from the ocean to the ice along the southern ice edge, especially on the western side. The sea ice force balance analysis shows that sea ice motion is largely associated with wind stress. The force due to divergence of the internal ice stress tensor is large near the land boundaries in the north, and it is small in the central and southern ice-covered region. During winter, which dominates the annual mean, it is found that the simulated sea ice was mainly formed in the northern Bering Sea, with the maximum ice growth rate occurring along the coast due to cold air from northerly winds and ice motion away from the coast. South of St Lawrence Island, winds drive the model sea ice southwestward from the north to the southwestern part of the ice-covered region. Along the ice edge in the western Bering Sea, model sea ice is melted by warm ocean water, which is carried by the simulated Bering Slope Current flowing to the northwest, resulting in the S-shaped asymmetric ice edge. In spring and fall, similar thermodynamic and dynamic

Sea Surface Height Variability and Eddy Statistical Properties in the Red Sea

KAUST Repository

Zhan, Peng

2013-01-01

Satellite sea surface height (SSH) data over 1992-2012 are analyzed to study the spatial and temporal variability of sea level in the Red Sea. Empirical orthogonal functions (EOF) analysis suggests the remarkable seasonality of SSH in the Red Sea

Highly variable Pliocene sea surface conditions in the Norwegian Sea

Directory of Open Access Journals (Sweden)

P. E. Bachem

2017-09-01

Full Text Available The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST and ice-rafted debris (IRD in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

Contemporary Arctic Sea Level

Science.gov (United States)

Cazenave, A. A.

2017-12-01

During recent decades, the Arctic region has warmed at a rate about twice the rest of the globe. Sea ice melting is increasing and the Greenland ice sheet is losing mass at an accelerated rate. Arctic warming, decrease in the sea ice cover and fresh water input to the Arctic ocean may eventually impact the Arctic sea level. In this presentation, we review our current knowledge of contemporary Arctic sea level changes. Until the beginning of the 1990s, Arctic sea level variations were essentially deduced from tide gauges located along the Russian and Norwegian coastlines. Since then, high inclination satellite altimetry missions have allowed measuring sea level over a large portion of the Arctic Ocean (up to 80 degree north). Measuring sea level in the Arctic by satellite altimetry is challenging because the presence of sea ice cover limits the full capacity of this technique. However adapted processing of raw altimetric measurements significantly increases the number of valid data, hence the data coverage, from which regional sea level variations can be extracted. Over the altimetry era, positive trend patterns are observed over the Beaufort Gyre and along the east coast of Greenland, while negative trends are reported along the Siberian shelf. On average over the Arctic region covered by satellite altimetry, the rate of sea level rise since 1992 is slightly less than the global mea sea level rate (of about 3 mm per year). On the other hand, the interannual variability is quite significant. Space gravimetry data from the GRACE mission and ocean reanalyses provide information on the mass and steric contributions to sea level, hence on the sea level budget. Budget studies show that regional sea level trends over the Beaufort Gyre and along the eastern coast of Greenland, are essentially due to salinity changes. However, in terms of regional average, the net steric component contributes little to the observed sea level trend. The sea level budget in the Arctic

Sea Surface Temperature and Ocean Color Variability in the South China Sea

Science.gov (United States)

Conaty, A. P.

2001-12-01

The South China Sea is a marginal sea in the Southeast Asian region whose surface circulation is driven by monsoons and whose surface currents have complex seasonal patterns. Its rich natural resources and strategic location have made its small islands areas of political dispute among the neighboring nations. This study aims to show the seasonal and interannual variability of sea surface temperature and ocean color in South China Sea. It makes use of NOAA's Advanced Very High Resolution Radiometer (AVHRR) satellite data sets on sea surface temperature for the period 1981-2000 and NASA's Nimbus-7 Coastal Zone Color Scanner (CZCS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite data sets on pigment concentration (ocean color) for the period 1981-1996 and 1997-2000, respectively. Transect lines were drawn along several potential hotspot areas to show the variability in sea surface temperature and pigment concentration through time. In-situ data on sea surface temperature along South China Sea were likewise plotted to see the variability with time. Higher seasonal variability in sea surface temperature was seen at higher latitudes. Interannual variability was within 1-3 Kelvin. In most areas, pigment concentration was higher during northern hemisphere winter and autumn, after the monsoon rains, with a maximum of 30 milligrams per cubic meter.

Vulnerability of marginal seas to sea level rise

Science.gov (United States)

Gomis, Damia; Jordà, Gabriel

2017-04-01

Sea level rise (SLR) is a serious thread for coastal areas and has a potential negative impact on society and economy. SLR can lead for instance to land loss, beach reduction, increase of the damage of marine storms on coastal infrastructures and to the salinization of underground water streams. It is well acknowledged that future SLR will be inhomogeneous across the globe, with regional differences of up to 100% with respect to global mean sea level (GMSL). Several studies have addressed the projections of SLR at regional scale, but most of them are based on global climate models (GCMs) that have a relatively coarse spatial resolution (>1°). In marginal seas this has proven to be a strong limitation, as their particular configurations require spatial resolutions that are not reachable by present GCMs. A paradigmatic case is the Mediterranean Sea, connected to the global ocean through the Strait of Gibraltar, a narrow passage of 14 km width. The functioning of the Mediterranean Sea involves a variety of processes including an overturning circulation, small-scale convection and a rich mesoscale field. Moreover, the long-term evolution of Mediterranean sea level has been significantly different from the global mean during the last decades. The observations of present climate and the projections for the next decades have lead some authors to hypothesize that the particular characteristics of the basin could allow Mediterranean mean sea level to evolve differently from the global mean. Assessing this point is essential to undertake proper adaptation strategies for the largely populated Mediterranean coastal areas. In this work we apply a new approach that combines regional and global projections to analyse future SLR. In a first step we focus on the quantification of the expected departures of future Mediterranean sea level from GMSL evolution and on the contribution of different processes to these departures. As a result we find that, in spite of its particularities

Deep-sea Hexactinellida (Porifera) of the Weddell Sea

Science.gov (United States)

Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

2004-07-01

New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

Interaction of pathogens with host cholesterol metabolism.

Science.gov (United States)

Sviridov, Dmitri; Bukrinsky, Michael

2014-10-01

Pathogens of different taxa, from prions to protozoa, target cellular cholesterol metabolism to advance their own development and to impair host immune responses, but also causing metabolic complications, for example, atherosclerosis. This review describes recent findings of how pathogens do it. A common theme in interaction between pathogens and host cholesterol metabolism is pathogens targeting lipid rafts of the host plasma membrane. Many intracellular pathogens use rafts as an entry gate, taking advantage of the endocytic machinery and high abundance of outward-looking molecules that can be used as receptors. At the same time, disruption of the rafts' functional capacity, achieved by the pathogens through a number of various means, impairs the ability of the host to generate immune response, thus helping pathogen to thrive. Pathogens cannot synthesize cholesterol, and salvaging host cholesterol helps pathogens build advanced cholesterol-containing membranes and assembly platforms. Impact on cholesterol metabolism is not limited to the infected cells; proteins and microRNAs secreted by infected cells affect lipid metabolism systemically. Given an essential role that host cholesterol metabolism plays in pathogen development, targeting this interaction may be a viable strategy to fight infections, as well as metabolic complications of the infections.

Sea Ice Drift Monitoring in the Bohai Sea Based on GF4 Satellite

Science.gov (United States)

Zhao, Y.; Wei, P.; Zhu, H.; Xing, B.

2018-04-01

The Bohai Sea is the inland sea with the highest latitude in China. In winter, the phenomenon of freezing occurs in the Bohai Sea due to frequent cold wave influx. According to historical records, there have been three serious ice packs in the Bohai Sea in the past 50 years which caused heavy losses to our economy. Therefore, it is of great significance to monitor the drift of sea ice and sea ice in the Bohai Sea. The GF4 image has the advantages of short imaging time and high spatial resolution. Based on the GF4 satellite images, the three methods of SIFT (Scale invariant feature - the transform and Scale invariant feature transform), MCC (maximum cross-correlation method) and sift combined with MCC are used to monitor sea ice drift and calculate the speed and direction of sea ice drift, the three calculation results are compared and analyzed by using expert interpretation and historical statistical data to carry out remote sensing monitoring of sea ice drift results. The experimental results show that the experimental results of the three methods are in accordance with expert interpretation and historical statistics. Therefore, the GF4 remote sensing satellite images have the ability to monitor sea ice drift and can be used for drift monitoring of sea ice in the Bohai Sea.

Climatology of sea breezes along the Red Sea coast of Saudi Arabia

KAUST Repository

Khan, Basit; Abualnaja, Yasser; Al-Subhi, Abdullah M.; Nellayaputhenpeedika, Mohammedali; Nellikkattu Thody, Manoj; Sturman, Andrew P.

2018-01-01

and Atmospheric Administration (NOAA) are used to investigate the climatology of sea breezes over the eastern side of the Red Sea region. Results show existence of separate sea breeze systems along different segments of the Red Sea coastline. Based on the physical

Priority setting of foodborne pathogens: disease burden and costs of selected enteric pathogens

NARCIS (Netherlands)

Kemmeren JM; Mangen MJJ; Duynhoven YTHP van; Havelaar AH; MGB

2006-01-01

Toxoplasmosis causes the highest disease burden among seven evaluated foodborne pathogens. This is the preliminary conclusion of a major study of the disease burden and related costs of foodborne pathogens. The other micro-organisms that were studied are Campylobacter spp., Salmonella spp.,

Seasonal variation of deep-sea bioluminescence in the Ionian Sea

International Nuclear Information System (INIS)

Craig, Jessica; Jamieson, Alan J.; Bagley, Philip M.; Priede, Imants G.

2011-01-01

The ICDeep (Image Intensified Charge Coupled Device for Deep sea research) profiler was used to measure the density of deep bioluminescent animals (BL) through the water column in the east, west and mid-Ionian Sea and in the Algerian Basin. A west to east decrease in BL density was found. Generalized additive modelling was used to investigate seasonal variation in the east and west Ionian Sea (NESTOR and NEMO neutrino telescope sites, respectively) from BL measurements in autumn 2008 and spring 2009. A significant seasonal effect was found in the west Ionian Sea (p<0.001), where a deep autumnal peak in BL density occurred between 500 and 2400 m. No significant seasonal variation in BL density was found in the east Ionian Sea (p=0.07). In both spring and autumn, significant differences in BL density were found through the water column between the east and west Ionian Sea (p<0.001).

Seasonal variation of deep-sea bioluminescence in the Ionian Sea

Energy Technology Data Exchange (ETDEWEB)

Craig, Jessica, E-mail: j.craig@abdn.ac.u [University of Aberdeen, Oceanlab, Main Street, Newburgh, Aberdeenshire, AB41 6AA (United Kingdom); Jamieson, Alan J.; Bagley, Philip M.; Priede, Imants G. [University of Aberdeen, Oceanlab, Main Street, Newburgh, Aberdeenshire, AB41 6AA (United Kingdom)

2011-01-21

The ICDeep (Image Intensified Charge Coupled Device for Deep sea research) profiler was used to measure the density of deep bioluminescent animals (BL) through the water column in the east, west and mid-Ionian Sea and in the Algerian Basin. A west to east decrease in BL density was found. Generalized additive modelling was used to investigate seasonal variation in the east and west Ionian Sea (NESTOR and NEMO neutrino telescope sites, respectively) from BL measurements in autumn 2008 and spring 2009. A significant seasonal effect was found in the west Ionian Sea (p<0.001), where a deep autumnal peak in BL density occurred between 500 and 2400 m. No significant seasonal variation in BL density was found in the east Ionian Sea (p=0.07). In both spring and autumn, significant differences in BL density were found through the water column between the east and west Ionian Sea (p<0.001).

Deep-sea geohazards in the South China Sea

Science.gov (United States)

Wu, Shiguo; Wang, Dawei; Völker, David

2018-02-01

Various geological processes and features that might inflict hazards identified in the South China Sea by using new technologies and methods. These features include submarine landslides, pockmark fields, shallow free gas, gas hydrates, mud diapirs and earthquake tsunami, which are widely distributed in the continental slope and reefal islands of the South China Sea. Although the study and assessment of geohazards in the South China Sea came into operation only recently, advances in various aspects are evolving at full speed to comply with National Marine Strategy and `the Belt and Road' Policy. The characteristics of geohazards in deep-water seafloor of the South China Sea are summarized based on new scientific advances. This progress is aimed to aid ongoing deep-water drilling activities and decrease geological risks in ocean development.

Tropism and pathogenicity of rickettsiae

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Tsuneo eUchiyama

2012-06-01

Full Text Available Rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as Rocky Mountain spotted fever, Mediterranean spotted fever, epidemic and murine typhus, etc. Although the vector ranges of each Rickettsia species are rather restricted; i.e., ticks belonging to Arachnida and lice and fleas belonging to Insecta usually act as vectors for spotted fever group and typhus group rickettsiae, respectively, it would be interesting to elucidate the mechanisms controlling the vector tropism of rickettsiae. This review discusses the factors determining the vector tropism of rickettsiae. In brief, the vector tropism of rickettsiae species is basically consistent with their tropism towards cultured tick and insect cells. The mechanisms responsible for rickettsiae pathogenicity are also described. Recently, genomic analyses of rickettsiae have revealed that they possess several genes that are homologous to those affecting the pathogenicity of other bacteria. Analyses comparing the genomes of pathogenic and nonpathogenic strains of rickettsiae have detected many factors that are related to rickettsial pathogenicity. It is also known that a reduction in the rickettsial genome has occurred during the course of its evolution. Interestingly, Rickettsia species with small genomes, such as Rickettsia prowazekii, are more pathogenic to humans than those with larger genomes. This review also examines the growth kinetics of pathogenic and nonpathogenic species of spotted fever group rickettsiae in mammalian cells. The growth of nonpathogenic species is restricted in these cells, which is mediated, at least in part, by autophagy. The superinfection of nonpathogenic rickettsiae-infected cells with pathogenic rickettsiae results in an elevated yield of the nonpathogenic rickettsiae and the growth of the pathogenic rickettsiae. Autophagy is restricted in these cells. These results are discussed in this review.