Waterfowl Research Articles

Conservation of Environment and Protection of Marginalized Fishing Communities of Lake Chilika in Orissa, India

Situated in the coastal belt of Orissa in India, Lake Chilika has been designated under the Ramsar Convention as a Wetland of International importance (IUCN) especially as water fowl Habitat (Iran, 1981). But, during the last few years the Lake has developed serious environmental problems so much so that the Bureau of Ramsar convention has placed it on its red list. Among those problems, the siltation at the Mugger Mukh (one ofthe openings ofthe Lake to the sea) and consequent reduction in tidal waves, decrease in the depth of water level, decreasing salinity, shrinkage of Lake area, deterioration of the condition of the Nalabana Bird Sanctuary situated in the Lake have been cited as the major ones. While various natural factors have been attributed to such an environmental degradation, an artificial factor i.e. shrimp aquaculture practiced by a few economic elites of the state and also a group of businessmen has been cited as a potential cause. The economically marginalized and environmentally conscious fishing community living near the Lake have thus started a very powerful movement supported by various other sections of the state. Since the Lake ecology and sustainability of the marginalized fishing masses are interrelated in this case, the paper attempts to focus on the artificial problem that has substantially contributed to the environmental degradation and analyze the socioeconomic problems that have evolved in a sociological context.

A model to control the epidemic of H5N1 influenza at the source

BackgroundNo country is fully prepared for a 1918-like pandemic influenza. Averting a pandemic of H5N1 influenza virus depends on the successful control of its endemicity, outbreaks in poultry and occasional spillage into human which carries a case-fatality rate of over 50%. The use of perimetric depopulation and vaccination has failed to halt the spread of the epidemic. Blanket vaccination for all poultry over a large geographical area is difficult. A combination of moratorium, segregation of water fowls from chickens and vaccination have been proved to be effective in the Hong Kong Special Administrative Region (HKSAR) since 2002 despite endemicity and outbreaks in neighbouring regions. Systematic surveillance in southern China showed that ducks and geese are the primary reservoirs which transmit the virus to chickens, minor poultry and even migratory birds.Presentation of the hypothesisWe hypothesize that this combination of moratorium, poultry segregation and targeted vaccination if successfully adapted to an affected district or province in any geographical region with high endemicity would set an example for the control in other regions.Testing the hypothesisA planned one-off moratorium of 3 weeks at the hottest month of the year should decrease the environmental burden as a source of re-infection. Backyard farms will then be re-populated by hatchlings from virus-free chickens and minor poultry only. Targeted immunization of the ducks and geese present only in the industrial farms and also the chickens would be strictly implemented as blanket immunization of all backyard poultry is almost impossible. Freely grazing ducks and geese would not be allowed until neutralizing antibodies of H5 subtype virus is achieved. As a proof of concept, a simple mathematical model with susceptible-infected-recovered (SIR) structure of coupled epidemics between aquatic birds (mainly ducks and geese) and chickens was used to estimate transmissibility within and between these two poultry populations. In the field the hypothesis is tested by prospective surveillance of poultry and immunocompetent patients hospitalized for severe pneumonia for the virus before and after the institution of these measures.Implications of the HypothesisA combination of targeted immunization with the correct vaccine, segregation of poultry species and moratorium of poultry in addition to the present surveillance, biosecurity and hygienic measures at the farm, market and personal levels could be important in the successful control of the H5N1 virus in poultry and human for an extensive geographical region with continuing outbreaks. Alternatively a lesser scale of intervention at the district level can be considered if there is virus detection without evidence of excess poultry deaths since asymptomatic shedding is common in waterfowls.

Influenza A Virus in Birds during Spring Migration in the Camargue, France

Wild aquatic birds are considered to be the natural reservoir for influenza A viruses, and previous studies have focused mainly on species in the orders Anseriformes and Charadriiformes. In this study, we surveyed a larger spectrum of potential hosts belonging to 10 avian orders. Cloacal swabs (n=1,044) from 72 free-living bird species, were analysed by reverse transcription-polymerase chain reaction for the presence of avian influenza virus. Only two Mediterranean Gulls (Larus melanocephalus) tested positive; one of these viruses was identified as an H9N2 subtype. The absence of infection among passerine birds supports the idea that the prevalence of avian influenza virus infection in terrestrial species is low.

SUSCEPTIBILITY OF WOOD DUCKS TO H5N1 HIGHLY PATHOGENIC AVIAN INFLUENZA VIRUS

Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have caused mortality in numerous species of wild birds; this is atypical for avian influenza virus (AIV) infections in these avian species, especially for species within the order Anseriformes. Although these infections document the susceptibility of wild birds to H5N1 HPAI viruses and the spillover of these viruses from infected domestic birds to wild birds, it is unknown whether H5N1 HPAI viruses can persist in free-living avian populations. In a previous study, we established that wood ducks (Aix sponsa) are highly susceptible to infection with H5N1 HPAI viruses. To quantify this susceptibility and further evaluate the likelihood of H5N1 HPAI viral maintenance in a wild bird population, we determined the concentration of virus required to produce infection in wood ducks. To accomplish this, 25 wood ducks were inoculated intranasally at 12-16 wk of age with decreasing concentrations of a H5N1 HPAI virus (A/Whooper Swan/Mongolia/244/05 [H5N1]). The median infectious dose and the lethal dose of H5N1 HPAI virus in wood ducks were very low (10(0.95) and 10(1.71) median embryo infectious dose [EID(50)]/ml, respectively) and less than that of chickens (10(2.80) and 10(2.80) EID(50)/ml). These results confirm that wood ducks are highly susceptible to infection with H5N1 HPAI virus. The data from this study, combined with what is known experimentally about H5N1 HPAI virus infection in wood ducks and viral persistence in aquatic environments, suggest that the wood duck would represent a sensitive indicator species for H5N1 HPAI. Results also suggest that the potential for decreased transmission efficiency associated with reduced viral shedding (especially from the cloaca) and a loss of environmental fitness (in water), may be offset by the ability of this virus to be transmitted through a very low infectious dose.

The Effects of Indicator Organism Type on Phenotypic Characterization of Host-Specificity and the Implications for Microbial Source Tracking

The Effects of Indicator Organism Type on Phenotypic Characterization of Host-Specificity and the Implications for Microbial Source TrackingThe objective of this study was to investigate the effects of indicator organism type on the host specificity of fatty acid methyl ester (FAME) profiles. For that purpose, the FAME profiles of enterococcus, Escherichia coli, fecal coliform (FC), and total coliform (TC) isolates cultured from fecal samples of 5 hosts (cow, swine, poultry, deer, and water fowl) and sewage were developed. These four...Author(s)Deniz YurtseverBerat Z. HaznedarogluTimur DunaevMetin DuranSourceProceedings of the Water Environment FederationSubjectSession 88: Bacteria: More Than a MovementDocument typeConference PaperPublisherWater Environment FederationPrint publication date Oct, 2007ISSN1938-6478SICI1938-6478(20071001)2007:11L.7063;1-DOI10.2175/193864707787223556Volume / Issue2007 / 11Content sourceWEFTECFirst / last page(s)7063 - 7071Copyright2007Word count422Subject keywordsFAME PROFILINGINDICATOR ORGANISMSMICROBIAL SOURCE TRACKINGTMDL

Formation of mixed invasions of waterfowl

It is established that wild and synanthropic waterfowl of the order Anseriformes (gadwell, mallard, graylag goose, teal, garganey, etc.) are possible sources of mixed invasions i.e., an etiological factor in forming and maintaining ill-being of domestic geese with respect to the following diseases: echinostomatidosis, amidostomosis, ganguleterikidosis, thominxosis, streptocarosis, echinuriosis, as well as ectoparasites (bird lice).

Isolation and Genetic Characterization of Avian Influenza Viruses and a Newcastle Disease Virus from Wild Birds in Barbados: 2003–2004

Zoonotic transmission of an H5N1 avian influenza A virus to humans in 2003-present has generated increased public health and scientific interest in the prevalence and variability of influenza A viruses in wild birds and their potential threat to human health. Migratory waterfowl and shorebirds are regarded as the primordial reservoir of all influenza A viral subtypes and have been repeatedly implicated in avian influenza outbreaks in domestic poultry and swine. All of the 16 hemagglutinin and nine neuraminidase influenza subtypes have been isolated from wild birds, but waterfowl of the order Anseriformes are the most commonly infected. Using 9-to-11-day-old embryonating chicken egg culture, virus isolation attempts were conducted on 168 cloacal swabs from various resident, imported, and migratory bird species in Barbados during the months of July to October of 2003 and 2004. Hemagglutination assay and reverse transcription-polymerase chain reaction were used to screen all allantoic fluids for the presence of hemagglutinating agents and influenza A virus. Hemagglutination positive-influenza negative samples were also tested for Newcastle disease virus (NDV), which is also found in waterfowl. Two influenza A viruses and one NDV were isolated from Anseriformes (40/168), with isolation rates of 5.0% (2/40) and 2.5% (1/40), respectively, for influenza A and NDV. Sequence analysis of the influenza A virus isolates showed them to be H4N3 viruses that clustered with other North American avian influenza viruses. This is the first report of the presence of influenza A virus and NDV in wild birds in the English-speaking Caribbean.

Bird schistosomes of wildfowl in the Czech Republic and Poland

In 2005, we dissected 102 wildfowl from the Czech Republic and 73 wildfowl from Poland including representatives of Anseriformes, Gruiformes and Gaviiformes. Schistosome infection was found in a total of 21 (29%) and 23 (23%) birds from Poland and the Czech Republic, respectively. All infected birds belonged to the order Anseriformes. The prevalences of nasal and visceral species were, respectively, 22% and 16% in Poland and 6% and 19% in the Czech Republic. Four species of schistosomes were found: Bilharziella polonica Kowalewski, 1895, Trichobilharzia regenti Horák, Koláfová et Dvorák, 1998, T. szidati Neuhaus, 1952, and an undetermined schistosome from the intestinal wall of Anas penelope L. The finding of T. szidati represents the first record of the parasite from natural final host since the species description.

Chemical status of selenium in evaporation basins for disposal of agricultural drainage

Evaporation basins (or ponds) are the most commonly used facilities for disposal of selenium-laden saline agricultural drainage in the closed hydrologic basin portion of the San Joaquin Valley, California. However concerns remain for potential risk from selenium (Se) toxicity to water fowl in these evaporation basins. In this study, we examined the chemical status of Se in both waters and sediments in two currently operating evaporation pond facilities in the Tulare Lake Drainage District. Some of the saline ponds have been colonized by brine-shrimp (Artemia), which have been harvested since 2001. We evaluated Se concentration and speciation, including selenate [Se(VI)], selenite [Se(IV)], and organic Se [org-Se or Se(-II)] in waters and sediment extracts, and fractionation (soluble, adsorbed, organic matter (OM)-associated, and Se(0) and other resistant forms) in sediments and organic-rich surface detrital layers from the decay of algal blooms. Selenium in ponds without vascular plants exhibited similar behavior to wetlands with vascular plant present, indicating that similar Se transformation processes and mechanisms had resulted in Se immobilization and an increase of reduced Se species [Se(IV), org-Se, and Se(0)] from Se(VI)-dominated input waters. Selenium concentrations in most pond waters were significantly lower than the influent drainage water. This decrease of dissolved Se concentration was accompanied by the increase of reduced Se species. Selenium accumulated preferentially in sediments of the initial pond cell receiving drainage water. Brine-shrimp harvesting activities did not affect Se speciation but may have reduced Se accumulation in surface detrital and sediments.

A Latex Agglutination Test for the Rapid Detection of Avian Influenza Virus Subtype H5N1 and its Clinical Application

A rapid and simple latex agglutination test (LAT) for the detection of avian influenza virus (AIV) subtype H5N1 in chicken allantoic fluids, tracheal swabs, and tissues was developed. Monoclonal antibodies against the hemagglutinin glycoprotein of H5N1 were covalently coupled onto the surface of carboxylated latex bead using a water-soluble carbodiimide to obtain sensitized latex particles (SLP). These SLPs strongly agglutinated in the presence of allantoic fluid containing H5N1, but not fluids containing other AIV sub-types such as HIN1, H3N2, H4N6, and H9N2. Using this LAT, the virus was detectable in tracheal swabs 24 hours to 30 days after inoculating chickens with H5N1, with detection rates ranging from 45.5 to 79.2%. Much higher rates of detection were obtained from tissues collected postmortem from H5N1 experimentally infected chickens; lung tissue yielded the highest detection rate (96.7%), followed by kidney, spleen, brain, and liver tissues (90%). Lower detection rates were achieved with heart (41.7%) and cloacal tissues (26.8%). When the LAT was compared with other detection methods, the agreement with the viral isolation, H5 antigen immunochromatographic test,and H5 real-time RT-PCR test was 93.97, 95.18, and 87.95%, respectively. The test was highly specific for H5N1 in chickens and water fowls and had sensitivity comparable to other diagnostic tests evaluated.

Influenza Virus Surveillance in Wild Birds in Italy: Results of Laboratory Investigations in 2003–2005

Following the avian influenza (AI) epidemics occurring in different areas of the world, a surveillance program funded by the Italian Ministry of Health was implemented. In the framework of this program, an investigation of wild birds was carried out to assess the circulation of AI viruses in their natural reservoir. More than 3000 samples, mainly cloacal swabs, were collected from migratory wild birds belonging to the orders Anseriformes and Charadriiformes. Samples were screened by means of a real-time reverse transcriptase polymerase chain reaction (RRT-PCR), then processed for attempted virus isolation in embryonated fowl's specific pathogen-free eggs. Approximately 5% of the samples were positive for type A influenza viruses by RRT-PCR, and from 14 of those samples AI viruses were isolated and fully characterized. The isolates, belonging to 8 different avian influenza virus subtype combinations (H10N4, H1N1, H4N6, H7N7, H7N4, H5N1, H5N2, and H5N3), were obtained from migratory Anseriformes.

Waterfowl potential as resevoirs of high pathogenic avian influenza H5N1 viruses

The high population of waterfowl subsequently with the high case fatality of poultry and people in West Java regency caused by HPAI H5N1 can raise possibility that waterfowl was a natural reservoir. This research aimed to prove that waterfowl in West Java served as reservoir of AI virus (primarily H5N1) and also identify the virus pathotype based on cleavage site of amino acid sequence. Cloacal swab sample was obtained from healthy and unvaccinated waterfowl from Sukabumi and Bogor Regency. Cloacal swab was propagated in 9 days old embryonic chicken eggs. Allantoic fluid was harvested at the 4 th day of incubation and then tested for hemagglutination, and positive isolate continued with virus sub-typing using PCR method. H5 gene from H5N1 isolate then sequenced using dideoxy termination method. Multiple alignment of nucleotide sequences were analysed using MEGA-3.1 program. Sub-typing using PCR method indicated the existence of 25 strain H5N1, 16 strain HxN1, 4 strain H5Nx and 9 virus ND. Characterization of cleavage site amino acid sequence indicated that all H5N1 sample were pathogenic with sequence QRERRRKKR (23 sample) dan QRESRRKKR (2 sample). Waterfowl was HPAI H5N1 virus reservoir. Asymptomatic infection in waterfowl, but the virus shedding gradually occurred and therefore it became potential source of H5N1 virus infection. Our findings suggest that immediate action is needed to prevent the transmission of highly pathogenic avian influenza viruses from the apparently healthy waterfowl into terrestrial poultry or human. Key Words: HPAI, H5N1, Reservoir, Water Fowl

Identification of a novel bile acid in swans, tree ducks, and geese: 3α,7α,15α-trihydroxy-5β-cholan-24-oic acid

By HPLC, a taurine-conjugated bile acid with a retention time different from that of taurocholate was found to be present in the bile of the black-necked swan, Cygnus melanocoryphus. The bile acid was isolated and its structure, established by (1)H and (13)C NMR and mass spectrometry, was that of the taurine N-acyl amidate of 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid. The compound was shown to have chromatographic and spectroscopic properties that were identical to those of the taurine conjugate of authentic 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid, previously synthesized by us from ursodeoxycholic acid. By HPLC, the taurine conjugate of 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid was found to be present in 6 of 6 species in the subfamily Dendrocygninae (tree ducks) and in 10 of 13 species in the subfamily Anserinae (swans and geese) but not in other subfamilies in the Anatidae family. It was also not present in species from the other two families of the order Anseriformes. 3alpha,7alpha,15alpha-Trihydroxy-5beta-cholan-24-oic acid is a new primary bile acid that is present in the biliary bile acids of swans, tree ducks, and geese and may be termed 15alpha-hydroxy-chenodeoxycholic acid.

Highly pathogenic avian influenza (H7N7): Vaccination of zoo birds and transmission to non-poultry species

In 2003 an outbreak of highly pathogenic avian influenza virus (H7N7) struck poultry in The Netherlands. A European Commission directive made vaccination of valuable species in zoo collections possible under strict conditions. We determined pre- and post-vaccination antibody titres in 211 birds by haemagglutination inhibition test as a measure of vaccine efficacy. After booster vaccination, 81.5% of vaccinated birds developed a titre of ≥40, while overall geometric mean titre (GMT) was 190 (95% CI: 144–251). Birds of the orders Anseriformes, Galliformes and Phoenicopteriformes showed higher GMT, and larger percentages developed titres ≥40 than those of the other orders. Antibody response decreased with increasing mean body weight in birds ≥1.5 kg body weight. In the vicinity of the outbreak, H7N7 was detected by RT-PCR in wild species (mallards and mute swans) kept in captivity together with infected poultry, illustrating the potential threat of transmission from poultry into other avian species, and the importance of protecting valuable avian species by means of vaccination.

Evaluation of a basin ecosystem in arid region using satellite remote sensing

In Central Asia, large-scale expansion of agriculture in Aral Sea basin caused by heavy exploitation of irrigation water from international rivers in the early 1960's. This resulted in the rapid shrinking of the natural wetlands and significant change in the ecosystems. The decrease in river water and the resultant shrinking of the water area have led to destruction of the natural environment. To evaluate such landscape changes satellite remote sensing is most useful. Thus, we started monitoring the ecosystem through investigation and using satellite remote sensing. The study site is the lower Syr-Darya region where is considered as the most unstable in the catchment environment. Ground-truth data of land surface was collected through expeditions from 1999 to 2003. Based on floristic composition and soil investigation, vegetation was classified by using multivariate and cluster analyses. Based on the classification, spectral reflectance, biomass, LAI and plant coverage were measured on each type of vegetation in summer, 2002 and 2003. We found that LAI is a good estimate of biomass, and LAI can be estimated from either NDVI or TSAVI depending on vegetation type in this region. Using these data and methods, we analyzed succession of vegetation on the dried bottom of Aral Sea and relationship between wetland and river flow changes, relationships between the occurrence of Pelican's colony and environmental factors of each lake. From the results, we found that artificial water control of upper irrigational canal is most important to rehabilitate declined ecosystem in this region. It is concluded that maintenance of water consumption will affect wetlands maintenance and preservation of water fowl.

Accumulation and depuration of microcystin produced by the cyanobacterium Microcystis in a freshwater snail

Seasonal changes in microcystin concentrations in a resident snail (Sinotaia histrica) and an edible clam (Corbicula sandai) in Lake Biwa were surveyed. To clarify both the accumulation and depuration of microcystins, experimental studies with microcystin were also carried out on the snail. In the field investigation, microcystin was detected from the hepatopancreas and intestine of S. histrica (up to 3.2 µg g−1 dry weight and 19.5 µg g−1 dry weight, respectively); however, no microcystin was detected in the hepatopancreas of C. sandai. In the laboratory experiment, the microcystin-LR concentration in the hepatopancreas of S. histrica reached a value of 436 µg g−1 dry weight on day 10 of 15 days of uptake, and a high value persisted despite a depuration period of 15 days. The depuration rate constant of microcystin and its biological half-life were 0.0828 day−1 and 8.4 days, respectively. These results indicate that S. histrica has a high ability to accumulate microcystin in its tissue. Because S. histrica is predated by fish and water fowl, it is likely to play an important role as a vector for microcystin in lakes with dense blooms of toxic cyanobacteria.

Sarcocystis spp. in birds of the order Anseriformes.

Having studied 342 birds of 20 species of the order Anseriformes, we found Sarcocystis cysts in 100 individuals (29.2+/-2.5%) belonging to 15 species. One macrocyst and four microcysts types have been determined. By means of light microscopy, the morphology of cyst walls and merozoites have been examined and morphometric data are presented. According to morphological features, macrocysts correspond to the S. rileyi species.

Avian host range of Chlamydophila spp. based on isolation, antigen detection and serology

Published reports and our own diagnostic data on the avian host range of avian Chlamydophila spp. are presented in an attempt to provide evidence for the large number of bird species that have been naturally infectedwith chlamydia. The term 'chlamydia-positive' is based on either isolation of the organism and antigen detection or on serological detection of circulating antibodies. The list of chlamydia-positive birds contains the six majordomestic species (chicken, turkey, Pekin duck, Muscovy duck, goose, and pigeon), the three minor domestic species (Japanese quail, bobwhite quail, and peafowl) and a total of 460 free-living or pet bird species in 30 orders. The order Psittaciformes contains by far the most (153 of 342; 45%) chlamydia-positive bird species. More than 20% of all species per order are positive for chlamydia in the orders Lariformes (gulls, 26 of 92species; 28%), Alciformes (alks, six of 23 species; 26%), Sphenisciformes (penguins, four of 16 species; 25%), and Anseriformes (ducks and geese, 33 of 157 species; 21%). Only 5% of all bird species (14 of 259 species) inthe order Phasianiformes (gallinaceus birds) are chlamydia-positive. The different percentages of chlamydiapositive bird species reflect: (i) a high rate of investigations (e.g. of domestic birds) compared with infrequenttesting (e.g. of Charadriiformes or Cuculiformes), (ii) frequent zoonotic implications (e.g. psittacine and columbiform birds), and (iii) an assumed high susceptibility to infection and subsequent seroconversion (e.g.waterfowl).

Characterization of avian influenza virus isolates submitted to the National Centre for Foreign Animal Disease between 1997 and 2001.

The National Centre for Foreign Animal Disease (NCFAD) in Winnipeg, Manitoba, is the Canadian Food Inspection Agency's (CFIA) newest high biocontainment laboratory. One of the functions of the NCFAD is to serve as a national reference laboratory for avian influenza. Between 1997 and 2001, 15 avian influenza virus isolates were characterized. These isolates originated from domestic poultry, imported caged birds held in quarantine, and wild birds. Diagnostic specimens were submitted to the NCFAD by CFIA field veterinarians, provincial veterinary diagnostic laboratories, and veterinary colleges. Characterization of isolates included the determination of H and N subtypes: H1, H6, H7, and H10 subtypes were isolated from domestic poultry; H3, H4, and three H13 viruses were isolated from water fowl, and six H3 viruses were isolated from caged birds being held in import quarantine. Selected isolates were characterized with respect to their pathogenic potential by intravenous inoculation of 4-to-6-wk-old chickens. A molecular-based protocol was used to assess the pathogenicity of one H7 isolate. During this period, work was also carried out toward validating our molecular pathotyping protocol for avian influenza viruses with H5 and H7 hemagglutinin subtypes.

MEASURING VALUES FOR WETLANDS PROTECTION IN A DEVELOPING COUNTRY FROM DOMESTIC AND INTERNATIONAL CITIZEN GROUPS

MEASURING VALUES FOR WETLANDS PROTECTION IN A DEVELOPING COUNTRY FROM DOMESTIC AND INTERNATIONAL CITIZEN GROUPS