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At least 505 records · Page 28Linked to original sources
USGS2014

Autonomous bed-sediment imaging-systems for revealing temporal variability of grain size

We describe a remotely operated video microscope system, designed to provide high-resolution images of seabed sediments. Two versions were developed, which differ in how they raise the camera from the seabed. The first used hydraulics and the second used the energy associated with wave orbital motion. Images were analyzed using automated frequency-domain methods, which following a rigorous partially supervised quality control procedure, yielded estimates to within 20% of the true size as determined by on-screen manual measurements of grains. Long-term grain-size variability at a sandy inner shelf site offshore of Santa Cruz, California, USA, was investigated using the hydraulic system. Eighteen months of high frequency (min to h), high-resolution (μm) images were collected, and grain size distributions compiled. The data constitutes the longest known high-frequency record of seabed-grain size at this sample frequency, at any location. Short-term grain-size variability of sand in an energetic surf zone at Praa Sands, Cornwall, UK was investigated using the ‘wave-powered’ system. The data are the first high-frequency record of grain size at a single location of a highly mobile and evolving bed in a natural surf zone. Using this technology, it is now possible to measure bed-sediment-grain size at a time-scale comparable with flow conditions. Results suggest models of sediment transport at sandy, wave-dominated, nearshore locations should allow for substantial changes in grain-size distribution over time-scales as short as a few hours.

California↗
USGS2013

Environmental factors that influence cyanobacteria and geosmin occurrence in reservoirs

Phytoplankton are small to microscopic, free-floating algae that inhabit the open water of freshwater, estuarine, and saltwater systems. In freshwater lake and reservoirs systems, which are the focus of this chapter, phytoplankton communities commonly consist of assemblages of the major taxonomic groups, including green algae, diatoms, dinoflagellates, and cyanobacteria. Cyanobacteria are a diverse group of single-celled organisms that can exist in a wide range of environments, not just open water, because of their adaptability [1-3]. It is the adaptability of cyanobacteria that enables this group to dominate the phytoplankton community and even form nuisance or harmful blooms under certain environmental conditions [3-6]. In fact, cyanobacteria are predicted to adapt favorably to future climate change in freshwater systems compared to other phytoplankton groups because of their tolerance to rising temperatures, enhanced vertical thermal stratification of aquatic ecosystems, and alterations in seasonal and interannual weather patterns [7, 8]. Understanding those environmental conditions that favor cyanobacterial dominance and bloom formation has been the focus of research throughout the world because of the concomitant production and release of nuisance and toxic cyanobacterial-derived compounds [4-6, 7-10]. However, the complex interaction among the physical, chemical, and biological processes within lakes, reservoirs, and large rivers often makes it difficult to identify primary environmental factors that cause the production and release of these cyanobacterial by-products.

South Carolina↗
USGS1974

Trichomoniasis in the Hawaiian barred dove

Two barred doves found in the south Kona district of the island of Hawaii were diagnosed as having trichomoniasis on the basis of gross and microscopic lesions. This brings the confirmed list of columbid species susceptible to natural trichomoniasis to four and is the first report of the disease from columbids in the Hawaiian Islands.

Hawaii↗
USGS1975

Fatal pox infection in a rough-legged hawk

Natural pox infection occurred in a free-living rough-legged hawk ( Buteo lagopus ) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks ( Buteo jamaicensis ) but not in great horned owls ( Bubo virginianus ) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

Journal of Wildlife Diseases↗
USGS1961

Renal coccidiosis in oldsquaws (Clangula hyemalis) from Alaska

Renal coccidiosis was found in 4 of 12 oldsquaw ducks ( Clangula hyemalis ) collected from the north slope of Alaska and Prince William Sound. Numerous 1 to 2 mm white foci were observed on the kidney surface of one bird. Microscopically, there was distention of renal tubules with oocysts, flattening of tubular epithelium, and interstitial accumulation of mononuclear cells. Kidneys from several other species of sea ducks from Prince William Sound were not infected.

Alaska↗
USGS1983

Hemorrhagic enteritis in captive American kestrels (Falco sparverius)

Hemorrhagic enteritis and hepatitis of suspected adenovirus etiology were the apparent cause of death of nine captive American kestrels. Cloacal hemorrhage was the only prominent gross lesion: disseminated hepatocellular necrosis, and intranuclear inclusion bodies were evident microscopically. Electron microscopy revealed numerous adenovirus-like particles associated with the hepatic lesions. Attempts to serologically identify the agent were unsuccessful.

Journal of Wildlife Diseases↗
USGS1995

Bothrigaster variolaris (Trematoda: Cyclocoelidae) infection in two Florida snail kites (Rostrhamus sociabilis plumbeus)

Two Florida snail kites ( Rostrhamus sociabilis plumbeus , Say) collected in August and December 1993 from Osceola County (28°15′N, 81°17′W) and Glades County (26°45′N, 81°10′W), Florida (USA), respectively, were infected with Bothrigaster variolaris (Trematoda: Cyclocoelidae); this parasite has not been reported previously from birds in the United States. One bird, a fledgling female, harbored 270 specimens of B. variolaris ; the helminths caused airsacculitis and bronchitis, possible contributing factors in the death of this bird. The other bird, a subadult female, was infected with 40 trematodes and had gross and microscopic lesions consistent with trauma as the cause of death.

Florida↗
USGS1998

Evaluation of two oral baiting systems for wild rodents

Tetracycline hydrochloride (TC)-treated peanut butter or rodent chow baits were distributed during March 1990, on separate 0.53 ha sites in Oglethorpe County, Georgia (USA). Rodents were trapped on a control site prior to bait distribution and on two baited sites 6 days post-distribution. Cleaned skulls from euthanized mammals were grossly examined for TC florescence using an ultraviolet (UV) light. Mandibles were sectioned and examined for TC fluorescence using an ultraviolet light microscope. All 21 cotton rats ( Sigmodon hispidus ), four eastern harvest mice ( Rithrodontomys humulis ), and two golden mice ( Ochrotomys nuttalli ) captured on the control site were negative for TC fluorescence. On the peanut butter bait site, mandible sections from 29 of 32 (91%) cotton rats, three of three (100%) eastern harvest mice, two of three (66%) golden mice, zero of five (0%) white-footed mice ( Peromyscus leucopus ), one of three (33%) short-tailed shrews ( Blarina brevicauda ), and zero of two (0%) least shrews ( Cryptotis parva ) were positive for TC. Results from the rodent chow bait site indicated that 18 of 25 (72%) cotton rats, zero of three (0%) eastern harvest mice, two of seven (29%) golden mice, zero of four (0%) white-footed mice, and zero of four (0%) least shrews were positive for TC fluorescence in mandible sections. These results suggest that a large portion of a free-ranging small rodent population can be administered biological markers or vaccines using baits.

Georgia↗
USGS2000

Pathogenicity of avian malaria in experimentally-infected Hawaii Amakihi

The introduction of avian malaria (Plasmodium relictum) and mosquitoes (Culex quinquefasciatus) to the Hawaiian Islands (USA) is believed to have played a major role in the decline and extinction of native Hawaiian honeycreepers (Drepanidinae). This introduced disease is thought to be one of the primary factors limiting recovery of honeycreepers at elevations below 1,200 m where native forest habitats are still relatively intact. One of the few remaining species of honeycreepers with a wide elevational distribution is the Hawaii Amakihi (Hernignathus virens). We measured morbidity and mortality in experimentally-infected Hawaii Amakihi that were captured in a high elevation, xeric habitat that is above the current range of the mosquito vector. Mortality among amakihi exposed to a single infective mosquito bite was 65% (13/20). All infected birds had significant declines in food consumption and a corresponding loss in body weight over the 60 day course of the experiment. Gross and microscopic lesions in birds that succumbed to malaria included enlargement and discoloration of the spleen and liver and parasitemias as high as 50% of circulating erythrocytes. Mortality in experimentally-infected amakihi was similar to that observed in Apapane (Himnatione sanguinea) and lower than that observed in Iiwi (Vestiaria coccinea) infected under similar conditions with the same parasite isolate. We conclude that the current elevational and geographic distribution of Hawaiian honeycreepers is determined by relative susceptibility to avian malaria.

Hawaii↗
USGS2001

Failure of tetracycline as a biomarker in batch-marking juvenile frogs

Recent widespread amphibian declines call for better techniques to assess population dynamics. Tetracycline as a biomarker in capture-recapture studies is one technique used successfully in fish, reptiles, and mammals. A two-phase experimental study was conducted to evaluate tetracycline as a biomarker in green frogs ( Rana clamitans ) and pickerel frogs ( Rana palustris ). In the first experimental phase tadpoles were exposed to water containing either 250 mg/l or 500 mg/l tetracycline for a period of 24 hr. During the second phase, juvenile frogs were exposed to tetracycline in water at 500 mg/l or given injections of tetracycline at the dose rate of 100 mg/kg body weight. At selected times several weeks later, under tricaine methanesulfonate anesthesia, a toe was surgically excised from each animal, sectioned and viewed under an ultraviolet microscope. No significant differences were found between the various treatments and control animals (untreated). Therefore, the use of tetracycline as a biomarker in anurans using these techniques is not recommended.

Journal of Wildlife Diseases↗
USGS2007

An outbreak of type C botulism in Herring Gulls (Larus argentatus) in Southeastern Sweden

From 2000 to 2004, over 10,000 seabirds, primarily Herring Gulls ( Larus argentatus ), died from an undetermined cause in the Blekinge archipelago in southeastern Sweden. In June 2004, 24 affected Herring Gulls were examined clinically, killed humanely, and 23 were examined by necropsy. Seven and 10 unaffected Herring Gulls collected from a local landfill site and from Iceland, respectively, served as controls. All affected birds showed similar neurologic signs, ranging from mild incoordination and weakness to severe flaccid paralysis of legs and wings, but generally were alert and responsive. All affected gulls were in normal nutritional condition, but were dehydrated and had empty stomachs. No gross or microscopic lesions, and no bacterial or viral pathogens were identified. Type C botulinum toxin was detected in the sera of 11 of 16 (69%) affected gulls by mouse inoculation. Type C botulism was the proximate cause of disease in 2004. Sera from 31% of birds tested from outbreaks in 2000 to 2003 also had detectable type C botulinum toxin by mouse inoculation. No large-scale botulism outbreak has been documented previously in this area. The source of toxin, initiating conditions, and thus, the ultimate cause of this outbreak are not known. This epidemic might signal environmental change in the Baltic Sea.

Journal of Wildlife Diseases↗
USGS2009

Knemidokoptic mange in Hawai`i `Amakihi (Hemignathus virens) on the island of Hawai`i

Lesions resembling knemidokoptic mange on the feet and tarsometatarsi of two Hawai`i `Amakihi ( Hemignathus virens ) were observed while the researchers were mist-netting wild passerines at Manuka Natural Area Reserve on the island of Hawai`i between 14 June 2007 and 19 June 2007. During subsequent mist-netting from September 2007 through February 2008, we found 26% (7/27) of the Hawai`i `Amakihi caught were similarly affected. Microscopic examination of skin scrapings from lesions of affected individuals revealed Knemidokoptes jamaicensis (Acari: Knemidokoptidae). This is the first report of Knemidokoptes spp. found in wild passerines in Hawai`i. No other wild passerines ( n =573) have been found with knemidokoptic mange during our islandwide study of Hawai`i `Amakihi.

Hawai`i↗
USGS2015

Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs ( Cynomys spp.), Colorado, USA

Prairie dogs ( Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice ( Peromyscus maniculatus ) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

Colorado↗
USGS2015

Experimental susceptibility of Wood Ducks ( Aix sponsa ) for West Nile virus

Detection of West Nile virus (WNV) has been reported in a variety of wild ducks in the US, but little is known about the pathogenesis and outcome of exposure of the disease in these species. Previous experimental studies of WNV in ducks either have challenged a small number of ducks with WNV or have tested domesticated ducks. To determine susceptibility and immune response, we challenged 7-wk-old Wood Ducks ( Aix sponsa ) with a 1999 American Crow ( Corvus brachyrhynchos ) isolate of WNV. Wood Ducks were susceptible to infection with the virus, and, although clinical signs or mortality were not observed, microscopic lesions were noted, particularly in the heart and brain. West Nile virus viremia peaked on day 2 postinfection (pi) at 10 4.54 plaque-forming units (PFU) of virus/mL serum and WNV was shed orally (between 10 2 and 10 2.9 PFU per swab) and cloacally. Specific anti-WNV antibody response was rapid, with anti-WNV IgM detected on day 3 pi followed on day 5 pi by anti-WNV IgG. Neutralizing antibodies were detected by plaque-reduction neutralization assay in one duck on day 4 pi, and in all sampled ducks on day 5. These results indicate that Wood Ducks are susceptible to WNV, but it is unlikely that significant WNV mortality events occur in Wood Ducks or that ducks play a significant role in transmission. However, WNV viremia was sufficient, in theory, to infect mosquitoes, and oral and cloacal shedding of the virus may increase the risk of infection to other waterbirds.

Journal of Wildlife Diseases↗
USGS2019

Leptospirosis in Northern Sea Otters (Enhydra lutris kenyoni) from Washington

We diagnosed leptospirosis in six northern sea otters ( Enhydra lutris kenyoni ) that stranded on beaches in Washington, US in 2002. Significant gross findings included cyanotic oral mucous membranes, renal swelling, congestion or pale streaks on the cut surface of the lobules, hematuria, dehydration, lymphadenopathy, pulmonary congestion and rarely adrenal hemorrhage and congestion. Histopathology showed lymphoplasmacytic tubulointerstitial nephritis with intraluminal spirochetes and immunoreactivity to leptospiral antigens in the renal tubules and interstitium. qPCR using kidney or urine for the leptospiral lipL32 gene was positive with cycle threshold values indicative of abundant or moderate amounts of nucleic acid. A microscopic agglutination test showed the highest serum antibody titer to serovar Pomona and titers to serovars Autumnalis, Bratislava, Hebdomadis, Grippo, Ictero, Pyrogenes, Ballum, Canicola, and Hardjo. While antibodies to Leptospira interrogans have been previously detected in sea otters, there are no reports of disease or descriptions of pathology.

Washington↗
USGS2021

Pathology of Lagovirus europaeus GI.2/RHDV2/b (rabbit hemorrhagic disease virus 2) in native North American lagomorphs

Rabbit hemorrhagic disease, a notifiable foreign animal disease in the US, was reported for the first time in wild native North American lagomorphs in April 2020 in the southwestern US. Affected species included the desert cottontail ( Sylvilagus audubonii ), mountain cottontail ( Sylvilagus nuttallii ), black-tailed jackrabbit ( Lepus californicus ), and antelope jackrabbit ( Lepus alleni ). Desert cottontails ( n =7) and black-tailed jackrabbits ( n =7) collected in April and May 2020 were necropsied at the US Geological Survey National Wildlife Health Center and tested positive for Lagovirus europaeus GI.2, also known as rabbit hemorrhagic disease virus 2 (GI.2/RHDV2/b), by real-time PCR at the US Department of Agriculture's Foreign Animal Disease Diagnostic Laboratory. Gross and microscopic lesions were similar to those reported in European rabbits ( Oryctolagus cuniculus ) and other hare ( Lepus ) species with GI.2/RHDV2/b infection; they included epistaxis (12/13; 92%); massive hepatocellular dissociation (14/14; 100%) and necrosis or apoptosis (11/11; 100%); pulmonary congestion (12/12; 100%), edema (12/13; 92%), and hemorrhage (11/12; 92%); and acute renal tubular injury (3/8; 38%). As in previous reports, massive hepatocellular dissociation and necrosis or apoptosis were the most diagnostically distinct finding. As North American Sylvilagus and Lepus species appear to be susceptible to fatal GI.2/RHDV2/b infection, additional work is needed to understand the host range, pathogenicity, and potential population effects of GI.2/RHDV2/b in North America.

Arizona, New Mexico, Texas↗
USGS1990

Mass-marking of otoliths of lake trout sac fry by temperature manipulation

The otoliths of 676,000 sac fry of lake trout Salvelinus namaycush in 1986, and of 1,100,000 in 1987, were marked by daily manipulation of water temperature. The fish were stocked into Lake Huron in the spring. Otolith marks consisted of groups of daily growth rings accentuated into recognizable patterns by steadily raising and lowering the temperature about 10 degrees C (from a base of 1-4 degrees C) over 14 h. In 1987, groups of marked and control fish were held for 6 months. The otoliths were removed from samples of the fish, embedded in epoxy, thin sectioned by grinding in the sagittal plane, etched, and viewed by using a combination of a compound microscope (400-1000x) and a video enhancement system. One or more readable otolith sections were obtained from 39 of a sample of 40 fish. Three independent readers examined 41 otoliths for marks and correctly classified the otoliths, with accuracies of 85, 98, and 100%, as being from marked or unmarked fish. The exact number of rings in a recognizable pattern sometimes differed from the number of temperature cycles to which the fish were exposed. Counts of daily rings within groups of six rings varied less than counts within groups of rings.

American Fisheries Society Symposium↗
USGS1988

Morphology of glochidia of Lampsilis higginsi (Bivalvia: Unionidae) compared with three related species

Glochidia of the endangered unionid mussel Lampsilis higginsi (Lea) are morphologically similar to those of several other species in the upper Mississippi River. Life history details, such as the timing of reproduction and identity of host fish, can be readily studied if the glochidia of L. higginsi can be distinguished from those of related species. Authors used light and scanning electron microscopy and statistical analyses of three shell measurements, shell length, shell height, and hinge length, to compare the glochidia of L. higginsi with those of L. radiata siliquoidea (Barnes), L. ventricosa (Barnes), and Ligumia recta (Lamarck). Glochidia of L. higginsi were differentiated by scanning electron microscopy on the basis of a combined examination of the position of the hinge ligament and the width of dorsal ridges, but were indistinguishable by light microscope examination or by statistical analyses of measurements.

American Malacological Bulletin↗