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Sample records for leech lake american

  1. An Array of Opportunities: Building a Sustainable Future at Leech Lake Tribal College

    Science.gov (United States)

    Buckland, Hannah

    2018-01-01

    With support from Leech Lake Tribal College (LLTC) in Cass Lake, Minnesota, solar energy infrastructure--as well as specialized training and well-paying jobs--are coming to the Leech Lake Nation. Rather than power LLTC's facilities, a 40- kilowatt solar garden installed on the college's campus during the 2017 fall semester, along with four similar…

  2. Hydrogeology and ground-water quality of glacial-drift aquifers, Leech Lake Indian Reservation, north-central Minnesota

    Science.gov (United States)

    Lindgren, R.J.

    1996-01-01

    Among the duties of the water managers of the Leech Lake Indian Reservation in north-central Minnesota are the development and protection of the water resources of the Reservation. The U.S. Geological Survey, in cooperation with the Leech Lake Indian Reservation Business Committee, conducted a three and one half-year study (1988-91) of the ground-water resources of the Leech Lake Indian Reservation. The objectives of this study were to describe the availability and quality of ground water contained in glacial-drift aquifers underlying the Reservation.

  3. A new glossiphoniid leech from Catemaco Lake, Veracruz, México.

    Science.gov (United States)

    Oceguera-Figueroa, Alejandro

    2008-04-01

    Haementeria acuecueyetzin n. sp. from Catemaco Lake, Veracruz, Mexico, is described based on the examination of 6 specimens. This new hematophagous leech species resembles other members of the genus in the number and position of the eyespots, number of compact salivary glands, and in the presence of 2 pairs of spheroidal mycetomes, but it is distinguished from the other species by having 6 rows of longitudinal smooth white papillae in the dorsal surface and numerous tubercles in dorsal and ventral surfaces. This new species represents the third species of Haementeria in the Northern Hemisphere of the Americas.

  4. Crystalline Repository Project: Review and comment of the Leech Lake Reservation Business Committee: Draft area recommendation report

    International Nuclear Information System (INIS)

    1986-09-01

    The Leech Lake Reservation Business Committee (LLRBC) has reviewed five documents related to the US Department of Energy's Crystalline Repository Project (CRP). They are the ''National Survey of Crystalline Rocks,'' ''General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories;' Final Siting Guidelines (10 CFR Part 960),'' ''Regional Characterization Reports for the North Central Region,'' the ''Region to Area Screening Methodology Document'' (SMD) and the ''Draft Area Recommendation Report'' (DARR). The comments and discussions of issues contained in this review will be considered in the preparation of the Final Area Recommendation Report, which will formally identify potentially acceptable sites for a second national repository for the permanent disposal of high level nuclear waste. Following a review of the above referenced documents, the LLRBC has concluded that the identification of potentially acceptable sites in the Draft Area Recommendation Report is based upon inferior and incomplete technical information being applied to a flawed screening process which, among other deficiencies, pays little attention to the importance of hydrological factors in the siting process. Although the DOE prefers that comments from states and tribes be directed at the Draft Area Recommendation Report alone, the Leech Lake Reservation Business Committee is extremely concerned about inadequacies in the ''National Survey of Crystalline Rocks'' (ORCD-1), which serves as the foundation for all siting work done to date. The national survey was conducted utilizing little of the time or staffing required for this important phase of the Crystalline Repository Program. As a result, the national survey is based upon out-of-date scientific literature, exaggerates certain screening variables that favor the selection of regions in the eastern US and arbitrarily eliminated the few western crystalline rock bodies that passed the questionable screening process utilized

  5. Medical leech therapy (Hirudotherapy

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2016-01-01

    Full Text Available Leeches have been used in medicine long time before BC. In recent years medical leech therapy has gained increasing interest in reconstructive surgery and pain management and other medical fields. The possible indications and success rates of this treatment are discussed. There is a special interest in salvage of flaps and grafts by the use of medical leeches. Retrospective analysis indicates a success rate of >80%. Randomized controlled trials have been performed in osteoarthritis. Case reports and smaller series are available for the treatment of chronic wounds, post-phlebitic syndrome and inflammatory skin diseases. The most common adverse effects are prolonged bleeding and infection by saprophytic intestinal bacteria of leeches. Medical leech therapy is a useful adjunct to other measures wound management.

  6. Incidental oligotrophication of North American Great Lakes.

    Science.gov (United States)

    Evans, Mary Anne; Fahnenstiel, Gary; Scavia, Donald

    2011-04-15

    Phytoplankton production is an important factor in determining both ecosystem stability and the provision of ecosystem goods and services. The expansive and economically important North American Great Lakes are subjected to multiple stressors and understanding their responses to those stresses is important for understanding system-wide ecological controls. Here we show gradual increases in spring silica concentration (an indicator of decreasing growth of the dominant diatoms) in all basins of Lakes Michigan and Huron (USA and Canadian waters) between 1983 and 2008. These changes indicate the lakes have undergone gradual oligotrophication coincident with and anticipated by nutrient management implementation. Slow declines in seasonal drawdown of silica (proxy for seasonal phytoplankton production) also occurred, until recent years, when lake-wide responses were punctuated by abrupt decreases, putting them in the range of oligotrophic Lake Superior. The timing of these dramatic production drops is coincident with expansion of populations of invasive dreissenid mussels, particularly quagga mussels, in each basin. The combined effect of nutrient mitigation and invasive species expansion demonstrates the challenges facing large-scale ecosystems and suggest the need for new management regimes for large ecosystems.

  7. When Leeches reveal Biodiversity

    DEFF Research Database (Denmark)

    Schnell, Ida Bærholm

    to provide information about vertebrate biodiversity. This thesis covers the development of a monitoring method based on iDNA extracted from terrestrial haematophagous leeches, a continuation of the work presented in Schnell et al., 2012. The chapters investigate and/or discuss different subjects regarding...

  8. Ocular leech infestation

    Directory of Open Access Journals (Sweden)

    Lee YC

    2015-02-01

    Full Text Available Yueh-Chang Lee, Cheng-Jen Chiu Department of Ophthalmology, Buddhist Tzu-Chi General Hospital, Hualien, Taiwan, ROC Abstract: This case report describes a female toddler with manifestations of ocular leech infestation. A 2-year-old girl was brought to our outpatient clinic with a complaint of irritable crying after being taken to a stream in Hualien 1 day previous, where she played in the water. The parents noticed that she rubbed her right eye a lot. Upon examination, the girl had good fix and follow in either eye. Slit-lamp examination showed conjunctival injection with a moving dark black–brown foreign body partly attached in the lower conjunctiva. After applying topical anesthetics, the leech, measuring 1 cm in length, was extracted under a microscope. The patient began using topical antibiotic and corticosteroid agents. By 1 week after extraction, the patient had no obvious symptoms or signs, except for a limited subconjunctival hemorrhage, and no corneal/scleral involvement was observed. Keywords: leech, ocular foreign body, conjunctival reaction, pediatric ophthalmology

  9. Ciprofloxacin-Resistant Aeromonas hydrophila Cellulitis following Leech Therapy

    Science.gov (United States)

    Giltner, Carmen L.; Bobenchik, April M.; Uslan, Daniel Z.; Deville, Jaime G.

    2013-01-01

    We report a case of surgical site infection with ciprofloxacin-resistant Aeromonas hydrophila following leech therapy. Antimicrobial and genetic analyses of leech and patient isolates demonstrated that the resistant isolates originated from the leech gut microbiota. These data suggest that ciprofloxacin monotherapy as a prophylaxis regimen prior to leech therapy may not be effective in preventing infection. PMID:23363826

  10. Internal contamination with leech in a turkey

    Directory of Open Access Journals (Sweden)

    Mahmoud Bahmani

    2015-02-01

    Full Text Available Leech enters to mouth and nose through water. Nose and nasopharynx mucosa are the most preferred places for leech attachment with epistaxis and respiratory distress symptoms. But the leeches may rarely stick deeper to trachea or esophagus which could cause hematemesis, hemoptysis and severe respiratory distress. Leech infestation can cause gastrointestinal, respiratory and genital bleeding in rare cases. Various animals such as ruminants, single-toed and carnivores, are easily infected with leeches. In May 2014, a 2-year-old turkey infected with leeches through the contaminated drinking water was referred to a veterinarian with respiratory distress symptoms, anxiety, bleeding from the mouth in Maze-Abdali Village located at 17 km from Dehloran City of Ilam Province in the west of Iran. After physical observations, a moving dark green particle was seen. Limnatis nilotica were detected after separation from the oral cavity of turkey. Respiratory distress and oral cavity bleeding should be regarded in the areas where spring and flooded water were infested with leeches. Untreated and contaminated waters consumption should be prohibited.

  11. High-mountain lakes provide a seasonal niche for migrant American dippers

    Science.gov (United States)

    J. M. Garwood; K. L. Pope; R. M. Bourque; M. D. Larson

    2009-01-01

    We studied summer use of high elevation lakes by American Dippers (Cinclus mexicanus) in the Trinity Alps Wilderness, California by conducting repeated point-count surveys at 16 study lakes coupled with a 5-year detailed survey of all available aquatic habitats in a single basin. We observed American Dippers during 36% of the point-count surveys...

  12. Leeches as a source of mammalian viral DNA and RNA - a study in medicinal leeches

    DEFF Research Database (Denmark)

    Kampmann, Marie-Louise; Schnell, Ida Bærholm; Jensen, Randi Holm

    2017-01-01

    V]) from nucleic acids extracted from medicinal leeches fed with blood spiked with each virus. All viruses except BHV showed a gradual decline in concentration from day 1 to 50, and all except BHV were detectable in at least half of the samples even after 50 days. BHV exhibited a rapid decline at day 27...... and was undetectable at day 50. Our findings in medicinal leeches indicate that leeches collected in the wild might be an untapped resource for detecting vertebrate viruses and could provide new opportunities to study wildlife viral diseases of rare species in challenging environments, where capturing and handling...

  13. An overview of leech and its therapeutic applications

    Directory of Open Access Journals (Sweden)

    Parimannan Sivachandran

    2015-05-01

    Full Text Available Hirudotherapy has a broad spectrum of therapeutic application in the medical field ranging from cardiology, gynaecology, ophthalmology, plastic and reconstructive surgeries. In medieval and early modern medicine, leeches were used to remove blood from patients in an attempt to balance the biological humours. Leeches are widely used to treat venous congestion in microvascular replantation, free and conventional flap surgery and traumatology. Recently, Food and Drug Administration has approved the usage of live leeches as medical device for therapeutic applications. Presently, some of the leech species have declined dramatically in its population due to the over utilization of leech for medicinal purposes and also due to pollution in several parts of the world particularly in European and Asian countries. This review presents an overview of leech including the history, biology, classification, and its application as medical device. Further, it also covers the controversies and misconception related to leech species identification and complications of post hirudotherapy.

  14. The literature review of Leech therapy

    Directory of Open Access Journals (Sweden)

    Jang Hyo-kil

    2010-03-01

    Full Text Available Objective : To review the trend of the study related to Leech therapy and to establish the hereafter direction for the study on Leech therapy. Methods : I reviewed and analyzed all the theses published in Domestic and Foreign research institution from 1990 to 2009. Results : The following results were obtained in this study. 1. Analyzed number of theses published, there was no significance per year. 2. Classified by theme of journal, journals related to surgery were most(41 journals, 75.92% among 54 kinds. 3. Classified by theses by research method and thesis types, case report accounted for nearly twothirds (52 pieces, 68.42% of all theses and consideration of document was next(9 pieces, 11.84%. 4. With the most case of venous congestion after plastic and reconstructive surgery(33 pieces, 63.46%, leech therapy was effective on illnesses such as haematoma, macroglossia, purpura, varicous vein, avulsion injury, neurovascular compression, diabetic neuropathy, penoscrotal oedema, buerger's disease, rheumatoid arthritis. 5. Two most appeared adverse effects were anemia and infection. Immediate blood transfusion was done for recovering anemia and prophylactic 3rd generation antibiotics to infection were emphasized in more than half of case reports. 6. All of consideration of documents was retrospective study of cases related leech therapy and 3 pieces of them emphasized prophyratic antibiotic treatment for preventing infection. 7. The study of clinical trail type started first in 2002 and osteoarthritis of knee and carpometacarpal joint were main target. As see above result, Leech therapy was effective cure and could be used in disease induced by venous congestion. And I think that it is necessary to perform additional study related to solution of problems about leech therapy and protocol for using in clinical practice.

  15. METALS AND METALLOIDS IN TISSUES OF AMERICAN ALLIGATORS IN THREE FLORIDA LAKES

    Science.gov (United States)

    Concentrations of metals and selenium were examined in tissues of American alligators (Alligator mississippiensis) from three lakes in central Florida, in one of which alligators have exhibited reproductive or developmental defects. Our overall objective was to determine whether ...

  16. Leech in urinary bladder causing hematuria.

    Science.gov (United States)

    Alam, Shadrul; Das Choudhary, Mrigen Kumar; Islam, Kabirul

    2008-02-01

    To estimate efficacy of normal saline in the management of hematuria caused by accidental entry of a leech per urethra into the urinary bladder. An intervention study was carried out in the Department of Pediatric Surgery of Sylhet MAG Osmani Medical College between January 1998 and December 2003. A total of 43 boys (mean age 8 years, SD+/-2.6) were enrolled. In all cases, a leech had entered the urinary bladder through the urethra causing hematuria. All patients were equipped with a self-retaining Foley catheter. They were managed by infusing 50ml of normal saline into the urinary bladder through the catheter that was then clamped for 3h. After removing the catheter, in all cases the whole leech was spontaneously expelled intact, dead or alive, within 2-24h during the subsequent act of micturition. Hematuria gradually diminished to a clear flow within the next 6h in 27 cases, 12h in 14 cases and 24h in two cases. All patients were followed up for 2 weeks, and none developed recurrent hematuria. Catheterization and irrigation of the urinary bladder with normal saline is a relatively simple, safe and inexpensive method of removing the leech and controlling hematuria.

  17. Observations of Lake-Breeze Events During the Toronto 2015 Pan-American Games

    Science.gov (United States)

    Mariani, Zen; Dehghan, Armin; Joe, Paul; Sills, David

    2018-01-01

    Enhanced meteorological observations were made during the 2015 Pan and Parapan American Games in Toronto in order to measure the vertical and horizontal structure of lake-breeze events. Two scanning Doppler lidars (one fixed and one mobile), a C-band radar, and a network including 53 surface meteorological stations (mesonet) provided pressure, temperature, humidity, and wind speed and direction measurements over Lake Ontario and urban areas. These observations captured the full evolution (prior, during, and after) of 27 lake-breeze events (73% of observation days) in order to characterize the convective and dynamic processes driving lake breezes at the local scale and mesoscale. The dominant signal of a passing lake-breeze front (LBF) was an increase in dew-point temperature of 2.3 ± 0.3°C, coinciding with a 180° shift in wind direction and a decrease in air temperature of 2.1 ± 0.2°C. Doppler lidar observations over the lake detected lake breezes 1 hour (on average) before detection by radar and mesonet. On days with the synoptic flow in the offshore direction, the lidars observed wedge-shaped LBFs with shallow depths, which inhibited the radar's ability to detect the lake breeze. The LBF's ground speed and inland penetration distance were found to be well-correlated (r = 0.78), with larger inland penetration distances occurring on days with non-opposing (non-offshore) synoptic flow. The observed enhanced vertical motion ({>} 1 m s^{-1}) at the LBF, observed by the lidar on 54% of lake-breeze days, was greater (at times {>} 2.5 m s^{-1}) than that observed in previous studies and longer-lasting over the lake than over land. The weaker and less pronounced lake-breeze structure over land is illustrated in two case studies highlighting the lifetime of the lake-breeze circulation and the impact of propagation distance on lake-breeze intensity.

  18. American Fisheries Society 136th Annual Meeting Lake Placid, NY 10-14 September, 2006

    Science.gov (United States)

    Einhouse, D.; Walsh, M.G.; Keeler, S.; Long, J.M.

    2005-01-01

    The New York Chapter of the American Fisheries Society and the New York State Department of Environmental Conservation invite you to experience the beauty of New York's famous Adirondack Park as the American Fisheries Society (AFS) convenes its 136th Annual Meeting in the legendary Olympic Village of Lake Placid, NY, 10-14 September 2006. Our meeting theme "Fish in the Balance" will explore the interrelation between fish, aquatic habitats, and man, highlighting the challenges facing aquatic resource professionals and the methods that have been employed to resolve conflicts between those that use or have an interest in our aquatic resources. As fragile as it is beautiful, the Adirondack Region is the perfect location to explore this theme. Bordered by Mirror Lake and its namesake, Lake Placid, the Village of Lake Placid has small town charm, but all of the conveniences that a big city would provide. Whether its reliving the magic of the 1980 hockey team's "Miracle on Ice" at the Lake Placid Olympic Center, getting a panoramic view of the Adirondack high peaks from the top of the 90 meter ski jumps, fishing or kayaking in adjacent Mirror Lake, hiking a mountain trail, or enjoying a quiet dinner or shopping excursion in the various shops and restaurants that line Main Street, Lake Placid has something for everyone.

  19. Medicinal leech therapy-an overall perspective.

    Science.gov (United States)

    Sig, Ali K; Guney, Mustafa; Uskudar Guclu, Aylin; Ozmen, Erkan

    2017-12-01

    Complementary medicine methods have a long history, but modern medicine has just recently focused on their possible modes of action. Medicinal leech therapy (MLT) or hirudotherapy, an old technique, has been studied by many researchers for possible effects on various diseases such as inflammatory diseases, osteoarthritis, and after different surgeries. Hirudo medicinalis has widest therapeutic usage among the leeches, but worldwide, many different species were tested and studied. Leeches secrete more than 20 identified bioactive substances such as antistasin, eglins, guamerin, hirudin, saratin, bdellins, complement, and carboxypeptidase inhibitors. They have analgesic, anti-inflammatory, platelet inhibitory, anticoagulant, and thrombin regulatory functions, as well as extracellular matrix degradative and antimicrobial effects, but with further studies, the spectrum of effects may widen. The technique is cheap, effective, easy to apply, and its modes of action have been elucidated for certain diseases. In conclusion, for treatment of some diseases, MLT is not an alternative, but is a complementary and/or integrative choice. MLT is a part of multidisciplinary treatments, and secretes various bioactive substances. These substances vary among species and different species should be evaluated for both treatment capability and their particular secreted molecules. There is huge potential for novel substances and these could be future therapeutics.

  20. External auditory canal leech: a rare case report of paediatric ...

    African Journals Online (AJOL)

    Leeches are blood sucking organism feed on human blood. While human bites are common, they rarely cause human internal infestation. We describe a rare case of a parasitic leech infestation of the External Auditory Canal (EAC). A two month old child presented to the Emergency department with a seven day history of ...

  1. Hunting leeches in the dense forests of Madagascar

    DEFF Research Database (Denmark)

    Bohmann, Kristine

    2013-01-01

    Identifying DNA from prey blood stored inside leeches reveals which animals the leeches have preyed on. This can be used to monitor wildlife. To find out whether this new wildlife screening method might be able to aid conservation efforts in Madagascar, the Centre for GeoGenetics has undertaken...

  2. Forest changes since Euro-American settlement and ecosystem restoration in the Lake Tahoe Basin, USA

    Science.gov (United States)

    Alan H. Taylor

    2007-01-01

    Pre Euro-American settlement forest structure and fire regimes for Jeffrey pine-white fir, red fir-western white pine, and lodgepole pine forests were quantified using stumps from trees cut in the 19th century to establish a baseline reference for ecosystem management in the Lake Tahoe Basin. Contemporary forests varied in different ways compared...

  3. A new leech species of Semiscolex (Arhynchobdellida: Semiscolecidae) from Lake Catemaco, Veracruz, Mexico Especie nueva de sanguijuela del género Semiscolex (Arhynchobdellida: Semiscolecidae) del lago de Catemaco, Veracruz, México

    OpenAIRE

    Alejandro Oceguera-Figueroa

    2006-01-01

    Semiscolex lamothei sp. nov. from Catemaco lake, Veracruz, México, is described based on the examination of 18 specimens. The new species differs from other species of the genus by the presence of 1/2 + 5 + 1/2 annuli between gonopores. The new species has morphological features previously not described for any other member of the genus, such as well-developed ejaculatory bulbs and postcaeca in the posterior part of the crop. This is the first record of the genus and the family in the norther...

  4. MARINE LEECH ANTICOAGULANT DIVERSITY AND EVOLUTION.

    Science.gov (United States)

    Tessler, Michael; Marancik, David; Champagne, Donald; Dove, Alistair; Camus, Alvin; Siddall, Mark E; Kvist, Sebastian

    2018-03-16

    Leeches (Annelida: Hirudinea) possess powerful salivary anticoagulants and, accordingly, are frequently employed in modern, authoritative medicine. Members of the almost exclusively marine family Piscicolidae account for 20% of leech species diversity, and feed on host groups (e.g., sharks) not encountered by their freshwater and terrestrial counterparts. Moreover, some species of Ozobranchidae feed on endangered marine turtles and have been implicated as potential vectors for the tumor-associated turtle herpesvirus. In spite of their ecological importance and unique host associations, there is a distinct paucity of data regarding the salivary transcriptomes of either of these families. Using next generation sequencing, we profiled transcribed, putative anticoagulants and other salivary bioactive compounds that have previously been linked to bloodfeeding from 7 piscicolid species (3 elasmobranch-feeders; 4 non-cartilaginous fish-feeders) and 1 ozobranchid species (2 samples). In total, 149 putative anticoagulants and bioactive loci were discovered in varying constellations throughout the different samples. The putative anticoagulants showed a broad spectrum of described antagonistic pathways, such as inhibition of factor Xa and platelet aggregation, that likely have similar bioactive roles in marine fish and turtles. A transcript with homology to ohanin, originally isolated from king cobras, was found in Cystobranchus vividus but is otherwise unknown from leeches. Estimation of selection pressures for the putative anticoagulants recovered evidence for both positive and purifying selection along several isolated branches in the gene trees and positive selection was also estimated for a few select codons in a variety of marine species. Similarly, phylogenetic analyses of the amino acid sequences for several anticoagulants indicated divergent evolution.

  5. Alternative leech vectors for frog and turtle trypanosomes.

    Science.gov (United States)

    Siddall, M E; Desser, S S

    1992-06-01

    Trypanosoma pipientis infections were achieved by exposing laboratory-raised bullfrog tadpoles (Rana catesbeiana) to the leech Desserobdella picta that had fed on infected frogs. Likewise, a laboratory-raised snapping turtle (Chelydra serpentina) was infected with Trypanosoma chrysemydis following exposure to infected Placobdella ornata. Transmission of the trypanosomes by these leeches constitutes new vector records for the parasites. The biology of D. picta and P. ornata suggests that they are more important in transmitting these flagellates than the species of leech previously reported as vectors.

  6. Prolonged bleeding on the neck in leech therapy: Case report

    Directory of Open Access Journals (Sweden)

    Atakan Savrun

    2015-12-01

    Full Text Available Superficial skin bleeding can usually be stopped by applying short-time compression, unless the patient suffers from coagulation disorders or uses anticoagulant. Because of the anticoagulant component of leech saliva, a leech bite may cause long-time bleeding, which cannot be stopped via compression. In this study, the case of a patient who applied leech therapy on her neck for the treatment of migraine has been presented. [Arch Clin Exp Surg 2015; 4(4.000: 234-237

  7. A new leech species of Semiscolex (Arhynchobdellida: Semiscolecidae from Lake Catemaco, Veracruz, Mexico Especie nueva de sanguijuela del género Semiscolex (Arhynchobdellida: Semiscolecidae del lago de Catemaco, Veracruz, México

    Directory of Open Access Journals (Sweden)

    Alejandro Oceguera-Figueroa

    2006-12-01

    Full Text Available Semiscolex lamothei sp. nov. from Catemaco lake, Veracruz, México, is described based on the examination of 18 specimens. The new species differs from other species of the genus by the presence of 1/2 + 5 + 1/2 annuli between gonopores. The new species has morphological features previously not described for any other member of the genus, such as well-developed ejaculatory bulbs and postcaeca in the posterior part of the crop. This is the first record of the genus and the family in the northern hemisphere of the Americas.Se describe Semiscolex lamothei sp. nov. del lago de Catemaco, Veracruz, México con base en 18 ejemplares. Se diferencia del resto de las especies del género por presentar 1/2 + 5 + 1/2 anillos entre los gonoporos. Esta nueva especie del género Semiscolex presenta características morfológicas no descritas en otros miembros del grupo, como bulbos eyaculadores bien desarrollados y postciegos en la región terminal del buche. Es el primer registro del género y de la familia en el hemisferio norte del continente americano.

  8. effect of physico-chemical parameters of water containing leech

    African Journals Online (AJOL)

    PROF EKWUEME

    analysis. Prior to the collection of the water, the temperature, pH conductivity were measured in situ, using the appropriate .... temperate climates were the ecological factors support ... leeches show endogenous rhythm of activity controlled.

  9. Clinical efficacy of Jalaukawacharana (leech application) in Thrombosed piles.

    Science.gov (United States)

    Bhagat, Pradnya J; Raut, Subhash Y; Lakhapati, Arun M

    2012-04-01

    'Arsha' (hemorrhoids) is an ailment that affects all economical groups of population. Though the disease is within the limits of management, it has its own complications like severe hemorrhage, inflammation, and thrombosis, by which a patient gets severe pain and is unable to continue his routine work. Prior to surgical treatment of hemorrhoids, associated conditions like inflammation, strangulation, thrombosis, etc. need to be managed. Thrombosed piles possibly occur due to high venous pressure associated with severe anal pain. Leech (Hirudina medicanalis) application is found to be effective in reducing pain. In thrombosed piles, leech application has shown thrombolytic action, which contributes in re-establishment of circulation. It is observed in the study that, pus and mucous discharge have been reduced after leech application; which may be due to antimicrobial and mucolytic properties of leech. This method of treatment is found to be effective and increase the quality of life in patients suffering with thrombosed piles.

  10. A clinical trial for evaluation of leech application in the management of Vicarcikā (Eczema

    Directory of Open Access Journals (Sweden)

    K M Pratap Shankar

    2014-01-01

    Conclusion : Leech application gives significant relief for the symptoms of eczema. The life quality of the patient also improved significantly after leech therapy. No adverse reactions were reported during the entire course of study.

  11. First report of freshwater leech Helobdella stagnalis (Rhyncobdellida: Glossiphoniidae as a parasite of an anuran amphibian

    Directory of Open Access Journals (Sweden)

    Rocco Tiberti

    2010-12-01

    Full Text Available The authors describe the first case of parasitism on anuran amphibian, Rana temporaria, by the freshwater leech Helobdella stagnalis, in a mountainous area of northwestern Italy. The presence of skin abrasions and haemorrhages attributable to leech attack discards the hypothesis of a simple phoretic relationship between leech and frog.

  12. Anti-leech activity of Scutellaria baicalensis and Morinda citrifolia extracts against Piscicola geometra

    Science.gov (United States)

    Rizky, P. N.; Cheng, T. C.; Nursyam, H.

    2018-04-01

    Piscicola geometra leeches are naturally infecting cobia juvenile. The leeches attach to cobia by sucking and biting its surface and provide the gate of second infection. Water extracts of Scutellaria baicalensis root and Morinda citrifolia leaves were used to be tested through In Vitro method to look for the anti-leeches activity against Piscicola geometra. In this study, a total number of 800 leeches from infected cobia were prepared. The anti-leech activity from water extract of S. baicalensis root and M. citrifolia leaves were compared in different dilutions of plant extracts for 96 hours. Significant anti-leech activity was observed with M. citrifolia leaves with 80% mortality of leeches. S. baicalensis root showed higher anti-leech activity with 100% mortality of leeches. The average time was needed for S.baicalensis root to paralyzing and kill the leeches were 8h, 40h, 48h, 72h, and 96h in various dilutions of S. baicalensis root. This study indicated that S. baicalensis water extract had a potent for new anti-leeches agent.

  13. Clinical uses of the medicinal leech: A practical review

    Directory of Open Access Journals (Sweden)

    B S Porshinsky

    2011-01-01

    Full Text Available The medicinal leech, Hirudo medicinalis, is an excellent example of the use of invertebrates in the treatment of human disease. Utilized for various medical indications since the ancient times, the medicinal leech is currently being used in a narrow range of well-defined and scientifically-grounded clinical applications. Hirudotherapy is most commonly used in the setting of venous congestion associated with soft tissue replantations and free flap-based reconstructive surgery. This is a comprehensive review of current clinical applications of hirudotherapy, featuring a comprehensive search of all major medical search engines (i.e. PubMed, Google Scholar, ScientificCommons and other cross-referenced sources. The authors focus on indications, contraindications, practical application/handling of the leech, and therapy-related complications.

  14. Do singing-ground surveys reflect american woodcock abundance in the western Great Lakes region?

    Science.gov (United States)

    Matthew R. Nelson,; Andersen, David E.

    2013-01-01

    The Singing-ground Survey (SGS) is the primary monitoring tool used to assess population status and trends of American woodcock (Scolopax minor). Like most broad-scale surveys, the SGS cannot be directly validated because there are no independent estimates of abundance of displaying male American woodcock at an appropriate spatial scale. Furthermore, because locations of individual SGS routes have generally remained stationary since the SGS was standardized in 1968, it is not known whether routes adequately represent the landscapes they were intended to represent. To indirectly validate the SGS, we evaluated whether 1) counts of displaying male American woodcock on SGS routes related to land-cover types known to be related to American woodcock abundance, 2) changes in counts of displaying male American woodcock through time were related to changes in land cover along SGS routes, and 3) land-cover type composition along SGS routes was similar to land-cover type composition of the surrounding landscape. In Wisconsin and Minnesota, USA, counts along SGS routes reflected known American woodcock-habitat relations. Increases in the number of woodcock heard along SGS routes over a 13-year period in Wisconsin were related to increasing amounts of early successional forest, decreasing amounts of mature forest, and increasing dispersion and interspersion of cover types. Finally, the cover types most strongly associated with American woodcock abundance were represented along SGS routes in proportion to their composition of the broader landscape. Taken together, these results suggest that in the western Great Lakes region, the SGS likely provides a reliable tool for monitoring relative abundance and population trends of breeding, male American woodcock.

  15. Bronchial Leech Infestation in a 15-Year-Old Female.

    Science.gov (United States)

    Moslehi, Mohammad Ashkan; Imanieh, Mohammad Hadi; Adib, Ali

    2016-01-01

    Foreign body aspiration (FBA) is a common incidence in young children. Leeches are rarely reported as FBA at any age. This study describes a 15-year-old female who presented with hemoptysis, hematemesis, coughs, melena, and anemia seven months prior to admission. Chest X-ray showed a round hyperdensity in the right lower lobe. A chest computed tomography (CT) demonstrated an area of consolidation and surrounding ground glass opacities in the right lower lobe. Hematological investigations revealed anemia. Finally, bronchoscopy was performed and a 5 cm leech was found within the right B 7-8 bronchus and removed by forceps and a Dormia basket.

  16. Some Biological Activities of Malaysian Leech Saliva Extract

    OpenAIRE

    Abdualrahman M. Abdualkader; Ahmed Merzouk; Abbas Mohammed Ghawi; and Mohammed Alaama

    2011-01-01

    Leeches were fed on the phagostimulatory solution through parafilm membrane. The satiated leeches were forced to regurgitate the solution by soaking them in an ice-container. The anticoagulant activity was ascertained using thrombin time assay (TT). The result revealed that the saliva concentration which increases TT by 100% (IC100) is 43.205µg/ml plasma. The antimicrobial activity of the saliva was tested against several bacterial spp. (E.coli, P.aeruginosa, B.cereus, Sal.typhi and S...

  17. MORPHOLOGICAL VARIATION IN HATCHLING AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM THREE FLORIDA LAKES

    Science.gov (United States)

    Morphological variation of 508 hatchling alligators from three lakes in north central Florida (Lakes Woodruff, Apopka, and Orange) was analyzed using multivariate statistics. Morphological variation was found among clutches as well as among lakes. Principal components analysis wa...

  18. Use of the mechanical leech for successful zone I replantation.

    Science.gov (United States)

    Kim, Sang Wha; Han, Hyun Ho; Jung, Sung-No

    2014-01-01

    Replantation of zone I finger injuries remains a challenge, particularly if the fingertip was previously scarred or atrophied, which makes it difficult to secure a suitable vein at the amputation site. In cases of artery-only anastomosis, we propose using a mechanical leech technique to maintain sufficient venous outflow until the internal circulation regenerates. We applied this procedure to eight patients who had zone 1 amputations without veins that were suitable for anastomosis. Emergent surgery was performed and an artery-only anastomosis was created. As there were no veins available, we cut a branch of the central artery and anastomosed it with a 24-gauge angioneedle, which served as a conduit for venous drainage. The overall survival rate for zone I replantation using mechanical leech was 87.5% and the average time to maintain the mechanical leech was 5 days. The mechanical leech technique may serve as an alternative option for the management of venous congestion when no viable veins are available.

  19. Use of the Mechanical Leech for Successful Zone I Replantation

    Directory of Open Access Journals (Sweden)

    Sang Wha Kim

    2014-01-01

    Full Text Available Replantation of zone I finger injuries remains a challenge, particularly if the fingertip was previously scarred or atrophied, which makes it difficult to secure a suitable vein at the amputation site. In cases of artery-only anastomosis, we propose using a mechanical leech technique to maintain sufficient venous outflow until the internal circulation regenerates. We applied this procedure to eight patients who had zone 1 amputations without veins that were suitable for anastomosis. Emergent surgery was performed and an artery-only anastomosis was created. As there were no veins available, we cut a branch of the central artery and anastomosed it with a 24-gauge angioneedle, which served as a conduit for venous drainage. The overall survival rate for zone I replantation using mechanical leech was 87.5% and the average time to maintain the mechanical leech was 5 days. The mechanical leech technique may serve as an alternative option for the management of venous congestion when no viable veins are available.

  20. Control of aquatic leeches (Lymnatis nilotica) us- ing Phytolacca ...

    African Journals Online (AJOL)

    also caused mortality of tadpoles, frogs and round worms found in streams while it doesn't cause any visible toxicity to .... immature age died of leech infestation. About 50 calves that were watered at .... vary depending on the type of water medium (Getachew Tilahun et al., 2002) and in cases where higher doses are ...

  1. Isolation and Analytical Characterization of Local Malaysian Leech Saliva

    Directory of Open Access Journals (Sweden)

    Mohamed Alaama

    2011-12-01

    Full Text Available Leech saliva contains biologically active compounds that are mainly proteins and peptides. In this study a modified and smooth extraction method of saliva was used without leeches' scarification. UV and Bradford Assay protein methods showed that the saliva extract contains high concentrations of proteins. RP-HPLC chromatogram revealed that more than 30 different peaks were observed in leech saliva extract. Gel electrophoresis revealed the existence of proteins and peptides with different molecular weights. The gel showed up to 25 different bands. Comparison of gel electrophoresis data with protein database revealed the closeness of four molecular weights to known proteins from Hirudinaria leech family. Other proteins detected by gel electrophoresis may be related to completely new biologically active proteins and peptides in the saliva extract or to a modification (isoforms of the existing ones or finally to a mixture of both.ABSTRAK: Air liur pacat secara biologinya mengandungi sebahagian besar campuran aktif protein dan peptida. Dalam kajian ini, kaedah pengestrakan air liur pacat yang telah diubah suai digunakan tanpa perlu membunuh pacat. Kaedah protein Cerakin UV dan Bradford menunjukkan air liur pacat yang diekstrak mengandungi konsentrasi protein yang tinggi. Kromatogram RP-HPLC memperlihatkan lebih daripada 30 puncak berbeza diperolehi semasa air liur pacat diekstrak. Gel elektroforesis memperlihatkan kewujudan protein dan peptida dengan berat molekul yang berbeza. Gel menunjukkan hingga 25 jalur yang berbeza. Perbandingan data menggunakan gel elektroforesis seiring dengan pangkalan data protein memperlihatkan persamaan empat berat molekul, dengan protein yang yang dikenali daripada keluarga pacat Hirudinaria. Jenis protein lain yang dikesan dengan menggunakan gel elektrofosis mungkin juga berkait secara biologinya dengan protein dan peptida aktif yang baru, dalam ekstrak air liur atau pengubahsuaian (beberapa jenis yang berbeza daripada

  2. GENETIC ANALYSIS OF THE CHINESE MITTEN CRAB (ERIOCHEIR SINENSIS) INTRODUCED TO THE NORTH AMERICAN GREAT LAKES AND ST. LAWRENCE SEAWAY

    Science.gov (United States)

    The Chinese mitten crab (Eriocheir sinensis) is a globally invasive organism, with established non-native populations in Europe and California, USA. Since 1965, there have been sixteen confirmed catches of E. sinensis in the North American Great Lakes and their associated waterw...

  3. Leech management before application on patient: a nationwide survey of practices in French university hospitals

    Directory of Open Access Journals (Sweden)

    Delphine Grau

    2018-02-01

    Full Text Available Abstract Background Leech therapy in plastic/reconstructive microsurgery significantly improves a successful outcome of flap salvage but the drawback is a risk of severe infection that results in a drop of the salvage rates from 70-80% to below 30%. We report the results of a national survey conducted in all the French university hospitals to assess the current extent of use of leech for medical practices in the hospital and to investigate maintenance, delivery practices and prevention of the risk of infection. Methods Data concerning conditions of storage, leech external decontamination, microbiological controls, mode of delivery and antibiotic prophylaxis were collected from all the French university hospitals in practicing leech therapy, on the basis of a standardized questionnaire. Results Twenty-eight of the 32 centers contacted filled the questionnaire, among which 23 practiced leech therapy, mostly with a centralized storage in the pharmacy; 39.1% of the centers declared to perform leech external decontamination and only 2 centers recurrent microbiological controls of the water storage. Leech delivery was mostly nominally performed (56.5%, but traceability of the leech batch number was achieved in only 39.1% of the cases. Only 5 centers declared that a protocol of antibiotic prophylaxis was systematically administered during leech therapy: either quinolone (2, sulfamethoxazole/trimethoprim (2 or amoxicillin/clavulanic acid (1. Conclusions Measures to prevent infectious complications before application to patient have to be better applied and guidelines of good practices are necessary.

  4. An improved anti-leech mechanism based on session identifier

    Science.gov (United States)

    Zhang, Jianbiao; Zhu, Tong; Zhang, Han; Lin, Li

    2012-01-01

    With the rapid development of information technology and extensive requirement of network resource sharing, plenty of resource hotlinking phenomenons appear on the internet. The hotlinking problem not only harms the interests of legal websites but also leads to a great affection to fair internet environment. The anti-leech technique based on session identifier is highly secure, but the transmission of session identifier in plaintext form causes some security flaws. In this paper, a proxy hotlinking technique based on session identifier is introduced firstly to illustrate these security flaws; next, this paper proposes an improved anti-leech mechanism based on session identifier, the mechanism takes the random factor as the core and detects hotlinking request using a map table that contains random factor, user's information and time stamp; at last the paper analyzes the security of mechanism in theory. The result reveals that the improved mechanism has the merits of simple realization, high security and great flexibility.

  5. Leeches as Sensor-bioindicators of River Contamination by PCBs

    Directory of Open Access Journals (Sweden)

    Gorzyslaw Poleszczuk

    2009-03-01

    Full Text Available The aim of the study was to evaluate the use of leeches of the genus Erpobdella as a means of assessing polychlorinated biphenyl contamination of watercourses. The River Skalice, heavily contaminated with PCBs, was selected as a model. The source of contamination was a road gravel processing factory in Rožmitál pod Třemšínem from which an estimated 1 metric ton of PCBs leaked in 1986. Levels of PCB were measured in leeches collected between 1992 to 2003 from 11 sites covering about 50 km of the river (the first sampling site upstream to the source of contamination and 10 sites downstream. The PCB indicator congeners IUPA no. 28, 52, 101, 118, 138, 153, and 180 were measured. Levels were highest at the four sampling sites nearest the source of pollution. The highest values of PCB congeners were found in 1992. PCB content decreased from 1992 to 2003 and with distance from the source. The study indicated that leeches of the genus Erpobdella are a suitable bioindicator of contamination in the surface layer of river sediments.

  6. Occurrence of three leech species (Annelida: Hirudinida) on fishes in the Kentucky River

    Science.gov (United States)

    Leeches were collected from six fish species distributed among four of ten sites sampled. The leech species observed were Myzobdella reducta (Meyer, 1940) and Myzobdella lugubris Leidy, 1851 of the family Piscicolidae and Placobdella pediculata Hemingway, 1908 of the family Gloss...

  7. Quaternary glaciation and hydrologic variation in the South American tropics as reconstructed from the Lake Titicaca drilling project

    Science.gov (United States)

    Fritz, Sherilyn C.; Baker, Paul A.; Seltzer, Geoffrey O.; Ballantyne, Ashley; Tapia, Pedro; Cheng, Hai; Edwards, R. Lawrence

    2007-11-01

    A 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative water balance and shallow closed-basin conditions in the lake. The apparent coincidence of positive water balance of Lake Titicaca and glacial growth in the adjacent Andes with Northern Hemisphere ice sheet expansion implies that regional water balance and glacial mass balance are strongly influenced by global-scale temperature changes, as well as by precessional forcing of the South American summer monsoon.

  8. Widespread Lake Highstands in the Southernmost Andean Altiplano during Heinrich Event 1: Implications for the South American Summer Monsoon

    Science.gov (United States)

    Chen, C. Y.; McGee, D.; Quade, J.

    2014-12-01

    Speleothem-based oxygen isotope records provide strong evidence of anti-phased behavior of the northern and southern hemisphere summer monsoons during Heinrich events, but we lack rigorous constraints on the amount of wetting or drying occurring in monsoon regions. Studies centered on shoreline deposits of closed-basin lakes are well suited for establishing such quantitative controls on water balance changes by providing unequivocal evidence of lake volume variations. Here we present new dating constraints on the highstands of several high-altitude (3800-4350 m) paleolakes in the southern Andean Altiplano, an outlying arid region of the Atacama Desert stretching across the Chilean-Bolivian-Argentinian border east of the Andes (20-25°S). These lakes once occupied the closed basins where only phreatic playas, dry salars, and shallow ponds exist today. Initial U-Th dating of massive shoreline tufas reveals that these deposits are dateable to within ±150 to 300 yrs due to high U concentrations and low initial Th content (as indicated by high 230Th/232Th). Our U-Th and 14C dates show that lake highstands predominantly occur between 18.5 and 14.5 kyrs BP, coinciding with Heinrich Event 1 (HE1) and the expansion of other nearby lakes, such as Lake Titicaca. Because of their (1) location at the modern-day southwestern edge of the summer monsoon, (2) intact shoreline preservation, and (3) precise age control, these lakes may uniquely enable us to reconstruct the evolution of water balance (P-E) changes associated with HE1. Hydrologic modeling constrained by temperature estimates provided by local glacial records is used to provide bounds for past precipitation changes. We also examine North Atlantic cooling as the mechanism for these changes by comparing a compilation of S. American lake level records with various hosing experiments and transient climate simulations at HE1. Our results lend us confidence in expanding our U-Th work to other shoreline tufas in the

  9. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  10. [A rare case report of laryngeal leech infestation in a 70-year-old man].

    Science.gov (United States)

    Anajar, Said; Tatari, Mohammed; Hassnaoui, Jawad; Abada, Reda; Rouadi, Sami; Roubal, Mohammed; Mahtar, Mohammed

    2017-01-01

    Foreign bodies in the upper respiratory tract are one of the most difficult otolaryngological emergencies; leeches are a very rare foreign bodies in the world. We report the case of a 70-year-old man with no past medical history presenting with laryngeal dyspnea associated with low abundant paroxysmal hemoptysis. The patient underwent nasofibroscopy showing the presence of a living and mobile organism at the subglottic level evoking a leech. Extraction was carried out under local anesthesia using laryngoscope and Magill forceps. The presence of a leech as a foreign body in the upper respiratory tract should be suspected in patients with a recent history of consumption of non-potable water.

  11. Determining the appropriate number and duration of leech therapy in congested tissues using tissue spectrophotometry and laser Doppler flowmetry.

    Science.gov (United States)

    Rothenberger, Jens; Petersen, Wiebke; Schaller, Hans-Eberhard; Held, Manuel

    2016-11-01

    A universal protocol determining the number of leeches and their application time does not exist. The aim of this study, therefore, is to quantify perfusion dynamics in venous congested tissues after leech application to get more detailed information about changes due to leech-induced skin microcirculation and to evaluate the usability of the Oxygen to See (O2C) device in terms of determining the appropriate number of leeches and the duration of therapy. Twelve patients with the need for leech therapy participated in the study. Perfusion dynamics of the congested tissue was assessed using the O2C device, which determines blood flow (BF), the relative amount of hemoglobin (rHB), and the oxygen saturation (SO2). Measurements were carried out before leech application and on various intervals like 10 minutes, one hour, and three hours after leech application. The leech application effectuated after 10 minutes a nonsignificant perfusion improvement, which further increased after one hour with a significant reduction of the relative amount of hemoglobin and a significant increase of blood flow and oxygen saturation (BF= +56.7%; rHB= -25.5%; SO2= +53.7%). After three hours, the values returned to the levels before leech administration. In two cases, in which further administration of leeches within the measurement period was necessary, no substantial perfusion changes were obtained. The results of this study forms a more precise pattern of microcirculatory changes of leech therapy in congested tissues. According to our measurements a venous drainage improvement can be expected in congested tissue one hour after leech administration. The O2C seems to be a useful method to determine the appropriate number and duration of leech therapy. © 2016 by the Wound Healing Society.

  12. Mercury transfer from fish carcasses to scavengers in boreal lakes: the use of stable isotopes of mercury

    International Nuclear Information System (INIS)

    Sarica, Jose; Amyot, Marc; Hare, Landis; Blanchfield, Paul; Bodaly, R.A.; Hintelmann, Holger; Lucotte, Marc

    2005-01-01

    Scavengers play an important role in the flow of energy, matter and pollutants through food webs. For methylmercury (MeHg), which biomagnifies along food chains, the movement of this metal from fish carcasses to aquatic scavengers has never been demonstrated. We measured the transfer of MeHg from fish carcasses to scavenging leeches in two lakes and in the laboratory. The results of a field experiment indicated that leeches were attracted to fish carcasses and that their Hg concentrations increased by as much as a factor of 5 during the time that Hg-rich fish were available for consumption. Under controlled conditions, we exposed leeches to 202 Hg-labelled fish that had been marked in situ following a whole lake 202 Hg addition. Leeches rapidly accumulated Hg from carcasses, and within two weeks assumed the isotopic signature of the carcasses. Necrophagous invertebrates could therefore return Hg from fish carcasses to other trophic levels in lakes. - Scavengers such as leeches accumulate mercury from fish carcasses which then may return into the food web

  13. The Leech with a taste for oranges / Merje Järv-Griffiths

    Index Scriptorium Estoniae

    Järv-Griffiths, Merje

    2007-01-01

    Rockansamblist Leech (kontserdid 23. nov. klubis Rockstar's Tallinnas, 30. nov. Lutsu Teatris Tartus ja 21. dets. festivalil Green Christmas Rakveres), heliplaadist "Tram-O-Gram" (vt. www.leechband.net)

  14. Tyrannobdella rex n. gen. n. sp. and the evolutionary origins of mucosal leech infestations.

    Directory of Open Access Journals (Sweden)

    Anna J Phillips

    Full Text Available BACKGROUND: Leeches have gained a fearsome reputation by feeding externally on blood, often from human hosts. Orificial hirudiniasis is a condition in which a leech enters a body orifice, most often the nasopharyngeal region, but there are many cases of leeches infesting the eyes, urethra, vagina, or rectum. Several leech species particularly in Africa and Asia are well-known for their propensity to afflict humans. Because there has not previously been any data suggesting a close relationship for such geographically disparate species, this unnerving tendency to be invasive has been regarded only as a loathsome oddity and not a unifying character for a group of related organisms. PRINCIPAL FINDINGS: A new genus and species of leech from Perú was found feeding from the nasopharynx of humans. Unlike any other leech previously described, this new taxon has but a single jaw with very large teeth. Phylogenetic analyses of nuclear and mitochondrial genes using parsimony and Bayesian inference demonstrate that the new species belongs among a larger, global clade of leeches, all of which feed from the mucosal surfaces of mammals. CONCLUSIONS: This new species, found feeding from the upper respiratory tract of humans in Perú, clarifies an expansion of the family Praobdellidae to include the new species Tyrannobdella rex n. gen. n. sp., along with others in the genera Dinobdella, Myxobdella, Praobdella and Pintobdella. Moreover, the results clarify a single evolutionary origin of a group of leeches that specializes on mucous membranes, thus, posing a distinct threat to human health.

  15. Comparison of effect of nicotine and levamisole and ivermectin on mortality of leech

    Directory of Open Access Journals (Sweden)

    Mahmoud Bahmani

    2014-02-01

    Full Text Available Objective: To study the effect of different doses of nicotine on Limnatis in comparison with levamisole and ivermectin. Methods: In this interventional experimental study in July 2012, the amount of 61 mature leeches of Limnatis nilotica species were collected and anti-parasitic effects of drug treatments using anti-leech method were assessed. So that, a leech was placed in the dishes with 600 mL spring water and leech's paralysis and death time were recorded accurately for 720 min. A total of 9 replicates were considered for each treatment. Six drug treatments were considered. Pharmacological treatments include nicotine (5, 1 0 and 20 mg doses, levamisole (1 0 mg, ivermectin (10 mg and distilled water. Data were analyzed using the Sigma ASA 2 software and pair t-test method with less than 0.05 confidence levels. Results: The results of present study show that doses of 5, 10 and 20 mg of nicotine, with time average of 2.44依0.52, 1.88依0.78 and 1.55依0.72 min cause to death of leeches. Ivermectin and levamisole cause to death of leeches, averaging 7.44依1.12 and 14.66依5.09 min, respectively. Distilled water treatment has been reported as an ineffective group. Data analysis showed that the group receiving 5 mg nicotine, had minimum time of death and there are statistical differences among all groups (P>0.05, but there are not significant differences between treatments receiving 10 mg nicotine, with 5 and 20 mg nicotine treatments. Conclusions: It appears that nicotine compound as the effective substance of tobacco plant has the strong anti-leech effect on Limnatis nilotica species and can be used as leech purposes in the future.

  16. Cleft lip surgery in Anglo-Saxon Britain: the Leech Book (circa A.D. 920).

    Science.gov (United States)

    Vrebos, J

    1986-05-01

    The Leech Book, the oldest known Anglo-Saxon herbarium, probably written in Winchester, circa A.D. 920, by Cyril Bald or at his special request, contains a short chapter on the surgical treatment of the cleft lip; this chapter apparently represents the first record in a medical manuscript of this treatment. The original Anglo-Saxon text is presented together with transcriptions into more modern English. The general value of the Leech Book is briefly studied.

  17. Leech therapy- a holistic approach of treatment in unani (greeko-arab) medicine.

    Science.gov (United States)

    Lone, Azad Hussain; Ahmad, Tanzeel; Anwar, Mohd; Habib, Shahida; Sofi, Gh; Imam, Hashmat

    2011-07-01

    The Unani System of Medicine also known as Greeko-Arab medicine, founded by Hippocrates is based on the concept of equilibrium and balance of natural body humours (blood, bile, black bile and phlegm). The imbalance in the quality and quantity of these humours leads to diseases whereas restoration of this balance maintains health of a person. The treatment methodology of diseases is based on four therapeutic modalities viz. Regimental therapy, Dieto-therapy, Pharmacotherapy and surgery. Irsale Alaq (Leech or Hirudo therapy) is one of the most important and widely practised methods of regimental therapy used for local evacuation of morbid humours. It is a procedure of treatment with the use of medicinal leeches. It has been suggested and successfully practised by Greeko-Arab physicians in the management of musculoskeletal diseases, gynaecological disorders, chronic skin diseases, thromboembolic diseases, varicose veins, ENT disorders etc since long. According to Unani doctrine, the efficacy of leech therapy is attributed to the analgesic and resolvent activities of leeches. However, from modern perspective, the saliva of leech contains about 100 pharmacologically active biological substances like Hirudin, hyaluronidase, vasodilators, anesthetics, antibacterial, fibrinases, collagenase etc. These substances are injected into human body while sucking of the blood and are responsible for the analgesic, anti inflammatory and anesthetic effects of leech therapy.

  18. The Leech method for diagnosing constipation: intra- and interobserver variability and accuracy

    International Nuclear Information System (INIS)

    Lorijn, Fleur de; Voskuijl, Wieger P.; Taminiau, Jan A.; Benninga, Marc A.; Rijn, Rick R. van; Henneman, Onno D.F.; Heijmans, Jarom; Reitsma, Johannes B.

    2006-01-01

    The data concerning the value of a plain abdominal radiograph in childhood constipation are inconsistent. Recently, positive results have been reported of a new radiographic scoring system, ''the Leech method'', for assessing faecal loading. To assess intra- and interobserver variability and determine diagnostic accuracy of the Leech method in identifying children with functional constipation (FC). A total of 89 children (median age 9.8 years) with functional gastrointestinal disorders were included in the study. Based on clinical parameters, 52 fulfilled the criteria for FC, six fulfilled the criteria for functional abdominal pain (FAP), and 31 for functional non-retentive faecal incontinence (FNRFI); the latter two groups provided the controls. To assess intra- and interobserver variability of the Leech method three scorers scored the same abdominal radiograph twice. A Leech score of 9 or more was considered as suggestive of constipation. ROC analysis was used to determine the diagnostic accuracy of the Leech method in separating patients with FC from control patients. Significant intraobserver variability was found between two scorers (P=0.005 and P<0.0001), whereas there was no systematic difference between the two scores of the other scorer (P=0.89). The scores between scorers differed systematically and displayed large variability. The area under the ROC curve was 0.68 (95% CI 0.58-0.80), indicating poor diagnostic accuracy. The Leech scoring method for assessing faecal loading on a plain abdominal radiograph is of limited value in the diagnosis of FC in children. (orig.)

  19. Installation Restoration Program. Phase II - Confirmation/Quantification. Stage 1 for American Lake Garden Tract, Washington.

    Science.gov (United States)

    1985-12-20

    Lake Garden Tract which houses a grocery K’- store, a barber shop, a laundromat , fast food drive-in, and an automobile repair shop which no longer...store, a barber shop, an insur- ance brokerage, a laundromat , a fast food restaurant, and several equestrian " L . riding and boarding facilities

  20. Some Biological Activities of Malaysian Leech Saliva Extract

    Directory of Open Access Journals (Sweden)

    Abdualrahman M. Abdualkader

    2011-12-01

    Full Text Available Normal 0 21 false false false MS X-NONE AR-SA Leeches were fed on the phagostimulatory solution through parafilm membrane. The satiated leeches were forced to regurgitate the solution by soaking them in an ice-container. The anticoagulant activity was ascertained using thrombin time assay (TT. The result revealed that the saliva concentration which increases TT by 100% (IC100 is 43.205µg/ml plasma. The antimicrobial activity of the saliva was tested against several bacterial spp. (E.coli, P.aeruginosa, B.cereus, Sal.typhi and S.aureus  and fungi spp. (C.albicans and C.neoformans. It was found that saliva has an inhibition activity against Sal.typhi (minimal inhibitory concentration MIC 78.253µg/ml, S.aureus (MIC 78.253µg/ml and E.coli (MIC 121.256µg/ml.ABSTRAK: Pacat-pacat diberi makan larutan phagostimulatory menerusi membran parafilem. Pacat-pacat yang kekenyangan itu dipaksa memuntahkan larutan tersebut dengan direndam di dalam bekas berisi ais. Aktiviti antigumpal ditentukan menggunakan cerakin masa trombin (TT. Keputusan menunjukkan kepekatan air liur pacat menyebabkan pertambahan TT sebanyak 100% (IC100 iaitu 43.205µg/ml plasma. Aktiviti antimikrob air liur telah diuji dengan pelbagai jenis bakteria (E.coli, P.aeruginosa, B.cereus, Sal.typhi dan S.aureus dan pelbagai jenis kulat (C.albicans and C.neoformans. Didapati air liur menghasilkan aktiviti perencatan terhadap Sal.typhi (kepekatan perencat minima (Minimal inhibitory concentration - MIC 78.253µg/ml, S.aureus (MIC 78.253µg/ml dan E.coli (MIC 121.256µg/ml.

  1. Comparison of the geochemical behaviour of plutonium, thorium and uranium in selected North American lakes

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Orlandini, K.A.

    1982-01-01

    The concentrations of all three elements were measured in both filtered water and suspended solids. The reduced (Pu +3 and Pu +4 ) and oxidized (PuO 2 + and PuO 2 2+ ) states of Pu were determined in replicate filtered water samples. Lakes were selected to represent a wide range of physical, chemical and biological conditions. The concentrations of Pu ranged from 1 x 10 -17 to 46 x 10 -17 M, of Th from 1.2 x 10 -12 to 620 x 10 -12 M, and of U from 4 x 10 -10 to 350 x 10 -10 M. The concentration of Pu was correlated with the concentration of Th (r = 0.7) in the lakes studied regardless of the proportion of Pu in the reduced form. There was no correlation between Pu and U concentrations in waters where the Pu was present in the oxidized form. The ratio of oxidized to reduced forms of Pu ranged from as high as 7 to -17 M in any lake water studied whereas that of reduced Pu ranged from about 2.8 x 10 -18 to 4.6 x 10 -16 M. Distribution coefficients (Ksub(dF)) were presented for each actinide. The distribution coefficients for each actinide were regressed against limnological parameters including mean depth, flushing time, pH, suspended solids, conductivity, total alkalinity, and dissolved organic carbon. The distribution coefficients for Pu(IV) and those of Th were found to be linear functions of the dissolved organic carbon content of the water. No significant correlations were found with other limnological parameters. A similar dependency of the distribution coefficient on dissolved organic carbon was observed for U in natural waters with low total alkalinity ( -4 M CaCO 3 ). When the alkalinity is > 0.5 mM and pH > 7.5, alkalinity rather than dissolved organic carbon appears to control the adsorption behaviour of U

  2. Allium sativum L.: the anti-immature leech (Limnatis nilotica) activity compared to Niclosomide.

    Science.gov (United States)

    Bahmani, Mahmoud; Abbasi, Javad; Mohsenzadegan, Ava; Sadeghian, Sirous; Ahangaran, Majid Gholami

    2013-03-01

    This study was carried out to determine the effects of methanolic extracts of Allium sativum L. on Limnatis nilotica compared with Niclosomide. In this experimental study in September 2010, a number of leeches (70 in total) from the southern area of Ilam province were prepared, and the effects of methanolic extract of A. sativum L. with Niclosomide as the control drug were compared and distilled water was evaluated as the placebo group which investigated L. nilotica using anti-leech assay. The average time of paralysis and death of L. nilotica for Niclosomide (1,250 mg/kg) and the methanol extract of A. sativum L. (600 μg/ml) were 6.22 ± 2.94 and 68.44 ± 28.39 min, respectively. Distilled water and garlic tablets at a dose of 400 mg were determined as the inert group. In this research, the attraction time of the leeches' death among different treatments is significant. In this study, it was determined that Niclosomide, with an intensity of 4+, and methanolic extracts of A. sativum L., with an intensity of 3+, have a good anti-leech effect and can be shown to be effective in cases of leech biting, while distilled water was negative.

  3. Intranasal leech (hirudiniasis) common mode of presentation and sites of lodgment

    International Nuclear Information System (INIS)

    Khan, K.A.; Rafique, A.; Rafique, A.; Babur, S.

    2013-01-01

    Objective: To assess the common mode of presentation and sites of lodgment in cases of nasal leech infestation. Design: Descriptive study. Place and Duration of Study: This study was conducted in the ENT Department of Shaikh Khalifa Bin Zayed Al Nahyan Hospital (CMH) Muzaffarabad from 10th Jan 2010 to 15th Feb 2012. Patients and Methods: After getting informed consent, total of 70 cases that fulfilled the inclusion criteria i.e patients irrespective of age and gender with a positive history of epistaxis and use of spring water for daily utilities and especially after exclusion of other known causes for epistaxis were included in this study. A thorough history followed by ENT examination including nasal endoscopy was carried out in each case and site of lodgment of leech documented. This was followed by removal of leech from nose. Results: The commonest mode of presentation of nasal leech was epistaxis (54.28%) and the commonest site of lodgment of leech was under the inferior turbinate (inferior meatus) (82.86%). Conclusion: This rare cause of epistaxis should be kept in mind once all other common causes are excluded especially if the patient belongs to low socioeconomic group and using fresh spring water for their consumption. A thorough search in the region of inferior meatus should be under taken aided by nasal endoscope if available. (author)

  4. A High-Resolution Biogenic Silica Record From Lake Titicaca, Peru-Bolivia: South American Millennial-Scale Climate Variability From 18-60 Kya

    Science.gov (United States)

    Ekdahl, E. J.; Fritz, S. C.; Stevens, L. R.; Baker, P. A.; Seltzer, G. O.

    2004-12-01

    Sediments recovered from a deep basin in Lake Titicaca, Peru-Boliva, were analyzed for biogenic silica (BSi) content by extraction of freeze dried sediments in 1% sodium carbonate. Sediments were dated using an age model developed from multiple 14C dates on bulk sediments. The BSi record shows distinct fluctuations in concentration and accumulation rate from 18 to 60 kya. Multi-taper method spectral analysis reveals a significant millennial-scale component to these fluctuations centered at 1370 years. High BSi accumulation rates correlate with enhanced benthic diatom preservation, suggesting that the BSi record is related to variations in lake water level. Modern-day Lake Titicaca lake level and precipitation are strongly related to northern equatorial Atlantic sea surface temperatures, with cooler SSTs related to wetter conditions. Subsequently, the spectral behavior of the GRIP ice core δ 18O record was investigated in order to estimate coherency and linkages between North Atlantic and tropical South American climate. GRIP data exhibit a significant 1370-year spectral peak which comprises approximately 26% of the total variability in the record. Despite a high degree of coherency between millennial-scale periodicities in Lake Titicaca BSi and GRIP δ 18O records, the Lake Titicaca silica record does not show longer term cooling cycles characteristic of D-O cycles found in the GRIP record. Rather, the Lake Titicaca record is highly periodic and more similar in nature to several Antarctic climate proxy records. These results suggest that while South American tropical climate varies in phase with North Atlantic climate, additional forcing mechanisms are manifest in the region which may include tropical Pacific and Southern Ocean variability.

  5. Local (Malaysian Leech as Alternative Healing Treatment and an Islamic Perspective

    Directory of Open Access Journals (Sweden)

    ZULHISYAM, A. K.

    2016-12-01

    Full Text Available The therapy is known from the time of extreme antiquity, dating back more than 2,500 years ago and still being practiced nowadays. This fact testifies to its efficiency in various health problems. In some cases, traditional medical practitioners use leeches for therapeutic healing treatment which is known as ‘cupping’. Such remedial method is quickly gaining acceptance amongst the local folks which is now becoming a thriving business. Some have made this treatment as their main business even though the therapy is quite recent for people in this country. This article discusses the process of cupping by using leech in the Islamic perspective and also the uniqueness of the hirudin protein in leeches respectively.

  6. Transmitter-induced glycogenolysis and gluconeogenesis in leech segmental ganglia.

    Science.gov (United States)

    Pennington, A J; Pentreath, V W

    1987-01-01

    1. The utilization and control of glycogen stores were studied in the isolated segmental ganglia of the horse leech, Haemopis sanguisuga. The glycogen in the ganglia was extracted and assayed fluorimetrically and its cellular localization and turnover studied by autoradiography in conjunction with [3H] glucose. 2. The glycogen levels were measured after incubation with different neurotransmitters for 60 min at 28 degrees C. The results for each experimental ganglion were compared to a paired control ganglion, and the results analysed by paired t-tests. 3. Several transmitter substances (5-HT, octopamine, dopamine, noradrenaline, histamine) produced reductions in glycogen (glycogenolysis); other transmitters (glutamate, GABA) produced increases in glycogen (gluconeogenesis); others (adenosine, glycine) produced reductions or increases, depending on concentration. Acetylcholine had no effect on the glycogen levels. 4. Most of the glycogen in the ganglia is localized in the packet glial cells, which surround the neuron perikarya. Autoradiographic analysis demonstrated that the effects of histamine and dopamine were principally on the glycogen in the glial cells. 5. Adenylate cyclase was demonstrated by electron microscope histochemistry to be localized on the plasma membranes of the glial cells, and to a lesser extent on the neuronal membranes. 6. It is concluded that the changes in glycogen in the glial cells may be party controlled by transmitters via adenylate cyclase. This may provide a sensitive mechanism for coupling neuronal activity with energy metabolism.

  7. Probabilistic Seismic Hazard Analysis of Victoria, British Columbia, Canada: Considering an Active Leech River Fault

    Science.gov (United States)

    Kukovica, J.; Molnar, S.; Ghofrani, H.

    2017-12-01

    The Leech River fault is situated on Vancouver Island near the city of Victoria, British Columbia, Canada. The 60km transpressional reverse fault zone runs east to west along the southern tip of Vancouver Island, dividing the lithologic units of Jurassic-Cretaceous Leech River Complex schists to the north and Eocene Metchosin Formation basalts to the south. This fault system poses a considerable hazard due to its proximity to Victoria and 3 major hydroelectric dams. The Canadian seismic hazard model for the 2015 National Building Code of Canada (NBCC) considered the fault system to be inactive. However, recent paleoseismic evidence suggests there to be at least 2 surface-rupturing events to have exceeded a moment magnitude (M) of 6.5 within the last 15,000 years (Morell et al. 2017). We perform a Probabilistic Seismic Hazard Analysis (PSHA) for the city of Victoria with consideration of the Leech River fault as an active source. A PSHA for Victoria which replicates the 2015 NBCC estimates is accomplished to calibrate our PSHA procedure. The same seismic source zones, magnitude recurrence parameters, and Ground Motion Prediction Equations (GMPEs) are used. We replicate the uniform hazard spectrum for a probability of exceedance of 2% in 50 years for a 500 km radial area around Victoria. An active Leech River fault zone is then added; known length and dip. We are determining magnitude recurrence parameters based on a Gutenberg-Richter relationship for the Leech River fault from various catalogues of the recorded seismicity (M 2-3) within the fault's vicinity and the proposed paleoseismic events. We seek to understand whether inclusion of an active Leech River fault source will significantly increase the probabilistic seismic hazard for Victoria. Morell et al. 2017. Quaternary rupture of a crustal fault beneath Victoria, British Columbia, Canada. GSA Today, 27, doi: 10.1130/GSATG291A.1

  8. The Leech method for diagnosing constipation: intra- and interobserver variability and accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Lorijn, Fleur de; Voskuijl, Wieger P.; Taminiau, Jan A.; Benninga, Marc A. [Emma Children' s Hospital, Department of Paediatric Gastroenterology and Nutrition, Amsterdam (Netherlands); Rijn, Rick R. van; Henneman, Onno D.F. [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Heijmans, Jarom [Emma Children' s Hospital, Department of Paediatric Gastroenterology and Nutrition, Amsterdam (Netherlands); Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Reitsma, Johannes B. [Academic Medical Centre, Department of Clinical Epidemiology and Biostatistics, Amsterdam (Netherlands)

    2006-01-01

    The data concerning the value of a plain abdominal radiograph in childhood constipation are inconsistent. Recently, positive results have been reported of a new radiographic scoring system, ''the Leech method'', for assessing faecal loading. To assess intra- and interobserver variability and determine diagnostic accuracy of the Leech method in identifying children with functional constipation (FC). A total of 89 children (median age 9.8 years) with functional gastrointestinal disorders were included in the study. Based on clinical parameters, 52 fulfilled the criteria for FC, six fulfilled the criteria for functional abdominal pain (FAP), and 31 for functional non-retentive faecal incontinence (FNRFI); the latter two groups provided the controls. To assess intra- and interobserver variability of the Leech method three scorers scored the same abdominal radiograph twice. A Leech score of 9 or more was considered as suggestive of constipation. ROC analysis was used to determine the diagnostic accuracy of the Leech method in separating patients with FC from control patients. Significant intraobserver variability was found between two scorers (P=0.005 and P<0.0001), whereas there was no systematic difference between the two scores of the other scorer (P=0.89). The scores between scorers differed systematically and displayed large variability. The area under the ROC curve was 0.68 (95% CI 0.58-0.80), indicating poor diagnostic accuracy. The Leech scoring method for assessing faecal loading on a plain abdominal radiograph is of limited value in the diagnosis of FC in children. (orig.)

  9. Genetic assessment of leech species from yak (Bos grunniens) in the tract of Northeast India.

    Science.gov (United States)

    Chatterjee, Nilkantha; Dhar, Bishal; Bhattarcharya, Debasis; Deori, Sourabh; Doley, Juwar; Bam, Joken; Das, Pranab J; Bera, Asit K; Deb, Sitangshu M; Devi, Ningthoujam Neelima; Paul, Rajesh; Malvika, Sorokhaibam; Ghosh, Sankar Kumar

    2018-01-01

    Yak is an iconic symbol of Tibet and high altitudes of Northeast India. It is highly cherished for milk, meat, and skin. However, yaks suffer drastic change in milk production, weight loss, etc, when infested by parasites. Among them, infestation by leeches is a serious problem in the Himalayan belt of Northeast India. The parasite feeds on blood externally or from body orifices, like nasopharynx, oral, rectum, etc. But there has been limited data about the leech species infesting the yak in that region because of the difficulties in morphological identification due to plasticity of the body, changes in shape, and surface structure and thus, warrants for the molecular characterization of leech. In anticipation, this study would be influential in proper identification of leech species infesting yak track and also helpful in inventorying of leech species in Northeast India. Here, we investigated, through combined approach of molecular markers and morphological parameters for the identification of leech species infesting yak. The DNA sequences of COI barcode fragment, 18S and 28S rDNA, were analyzed for species identification. The generated sequences were subjected to similarity match in global database and analyzed further through Neighbour-Joining, K2P distance based as well as ML approach. Among the three markers, only COI was successful in delineating species whereas the 18S and 28S failed to delineate the species. Our study confirmed the presence of the species from genus Hirudinaria, Haemadipsa, Whitmania, and one species Myxobdella annandalae, which has not been previously reported from this region.

  10. Microsurgical replantation and postoperative leech treatment of a large severed nasal segment

    DEFF Research Database (Denmark)

    Stemann Andersen, Peter; Elberg, Jens Jørgen

    2012-01-01

    The survival of a microsurgically replanted segment of nose in a 41-year-old woman was facilitated by the assistance of the medicinal leech Hirudo medicinalis. An arterial microanastomosis was made to a severed partial segment of nose with no possibility of recreating a venous anastomosis. The re....... The resulting venous congestion was treated with nine days of treatment with a medical leech until venous neovascularisation had been achieved. At follow-up six months after discharge there was a well-heeled nasal segment and a satisfying functional - as well as cosmetic - result....

  11. Medicinal Leech Therapy for Glans Penis Congestion After Primary Bladder Exstrophy-Epispadias Repair in an Infant: A Case Report.

    Science.gov (United States)

    Wagenheim, Gavin N; Au, Jason; Gargollo, Patricio C

    2016-01-01

    Many postoperative complications have been reported after repair of classic bladder exstrophy. We present a case of medicinal leech therapy for glans penis congestion following exstrophy repair in an infant. A 2-week-old male with classic bladder exstrophy underwent complete primary repair. On postoperative day 1, he developed rapidly worsening glans penis venous congestion. Medicinal leech therapy was instituted with antibiotics and blood transfusions to maintain a hematocrit >30%. After 24 hours, venous congestion improved and therapy was discontinued. The patient's remaining hospital course was uncomplicated. Medicinal leeches are an effective therapy to relieve glans penis venous congestion. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. The leech nervous system: a valuable model to study the microglia involvement in regenerative processes.

    Science.gov (United States)

    Le Marrec-Croq, Françoise; Drago, Francesco; Vizioli, Jacopo; Sautière, Pierre-Eric; Lefebvre, Christophe

    2013-01-01

    Microglia are intrinsic components of the central nervous system (CNS). During pathologies in mammals, inflammatory processes implicate the resident microglia and the infiltration of blood cells including macrophages. Functions of microglia appear to be complex as they exhibit both neuroprotective and neurotoxic effects during neuropathological conditions in vivo and in vitro. The medicinal leech Hirudo medicinalis is a well-known model in neurobiology due to its ability to naturally repair its CNS following injury. Considering the low infiltration of blood cells in this process, the leech CNS is studied to specify the activation mechanisms of only resident microglial cells. The microglia recruitment is known to be essential for the usual sprouting of injured axons and does not require any other glial cells. The present review will describe the questions which are addressed to understand the nerve repair. They will discuss the implication of leech factors in the microglial accumulation, the identification of nerve cells producing these molecules, and the study of different microglial subsets. Those questions aim to better understand the mechanisms of microglial cell recruitment and their crosstalk with damaged neurons. The study of this dialog is necessary to elucidate the balance of the inflammation leading to the leech CNS repair.

  13. The Leech Nervous System: A Valuable Model to Study the Microglia Involvement in Regenerative Processes

    Directory of Open Access Journals (Sweden)

    Françoise Le Marrec-Croq

    2013-01-01

    Full Text Available Microglia are intrinsic components of the central nervous system (CNS. During pathologies in mammals, inflammatory processes implicate the resident microglia and the infiltration of blood cells including macrophages. Functions of microglia appear to be complex as they exhibit both neuroprotective and neurotoxic effects during neuropathological conditions in vivo and in vitro. The medicinal leech Hirudo medicinalis is a well-known model in neurobiology due to its ability to naturally repair its CNS following injury. Considering the low infiltration of blood cells in this process, the leech CNS is studied to specify the activation mechanisms of only resident microglial cells. The microglia recruitment is known to be essential for the usual sprouting of injured axons and does not require any other glial cells. The present review will describe the questions which are addressed to understand the nerve repair. They will discuss the implication of leech factors in the microglial accumulation, the identification of nerve cells producing these molecules, and the study of different microglial subsets. Those questions aim to better understand the mechanisms of microglial cell recruitment and their crosstalk with damaged neurons. The study of this dialog is necessary to elucidate the balance of the inflammation leading to the leech CNS repair.

  14. The Physiology and Mechanics of Undulatory Swimming: A Student Laboratory Exercise Using Medicinal Leeches

    Science.gov (United States)

    Ellerby, David J.

    2009-01-01

    The medicinal leech is a useful animal model for investigating undulatory swimming in the classroom. Unlike many swimming organisms, its swimming performance can be quantified without specialized equipment. A large blood meal alters swimming behavior in a way that can be used to generate a discussion of the hydrodynamics of swimming, muscle…

  15. Land Leeches of the g. Haemadipsa (Haemadipsoidea: Haemadipsidae). I. Conditions Essential to Laboratory Colonization.

    Science.gov (United States)

    1982-05-01

    minutes (44). Engorged haemadipsid leeches exhibit such obvious distension of their body that some observers have compared their appearance to...34 Jaws are muscular ridges set in the oral cavity, some armed with teeth, which incise the integument of the host to engorge on blood; one family

  16. Leech presence on Iberian Brown Frog, Rana iberica, (Amphibia: Anura: Ranidae from north-western Spain

    Directory of Open Access Journals (Sweden)

    César Ayres

    2008-12-01

    Full Text Available The authors describe a case of parasitism on Rana iberica by two species of leeches, Batracobdella sp. and Hirudo medicinalis, in a mountainous area of north-western Spain. Conservation implications of high parasite load on small and isolated populations are discussed.

  17. An unusual cause of severe dyspnea: A laryngeal live leech: Case report.

    Science.gov (United States)

    Anajar, Said; Ansari, Rachid; Hassnaoui, Jawad; Abada, Reda; Roubal, Mohammed; Mahtar, Mohammed

    2017-01-01

    Foreign bodies in the upper airways are one of the most challenging otolaryngology emergencies, leeches present a very rare cause of airway foreign bodies around the world. A 6-year-old girl was referred to our otolaryngology department at a tertiary university hospital with a severe dyspnea and hemoptysis. Nasofibroscopy revealed a dark living leech in the supraglottic area which extends to the glottis. The patient was urgently admitted to the operating room, the leech was grasped and removed with a foreign body forceps with a full length of more than 6cm. All symptoms were relieved post operatively and she was discharged one day later. Leeches should be suspected as an airway foreign body in patients with a recent history of drinking from stream water. Prevention remains the best treatment for such cases based simply on hygiene measures like not drinking stream water directly and filtering drinking water before it is used. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Behavioral choice across leech species: chacun à son goût.

    Science.gov (United States)

    Gaudry, Q; Ruiz, N; Huang, T; Kristan, W B; Kristan, W B

    2010-04-01

    At any one time, animals are simultaneously bombarded with many sensory stimuli, but they typically choose to respond to only a few of them. We used multidimensional analysis to determine the behavioral responses of six species of leeches to stimulation, as the responses are affected by species identity, diet, behavioral state and stimulus location. Our results show that each of the species tested while not feeding displayed remarkably similar behaviors in response to tactile stimulation of the surface of the body. When not feeding, stimulus location was the most reliable factor in determining behavioral response. While feeding, the three sanguivorous (bloodsucking) species tested ignored stimulation, whereas the three carnivorous leeches abandoned feeding in favor of locomotory responses, regardless of phylogenetic relationships. In the sanguivorous leeches, feeding abolished all mechanically elicited responses and mechanical stimulation in turn had no effect on feeding. We also show that the behavioral hierarchy of leeches was fixed and unchanging even in species that can consume both a carnivorous and a sanguivorous diet.

  19. Field evidence for leech-borne transmission of amphibian Ichthyophonus sp.

    Science.gov (United States)

    Raffel, Thomas R; Dillard, James R; Hudson, Peter J

    2006-12-01

    Parasites have been implicated in mass mortality events and population declines of amphibians around the world. One pathogen associated with mortality events in North America is an Ichthyophonus sp.-like organism that affects red-spotted newts (Notophthalmus viridescens) and several frog species, yet little is known about the distribution of this pathogen in wild populations or the mechanism of transmission. In an effort to identify factors influencing the distribution and abundance of this pathogen, we measured Ichthyophonus sp. prevalence and a series of factors that could contribute to transmission in 16 newt populations during spring 2004. In contrast to our initial hypotheses of trophic transmission, several lines of evidence suggested a role for the amphibian leech (Placobdella picta) in Ichthyophonus sp. transmission. We propose the mechanistic hypothesis that a leech acquires Ichthyophonus sp. infection when inserting its proboscis into the muscles beneath the skin of infected newts and transmits the infection to other newts in subsequent feeding bouts. We also found effects of host sex, body mass, and breeding condition on Ichthyophonus sp. prevalence and the number of attached leeches. The number of leeches attached to newts was strongly related to the proportion of newt habitat containing emergent vegetation, suggesting that anthropogenic eutrophication might lead to more frequent or severe outbreaks of Ichthyophonus sp. infection in amphibians.

  20. An unusual cause of severe dyspnea: A laryngeal live leech: Case report

    Directory of Open Access Journals (Sweden)

    Said Anajar

    2017-01-01

    Conclusion: Leeches should be suspected as an airway foreign body in patients with a recent history of drinking from stream water. Prevention remains the best treatment for such cases based simply on hygiene measures like not drinking stream water directly and filtering drinking water before it is used.

  1. Intracellular recording, sensory field mapping, and culturing identified neurons in the leech, Hirudo medicinalis.

    Science.gov (United States)

    Titlow, Josh; Majeed, Zana R; Nicholls, John G; Cooper, Robin L

    2013-11-04

    The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of neurophysiology, neuroethology, and developmental biology. The goal of this report is to consolidate experimental techniques from the leech system into a single article that will be of use to physiologists with expertise in other nervous system preparations, or to biology students with little or no electrophysiology experience. We demonstrate how to dissect the leech for recording intracellularly from identified neural circuits in the ganglion. Next we show how individual cells of known function can be removed from the ganglion to be cultured in a Petri dish, and how to record from those neurons in culture. Then we demonstrate how to prepare a patch of innervated skin to be used for mapping sensory or motor fields. These leech preparations are still widely used to address basic electrical properties of neural networks, behavior, synaptogenesis, and development. They are also an appropriate training module for neuroscience or physiology teaching laboratories.

  2. Infections following the application of leeches: two case reports and review of the literature

    Directory of Open Access Journals (Sweden)

    Maetz Benjamin

    2012-10-01

    Full Text Available Abstract Introduction Since the 1980s, leeches have been ingeniously used in the management of venous flap congestion. The presence of anticoagulative substances in their saliva improves the blood drainage. Their digestive tract contains several bacterial species, the main ones being Aeromonas hydrophila and Aeromonas veronii biovar sobria, which contribute to the digestion of ingested blood. These bacteria can be the cause of infections. Case presentation We report two cases of septicemia related to Aeromonas veronii biovar sobria that presented after leeches had been applied to congested transverse rectus abdominis myocutaneous flaps for delayed mammary reconstructions. Patient number 1 was a 55-year-old Caucasian woman who underwent a delayed breast reconstruction procedure. On the sixth postoperative day she showed a clinical presentation of septicemia. Aeromonas veronii biovar sobria was identified in the patient’s skin and blood bacteriological samples. Her fever ceased after 4 days of antibiotic treatment. Patient number 2 was a 56-year-old Caucasian woman who underwent a delayed breast reconstruction procedure. On the seventh postoperative day we noticed that she showed a clinical presentation of septicemia. Aeromonas veronii biovar sobria was identified in the patient’s blood cultures and local bacteriological samples. An antibiogram showed resistance to amoxicillin/clavulanic acid. Her fever ceased on the eleventh postoperative day after 4 days of antibiotic treatment. Conclusion The rate of infection after application of leeches is not negligible. The concentration of Aeromonas inside the digestive tracts of leeches largely decreases when the patient is under antibiotic therapy. These germs are sensitive to third-generation cephalosporins and fluoroquinolones and resistant to amoxicillin/clavulanic acid. We recommend preventive treatment based on classical measures of asepsis and on oral antibioprophylaxy with a fluoroquinolone

  3. Post-Clovis survival of American Mastodon in the southern Great Lakes Region of North America

    Science.gov (United States)

    Woodman, N.; Beavan, Athfield N.

    2009-01-01

    The end of the Pleistocene in North America was marked by a wave of extinctions of large mammals, with the last known appearances of many species falling between ca. 11,000-10,000??14C yr BP. Temporally, this period overlaps with the Clovis Paleoindian cultural complex (11,190-10,530??14C yr BP) and with sudden climatic changes that define the beginning of the Younger Dryas chronozone (ca. 11,000-10,000??14C yr BP), both of which have been considered as potential proximal causes of this extinction event. Radiocarbon dating of enamel and filtered bone collagen from an extinct American Mastodon (Mammut americanum) from northern Indiana, USA, by accelerator mass spectrometer yielded direct dates of 10,055 ?? 40??14C yr BP and 10,032 ?? 40??14C yr BP, indicating that the animal survived beyond the Clovis time period and into the late Younger Dryas. Although the late survival of this species in mid-continental North America does not remove either humans or climatic change as contributing causes for the late Pleistocene extinctions, neither Clovis hunters nor the climatic perturbations initiating the Younger Dryas chronozone were immediately responsible for driving mastodons to extinction. ?? 2009 University of Washington.

  4. Post-Clovis survival of American Mastodon in the southern Great Lakes Region of North America

    Science.gov (United States)

    Woodman, Neal; Beavan Athfield, Nancy

    2009-11-01

    The end of the Pleistocene in North America was marked by a wave of extinctions of large mammals, with the last known appearances of many species falling between ca. 11,000-10,000 14C yr BP. Temporally, this period overlaps with the Clovis Paleoindian cultural complex (11,190-10,530 14C yr BP) and with sudden climatic changes that define the beginning of the Younger Dryas chronozone (ca. 11,000-10,000 14C yr BP), both of which have been considered as potential proximal causes of this extinction event. Radiocarbon dating of enamel and filtered bone collagen from an extinct American Mastodon ( Mammut americanum) from northern Indiana, USA, by accelerator mass spectrometer yielded direct dates of 10,055 ± 40 14C yr BP and 10,032 ± 40 14C yr BP, indicating that the animal survived beyond the Clovis time period and into the late Younger Dryas. Although the late survival of this species in mid-continental North America does not remove either humans or climatic change as contributing causes for the late Pleistocene extinctions, neither Clovis hunters nor the climatic perturbations initiating the Younger Dryas chronozone were immediately responsible for driving mastodons to extinction.

  5. A comparison study on the anti-leech effects of onion (Allium cepa L and ginger (Zingiber officinale with levamisole and triclabendazole

    Directory of Open Access Journals (Sweden)

    Bahmani Mahmoud

    2013-01-01

    Full Text Available Introduction: Leech may indwell in mucosa of the pharynx, tonsil, esophagus, nose, nasopharyngeal and rarely in larynx of hosts, however, the effective drugs against this parasite is scarce. This study was aimed to evaluate and compare the anti-leech effect of methanolic extract of onion (Allium cepa L and ginger (Zingiber officinale with levamisole and triclabendazole. Materials and Methods: In this study, 60 leeches (Limnatis nilotica were collected from south of Ilam. The anti-leech effect of methanolic extract of onion and ginger in comparison with levamisole and triclabendazole drugs (positive controls were evaluated. Distilled water was used as negative control. Paralysis and death of leeches were recorded in 720 minutes. Results: Lethal effect of methanolic extract of ginger against Limnatis nilotica was equal to levamisole and more than triclabendazole and methanolic extract of onion. Conclusion: Ginger equal to levamisole has anti-leech activity and its methanolic extract might be used against Limnatis nilotica.

  6. Application of the North American Multi-Model Ensemble to seasonal water supply forecasting in the Great Lakes basin through the use of the Great Lakes Seasonal Climate Forecast Tool

    Science.gov (United States)

    Gronewold, A.; Apps, D.; Fry, L. M.; Bolinger, R.

    2017-12-01

    The U.S. Army Corps of Engineers (USACE) contribution to the internationally coordinated 6-month forecast of Great Lakes water levels relies on several water supply models, including a regression model relating a coming month's water supply to past water supplies, previous months' precipitation and temperature, and forecasted precipitation and temperature. Probabilistic forecasts of precipitation and temperature depicted in the Climate Prediction Center's seasonal outlook maps are considered to be standard for use in operational forecasting for seasonal time horizons, and have provided the basis for computing a coming month's precipitation and temperature for use in the USACE water supply regression models. The CPC outlook maps are a useful forecast product offering insight into interpretation of climate models through the prognostic discussion and graphical forecasts. However, recent evolution of USACE forecast procedures to accommodate automated data transfer and manipulation offers a new opportunity for direct incorporation of ensemble climate forecast data into probabilistic outlooks of water supply using existing models that have previously been implemented in a deterministic fashion. We will present results from a study investigating the potential for applying data from the North American Multi-Model Ensemble to operational water supply forecasts. The use of NMME forecasts is facilitated by a new, publicly available, Great Lakes Seasonal Climate Forecast Tool that provides operational forecasts of monthly average temperatures and monthly total precipitation summarized for each lake basin.

  7. Exotic Homoclinic Surface of a Saddle-Node Limit Cycle in a Leech Neuron Model

    Science.gov (United States)

    Yooer, Chi-Feng; Wei, Fang; Xu, Jian-Xue; Zhang, Xin-Hua

    2011-03-01

    We carry out numerical and theoretical investigations on the global unstable invariant set (manifold) of a saddle-node limit cycle in a leech heart interneuron model. The corresponding global bifurcation is accompanied by an explosion of secondary bifurcations of limit cycles and the emergence of loop-shaped bifurcation structures. The dynamical behaviors of the trajectories of the invariant set are very complicated and can only be partially explained by existing theories.

  8. A new lineage of trypanosomes from Australian vertebrates and terrestrial bloodsucking leeches (Haemadipsidae).

    Science.gov (United States)

    Hamilton, P B; Stevens, J R; Gidley, J; Holz, P; Gibson, W C

    2005-04-01

    Little is known about the trypanosomes of indigenous Australian vertebrates and their vectors. We surveyed a range of vertebrates and blood-feeding invertebrates for trypanosomes by parasitological and PCR-based methods using primers specific to the small subunit ribosomal RNA (SSU rRNA) gene of genus Trypanosoma. Trypanosome isolates were obtained in culture from two common wombats, one swamp wallaby and an Australian bird (Strepera sp.). By PCR, blood samples from three wombats, one brush-tailed wallaby, three platypuses and a frog were positive for trypanosome DNA. All the blood-sucking invertebrates screened were negative for trypanosomes both by microscopy and PCR, except for specimens of terrestrial leeches (Haemadipsidae). Of the latter, two Micobdella sp. specimens from Victoria and 18 Philaemon sp. specimens from Queensland were positive by PCR. Four Haemadipsa zeylanica specimens from Sri Lanka and three Leiobdella jawarerensis specimens from Papua New Guinea were also PCR positive for trypanosome DNA. We sequenced the SSU rRNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) genes in order to determine the phylogenetic positions of the new vertebrate and terrestrial leech trypanosomes. In trees based on these genes, Australian vertebrate trypanosomes fell in several distinct clades, for the most part being more closely related to trypanosomes outside Australia than to each other. Two previously undescribed wallaby trypanosomes fell in a clade with Trypanosoma theileri, the cosmopolitan bovid trypanosome, and Trypanosoma cyclops from a Malaysian primate. The terrestrial leech trypanosomes were closely related to the wallaby trypanosomes, T. cyclops and a trypanosome from an Australian frog. We suggest that haemadipsid leeches may be significant and widespread vectors of trypanosomes in Australia and Asia.

  9. Human recombinant RNASET2-induced inflammatory response and connective tissue remodeling in the medicinal leech.

    Science.gov (United States)

    Baranzini, Nicolò; Pedrini, Edoardo; Girardello, Rossana; Tettamanti, Gianluca; de Eguileor, Magda; Taramelli, Roberto; Acquati, Francesco; Grimaldi, Annalisa

    2017-05-01

    In recent years, several studies have demonstrated that the RNASET2 gene is involved in the control of tumorigenicity in ovarian cancer cells. Furthermore, a role in establishing a functional cross-talk between cancer cells and the surrounding tumor microenvironment has been unveiled for this gene, based on its ability to act as an inducer of the innate immune response. Although several studies have reported on the molecular features of RNASET2, the details on the mechanisms by which this evolutionarily conserved ribonuclease regulates the immune system are still poorly defined. In the effort to clarify this aspect, we report here the effect of recombinant human RNASET2 injection and its role in regulating the innate immune response after bacterial challenge in an invertebrate model, the medicinal leech. We found that recombinant RNASET2 injection induces fibroplasias, connective tissue remodeling and the recruitment of numerous infiltrating cells expressing the specific macrophage markers CD68 and HmAIF1. The RNASET2-mediated chemotactic activity for macrophages has been further confirmed by using a consolidated experimental approach based on injection of the Matrigel biomatrice (MG) supplemented with recombinant RNASET2 in the leech body wall. One week after injection, a large number of CD68 + and HmAIF-1 + macrophages massively infiltrated MG sponges. Finally, in leeches challenged with lipopolysaccharides (LPS) or with the environmental bacteria pathogen Micrococcus nishinomiyaensis, numerous macrophages migrating to the site of inoculation expressed high levels of endogenous RNASET2. Taken together, these results suggest that RNASET2 is likely involved in the initial phase of the inflammatory response in leeches.

  10. Multiple changes in peptide and lipid expression associated with regeneration in the nervous system of the medicinal leech.

    Directory of Open Access Journals (Sweden)

    Céline Meriaux

    2011-04-01

    Full Text Available The adult medicinal leech central nervous system (CNS is capable of regenerating specific synaptic circuitry after a mechanical lesion, displaying evidence of anatomical repair within a few days and functional recovery within a few weeks. In the present work, spatiotemporal changes in molecular distributions during this phenomenon are explored. Moreover, the hypothesis that neural regeneration involves some molecular factors initially employed during embryonic neural development is tested.Imaging mass spectrometry coupled to peptidomic and lipidomic methodologies allowed the selection of molecules whose spatiotemporal pattern of expression was of potential interest. The identification of peptides was aided by comparing MS/MS spectra obtained for the peptidome extracted from embryonic and adult tissues to leech transcriptome and genome databases. Through the parallel use of a classical lipidomic approach and secondary ion mass spectrometry, specific lipids, including cannabinoids, gangliosides and several other types, were detected in adult ganglia following mechanical damage to connected nerves. These observations motivated a search for possible effects of cannabinoids on neurite outgrowth. Exposing nervous tissues to Transient Receptor Potential Vanilloid (TRPV receptor agonists resulted in enhanced neurite outgrowth from a cut nerve, while exposure to antagonists blocked such outgrowth.The experiments on the regenerating adult leech CNS reported here provide direct evidence of increased titers of proteins that are thought to play important roles in early stages of neural development. Our data further suggest that endocannabinoids also play key roles in CNS regeneration, mediated through the activation of leech TRPVs, as a thorough search of leech genome databases failed to reveal any leech orthologs of the mammalian cannabinoid receptors but revealed putative TRPVs. In sum, our observations identify a number of lipids and proteins that may

  11. Experimental Investigation on the Morphology and Adhesion Mechanism of Leech Posterior Suckers.

    Directory of Open Access Journals (Sweden)

    Huashan Feng

    Full Text Available The posterior sucker of a leech represents a fascinating natural system that allows the leech to adhere to different terrains and substrates. However, the mechanism of adhesion and desorption has not yet to be elucidated. In order to better understand how the adhesion is performed, we analyzed the surface structure, adsorption movements, the muscles' distribution, physical characteristics, and the adsorption force of the leech posterior suckers by experimental investigation. Three conclusions can be drawn based on the obtained experimental results. First, the adhesion by the posterior sucker is wet adhesion, because the surface of the posterior sucker is smooth and the sealing can only be achieved on wet surfaces. Second, the deformation texture, consisting of soft collagen tissues and highly ductile epidermal tissues, plays a key role in adhering to rough surfaces. Finally, the adhesion and desorption is achieved by the synergetic operation of six muscle fibers working in different directions. Concrete saying, directional deformation of the collagen/epithermal interface driven by spatially-distributed muscle fibers facilitates the excretion of fluids in the sucker venter, thus allowing liquid sealing. Furthermore, we found that the adhesion strength is directly related to the size of the contact surface which is generated and affected by the sucker deformation. Such an underlying physical mechanism offers potential cues for developing innovative bio-inspired artificial adhesion systems.

  12. A sensor-based energy balance method for the distributed estimation of evaporation over the North American Great Lakes

    Science.gov (United States)

    Fries, K. J.; Kerkez, B.; Gronewold, A.; Lenters, J. D.

    2014-12-01

    We introduce a novel energy balance method to estimate evaporation across large lakes using real-time data from moored buoys and mobile, satellite-tracked drifters. Our work is motivated by the need to improve our understanding of the water balance of the Laurentian Great Lakes basin, a complex hydrologic system that comprises 90% of the United States' and 20% of the world's fresh surface water. Recently, the lakes experienced record-setting water level drops despite above-average precipitation, and given that lake surface area comprises nearly one third of the entire basin, evaporation is suspected to be the primary driver behind the decrease in water levels. There has historically been a need to measure evaporation over the Great Lakes, and recent hydrological phenomena (including not only record low levels, but also extreme changes in ice cover and surface water temperatures) underscore the urgency of addressing that need. Our method tracks the energy fluxes of the lake system - namely net radiation, heat storage and advection, and Bowen ratio. By measuring each of these energy budget terms and combining the results with mass-transfer based estimates, we can calculate real-time evaporation rates on sub-hourly timescales. To mitigate the cost prohibitive nature of large-scale, distributed energy flux measurements, we present a novel approach in which we leverage existing investments in seasonal buoys (which, while providing intensive, high quality data, are costly and sparsely distributed across the surface of the Great Lakes) and then integrate data from less costly satellite-tracked drifter data. The result is an unprecedented, hierarchical sensor and modeling architecture that can be used to derive estimates of evaporation in real-time through cloud-based computing. We discuss recent deployments of sensor-equipped buoys and drifters, which are beginning to provide us with some of the first in situ measurements of overlake evaporation from Earth's largest lake

  13. A comparison of mercury levels in feathers and eggs of osprey (Pandion haliaetus) in the North American Great Lakes.

    Science.gov (United States)

    Hughes, K D; Ewins, P J; Clark, K E

    1997-11-01

    Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three "naturally formed" lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991-1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28-35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects.

  14. Manoomin: place-based research with Native American students on wild rice lakes on the Fond du Lac Band of Lake Superior Chippewa Reservation, northern Minnesota

    Science.gov (United States)

    Ito, E.; Myrbo, A.; Dalbotten, D. M.; Pellerin, H.; Greensky, L.; Howes, T.; Wold, A.; McEathron, M. A.; Shanker, V.

    2010-12-01

    The manoomin project is a collaboration between Fond du Lac Tribal and Community College (Cloquet, MN), the Reservation’s Resource Management Division, and the University of Minnesota funded by the NSF GEO-OEDG Program. It builds on a successful seven-year history of collaboration between these parties, including regular science camps (gidaakiimanaanimigawig, Our Earth Lodge) for students of a wide range of ages. We are working as a team with Native students to study the history of wild rice (manoomin; Zizania palustris), a culturally important resource, growing on Reservation lakes. The joint project takes two main approaches: study of sediment core samples collected from Reservation lakes; and the collection of traditional knowledge about wild rice from the Elders. Science campers collect lake cores during winter with the assistance of the U of MN’s LacCore (National Lacustrine Core Facility) and Resource Management and visit LacCore to log, split and describe cores soon thereafter. Academic mentors with a range of specialties (phytoliths, pollen, plant macrofossils, sedimentology, geochemistry, magnetics) spend 1-2 weeks during the summer with small groups of college-age (>18, many nontraditional) student interns working on a particular paleoenvironmental proxy from the sediment cores. Younger students (middle and high school) also work in small teams in half day units with the same mentors. All campers become comfortable in an academic setting, gain experience working in research labs learning and practicing techniques, and jointly interpret collective results. The continuation of the project over five years (2009-2014) will allow these students to develop relationships with scientists and to receive mentoring beyond the laboratory as they make transitions into 2- and 4-year colleges and into graduate school. Their research provides historical and environmental information that is relevant to their own land that will be used by Resource Management which is

  15. Lake oxygen isotopes as recorders of North American Rocky Mountain hydroclimate: Holocene patterns and variability at multi-decadal to millennial time scales

    Science.gov (United States)

    Anderson, Lesleigh; Max Berkelhammer,; Barron, John A.; Steinman, Byron A.; Finney, Bruce P.; Abbott, Mark B.

    2016-01-01

    Lake sediment oxygen isotope records (calcium carbonate-δ18O) in the western North American Cordillera developed during the past decade provide substantial evidence of Pacific ocean–atmosphere forcing of hydroclimatic variability during the Holocene. Here we present an overview of 18 lake sediment δ18O records along with a new compilation of lake water δ18O and δ2H that are used to characterize lake sediment sensitivity to precipitation-δ18O in contrast to fractionation by evaporation. Of the 18 records, 14 have substantial sensitivity to evaporation. Two records reflect precipitation-δ18O since the middle Holocene, Jellybean and Bison Lakes, and are geographically positioned in the northern and southern regions of the study area. Their comparative analysis indicates a sequence of time-varying north–south precipitation-δ18O patterns that is evidence for a highly non-stationary influence by Pacific ocean–atmosphere processes on the hydroclimate of western North America. These observations are discussed within the context of previous research on North Pacific precipitation-δ18O based on empirical and modeling methods. The Jellybean and Bison Lake records indicate that a prominent precipitation-δ18O dipole (enriched-north and depleted-south) was sustained between ~ 3.5 and 1.5 ka, which contrasts with earlier Holocene patterns, and appears to indicate the onset of a dominant tropical control on North Pacific ocean–atmosphere dynamics. This remains the state of the system today. Higher frequency reversals of the north–south precipitation-δ18O dipole between ~ 2.5 and 1.5 ka, and during the Medieval Climate Anomaly and the Little Ice Age, also suggest more varieties of Pacific ocean–atmosphere modes than a single Pacific Decadal Oscillation (PDO) type analogue. Results indicate that further investigation of precipitation-δ18O patterns on short (observational) and long (Holocene) time scales is needed to improve our understanding of the

  16. Lake oxygen isotopes as recorders of North American Rocky Mountain hydroclimate: Holocene patterns and variability at multi-decadal to millennial time scales

    Science.gov (United States)

    Anderson, Lesleigh; Berkelhammer, Max; Barron, John A.; Steinman, Byron A.; Finney, Bruce P.; Abbott, Mark B.

    2016-02-01

    Lake sediment oxygen isotope records (calcium carbonate-δ18O) in the western North American Cordillera developed during the past decade provide substantial evidence of Pacific ocean-atmosphere forcing of hydroclimatic variability during the Holocene. Here we present an overview of 18 lake sediment δ18O records along with a new compilation of lake water δ18O and δ2H that are used to characterize lake sediment sensitivity to precipitation-δ18O in contrast to fractionation by evaporation. Of the 18 records, 14 have substantial sensitivity to evaporation. Two records reflect precipitation-δ18O since the middle Holocene, Jellybean and Bison Lakes, and are geographically positioned in the northern and southern regions of the study area. Their comparative analysis indicates a sequence of time-varying north-south precipitation-δ18O patterns that is evidence for a highly non-stationary influence by Pacific ocean-atmosphere processes on the hydroclimate of western North America. These observations are discussed within the context of previous research on North Pacific precipitation-δ18O based on empirical and modeling methods. The Jellybean and Bison Lake records indicate that a prominent precipitation-δ18O dipole (enriched-north and depleted-south) was sustained between ~ 3.5 and 1.5 ka, which contrasts with earlier Holocene patterns, and appears to indicate the onset of a dominant tropical control on North Pacific ocean-atmosphere dynamics. This remains the state of the system today. Higher frequency reversals of the north-south precipitation-δ18O dipole between ~ 2.5 and 1.5 ka, and during the Medieval Climate Anomaly and the Little Ice Age, also suggest more varieties of Pacific ocean-atmosphere modes than a single Pacific Decadal Oscillation (PDO) type analogue. Results indicate that further investigation of precipitation-δ18O patterns on short (observational) and long (Holocene) time scales is needed to improve our understanding of the processes that drive

  17. Transpressional Tectonics across the N. American-Caribbean Plate Boundary: Preliminary Results of a Multichannel Seismic Survey of Lake Azuei, Haiti.

    Science.gov (United States)

    Hearn, C. K.; Cormier, M. H.; Sloan, H.; Wattrus, N. J.; Boisson, D.; Brown, B.; Guerrier, K.; King, J. W.; Knotts, P.; Momplaisir, R.; Sorlien, C. C.; Stempel, R.; Symithe, S. J.; Ulysse, S. M. J.

    2017-12-01

    On January 12, 2010, a Mw 7.0 earthquake struck Haiti, killing over 200,000 people and devastating the Capital city of Port-au-Prince and the surrounding regions. It ruptured a previously unknown blind-thrust fault that abuts the Enriquillo Plantain Garden Fault (EPGF), one of two transform faults that define the North American-Caribbean plate boundary. That earthquake highlighted how transpression across this complex boundary is accommodated by slip partitioning into strike-slip and compressional structures. Because the seismic hazard is higher for a rupture on a reverse or oblique-slip fault than on a vertical strike-slip fault, the need to characterize the geometry of that fault system is clear. Lake Azuei overlies this plate boundary 60 km east of the 2010 epicenter. The lake's 23 km long axis trends NW-SE, parallel to the Haitian fold-and-thrust belt and oblique to the EPGF. This tectonic context makes it an ideal target for investigating the partitioning of plate motion between strike-slip and compressional structures. In January 2017, we acquired 222 km of multichannel seismic (MCS) profiles in the lake, largely concurrent with subbottom seismic (CHIRP) profiles. The MCS data were acquired using a high-frequency BubbleGun source and a 75 m-long, 24-channel streamer, achieving a 24 seismic fold with a penetration of 200 m below lakebed. With the goal of resolving tectonic structures in 3-D, survey lines were laid out in a grid with profiles spaced 1.2 km apart. Additional profiles were acquired at the SE end of the lake where most of the tectonic activity is presumably occurring. The co-located CHIRP and MCS profiles document the continuity of tectonic deformation between the surficial sediments and the deeper strata. Preliminary processing suggests that a SW-dipping blind thrust fault, expressed updip as a large monocline fold, may control the western edge of the lake. Gentle, young folds that protrude from the flat lakebed are also imaged with the CHIRP

  18. Spatial patterns and temporal trends in mercury concentrations, precipitation depths, and mercury wet deposition in the North American Great Lakes region, 2002–2008

    International Nuclear Information System (INIS)

    Risch, Martin R.; Gay, David A.; Fowler, Kathleen K.; Keeler, Gerard J.; Backus, Sean M.; Blanchard, Pierrette; Barres, James A.; Dvonch, J. Timothy

    2012-01-01

    Annual and weekly mercury (Hg) concentrations, precipitation depths, and Hg wet deposition in the Great Lakes region were analyzed by using data from 5 monitoring networks in the USA and Canada for a 2002–2008 study period. High-resolution maps of calculated annual data, 7-year mean data, and net interannual change for the study period were prepared to assess spatial patterns. Areas with 7-year mean annual Hg concentrations higher than the 12 ng per liter water-quality criterion were mapped in 4 states. Temporal trends in measured weekly data were determined statistically. Monitoring sites with significant 7-year trends in weekly Hg wet deposition were spatially separated and were not sites with trends in weekly Hg concentration. During 2002–2008, Hg wet deposition was found to be unchanged in the Great Lakes region and its subregions. Any small decreases in Hg concentration apparently were offset by increases in precipitation. - Highlights: ► Data from 5 Hg and precipitation networks in the USA and Canada were combined for the first time. ► High-resolution maps and statistical trends tests were used for spatial and temporal data analysis. ► Some 7-year mean annual Hg concentrations exceeded a 12 ng per liter water-quality criterion. ► Small, localized decreases in Hg concentration were offset by increases in precipitation. ► Hg wet deposition was unchanged in the Great Lakes region and its subregions during 2002–2008. - Analysis of monitoring data from 5 networks in the USA and Canada determined that mercury wet deposition was unchanged in the North American Great Lakes region during 2002–2008.

  19. Comparative and evaluation of anti-leech (Limnatis Nilotica effect of Olive (Olea Europaea L. with Levamisol and Tiabendazole

    Directory of Open Access Journals (Sweden)

    Majid Gholami-Ahangaran

    2012-05-01

    Full Text Available Objective: Until now, there is no registered drug for treatment of complications with leech in the world. According to the available scientific evidence, Olive is an effective anti-parasitic plant. Hence, in the present experiment we studied the inhibitory and killing effect of Olive methanolic extract on Limnatis nilotica. Methods: In this study, 100 leeches (Limnatis nilotica were collected from some wells in western area of Iran (south region in Ilam province and evaluated the antileech effects of Olive methanolic extract (Olea europaea L. in comparison with levamisole and tinidazole. Results: The results indicated no effect of tinidasole and distilled water on killing or mortality rate of the leeches but Olea europaea L. plant and levamisole have more effect on the L. nilotica. The mean death time of leech for levamisole and Olive determined 10依0.98 and 210依 24.1 minutes, respectively. Conclusions: The results showed that treatments of Olive methanolic extract and levamisole have the most effects on leeches and could be used as natural anti-L. nilotica. However it is necessary to achieve further studies for confirm of this subject.

  20. Reciprocal immune benefit based on complementary production of antibiotics by the leech Hirudo verbana and its gut symbiont Aeromonas veronii.

    Science.gov (United States)

    Tasiemski, Aurélie; Massol, François; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Roger, Emmanuel; Rodet, Franck; Fournier, Isabelle; Thomas, Frédéric; Salzet, Michel

    2015-12-04

    The medicinal leech has established a long-term mutualistic association with Aeromonas veronii, a versatile bacterium which can also display free-living waterborne and fish- or human-pathogenic lifestyles. Here, we investigated the role of antibiotics in the dynamics of interaction between the leech and its gut symbiont Aeromonas. By combining biochemical and molecular approaches, we isolated and identified for the first time the antimicrobial peptides (AMPs) produced by the leech digestive tract and by its symbiont Aeromonas. Immunohistochemistry data and PCR analyses evidenced that leech AMP genes are induced in the gut epithelial cells when Aeromonas load is low (starved animals), while repressed when Aeromonas abundance is the highest (post blood feeding). The asynchronous production of AMPs by both partners suggests that these antibiotic substances (i) provide them with reciprocal protection against invasive bacteria and (ii) contribute to the unusual simplicity of the gut microflora of the leech. This immune benefit substantially reinforces the evidence of an evolutionarily stable association between H. verbana and A. veronii. Altogether these data may provide insights into the processes making the association with an Aeromonas species in the digestive tract either deleterious or beneficial.

  1. Respiratory adaptations to oxygen lack in three species of Glossiphoniidae (Hirudinea) in Lake Esrom, Denmark

    DEFF Research Database (Denmark)

    Pohle, B. D.; Hamburger, K.

    2005-01-01

    The weight-specific respiration rate (µl O2 mg-1 AFDW h-1) of three species of leech from Lake Esrom, Denmark, Glossiphonia concolor, G. complanata and Helobdella stagnalis was measured in a closed stirred chamber with a micro electrode. At declining oxygen concentration (mg O2 l-1) all three spe...... at 10 and 20 °C, respectively. The results were discussed in relation to habitat and spatial distribution of the three species in the lake....

  2. A homologous form of human interleukin 16 is implicated in microglia recruitment following nervous system injury in leech Hirudo medicinalis.

    Science.gov (United States)

    Croq, Françoise; Vizioli, Jacopo; Tuzova, Marina; Tahtouh, Muriel; Sautiere, Pierre-Eric; Van Camp, Christelle; Salzet, Michel; Cruikshank, William W; Pestel, Joel; Lefebvre, Christophe

    2010-11-01

    In contrast to mammals, the medicinal leech Hirudo medicinalis can completely repair its central nervous system (CNS) after injury. This invertebrate model offers unique opportunities to study the molecular and cellular basis of the CNS repair processes. When the leech CNS is injured, microglial cells migrate and accumulate at the site of lesion, a phenomenon known to be essential for the usual sprouting of injured axons. In the present study, we demonstrate that a new molecule, designated HmIL-16, having functional homologies with human interleukin-16 (IL-16), has chemotactic activity on leech microglial cells as observed using a gradient of human IL-16. Preincubation of microglial cells either with an anti-human IL-16 antibody or with anti-HmIL-16 antibody significantly reduced microglia migration induced by leech-conditioned medium. Functional homology was demonstrated further by the ability of HmIL-16 to promote human CD4+ T cell migration which was inhibited by antibody against human IL-16, an IL-16 antagonist peptide or soluble CD4. Immunohistochemistry of leech CNS indicates that HmIL-16 protein present in the neurons is rapidly transported and stored along the axonal processes to promote the recruitment of microglial cells to the injured axons. To our knowledge, this is the first identification of a functional interleukin-16 homologue in invertebrate CNS. The ability of HmIL-16 to recruit microglial cells to sites of CNS injury suggests a role for HmIL-16 in the crosstalk between neurons and microglia in the leech CNS repair.

  3. Evidence for a novel chemotactic C1q domain-containing factor in the leech nerve cord.

    Science.gov (United States)

    Tahtouh, Muriel; Croq, Françoise; Vizioli, Jacopo; Sautiere, Pierre-Eric; Van Camp, Christelle; Salzet, Michel; Daha, Mohamed R; Pestel, Joël; Lefebvre, Christophe

    2009-02-01

    In vertebrates, central nervous system (CNS) protection is dependent on many immune cells including microglial cells. Indeed, activated microglial cells are involved in neuroinflammation mechanisms by interacting with numerous immune factors. Unlike vertebrates, some lophotrochozoan invertebrates can fully repair their CNS following injury. In the medicinal leech Hirudo medicinalis, the recruitment of microglial cells at the lesion site is essential for sprouting of injured axons. Interestingly, a new molecule homologous to vertebrate C1q was characterized in leech, named HmC1q (for H. medicinalis) and detected in neurons and glial cells. In chemotaxis assays, leech microglial cells were demonstrated to respond to human C1q. The chemotactic activity was reduced when microglia was preincubated with signaling pathway inhibitors (Pertussis Toxin or wortmannin) or anti-human gC1qR antibody suggesting the involvement of gC1qR in C1q-mediated migration in leech. Assays using cells preincubated with NO chelator (cPTIO) showed that C1q-mediated migration was associated to NO production. Of interest, by using anti-HmC1q antibodies, HmC1q released in the culture medium was shown to exhibit a similar chemotactic effect on microglial cells as human C1q. In summary, we have identified, for the first time, a molecule homologous to mammalian C1q in leech CNS. Its chemoattractant activity on microglia highlights a new investigation field leading to better understand leech CNS repair mechanisms.

  4. Occurrence of the Leech, Pontobdella muricata Linnaeus, on Elasmobranch Species in the Northern and Central Adriatic Sea.

    Science.gov (United States)

    Bolognini, Luca; Leoni, Simone; Polidori, Piero; Grati, Fabio; Scarcella, Giuseppe; Pellini, Giulio; Domenichetti, Filippo; Ferrà, Carmen; Fabi, Gianna

    2016-12-01

    This study provides a parasitological analysis of the elasmobranch species caught in the northern and central Adriatic Sea. Sixty-two marine leeches were recorded on 747 individuals of Raja clavata Linnaeus, 1758 (thornback ray), Myliobatis aquila Linnaeus, 1758 (common eagle ray), and Torpedo marmorata Risso, 1810 (marbled torpedo ray) caught in 56 hauls over a 5 yr period. All leeches were identified as Pontobdella muricata, which is a typical ectoparasite of benthic elasmobranchs. The prevalence of infection ranged from 7.11% on R. clavata to 12.00% on M. aquila. The intensity of infection, the preferential sites of attachment to the host, and the periodicity of infection were evaluated.

  5. Leech Therapy For The Treatment Of Venous Congestion In Flaps, Digital Re-Plants And Revascularizations - A Two-Year Review From A Regional Centre.

    Science.gov (United States)

    Butt, Ahsan Masood; Ismail, Amir; Lawson-Smith, Matthew; Shahid, Muhammad; Webb, Jill; Chester, Darren L

    2016-01-01

    Leeches are a well-recognized treatment for congested tissue. This study reviewed the efficacy of leech therapy for salvage of venous congested flaps and congested replanted or revascularized hand digits over a 2-year period. All patients treated with leeches between 1 Oct 2010 and 30 Sep 2012 (two years) at Queen Elizabeth Hospital, Birmingham, UK were included in the study. Details regarding mode of injury requiring reconstruction, surgical procedure, leech therapy duration, subsequent surgery requirement and tissue salvage rates were recorded. Twenty tissues in 18 patients required leeches for tissue congestion over 2 years: 13 men and 5 women. The mean patient age was 41 years (range 17-79). The defect requiring reconstruction was trauma in 16 cases, following tumour resection in two, and two miscellaneous causes. Thirteen cases had flap reconstruction and seven digits in six patients had hand digit replantations or revascularisation. Thirteen of 20 cases (65%) had successful tissue salvage following leech therapy for congestion (77% in 10 out of 13 flaps, and 43% in 3 of 7 digits). The rate of tissue salvage in pedicled flaps was good 6/6 (100%) and so was in digital revascularizations 2/3 (67%), but poor in digital re-plants 1/4 (25%) and free flaps 0/2 (0%). Leeches are a helpful tool for congested tissue salvage and in this study, showed a greater survival benefit for pedicled flaps than for free flaps or digital replantations.

  6. Emergence of Viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity.

    Science.gov (United States)

    Thompson, Tarin M; Batts, William N; Faisal, Mohamed; Bowser, Paul; Casey, James W; Phillips, Kenneth; Garver, Kyle A; Winton, James; Kurath, Gael

    2011-08-29

    Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North America. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with previously naive host populations.

  7. Emergence of viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity

    Science.gov (United States)

    Thompson, T.M.; Batts, W.N.; Faisal, M.; Bowser, P.; Casey, J.W.; Phillips, K.; Garver, K.A.; Winton, J.; Kurath, G.

    2011-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North Ame­rica. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from ­individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with ­previously naïve host populations.

  8. Age, growth and sex composition of the American smelt Osmerus mordax(Mitchill), of western Lake Superior

    Science.gov (United States)

    Bailey, Merryll M.

    1964-01-01

    This study is based on 4,561 smelt collected in Chequamegon Bay, the Apostle Islands, the Brule River, and Superior Harbor, all in western Lake Superior. Commercial production in the Great Lakes (U.S. and Canada combined) reached a peak of nearly 16 million pounds in 1960. Production in Lake Superior has generally been small but increased during the 1950's to reach 948,000 pounds in 1960. All O-group and spring I-group smelt had scales with sufficient sculpturing to permit detection of the first annulus. Annulus formation began after 6 June in 1960. In 1961, all smelt had completed the annulus by 24 August. The body-scale relation is a straight line with an intercept of -0.9 inch on the axis of fish length. The weight of western Lake Superior smelt increased as the 2.952 power of the length. A large range of length in each age group and resulting overlap of age-groups II-VI made length a poor index of age. Female smelt grew faster than males after the second year and dominated strongly in age-groups IV-VII. Both sexes made their best annual growth in length (3.3 inches) during their second year of life; the largest weight increments (0.74 ounce, males; 0.85 ounce, females) came in the third year. Best production from a commercial pound net in 1961 occurred when the sex ratios of spawning smelt were nearest 50:50. Spawning male smelt were consistently shorter than females and the average lengths of both sexes decreased as the spawning season progressed. Shortest mature smelt of each sex were 5.0 to 5.2 inches but the males are probably the first to reach 100 percent maturity. All year-old smelt were immature. Among 2-year-old fish, 40.7 per cent of the males and 17.7 percent of the females had reached maturity. All smelt more than 2 years old were mature. Ovaries of 10 smelt contained an average of 31,338 eggs for fish 7.3 to 8.8 inches long.

  9. Correlated conductance parameters in leech heart motor neurons contribute to motor pattern formation.

    Science.gov (United States)

    Lamb, Damon G; Calabrese, Ronald L

    2013-01-01

    Neurons can have widely differing intrinsic membrane properties, in particular the density of specific conductances, but how these contribute to characteristic neuronal activity or pattern formation is not well understood. To explore the relationship between conductances, and in particular how they influence the activity of motor neurons in the well characterized leech heartbeat system, we developed a new multi-compartmental Hodgkin-Huxley style leech heart motor neuron model. To do so, we evolved a population of model instances, which differed in the density of specific conductances, capable of achieving specific output activity targets given an associated input pattern. We then examined the sensitivity of measures of output activity to conductances and how the model instances responded to hyperpolarizing current injections. We found that the strengths of many conductances, including those with differing dynamics, had strong partial correlations and that these relationships appeared to be linked by their influence on heart motor neuron activity. Conductances that had positive correlations opposed one another and had the opposite effects on activity metrics when perturbed whereas conductances that had negative correlations could compensate for one another and had similar effects on activity metrics.

  10. A new molecular logic for BMP-mediated dorsoventral patterning in the leech Helobdella.

    Science.gov (United States)

    Kuo, Dian-Han; Weisblat, David A

    2011-08-09

    Bone morphogenetic protein (BMP) signaling is broadly implicated in dorsoventral (DV) patterning of bilaterally symmetric animals [1-3], and its role in axial patterning apparently predates the birth of Bilateria [4-7]. In fly and vertebrate embryos, BMPs and their antagonists (primarily Sog/chordin) diffuse and interact to generate signaling gradients that pattern fields of cells [8-10]. Work in other species reveals diversity in essential facets of this ancient patterning process, however. Here, we report that BMP signaling patterns the DV axis of segmental ectoderm in the leech Helobdella, a clitellate annelid (superphylum Lophotrochozoa) featuring stereotyped developmental cell lineages, but the detailed mechanisms of DV patterning in Helobdella differ markedly from fly and vertebrates. In Helobdella, BMP2/4s are expressed broadly, rather than in dorsal territory, whereas a dorsally expressed BMP5-8 specifies dorsal fate by short-range signaling. A BMP antagonist, gremlin, is upregulated by BMP5-8 in dorsolateral, rather than ventral territory, and yet the BMP-antagonizing activity of gremlin is required for normal ventral cell fates. Gremlin promotes ventral fates without disrupting dorsal fates by selectively inhibiting BMP2/4s, not BMP5-8. Thus, DV patterning in the development of the leech revealed unexpected evolutionary plasticity of the conserved BMP patterning system, presumably reflecting its adaptation to different modes of embryogenesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Rediscovery of two rare butterflies Papilio elephenor Doubleday, 1845 and Shijimia moorei Leech, 1889 from proposed Ripu-Chirang Wildlife Sanctuary, Assam, India

    Directory of Open Access Journals (Sweden)

    K. Choudhury

    2010-04-01

    Full Text Available Two rare butterflies Papilio elephenor Doubleday, 1886 and Moore’s Cupid Shijimia moorei Leech, 1889 were rediscovered from the proposed Ripu-Chirang Wildlife Sanctuary, Assam, India.

  12. From the Worm in a Bottle of Mezcal: iDNA Confirmation of a Leech Parasitizing the Antillean Manatee.

    Science.gov (United States)

    Pérez-Flores, J; Rueda-Calderon, H; Kvist, S; Siddall, M E; Oceguera-Figueroa, A

    2016-10-01

    Invertebrate-derived ingested DNA (iDNA) is quickly proving to be a valuable, non-invasive tool for monitoring vertebrate species of conservation concern. Using the DNA barcoding locus, we successfully identified both the blood-feeding leech Haementeria acuecueyetzin and its blood meal-the latter is shown to be derived from the Caribbean manatee, Trichechus manatus . DNA amplification was successful despite the fact that the specimen was fixed in Mezcal (a beverage distilled from agave). We report the first confirmed case of a leech feeding on a manatee, the first record of H. acuecueyetzin for the State of Chiapas and, to our knowledge, the first case of successful DNA amplification of a biological sample fixed in Mezcal other than the caterpillar "worms" more commonly found in that beverage.

  13. The use of medicinal leeches in fingertip replantation without venous anastomosis - case report of a 4-year-old patient.

    Science.gov (United States)

    Streit, L; Dvořák, Z; Novák, O; Stiborová, S; Veselý, J

    2014-01-01

    Replantation of amputated fingertip is a technical challenge to the microsurgeons. The success rate depends directly on the availability and the size of preserved vessels and on the degree of their damage. In distal digital amputations, veins are usually not easily recovered or even absent, and thus high number of replantation procedures fails because of the venous congestion. The use of medicinal leeches is a treatment option for venous congestion of replanted fingers. A case report of a 4-year-old patient after fingertip replantation without venous anastomosis when temporary venous drainage was provided by an application of medicinal leeches is reported together with literature review. We observed an unusually short duration of venous congestion (48 hours) and there was no need of blood transfusion.

  14. Construction of a medicinal leech transcriptome database and its application to the identification of leech homologs of neural and innate immune genes

    Directory of Open Access Journals (Sweden)

    Wincker Patrick

    2010-06-01

    Full Text Available Abstract Background The medicinal leech, Hirudo medicinalis, is an important model system for the study of nervous system structure, function, development, regeneration and repair. It is also a unique species in being presently approved for use in medical procedures, such as clearing of pooled blood following certain surgical procedures. It is a current, and potentially also future, source of medically useful molecular factors, such as anticoagulants and antibacterial peptides, which may have evolved as a result of its parasitizing large mammals, including humans. Despite the broad focus of research on this system, little has been done at the genomic or transcriptomic levels and there is a paucity of openly available sequence data. To begin to address this problem, we constructed whole embryo and adult central nervous system (CNS EST libraries and created a clustered sequence database of the Hirudo transcriptome that is available to the scientific community. Results A total of ~133,000 EST clones from two directionally-cloned cDNA libraries, one constructed from mRNA derived from whole embryos at several developmental stages and the other from adult CNS cords, were sequenced in one or both directions by three different groups: Genoscope (French National Sequencing Center, the University of Iowa Sequencing Facility and the DOE Joint Genome Institute. These were assembled using the phrap software package into 31,232 unique contigs and singletons, with an average length of 827 nt. The assembled transcripts were then translated in all six frames and compared to proteins in NCBI's non-redundant (NR and to the Gene Ontology (GO protein sequence databases, resulting in 15,565 matches to 11,236 proteins in NR and 13,935 matches to 8,073 proteins in GO. Searching the database for transcripts of genes homologous to those thought to be involved in the innate immune responses of vertebrates and other invertebrates yielded a set of nearly one hundred

  15. Construction of a medicinal leech transcriptome database and its application to the identification of leech homologs of neural and innate immune genes.

    Science.gov (United States)

    Macagno, Eduardo R; Gaasterland, Terry; Edsall, Lee; Bafna, Vineet; Soares, Marcelo B; Scheetz, Todd; Casavant, Thomas; Da Silva, Corinne; Wincker, Patrick; Tasiemski, Aurélie; Salzet, Michel

    2010-06-25

    The medicinal leech, Hirudo medicinalis, is an important model system for the study of nervous system structure, function, development, regeneration and repair. It is also a unique species in being presently approved for use in medical procedures, such as clearing of pooled blood following certain surgical procedures. It is a current, and potentially also future, source of medically useful molecular factors, such as anticoagulants and antibacterial peptides, which may have evolved as a result of its parasitizing large mammals, including humans. Despite the broad focus of research on this system, little has been done at the genomic or transcriptomic levels and there is a paucity of openly available sequence data. To begin to address this problem, we constructed whole embryo and adult central nervous system (CNS) EST libraries and created a clustered sequence database of the Hirudo transcriptome that is available to the scientific community. A total of approximately 133,000 EST clones from two directionally-cloned cDNA libraries, one constructed from mRNA derived from whole embryos at several developmental stages and the other from adult CNS cords, were sequenced in one or both directions by three different groups: Genoscope (French National Sequencing Center), the University of Iowa Sequencing Facility and the DOE Joint Genome Institute. These were assembled using the phrap software package into 31,232 unique contigs and singletons, with an average length of 827 nt. The assembled transcripts were then translated in all six frames and compared to proteins in NCBI's non-redundant (NR) and to the Gene Ontology (GO) protein sequence databases, resulting in 15,565 matches to 11,236 proteins in NR and 13,935 matches to 8,073 proteins in GO. Searching the database for transcripts of genes homologous to those thought to be involved in the innate immune responses of vertebrates and other invertebrates yielded a set of nearly one hundred evolutionarily conserved sequences

  16. leech infestation

    African Journals Online (AJOL)

    GB

    2013-03-01

    Mar 1, 2013 ... fish, amphibians, and mammals. Infestation occurs by drinking infested water from quiet streams, pools and springs. They attach to their hosts ... trauma, foreign body ingestion, throat pain, fever, dysphagia and drug intake. He has no malena, haematuria, epistaxis or ecchymotic spots on the body. He had ...

  17. Paleosecular variations from lake sediments

    International Nuclear Information System (INIS)

    Lund, S.P.; Banerjee, S.K.

    1979-01-01

    Data are presented on the secular variations of the magnetization of wet and dry lake sediments for 17 North American locations. The usefullness of this data in terms of the geomagnetic field is discussed

  18. Conversion of recombinant hirudin to the natural form by in vitro tyrosine sulfation. Differential substrate specificities of leech and bovine tyrosylprotein sulfotransferases.

    Science.gov (United States)

    Niehrs, C; Huttner, W B; Carvallo, D; Degryse, E

    1990-06-05

    Hirudin, a tyrosine-sulfated protein secreted by the leech Hirudo medicinalis, is one of the most potent anticoagulants known. The hirudin cDNA has previously been cloned and has been expressed in yeast, but the resulting recombinant protein was found to be produced in the unsulfated form, which is known to have an at least 10 times lower affinity for thrombin than the naturally occurring tyrosine-sulfated hirudin. Here we describe the in vitro tyrosine sulfation of recombinant hirudin by leech and bovine tyrosylprotein sulfotransferase (TPST). With both enzymes, in vitro sulfation of recombinant hirudin occurred at the physiological site (Tyr-63) and rendered the protein biochemically and biologically indistinguishable from natural hirudin. However, leech TPST had an over 20-fold lower apparent Km value for recombinant hirudin than bovine TPST. Further differences in the catalytic properties of leech and bovine TPSTs were observed when synthetic peptides were tested as substrates. Moreover, a synthetic peptide corresponding to the 9 carboxyl-terminal residues of hirudin (which include Tyr-63) was sulfated by leech TPST with a similar apparent Km value as full length hirudin, indicating that structural determinants residing in the immediate vicinity of Tyr-63 are sufficient for sulfation to occur.

  19. The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas)

    International Nuclear Information System (INIS)

    Greenblatt, Rebecca J.; Work, Thierry M.; Balazs, George H.; Sutton, Claudia A.; Casey, Rufina N.; Casey, James W.

    2004-01-01

    Fibropapillomatosis (FP) of marine turtles is a neoplastic disease of ecological concern. A fibropapilloma-associated turtle herpesvirus (FPTHV) is consistently present, usually at loads exceeding one virus copy per tumor cell. DNA from an array of parasites of green turtles (Chelonia mydas) was examined with quantitative PCR (qPCR) to determine whether any carried viral loads are sufficient to implicate them as vectors for FPTHV. Marine leeches (Ozobranchus spp.) were found to carry high viral DNA loads; some samples approached 10 million copies per leech. Isopycnic sucrose density gradient/qPCR analysis confirmed that some of these copies were associated with particles of the density of enveloped viruses. The data implicate the marine leech Ozobranchus as a mechanical vector for FPTHV. Quantitative RT-PCR analysis of FPTHV gene expression indicated that most of the FPTHV copies in a fibropapilloma have restricted DNA polymerase expression, suggestive of latent infection

  20. Ecology of playa lakes

    Science.gov (United States)

    Haukos, David A.; Smith, Loren M.

    1992-01-01

    Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

  1. Clinical report of still-birth in a goat due to leech infestation

    Directory of Open Access Journals (Sweden)

    Y Gharedaghi

    2010-08-01

    At autumn 2009 a four year old pregnant white indigenous female goat was referred to the veterinary clinic located in Sarab. At initial examinations clinical symptoms such as cachexia, sever pains of parturition, rest less and provocation was seen and as the result of these sever pains tachycardia, tachy pnea, teeth grinding and grades of anemia was seen at mucous membranes and the animal could not stand. The fetus had entered the pelvic canal with flexion of the metacarpus and following correction of this position, it was extracted manually. The newly born kid had anasarcus and generalized edema in the forelimbs, hindlimbs and skull. During manual extraction of the fetus, 20 worms about 10–12 cm in length were discharged from the goats vagina. Isolated parasitic samples from the animal were fixed in %10 formalin and were referred to the parasitological laboratory of veterinary faculty of Islamic Azad university- Tabriz Branch. After further examinations they were identified as limnatis nilotica leeches. The kid goat died hours after birth because of respiratory difficulties.

  2. [Leeches, phytotherapy and physiotherapy in osteo-arthrosis of the knee--a geriatric case study].

    Science.gov (United States)

    Teut, Michael; Warning, Albrecht

    2008-10-01

    Chronic pain is a serious problem for geriatric patients. Conventional pharmacotherapy with nonsteroidal anti-inflammatory drugs or opiates is often accompanied by serious side effects. An 87-year-old woman with severe joint pain due to osteoarthritis of the knee presented with side effects from fentanyl therapy. She was subsequently treated in an inpatient setting with leeches, phytotherapy, physiotherapy and three single doses of metamizol. Prospective single-case study. Pain reduction was assessed with a numeric rating scale (0-10; 0 = minimum; 10 = maximum), mobility by walking distance, and activities of daily living by Barthel index. The association between complementary therapy and the changes observed in the patient under treatment were evaluated using cognition-based medicine. Under complementary therapy, the patient experienced a clear reduction in pain (from 8 to 3 points on the numeric rating scale); regained the ability to walk (increase in walking distance from 0 to 70 m); and showed improvements in activities of daily living (increase in Barthel index from 45 to 65). An association between pain reduction and the complementary treatment setting seems likely. The role of complementary pain therapy in geriatric patients should be evaluated systematically. 2008 S. Karger AG, Basel

  3. Effect of low potassium concentration on cadmium induced epileptiform activity of leech retzius neurons

    Directory of Open Access Journals (Sweden)

    Milićević Nebojša

    2016-01-01

    Full Text Available Epilepsies have a large significance and require detailed investigation of cellular mechanisms that lead to this disorder. Environmental, especially industrial, toxins are having increasingly more prominent role in these investigations. The aim of our research was to investigate the significance of Cd2+ in generation of epileptiform electrical activity of neurons, and the role of Na+/K+ pump in mechanisms that lead to cessation of this activity. Experiments were performed on Retzius nerve cells of the leech Haemopis sanguisuga. Intracellularly placed microelectrodes were used to measure membrane potential changes upon administration of Cd2+ (100 µmol/l, and the same concentration of Cd2+ in low K+ (1 mmol/l solution. In our experiments Cd2+ led to generation of rhythmic repetitive oscillatory activity. This activity closely resembles paroxysmal depolarizing shifts (PDS which represent the cellular basis of epilepsy. Cd2+ induced epileptiform activity had the following characteristics: frequency of 3.9±0.8 PDS/minute, PDS duration of 4.0±0.3 s, and PDS amplitude of 8.1±0.7 mV. Cd2+ induces effects similar to those of Ni2+ and Co2+, but in 30 times smaller concentration. Application of Cd2+ in low K+ solution led to a significant reduction of PDS frequency (by 2.34±0.55 PDS/minute, p<0.05, Student's t-test, highly significant increase in PDS duration (by 2.84±0.23 s, p<0.01, Student's t-test and highly significant reduction in PDS amplitude (by 1.91±0.33 mV, p=0.01, Student's t-test. Our results show that Cd2+ is a potent initiator of epileptiform activity, and that Na+/K+ pump significantly affects this activity and has a potentially important role in mechanisms that lead to its cessation.

  4. Propensity for Bistability of Bursting and Silence in the Leech Heart Interneuron

    Directory of Open Access Journals (Sweden)

    Tatiana Dashevskiy

    2018-02-01

    Full Text Available The coexistence of neuronal activity regimes has been reported under normal and pathological conditions. Such multistability could enhance the flexibility of the nervous system and has many implications for motor control, memory, and decision making. Multistability is commonly promoted by neuromodulation targeting specific membrane ionic currents. Here, we investigated how modulation of different ionic currents could affect the neuronal propensity for bistability. We considered a leech heart interneuron model. It exhibits bistability of bursting and silence in a narrow range of the leak current parameters, conductance (gleak and reversal potential (Eleak. We assessed the propensity for bistability of the model by using bifurcation diagrams. On the diagram (gleak, Eleak, we mapped bursting and silent regimes. For the canonical value of Eleak we determined the range of gleak which supported the bistability. We use this range as an index of propensity for bistability. We investigated how this index was affected by alterations of ionic currents. We systematically changed their conductances, one at a time, and built corresponding bifurcation diagrams in parameter planes of the maximal conductance of a given current and the leak conductance. We found that conductance of only one current substantially affected the index of propensity; the increase of the maximal conductance of the hyperpolarization-activated cationic current increased the propensity index. The second conductance with the strongest effect was the conductance of the low-threshold fast Ca2+ current; its reduction increased the propensity index although the effect was about two times smaller in magnitude. Analyzing the model with both changes applied simultaneously, we found that the diagram (gleak, Eleak showed a progressively expanded area of bistability of bursting and silence.

  5. The efficacy and safety of medical leech therapy for osteoarthritis of the knee: A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Wang, Haixia; Zhang, Jing; Chen, Liyan

    2018-06-01

    It is controversial on whether medical leech therapy is effective in improving pain and functional outcome in patients with knee osteoarthritis (OA). Therefore, we perform a meta-analysis from randomized controlled trials (RCTs) to evaluate the efficacy and safety of medical leech therapy in patients with knee OA. The PubMed, EMBASE, ScienceDirect, and Cochrane Library databases were systematically searched for literature up to January 2018. RCTs involving medical leech therapy in patients with knee OA were included. Two independent reviewers performed independent data abstraction. The I 2 statistic was used to assess heterogeneity. A fixed or random effects model was adopted for meta-analysis. All meta-analyses were performed by using STATA 12.0. Four RCTs with 264 patients were included in this meta-analysis. The current meta-analysis showed that there were significant differences in terms of visual analogue scale (VAS) scores and WOMAC scores at 1 week, 4weeks and 7 weeks compared with control groups. However, leech therapy was associated with a significantly higher incidence of adverse events. The overall evidence quality is moderate, which means that further research is likely to significantly change confidence in the effect estimate but may change the estimate. Medical leech therapy was associated with a significantly improved outcome in pain relief and functional recovery in patients with symptomatic knee OA. However, given the inherent limitations in the included studies, this conclusion should be interpreted cautiously. Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  6. RELIABILITY OF BARR, LEECH, AND BLETHYN SCORE IN USING OF PLAIN RADIOGRAPHY IN DETERMINING FECAL IMPACTION IN CHILDREN WITH AND WITHOUT CONSTIPATION

    Directory of Open Access Journals (Sweden)

    Afshin REZAZADEH

    Full Text Available ABSTRACT Background - Several scoring was developed for evaluation of children with fecal retention using plain radiograph. There are controversies about specificity and sensitivity of these scoring system. Objectives - The aim of this study was to evaluate Barr, Blethyn, and Leech score in evaluation of fecal load in plain radiograph. Methods - This case control study was conducted on children aged 2-14 years old with abdominal pain who visited Abuzar children's Hospital of Ahvaz University of Medical Sciences. This study was conducted in fall season. Children with history of previous abdominal surgery, any systemic illness including sickle cell anemia were excluded. Children with constipation were placed in case group. Subjects without constipation were placed in control group. Subjects without exclusion criteria were examined by physician who is blind to aim of the study. Careful history and physical examination was done. Demographic features, history of gastrointestinal problem, duration of abdominal pain, defecation habit, stool consistency (loose, hard, and results of physical examination were recorded. Rome III criteria was used for definition of constipation. Abdominal x-ray was ordered for each patients. Abdominal radiography was reviewed by radiologist. Barr, Leach, and Blethyn scores were calculated for each case. Results - In this study 102 children with functional constipation and 102 children without constipation as a control were included. Mean ±SD for case and control group was 68.39±34.88 and 69.46±32.60 (P=0.82.Leech score (mean ±SD was 11.05±2.177 and 5.67±3.228 for case and control group respectively (P<0.0001. Barr score (mean ±SD was 14.86±3.54 and 7.16±5.59 for case and control group respectively (P=<0.0001. Blethyn (mean ±SD score was 1.97±0.667 and 1.04±0.900 for case and control group respectively (P=0.000. Sensitivity and specificity of Barr score was 83% and 79% respectively. Sensitivity and specificity of

  7. Interaction of HmC1q with leech microglial cells: involvement of C1qBP-related molecule in the induction of cell chemotaxis

    Directory of Open Access Journals (Sweden)

    Tahtouh Muriel

    2012-02-01

    Full Text Available Abstract Background In invertebrates, the medicinal leech is considered to be an interesting and appropriate model to study neuroimmune mechanisms. Indeed, this non-vertebrate animal can restore normal function of its central nervous system (CNS after injury. Microglia accumulation at the damage site has been shown to be required for axon sprouting and for efficient regeneration. We characterized HmC1q as a novel chemotactic factor for leech microglial cell recruitment. In mammals, a C1q-binding protein (C1qBP alias gC1qR, which interacts with the globular head of C1q, has been reported to participate in C1q-mediated chemotaxis of blood immune cells. In this study, we evaluated the chemotactic activities of a recombinant form of HmC1q and its interaction with a newly characterized leech C1qBP that acts as its potential ligand. Methods Recombinant HmC1q (rHmC1q was produced in the yeast Pichia pastoris. Chemotaxis assays were performed to investigate rHmC1q-dependent microglia migration. The involvement of a C1qBP-related molecule in this chemotaxis mechanism was assessed by flow cytometry and with affinity purification experiments. The cellular localization of C1qBP mRNA and protein in leech was investigated using immunohistochemistry and in situ hybridization techniques. Results rHmC1q-stimulated microglia migrate in a dose-dependent manner. This rHmC1q-induced chemotaxis was reduced when cells were preincubated with either anti-HmC1q or anti-human C1qBP antibodies. A C1qBP-related molecule was characterized in leech microglia. Conclusions A previous study showed that recruitment of microglia is observed after HmC1q release at the cut end of axons. Here, we demonstrate that rHmC1q-dependent chemotaxis might be driven via a HmC1q-binding protein located on the microglial cell surface. Taken together, these results highlight the importance of the interaction between C1q and C1qBP in microglial activation leading to nerve repair in the medicinal

  8. Interaction of HmC1q with leech microglial cells: involvement of C1qBP-related molecule in the induction of cell chemotaxis.

    Science.gov (United States)

    Tahtouh, Muriel; Garçon-Bocquet, Annelise; Croq, Françoise; Vizioli, Jacopo; Sautière, Pierre-Eric; Van Camp, Christelle; Salzet, Michel; Nagnan-le Meillour, Patricia; Pestel, Joël; Lefebvre, Christophe

    2012-02-22

    In invertebrates, the medicinal leech is considered to be an interesting and appropriate model to study neuroimmune mechanisms. Indeed, this non-vertebrate animal can restore normal function of its central nervous system (CNS) after injury. Microglia accumulation at the damage site has been shown to be required for axon sprouting and for efficient regeneration. We characterized HmC1q as a novel chemotactic factor for leech microglial cell recruitment. In mammals, a C1q-binding protein (C1qBP alias gC1qR), which interacts with the globular head of C1q, has been reported to participate in C1q-mediated chemotaxis of blood immune cells. In this study, we evaluated the chemotactic activities of a recombinant form of HmC1q and its interaction with a newly characterized leech C1qBP that acts as its potential ligand. Recombinant HmC1q (rHmC1q) was produced in the yeast Pichia pastoris. Chemotaxis assays were performed to investigate rHmC1q-dependent microglia migration. The involvement of a C1qBP-related molecule in this chemotaxis mechanism was assessed by flow cytometry and with affinity purification experiments. The cellular localization of C1qBP mRNA and protein in leech was investigated using immunohistochemistry and in situ hybridization techniques. rHmC1q-stimulated microglia migrate in a dose-dependent manner. This rHmC1q-induced chemotaxis was reduced when cells were preincubated with either anti-HmC1q or anti-human C1qBP antibodies. A C1qBP-related molecule was characterized in leech microglia. A previous study showed that recruitment of microglia is observed after HmC1q release at the cut end of axons. Here, we demonstrate that rHmC1q-dependent chemotaxis might be driven via a HmC1q-binding protein located on the microglial cell surface. Taken together, these results highlight the importance of the interaction between C1q and C1qBP in microglial activation leading to nerve repair in the medicinal leech.

  9. La sanguijuela, un gusano en la historia de la salud The leeches, a worm in the history of health

    Directory of Open Access Journals (Sweden)

    María Pilar Manrique Sáez

    2008-12-01

    Full Text Available El uso de sanguijuelas ha sido una terapia que ha venido usándose desde las antiguas civilizaciones hasta principios del siglo XX como tratamiento indispensable para diversas dolencias, cayendo en desuso como consecuencia del gran avance científico y considerándose un tratamiento sin valor, atrasado y decadente. El presente articulo pretende dar a conocer la terapia con sanguijuelas, su auge desde la antigüedad, su decadencia y el nuevo renacer actual en el postoperatorio de la microcirugía plástica reconstructiva para prevenir el éxtasis venoso, así como en traumatología en el tratamiento de las artrosis. Dicha terapia se está aplicando en numerosos países, incluyendo España en donde su uso es una realidad en Hospitales y servicios muy concretos.The use of leeches is a medical therapy which has been used since ancient civilizations until the first decades of the XXth century. It is an irreplaceable remedy to treat many types of illness, however, it fell into disuse due to the increasing confidence in scientific development and because it became considered old-fashioned, obsolete and valueless. The present paper tries to release the therapy with leeches, its peak in the ancient times, its later disuse and the recent reappearance in the post-operative of plastic microsurgical reconstruction in order to prevent the poisoning ecstasy and also in the degenerative osteoarthritis treatment. This therapy is being applied to numerous countries, Spain included, where it is being used at hospitals in particular medical services.

  10. Bioaccumulation of radionuclides in fertilized Canadian Shield lake basins

    International Nuclear Information System (INIS)

    Bird, G.A.; Schwartz, W.J.; Hesslein, R.H.; Mills, K.H.; Turner, M.A.

    1998-01-01

    Radionuclide tracers of heavy metals ( 59 Fe, 60 Co, 65 Zn, 75 Se 85 Sr, 134 Cs and 203 Hg) representing potential contamination from nuclear power plants, industry and agriculture were added to separate basins of Lake 226, Experimental Lakes Area, northwestern Ontario. The two basins were part of a eutrophication experiment and differed in their trophic status; the north basin (L226N) was eutrophic whereas the south basin (L226S) was mesotrophic. Our objective was to determine the uptake of the radionuclides by biota and the effect of lake trophic status on their bioaccumulation. The trophic status of the lakes did not appear to have a marked effect on the accumulation of radionuclides by the biota. This may have been because of a mid-summer leakage of nutrients between the basins which enhanced primary production in L226S, because there is a time lag between primary production and the availability of the radionuclides to the fishes or because trophic status does not affect the uptake of at least some of these radionuclides. However, there was a tendency for faster uptake of the radionuclides in L226N by fish than L226S, but the differences were not significant. Concentrations in the biota generally decreased in the order: fathead minnow>pearl dace>tadpoles>slimy sculpin>leeches. Concentrations in biota generally decreased in the order: 65 Zn> 203 Hg> 75 Se> 134 Cs> 60 Co> 85 Sr= 59 Fe. Cobalt-60 concentrations in tadpoles were greater than in the other biota. Radionuclide concentrations in the tissues of lake whitefish indicated that uptake was predominately from food. Radionuclide concentrations were usually higher in the posterior gut, liver and kidney than in other tissues, whereas body burdens were generally high in the muscle for 75 Se, 134 Cs and 203 Hg; kidney and gut for 60 Co; and bone for 65 Zn and 75 Se. Mercury-203 burdens were also high in the bone and gut

  11. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    Lake Cadagno (26 ha) is a crenogenic meromictic lake located in the Swiss Alps at 1921 m asl with a maximum depth of 21 m. The presence of crystalline rocks and a dolomite vein rich in gypsum in the catchment area makes the lake a typical “sulphuretum ” dominated by coupled carbon and sulphur...... cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

  12. Playa Lakes

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the spatial distribution of soil units associated with playa lakes. Specific soil types have been designated by the...

  13. First record of Stibarobdella moorei (Annelida, Hirudinea, Piscicolidae a marine leech parasitizing Octopus bimaculatus (Mollusca: Octopodidae from the Mexican Pacific coast

    Directory of Open Access Journals (Sweden)

    López-Peraza D. J.

    2017-12-01

    Full Text Available The occurrence of the parasitic marine leech Stibarobdella moorei (Oka, 1910 (Hirudinea: Piscicolidae along the northwest Mexican Pacific coast is described for the first time. This ectoparasite was collected from the skin of the Octopus bimaculatus (Verril, 1983 (Mollusca: Octopodidae. Stibarobdella loricata (Hardig, 1924 is synonymized with S. moorei as this species resembles other species of the genus based on tubercle patterns and the presence of papillae and a marginal fringe on the oral sucker. The present finding throws new light on the biodiversity and host preference of the ectoparasite and suggests a successful migration to unusual host. The coast of the Pacific Ocean, particularly in the Bay of Los Angeles, Baja California, Mexico is a new geographical distribution area for S. moorei, and O. bimaculatus is a new host reported for this leech. The morphology of this ectoparasite is briefly described.

  14. First record of Stibarobdella moorei (Annelida, Hirudinea, Piscicolidae) a marine leech parasitizing Octopus bimaculatus (Mollusca: Octopodidae) from the Mexican Pacific coast

    OpenAIRE

    López-Peraza D. J.; Hernández-Rodríguez M.; Barón-Sevilla B.; Bückle-Ramírez L. F.; Grano-Maldonado M. I.

    2017-01-01

    The occurrence of the parasitic marine leech Stibarobdella moorei (Oka, 1910) (Hirudinea: Piscicolidae) along the northwest Mexican Pacific coast is described for the first time. This ectoparasite was collected from the skin of the Octopus bimaculatus (Verril, 1983) (Mollusca: Octopodidae). Stibarobdella loricata (Hardig, 1924) is synonymized with S. moorei as this species resembles other species of the genus based on tubercle patterns and the presence of papillae and a marginal fringe on the...

  15. Mechanism of ammonia excretion in the freshwater leech Nephelopsis obscura: characterization of a primitive Rh protein and effects of high environmental ammonia

    Science.gov (United States)

    Quijada-Rodriguez, Alex R.; Treberg, Jason R.

    2015-01-01

    Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)−1·h−1 ammonia and 14.7 ± 1.9 nmol·gFW−1·h−1 urea. Exposure to high and low pH hampered and enhanced, respectively, ammonia excretion rates, indicating an acid-linked ammonia trapping mechanism across the skin epithelia. Accordingly, compared with body tissues, the skin exhibited elevated mRNA expression levels of a newly identified Rhesus protein and at least in tendency the Na+/K+-ATPase. Pharmacological experiments and enzyme assays suggested an ammonia excretion mechanism that involves the V-ATPase, Na+/K+-ATPase, and carbonic anhydrase, but not necessarily a functional microtubule system. Most importantly, functional expression studies of the identified Rh protein cloned from leech skin tissue revealed an ammonia transport capability of this protein when expressed in yeast. The leech Rh-ammonia transporter (NoRhp) is a member of the primitive Rh protein family, which is a sister group to the common ancestor of vertebrate ammonia-transporting Rh proteins. Exposure to high environmental ammonia (HEA) caused a new adjustment of body ammonia, accompanied with a decrease in NoRhp and Na+/K+-ATPase mRNA levels, but unaltered ammonia excretion rates. To our knowledge, this is only the second comprehensive study regarding the ammonia excretion mechanisms in a freshwater invertebrate, but our results show that basic processes of ammonia excretion appear to also be comparable to those found in freshwater fish, suggesting an early evolution of ionoregulatory mechanisms in freshwater organisms. PMID:26180186

  16. Infections of Hypostomus spp. by Trypanosoma spp. and leeches: a study of hematology and record of these hirudineans as potential vectors of these hemoflagellates

    Directory of Open Access Journals (Sweden)

    Lincoln Lima Corrêa

    Full Text Available Abstract Among Kinetoplastida, the Trypanosoma is the genus with the highest occurrence infecting populations of marine fish and freshwater in the world, with high levels of prevalence, causing influences fish health and consequent economic losses, mainly for fish populations in situation stress. This study investigated infections of Hypostomus spp. by Trypanosoma spp. and leeches, as well as blood parameters of this host in the network of tributaries of the Tapajós River in the state of Pará, in the eastern Amazon region in Brazil. Of the 47 hosts examined, 89.4% were parasitized by Trypanosoma spp. and 55.4% also had leeches attached around the mouth. The intensity of Trypanosoma spp. increased with the size of the host, but the body conditions were not influenced by the parasitism. The number of red blood cells, and hemoglobin, mean corpuscular volume (MCV, mean corpuscular hemoglobin concentration (MCHC, mean corpuscular hemoglobin (MCH, total number of leukocytes and thrombocytes showed variations and negative correlation with the intensity of Trypanosoma spp. in the blood of the hosts. The results suggest that the leeches were vectors of Trypanosoma spp. in Hypostomus spp.

  17. Antibiotic susceptibility of body surface and gut micro flora of two aquatic leech species (Hirudinaria manillensis and Hirudinaria javanica in Malaysia

    Directory of Open Access Journals (Sweden)

    Parimannan Sivachandran

    2013-08-01

    Full Text Available Objective: To elucidate the antibiotic susceptibility of body surface and gut associated microflora of two local aquatic leech species Hirudinaria manillensis and Hirudinaria javanica. Methods: Four commercially available antibiotics (doxycycline, chloramphenicol, tetracycline and ciprofloxacin were used in this study. A total of 13 isolated gut and two surface micro flora from Hirudinaria manillensis and two gut and two surface micro flora from Hirudinaria javanica were tested for their antibiotic susceptibility. Results: Based on the susceptibility, it was observed that all the isolated bacteria were found to be susceptible to at least three of the antibiotics except Microbacterium resistens, Serratia marcescens and Morganella morganii. This study also found that the bacterial species Bacillus fusiformis has displayed resistance against tetracycline and Tsukamurella inchonensis against chloramphenicol. Conclusions: Among all the antibiotics tested, ciprofloxacin was found to be the best bactericidal agent. The immersion of leeches in ciprofloxacin before the application to the patient may be beneficial to prevent invasive infection of the patient. Further study is needed to sterilize the live leech by immersion/oral mode of administration for the tested antibiotics.

  18. Principles of lake sedimentology

    International Nuclear Information System (INIS)

    Janasson, L.

    1983-01-01

    This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index

  19. Great Lakes

    Science.gov (United States)

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

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

  20. Energy utilization and gluconeogenesis in isolated leech segmental ganglia: Quantitative studies on the control and cellular localization of endogenous glycogen.

    Science.gov (United States)

    Pennington, A J; Pentreath, V W

    1988-01-01

    The isolated segmental ganglia of the horse leech Haemopis sanguisuga were used as a model system to study the utilization and control of glycogen stores within nervous tissue. The glycogen in the ganglia was extracted and assayed fluorimentrically and its cellular localization and turnover studied by autoradiography in conjunction with [(3)H]glucose. We measured the glycogen after various periods of electrical stimulation and after incubation with K(+), Ca(2+), ouabain and glucose. The results for each experimental ganglion were compared to a paired control ganglion and the results analysed by paired t-tests. Electrical stimulation caused sequential changes in glycogen levels: a reduction of up to 67% (5-10 min); followed by an increase of up to 124% (between 15-50 min); followed by a reduction of up to 63% (60-90 min). Values were calculated for glucose utilization (e.g. 0.53 ?mol glucose/gm wet weight/min after 90 min) and estimates derived for glucose consumption per action potential per neuron (e.g. 0.12 fmol at 90 min). Glucose (1.5-10 mM) increased the amount of glycogen (1.5 mM by 30% at 60 min) and attenuated the effects of electrical stimulation. Ouabain (1 mM) blocked the effect of 5 min electrical stimulation. Nine millimolar K(+) increased glycogen by 27% after 10 min and decreased glycogen by 34% after 60 min; 3 mM Ca(2+) had no effect after 10 or 20 min and decreased glycogen by 29% after 60 min. Other concentrations of K(+) and Ca(2+) reduced glycogen after 60 min. Autoradiographic analysis demonstrated that the effects of elevated K(+) were principally within the glial cells. We conclude that (i) the glycogen stores in the glial cells of leech segmental ganglia provide an endogenous energy source which can support sustained neuronal activity, (ii) both electrical stimulation and elevated K(+) can induce gluconeogenesis within the ganglia, (iii) that electrical activation of neurons produces changes in the glycogen in the glial cells which are

  1. A central pattern generator producing alternative outputs: phase relations of leech heart motor neurons with respect to premotor synaptic input.

    Science.gov (United States)

    Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

    2007-11-01

    The central pattern generator (CPG) for heartbeat in leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts: synchronous and peristaltic. Using extracellular techniques, we recorded, in 61 isolated nerve cords, the activity of motor neurons in conjunction with the phase reference premotor heart interneuron, HN(4), and another premotor interneuron that allowed us to assess the coordination mode. These data were then coupled with a previous description of the temporal pattern of premotor interneuron activity in the two coordination modes to synthesize a global phase diagram for the known elements of the CPG and the entire motor neuron ensemble. These average data reveal the stereotypical side-to-side asymmetric patterns of intersegmental coordination among the motor neurons and show how this pattern meshes with the activity pattern of premotor interneurons. Analysis of animal-to-animal variability in this coordination indicates that the intersegmental phase progression of motor neuron activity in the midbody in the peristaltic coordination mode is the most stereotypical feature of the fictive motor pattern. Bilateral recordings from motor neurons corroborate the main features of the asymmetric motor pattern.

  2. A central pattern generator producing alternative outputs: pattern, strength, and dynamics of premotor synaptic input to leech heart motor neurons.

    Science.gov (United States)

    Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

    2007-11-01

    The central pattern generator (CPG) for heartbeat in medicinal leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts, synchronous and peristaltic. Using extracellular recordings from premotor interneurons and voltage-clamp recordings of ipsilateral segmental motor neurons in 69 isolated nerve cords, we assessed the strength and dynamics of premotor inhibitory synaptic output onto the entire ensemble of heart motor neurons and the associated conduction delays in both coordination modes. We conclude that premotor interneurons establish a stereotypical pattern of intersegmental synaptic connectivity, strengths, and dynamics that is invariant across coordination modes, despite wide variations among preparations. These data coupled with a previous description of the temporal pattern of premotor interneuron activity and relative phasing of motor neuron activity in the two coordination modes enable a direct assessment of how premotor interneurons through their temporal pattern of activity and their spatial pattern of synaptic connectivity, strengths, and dynamics coordinate segmental motor neurons into a functional pattern of activity.

  3. Bathymetry of Lake Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  4. Bathymetry of Lake Ontario

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  5. Bathymetry of Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  6. Great Lakes Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and...

  7. Bathymetry of Lake Huron

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  8. New tentacled leech Ceratobdella quadricornuta n. g., n. sp. (Hirudinida: Piscicolidae) parasitic on the starry skate Raja georgiana Norman from the Scotia Sea, Antarctica.

    Science.gov (United States)

    Utevsky, Andrei; Gordeev, Ilya

    2015-07-01

    A new fish leech Ceratobdella quadricornuta n. g., n. sp. (Hirudinida: Piscicolidae), a parasite of the Antarctic skate Raja georgiana Norman (Rajiformes: Rajidae) collected between the Falkland Islands and South Georgia Island in the Scotia Sea, is described and compared with related genera. Ceratobdella quadricornuta is characterised by an uncommon appearance of its anterior sucker bearing four well-developed tentacles and a unique combination of features of the reproductive and digestive systems: crop and intestine equally developed, posterior crop caeca separated; accessory glands, conductive tissue and external copulatory area lacking; common part of ejaculatory ducts (common atrium) voluminous and muscular, male copulatory bursa short, small ovisacs opening into female copulatory bursa (vagina).

  9. Great Lakes Science Center

    Data.gov (United States)

    Federal Laboratory Consortium — Since 1927, Great Lakes Science Center (GLSC) research has provided critical information for the sound management of Great Lakes fish populations and other important...

  10. The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Superstellar Metallicity

    Science.gov (United States)

    Skemer, Andrew J.; Morley, Caroline V.; Zimmerman, Neil T.; Skrutskie, Michael F.; Leisenring, Jarron; Buenzli, Esther; Bonnefoy, Mickael; Bailey, Vanessa; Hinz, Philip; Defrére, Denis; Esposito, Simone; Apai, Dániel; Biller, Beth; Brandner, Wolfgang; Close, Laird; Crepp, Justin R.; De Rosa, Robert J.; Desidera, Silvano; Eisner, Josh; Fortney, Jonathan; Freedman, Richard; Henning, Thomas; Hofmann, Karl-Heinz; Kopytova, Taisiya; Lupu, Roxana; Maire, Anne-Lise; Males, Jared R.; Marley, Mark; Morzinski, Katie; Oza, Apurva; Patience, Jenny; Rajan, Abhijith; Rieke, George; Schertl, Dieter; Schlieder, Joshua; Stone, Jordan; Su, Kate; Vaz, Amali; Visscher, Channon; Ward-Duong, Kimberly; Weigelt, Gerd; Woodward, Charles E.

    2016-02-01

    As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly imaged exoplanets were all L type. Recently, Kuzuhara et al. announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ˜500 K temperature that bridges the gap between the first directly imaged planets (˜1000 K) and our own solar system's Jupiter (˜130 K). We observed GJ 504 b in three narrow L-band filters (3.71, 3.88, and 4.00 μm), spanning the red end of the broad methane fundamental absorption feature (3.3 μm) as part of the LBTI Exozodi Exoplanet Common Hunt (LEECH) exoplanet imaging survey. By comparing our new photometry and literature photometry with a grid of custom model atmospheres, we were able to fit GJ 504 b's unusual spectral energy distribution for the first time. We find that GJ 504 b is well fit by models with the following parameters: Teff = 544 ± 10 K, g Germany. LBT Corporation partners are the University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrophisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota, and University of Virginia.

  11. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

  12. Limnology of Eifel maar lakes

    National Research Council Canada - National Science Library

    Scharf, Burkhard W; Björk, Sven

    1992-01-01

    ... & morphometry - Physical & chemical characteristics - Calcite precipitation & solution in Lake Laacher See - Investigations using sediment traps in Lake Gemundener Maar - Phytoplankton of Lake Weinfelder Maar...

  13. Bathymetry of Lake Erie and Lake Saint Clair

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

  14. THE LEECH EXOPLANET IMAGING SURVEY: CHARACTERIZATION OF THE COLDEST DIRECTLY IMAGED EXOPLANET, GJ 504 b, AND EVIDENCE FOR SUPERSTELLAR METALLICITY

    Energy Technology Data Exchange (ETDEWEB)

    Skemer, Andrew J.; Leisenring, Jarron; Bailey, Vanessa; Hinz, Philip; Defrére, Denis; Apai, Dániel; Close, Laird; Eisner, Josh [Steward Observatory, University of Arizona, 933 North Cherry Ave. Tucson, AZ 85721 (United States); Morley, Caroline V.; Fortney, Jonathan [University of California, Santa Cruz, 1156 High St. Santa Cruz, CA 95064 (United States); Zimmerman, Neil T.; Buenzli, Esther; Bonnefoy, Mickael; Biller, Beth; Brandner, Wolfgang [Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg (Germany); Skrutskie, Michael F. [University of Virginia, 530 McCormick Rd., Charlottesville, VA 22904 (United States); Esposito, Simone [Istituto Nazionale di Astrofisica-Arcetri Astrophysical Observatory, Largo Enrico Fermi 5, 50125, Florence (Italy); Crepp, Justin R. [Notre Dame University, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); De Rosa, Robert J. [Arizona State University, 781 South Terrace Rd, Tempe, AZ 85281 (United States); Desidera, Silvano [Istituto Nazionale di Astrofisica-Padova Astronomical Observatory, Vicolo dell’Osservatorio 5, 35122 Padova (Italy); and others

    2016-02-01

    As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly imaged exoplanets were all L type. Recently, Kuzuhara et al. announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ∼500 K temperature that bridges the gap between the first directly imaged planets (∼1000 K) and our own solar system's Jupiter (∼130 K). We observed GJ 504 b in three narrow L-band filters (3.71, 3.88, and 4.00 μm), spanning the red end of the broad methane fundamental absorption feature (3.3 μm) as part of the LBTI Exozodi Exoplanet Common Hunt (LEECH) exoplanet imaging survey. By comparing our new photometry and literature photometry with a grid of custom model atmospheres, we were able to fit GJ 504 b's unusual spectral energy distribution for the first time. We find that GJ 504 b is well fit by models with the following parameters: T{sub eff} = 544 ± 10 K, g < 600 m s{sup −2}, [M/H] = 0.60 ± 0.12, cloud opacity parameter of f{sub sed} = 2–5, R = 0.96 ± 0.07 R{sub Jup}, and log(L) = −6.13 ± 0.03 L{sub ⊙}, implying a hot start mass of 3–30 M{sub jup} for a conservative age range of 0.1–6.5 Gyr. Of particular interest, our model fits suggest that GJ 504 b has a superstellar metallicity. Since planet formation can create objects with nonstellar metallicities, while binary star formation cannot, this result suggests that GJ 504 b formed like a planet, not like a binary companion.

  15. Estimating Spring Condensation on the Great Lakes

    Science.gov (United States)

    Meyer, A.; Welp, L.

    2017-12-01

    The Laurentian Great Lakes region provides opportunities for shipping, recreation, and consumptive water use to a large part of the United States and Canada. Water levels in the lakes fluctuate yearly, but attempts to model the system are inadequate because the water and energy budgets are still not fully understood. For example, water levels in the Great Lakes experienced a 15-year low period ending in 2013, the recovery of which has been attributed partially to decreased evaporation and increased precipitation and runoff. Unlike precipitation, the exchange of water vapor between the lake and the atmosphere through evaporation or condensation is difficult to measure directly. However, estimates have been constructed using off-shore eddy covariance direct measurements of latent heat fluxes, remote sensing observations, and a small network of monitoring buoys. When the lake surface temperature is colder than air temperature as it is in spring, condensation is larger than evaporation. This is a relatively small component of the net annual water budget of the lakes, but the total amount of condensation may be important for seasonal energy fluxes and atmospheric deposition of pollutants and nutrients to the lakes. Seasonal energy fluxes determine, and are influenced by, ice cover, water and air temperatures, and evaporation in the Great Lakes. We aim to quantify the amount of spring condensation on the Great Lakes using the National Center for Atmospheric Prediction North American Regional Reanalysis (NCEP NARR) Data for Winter 2013 to Spring 2017 and compare the condensation values of spring seasons following high volume, high duration and low volume, low duration ice cover.

  16. Na(+)/K(+) pump interacts with the h-current to control bursting activity in central pattern generator neurons of leeches.

    Science.gov (United States)

    Kueh, Daniel; Barnett, William H; Cymbalyuk, Gennady S; Calabrese, Ronald L

    2016-09-02

    The dynamics of different ionic currents shape the bursting activity of neurons and networks that control motor output. Despite being ubiquitous in all animal cells, the contribution of the Na(+)/K(+) pump current to such bursting activity has not been well studied. We used monensin, a Na(+)/H(+) antiporter, to examine the role of the pump on the bursting activity of oscillator heart interneurons in leeches. When we stimulated the pump with monensin, the period of these neurons decreased significantly, an effect that was prevented or reversed when the h-current was blocked by Cs(+). The decreased period could also occur if the pump was inhibited with strophanthidin or K(+)-free saline. Our monensin results were reproduced in model, which explains the pump's contributions to bursting activity based on Na(+) dynamics. Our results indicate that a dynamically oscillating pump current that interacts with the h-current can regulate the bursting activity of neurons and networks.

  17. Lake or Pond WBID

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT DEC (Vermont Department of Environmental Conservation) manages an inventory of lake and pond information. The "Lakes and Ponds Inventory" stores the Water...

  18. National Lakes Assessment Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S. The U.S....

  19. DNR 24K Lakes

    Data.gov (United States)

    Minnesota Department of Natural Resources — Medium scale lake polygons derived from the National Wetlands Inventory (NWI) polygons and MnDOT Basemap lake delineations. Integrated with the DNR 24K Streams...

  20. Great Lakes rivermouths: a primer for managers

    Science.gov (United States)

    Pebbles, Victoria; Larson, James; Seelbach, Paul; Pebbles, Victoria; Larson, James; Seelbach, Paul

    2013-01-01

    Between the North American Great Lakes and their tributaries are the places where the confluence of river and lake waters creates a distinct ecosystem: the rivermouth ecosystem. Human development has often centered around these rivermouths, in part, because they provide a rich array of ecosystem services. Not surprisingly, centuries of intense human activity have led to substantial pressures on, and alterations to, these ecosystems, often diminishing or degrading their ecological functions and associated ecological services. Many Great Lakes rivermouths are the focus of intense restoration efforts. For example, 36 of the active Great Lakes Areas of Concern (AOCs) are rivermouths or areas that include one or more rivermouths. Historically, research of rivermouth ecosystems has been piecemeal, focused on the Great Lakes proper or on the upper reaches of tributaries, with little direct study of the rivermouth itself. Researchers have been divided among disciplines, agencies and institutions; and they often work independently and use disparate venues to communicate their work. Management has also been fragmented with a focus on smaller, localized, sub-habitat units and socio-political or economic elements, rather than system-level consideration. This Primer presents the case for a more holistic approach to rivermouth science and management that can enable restoration of ecosystem services with multiple benefits to humans and the Great Lakes ecosystem. A conceptual model is presented with supporting text that describes the structures and processes common to all rivermouths, substantiating the case for treating these ecosystems as an identifiable class.1 Ecological services provided by rivermouths and changes in how humans value those services over time are illustrated through case studies of two Great Lakes rivermouths—the St. Louis River and the Maumee River. Specific ecosystem services are identified in italics throughout this Primer and follow definitions described

  1. Western Alaska ESI: LAKES (Lake Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing lakes and land masses used in the creation of the Environmental Sensitivity Index (ESI) for Western Alaska. The...

  2. Pollution at Lake Mariut

    International Nuclear Information System (INIS)

    Nour ElDin, H.; Halim, S. N.; Shalby, E.

    2004-01-01

    Lake Mariut, south Alexandria, Egypt suffered in the recent decades from intensive pollution as a result of a continuous discharge of huge amounts of agriculture wastewater that contains a large concentration of the washed pesticides and fertilizers in addition to domestic and industrial untreated wastewater. The over flow from the lake is discharged directly to the sea through El-Max pumping station via EI-Umum drain. Lake Mariout is surrounded by a huge number of different industrial activities and also the desert road is cutting the lake, this means that a huge number of various pollutants cycle through the air and settle down in the lake, by the time and during different seasons these pollutants after accumulation and different chemical interactions will release again from the lake to the surrounding area affecting the surrounding zone

  3. Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA

    Science.gov (United States)

    Garcia, Anna L.; Knott, Jeffrey R.; Mahan, Shannon; Bright, Jordan

    2014-01-01

    Accurate reconstruction of the paleo-Mojave River and pluvial lake (Harper, Manix, Cronese, and Mojave) system of southern California is critical to understanding paleoclimate and the North American polar jet stream position over the last 500 ka. Previous studies inferred a polar jet stream south of 35°N at 18 ka and at ~ 40°N at 17–14 ka. Highstand sediments of Harper Lake, the upstream-most pluvial lake along the Mojave River, have yielded uncalibrated radiocarbon ages ranging from 24,000 to > 30,000 14C yr BP. Based on geologic mapping, radiocarbon and optically stimulated luminescence dating, we infer a ~ 45–40 ka age for the Harper Lake highstand sediments. Combining the Harper Lake highstand with other Great Basin pluvial lake/spring and marine climate records, we infer that the North American polar jet stream was south of 35°N about 45–40 ka, but shifted to 40°N by ~ 35 ka. Ostracodes (Limnocythere ceriotuberosa) from Harper Lake highstand sediments are consistent with an alkaline lake environment that received seasonal inflow from the Mojave River, thus confirming the lake was fed by the Mojave River. The ~ 45–40 ka highstand at Harper Lake coincides with a shallowing interval at downstream Lake Manix.

  4. Great Lakes Literacy Principles

    Science.gov (United States)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

    Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

  5. The Key Lake project

    International Nuclear Information System (INIS)

    1991-01-01

    Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included

  6. Reconstructing Heat Fluxes Over Lake Erie During the Lake Effect Snow Event of November 2014

    Science.gov (United States)

    Fitzpatrick, L.; Fujisaki-Manome, A.; Gronewold, A.; Anderson, E. J.; Spence, C.; Chen, J.; Shao, C.; Posselt, D. J.; Wright, D. M.; Lofgren, B. M.; Schwab, D. J.

    2017-12-01

    The extreme North American winter storm of November 2014 triggered a record lake effect snowfall (LES) event in southwest New York. This study examined the evaporation from Lake Erie during the record lake effect snowfall event, November 17th-20th, 2014, by reconstructing heat fluxes and evaporation rates over Lake Erie using the unstructured grid, Finite-Volume Community Ocean Model (FVCOM). Nine different model runs were conducted using combinations of three different flux algorithms: the Met Flux Algorithm (COARE), a method routinely used at NOAA's Great Lakes Environmental Research Laboratory (SOLAR), and the Los Alamos Sea Ice Model (CICE); and three different meteorological forcings: the Climate Forecast System version 2 Operational Analysis (CFSv2), Interpolated observations (Interp), and the High Resolution Rapid Refresh (HRRR). A few non-FVCOM model outputs were also included in the evaporation analysis from an atmospheric reanalysis (CFSv2) and the large lake thermodynamic model (LLTM). Model-simulated water temperature and meteorological forcing data (wind direction and air temperature) were validated with buoy data at three locations in Lake Erie. The simulated sensible and latent heat fluxes were validated with the eddy covariance measurements at two offshore sites; Long Point Lighthouse in north central Lake Erie and Toledo water crib intake in western Lake Erie. The evaluation showed a significant increase in heat fluxes over three days, with the peak on the 18th of November. Snow water equivalent data from the National Snow Analyses at the National Operational Hydrologic Remote Sensing Center showed a spike in water content on the 20th of November, two days after the peak heat fluxes. The ensemble runs presented a variation in spatial pattern of evaporation, lake-wide average evaporation, and resulting cooling of the lake. Overall, the evaporation tended to be larger in deep water than shallow water near the shore. The lake-wide average evaporations

  7. Limnology of Eifel maar lakes

    National Research Council Canada - National Science Library

    Scharf, Burkhard W; Björk, Sven

    1992-01-01

    ... : Species composition & seasonal periodicity - Qualitative & quantitative investigations on cladoceran zooplankton of oligotrophic maar lakes - Population dynamics of pelagic copepods in maar lakes - Population dynamics...

  8. Zebra mussels invade Lake Erie muds

    Science.gov (United States)

    Berkman, Paul Arthur; Haltuch, Melissa A.; Tichich, Emily; Garton, David W.; Kennedy, Gregory W.; Gannon, John E.; Mackey, Scudder D.; Fuller, Jonathan A.; Liebenthal, Dale L.

    1998-01-01

    Zebra mussels (Dreissena polymorpha) originated in western Russia but have now become widespread in Europe and North America. They are widely known for their conspicuous invasion of rocks and other hard substrates in North American and European watersheds. We have found beds of zebra mussels directly colonizing sand and mud sediments each year across hundreds of square kilometres of North America's Lake Erie. This transformation of sedimentary habitats into mussel beds represents an unforeseen change in the invasive capacity of this species.

  9. Lakes, Lagerstaetten, and Evolution

    Science.gov (United States)

    Kordesch, E. G.; Park, L. E.

    2001-12-01

    The diversity of terrestrial systems is estimated to be greater than in the marine realm. However no hard data yet exists to substantiate this claim. Ancient lacustrine deposits may preserve an exceptionally diverse fossil fauna and aid in determining continental faunal diversities. Fossils preserved in lake deposits, especially those with exceptional preservation (i.e. Konservat Lagerstaetten), may represent a dependable method for determining species diversity changes in the terrestrial environment because of their faunal completeness. Important Konservat Lagerstaetten, such as the Green River Formation (US) and Messel (Germany), both Eocene in age, are found in lake sediments and show a remarkable faunal diversity for both vertebrates and invertebrates. To date information from nearly 25 lake lagerstaetten derived from different types of lake basins from the Carboniferous to the Miocene have been collected and described. Carboniferous sites derive from the cyclothems of Midcontinent of the US while many Cenozoic sites have been described from North and South America as well as Europe and Australia. Asian sites contain fossils from the Mesozoic and Cenozoic. With this data, insight into the evolutionary processes associated with lake systems can be examined. Do lakes act as unique evolutionary crucibles in contrast to marine systems? The speciation of cichlid fishes in present-day African lakes appears to be very high and is attributed to the diversity of environments found in large rift lakes. Is this true of all ancient lakes or just large rift lakes? The longevity of a lake system may be an important factor in allowing speciation and evolutionary processes to occur; marine systems are limited only in the existence of environments as controlled by tectonics and sea level changes, on the order of tens of millions of years. Rift lakes are normally the longest lived in the millions of years. Perhaps there are only certain types of lakes in which speciation of

  10. Ecology of Meromictic Lakes

    NARCIS (Netherlands)

    Gulati, R.D.; Zadereev, E.S.; Degermendzhy, A.G.

    2017-01-01

    This volume presents recent advances in the research on meromictic lakes and a state-of-the art overview of this area. After an introduction to the terminology and geographic distribution of meromictic lakes, three concise chapters describe their physical, chemical and biological features. The

  11. Comparison of the effects of millimeter wave irradiation, general bath heating, and localized heating on neuronal activity in the leech ganglion

    Science.gov (United States)

    Romanenko, Sergii; Siegel, Peter H.; Wagenaar, Daniel A.; Pikov, Victor

    2013-02-01

    The use of electrically-induced neuromodulation has grown in importance in the treatment of multiple neurological disorders such as Parkinson's disease, dystonia, epilepsy, chronic pain, cluster headaches and others. While electrical current can be applied locally, it requires placing stimulation electrodes in direct contact with the neural tissue. Our goal is to develop a method for localized application of electromagnetic energy to the brain without direct tissue contact. Toward this goal, we are experimenting with the wireless transmission of millimeter wave (MMW) energy in the 10-100 GHz frequency range, where penetration and focusing can be traded off to provide non-contact irradiation of the cerebral cortex. Initial experiments have been conducted on freshly-isolated leech ganglia to evaluate the real-time changes in the activity of individual neurons upon exposure to the MMW radiation. The initial results indicate that low-intensity MMWs can partially suppress the neuronal activity. This is in contrast to general bath heating, which had an excitatory effect on the neuronal activity. Further studies are underway to determine the changes in the state of the membrane channels that might be responsible for the observed neuromodulatory effects.

  12. Na+/K+ pump interacts with the h-current to control bursting activity in central pattern generator neurons of leeches

    Science.gov (United States)

    Kueh, Daniel; Barnett, William H; Cymbalyuk, Gennady S; Calabrese, Ronald L

    2016-01-01

    The dynamics of different ionic currents shape the bursting activity of neurons and networks that control motor output. Despite being ubiquitous in all animal cells, the contribution of the Na+/K+ pump current to such bursting activity has not been well studied. We used monensin, a Na+/H+ antiporter, to examine the role of the pump on the bursting activity of oscillator heart interneurons in leeches. When we stimulated the pump with monensin, the period of these neurons decreased significantly, an effect that was prevented or reversed when the h-current was blocked by Cs+. The decreased period could also occur if the pump was inhibited with strophanthidin or K+-free saline. Our monensin results were reproduced in model, which explains the pump’s contributions to bursting activity based on Na+ dynamics. Our results indicate that a dynamically oscillating pump current that interacts with the h-current can regulate the bursting activity of neurons and networks. DOI: http://dx.doi.org/10.7554/eLife.19322.001 PMID:27588351

  13. Isolation, characterization, and expression of Le-msx, a maternally expressed member of the msx gene family from the glossiphoniid leech, Helobdella.

    Science.gov (United States)

    Master, V A; Kourakis, M J; Martindale, M Q

    1996-12-01

    The msx gene family is one of the most highly conserved of the nonclustered homeobox-containing genes. We have isolated an msx homolog (Le-msx) from the glossiphoniid leech, Helobdella robusta, and characterized its pattern of expression by whole mount in situ hybridization. In situ expression and reverse transcription polymerase chain reaction (RT-PCR) data results show that Le-msx is a maternal transcript initially uniformly distributed in the cortex of immature oocytes that becomes asymmetrically localized to the polar regions of the uncleaved zygote. This is the earliest reported expression for the msx gene family and the first maternally expressed homeodomain-containing transcription factor reported in annelids. During embryonic development, Le-msx is expressed in all 10 embryonic stem cells and their segmental founder cell descendants. At midembryonic stages, Le-msx is expressed in the expanding germinal plate. Le-msx is confined to the central nervous system and nephridia at late (stage 9) stages and subsequently disappears from nephridia. In addition, we present a phylogenetic hypothesis for the evolution of the msx gene family, including the identification of a putative C. elegans msx homolog and the realignment of the sponge msx homolog to the NK class of homeodomain genes.

  14. Differential expression of conserved germ line markers and delayed segregation of male and female primordial germ cells in a hermaphrodite, the leech helobdella.

    Science.gov (United States)

    Cho, Sung-Jin; Vallès, Yvonne; Weisblat, David A

    2014-02-01

    In sexually reproducing animals, primordial germ cells (PGCs) are often set aside early in embryogenesis, a strategy that minimizes the risk of genomic damage associated with replication and mitosis during the cell cycle. Here, we have used germ line markers (piwi, vasa, and nanos) and microinjected cell lineage tracers to show that PGC specification in the leech genus Helobdella follows a different scenario: in this hermaphrodite, the male and female PGCs segregate from somatic lineages only after more than 20 rounds of zygotic mitosis; the male and female PGCs share the same (mesodermal) cell lineage for 19 rounds of zygotic mitosis. Moreover, while all three markers are expressed in both male and female reproductive tissues of the adult, they are expressed differentially between the male and female PGCs of the developing embryo: piwi and vasa are expressed preferentially in female PGCs at a time when nanos is expressed preferentially in male PGCs. A priori, the delayed segregation of male and female PGCs from somatic tissues and from one another increases the probability of mutations affecting both male and female PGCs of a given individual. We speculate that this suite of features, combined with a capacity for self-fertilization, may contribute to the dramatically rearranged genome of Helobdella robusta relative to other animals.

  15. Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

    African Journals Online (AJOL)

    Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

  16. Lake trout in northern Lake Huron spawn on submerged drumlins

    Science.gov (United States)

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  17. Paleo-radioecology of Lake Sevan, Armenia

    International Nuclear Information System (INIS)

    Nalbandyan, A.; Ananyan, V.; Burnett, W.; Cable, J.

    2005-01-01

    This joint Armenian-American research was performed on Lake Sevan in period 2002-2004 in the frame of a NFSAT/CRDF project P aleoecology and paleo-radioecology of Lake Sevan, Armenia . The basic goal was conducting a detailed paleolimnological and radio-ecological study of Lake Sevan by sediment dating with 210Pb and 137Cs and geochemical analyses of sediment cores to reveal both natural and man-made changes that occurred in the lake over the last 120 years. The research was being performed by the CENS Laboratory of Radioecology and the Departments of Oceanography at the FSU and LSU (USA). The study object - Lake Sevan, the second highest freshwater lake in the world - is situated at a height 1916 m a.s.l. Such geographical position makes the lake an ideal site for obtaining and preserving valuable historical radio-ecological records of natural variations, man-induced changes, global fallout after nuclear weapon testing and the 1986 Chernobyl accident. Coring was accomplished during two cruises in 2002 and 2003. Sediment cores up to ∼ 1 m in length were collected from 8 locations in the Sevan. An important part of this research was sediment dating via analysis of 210Pb and 137Cs by direct-spectrometry (FSU, LSU). 226Ra, 137Cs, 40K, 234Th concentrations were determined at CENS through a low-background -spectrometry. To explore the possibility of ecological changes we analyzed several ecological indicators in the lake sediments: biogenic Si, total and available P (AVP), carbonates, and organic carbon. As found out, 210Pb is mainly concentrated in upper sediment layers (0-30cm), deeper its contents significantly decrease and approach equilibrium with 226Ra; 137Cs accumulates in the upper sediment layer (0-50cm) and shows two maxima representing fallout from the 1986 Chernobyl accident and from global bomb-testing that reached the peak in 1963. The ages of each level in the cores were calculated through CRS (constant rate of supply) model. There are some substantial

  18. Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

    Science.gov (United States)

    Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

  19. Yellowstone Lake Nanoarchaeota

    Directory of Open Access Journals (Sweden)

    Scott eClingenpeel

    2013-09-01

    Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

  20. Whiting in Lake Michigan

    Science.gov (United States)

    2002-01-01

    Satellites provide a view from space of changes on the Earth's surface. This series of images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the Orbview-2 satellite shows the dramatic change in the color of Lake Michigan during the summer. The bright color that appears in late summer is probably caused by calcium carbonate-chalk-in the water. Lake Michigan always has a lot of calcium carbonate in it because the floor of the lake is limestone. During most of the year the calcium carbonate remains dissolved in the cold water, but at the end of summer the lake warms up, lowering the solubility of calcium carbonate. As a result, the calcium carbonate precipitates out of the water, forming clouds of very small solid particles that appear as bright swirls from above. The phenomenon is appropriately called a whiting event. A similar event occured in 1999, but appears to have started later and subsided earlier. It is also possible that a bloom of the algae Microcystis is responsible for the color change, but unlikely because of Lake Michigan's depth and size. Microcystis blooms have occured in other lakes in the region, however. On the shore of the lake it is possible to see the cities of Chicago, Illinois, and Milwaukee, Wisconsin. Both appear as clusters of gray-brown pixels. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  1. The marine leech Stibarobdella loricata (Harding, 1924 (Hirudinea, Piscicolidae, parasitic on the angel shark Squatina spp. and sandtiger shark Carcharias taurus Rafinesque, 1810 (Chondrichthyes: Squatinidae, Carchariidae in Southern Brazilian waters

    Directory of Open Access Journals (Sweden)

    Soto J. M. R.

    2003-01-01

    Full Text Available The presence of the marine leech, Stibarobdella loricata (Harding, 1924 (Hirudinea, Piscicolidae, is reported on the southern coast of Brazil, based on seven lots with 47 specimens, between 71 and 182 mm in total length, collected on the dorsal region of angel sharks, Squatina argentina (Marini, 1930; S. guggenheim Marini, 1936; S. punctata Marini, 1936 (Chondrichthyes, Squatinidae; and on the head of a sandtiger shark, Carcharias taurus Rafinesque, 1810 (Chondrichthyes, Carchariidae. This is the first record of S. loricata in the western Atlantic and of its parasitic association with S. argentina, S. guggenheim, S. punctata, and C. taurus.

  2. Lake sediments as natural seismographs: Earthquake-related deformations (seismites) in central Canadian lakes

    Science.gov (United States)

    Doughty, M.; Eyles, N.; Eyles, C. H.; Wallace, K.; Boyce, J. I.

    2014-11-01

    -transparent postglacial silty-clay laminations. Postglacial neotectonic activity is recorded by co-seismic water-escape structures, faults, slumps and debris flows in Lake Simcoe (above a terrane boundary) and especially within lakes Timiskaming and Kipawa, recording ongoing deformation within the WQSZ. High resolution seismo-stratigraphic data presented here support the model that ongoing mid-plate earthquake activity is a consequence of brittle deformation of the upper crust of the North American plate. Such activity appears to have been greatest during deglaciation but continues today.

  3. Halls Lake 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salt marsh habitats along the shoreline of Halls Lake are threatened by wave erosion, but the reconstruction of barrier islands to reduce this erosion will modify or...

  4. Lake Level Reconstructions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past lake levels, mostly related to changes in moisture balance (evaporation-precipitation). Parameter keywords describe what was measured in this data...

  5. The Key Lake project

    International Nuclear Information System (INIS)

    Glattes, G.

    1985-01-01

    Aspects of project financing for the share of the Canadian subsidiary of Uranerzbergbau-GmbH, Bonn, in the uranium mining and milling facility at Key Lake, Saskatchewan, by a Canadian bank syndicate. (orig.) [de

  6. Great Lakes Ice Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the 2001/2002...

  7. Foy Lake paleodiatom data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Percent abundance of 109 diatom species collected from a Foy Lake (Montana, USA) sediment core that was sampled every ∼5–20 years, yielding a ∼7 kyr record over 800...

  8. Dragon Lake, Siberia

    Science.gov (United States)

    2002-01-01

    Nicknamed 'Dragon Lake,' this body of water is formed by the Bratskove Reservoir, built along the Angara river in southern Siberia, near the city of Bratsk. This image was acquired in winter, when the lake is frozen. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on December 19, 1999. This is a natural color composite image made using blue, green, and red wavelengths. Image provided by the USGS EROS Data Center Satellite Systems Branch

  9. Lake Chad, Chad, Africa

    Science.gov (United States)

    1992-01-01

    Hydrologic and ecologic changes in the Lake Chad Basin are shown in this Oct 1992 photograph. In space photo documentation, Lake Chad was at its greatest area extent (25,000 sq. km.) during Gemini 9 in June 1966 (see S66-38444). Its reduction during the severe droughts from 1968 to 1974 was first noted during Skylab (1973-1974). After the drought began again in 1982, the lake reached its minimum extent (1,450 sq. km.) in Space Shuttle photographs taken in 1984 and 1985. In this STS-52 photograph, Lake Chad has begun to recover. The area of the open water and interdunal impoundments in the southern basin (the Chari River Basin) is estimated to be 1,900 to 2100 sq. km. Note the green vegetation in the valley of the K'Yobe flow has wetted the northern lake basin for the first time in several years. There is evidence of biomass burning south of the K'Yobe Delta and in the vegetated interdunal areas near the dike in the center of the lake. Also note the dark 'Green Line' of the Sahel (the g

  10. Resilience and Restoration of Lakes

    Directory of Open Access Journals (Sweden)

    Stephen R. Carpenter

    1997-06-01

    Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

  11. Is Lake Chabot Eutrophic?

    Science.gov (United States)

    Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

    2013-12-01

    Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

  12. Stable carbon isotope biogeochemistry of lakes along a trophic gradient

    NARCIS (Netherlands)

    de Kluijver, A.; Schoon, P.L.; Downing, J.A.; Schouten, S.; Middelburg, J.J.

    2014-01-01

    The stable carbon (C) isotope variability of dissolved inorganic and organic C (DIC and DOC), particulate organic carbon (POC), glucose and polar-lipid derived fatty acids (PLFAs) was studied in a survey of 22 North American oligotrophic to eutrophic lakes. The d13C of different PLFAs were used as

  13. Glacial lake inventory and lake outburst potential in Uzbekistan.

    Science.gov (United States)

    Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

    2017-08-15

    Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m 2 . As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Sedimentation influx and volcanic interactions in the Fuji Five Lakes: implications for paleoseismological records

    Science.gov (United States)

    Lamair, Laura; Hubert-Ferrari, Aurélia; Yamamoto, Shinya; El Ouahabi, Meriam; Garrett, Ed; Shishikura, Masanobu; Schmidt, Sabine; Boes, Evelien; Obrochta, Stephen; Nakamura, Atsunori; Miyairi, Yosuke; Yokoyama, Yusuke; De Batist, Marc; Heyvaert, Vanessa M. A.

    2017-04-01

    The Fuji Fives Lakes are located at the foot of Mount Fuji volcano close to the triple junction, where the North American Plate, the Eurasian plate and the Philippine Sea Plate meet. These lakes are ideally situated to study Mount Fuji volcanism and the interaction between volcanism, changes in lake sedimentation rates and the ability of lakes to record paleoearthquakes. Here, we present newly acquired geological data of Lake Yamanaka and Lake Motosu, including seismic reflection profiles, gravity and piston cores. These two lakes and their respective watersheds were affected by several eruptions of Mount Fuji. Lake Yamanaka, a very shallow lake (max. depth 14 m), was heavily impacted by the scoria fall-out of the A.D. 1707 Hoei eruption of Mount Fuji. A detailed investigation of the effect of the Hoei eruption was conducted on short gravity cores, using high resolution XRD, C/N and 210Pb/137Cs analyses. The preliminary results suggest that the sedimentation rate of Lake Yamanaka drastically reduced after the Hoei eruption, followed by an increase until the present day. Similarly, lacustrine sedimentation in Lake Motosu (max. depth 122 m) was disturbed by Mount Fuji volcanism at a larger scale. The watershed of Lake Motosu was impacted by several lava flows and scoria cones. For example, the Omuro scoria cone reduced the catchment size of Lake Motosu and modified its physiography. The related scoria fall out covered an extensive part of the lake catchment and reduced terrigenous sedimentary influx to Lake Motosu. Within the deep basin of Lake Motosu, seismic reflection data shows two different periods that are distinguished by a major change in the dominant sedimentary processes. During the first period, sublacustrine landslides and turbidity currents were the dominant sedimentation processes. During the second one, the seismic stratigraphy evidences only deposition of numerous turbidites interrupting the hemipelagic sedimentation. Changes in sedimentary processes

  15. American Women and American Studies.

    Science.gov (United States)

    Chmaj, Betty E.

    The American Studies Association (ASA) is an interprofessional group, representing a cross-section of persons from American literature, American history, the social sciences, philosophy, archeology, Black Studies, Urban Studies, American Studies, and others. This document by the ASA Commission on the Status of Women includes: (1) a report of the…

  16. Lake Morphometry for NHD Lakes in Tennessee Region 6 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  17. Lake Morphometry for NHD Lakes in Ohio Region 5 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  18. Lake Morphometry for NHD Lakes in California Region 18 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  19. Investigating Summer Thermal Stratification in Lake Ontario

    Science.gov (United States)

    James, S. C.; Arifin, R. R.; Craig, P. M.; Hamlet, A. F.

    2017-12-01

    Seasonal temperature variations establish strong vertical density gradients (thermoclines) between the epilimnion and hypolimnion. Accurate simulation of vertical mixing and seasonal stratification of large lakes is a crucial element of the thermodynamic coupling between lakes and the atmosphere in integrated models. Time-varying thermal stratification patterns can be accurately simulated with the versatile Environmental Fluid Dynamics Code (EFDC). Lake Ontario bathymetry was interpolated onto a 2-km-resolution curvilinear grid with vertical layering using a new approach in EFDC+, the so-called "sigma-zed" coordinate system which allows the number of vertical layers to be varied based on water depth. Inflow from the Niagara River and outflow to the St. Lawrence River in conjunction with hourly meteorological data from seven local weather stations plus three-hourly data from the North American Regional Reanalysis govern the hydrodynamic and thermodynamic responses of the Lake. EFDC+'s evaporation algorithm was updated to more accurately simulate net surface heat fluxes. A new vertical mixing scheme from Vinçon-Leite that implements different eddy diffusivity formulations above and below the thermocline was compared to results from the original Mellor-Yamada vertical mixing scheme. The model was calibrated by adjusting solar-radiation absorption coefficients in addition to background horizontal and vertical mixing parameters. Model skill was evaluated by comparing measured and simulated vertical temperature profiles at shallow (20 m) and deep (180 m) locations on the Lake. These model improvements, especially the new sigma-zed vertical discretization, accurately capture thermal-stratification patterns with low root-mean-squared errors when using the Vinçon-Leite vertical mixing scheme.

  20. Real-estate lakes

    Science.gov (United States)

    Rickert, David A.; Spieker, Andrew Maute

    1971-01-01

    Since the dawn of civilization waterfront land has been an irresistible attraction to man. Throughout history he has sought out locations fronting on oceans, rivers, and lakes. Originally sought for proximity .to water supply and transportation, such locations are now sought more for their esthetic qualities and for recreation. Usable natural waterfront property is limited, however, and the more desirable sites in many of our urban areas have already been taken. The lack of available waterfront sites has led to the creation of many artificial bodies of water. The rapid suburbanization that has characterized urban growth in America since the end of World War II, together with increasing affluence and le-isure time, has created a ready market for waterfront property. Accordingly, lake-centered subdivisions and developments dot the suburban landscape in many of our major urban areas. Literally thousands of lakes surrounded by homes have materialized during this period of rapid growth. Recently, several "new town" communities have been planned around this lake-centered concept. A lake can be either an asset or a liaoility to a community. A clean, clear, attractively landscaped lake is a definite asset, whereas a weed-choked, foul-smelling mudhole is a distinct liability. The urban environment poses both problems and imaginative opportunities in the development of lakes. Creation of a lake causes changes in all aspects of the environment. Hydrologic systems and ecological patterns are usually most severely altered. The developer should be aware of the potential changes; it is not sufficient merely to build a dam across a stream or to dig a hole in the ground. Development of Gl a successful lake requires careful planning for site selection and design, followed by thorough and cc ntinual management. The purpose of this report is to describe the characteristics of real-estate lakes, to pinpoint potential pmblems, and to suggest possible planning and management guidelines

  1. Lake Michigan lake trout PCB model forecast post audit

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  2. Methane emissions from permafrost thaw lakes limited by lake drainage.

    NARCIS (Netherlands)

    van Huissteden, J.; Berrittella, C.; Parmentier, F.J.W.; Mi, Y.; Maximov, T.C.; Dolman, A.J.

    2011-01-01

    Thaw lakes in permafrost areas are sources of the strong greenhouse gas methane. They develop mostly in sedimentary lowlands with permafrost and a high excess ground ice volume, resulting in large areas covered with lakes and drained thaw-lake basins (DTLBs; refs,). Their expansion is enhanced by

  3. Great Lakes Environmental Database (GLENDA)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Great Lakes Environmental Database (GLENDA) houses environmental data on a wide variety of constituents in water, biota, sediment, and air in the Great Lakes area.

  4. Functional microbiology of soda lakes

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.L.; Muyzer, G.

    2015-01-01

    Soda lakes represent unique permanently haloalkaline system. Despite the harsh conditions, they are inhabited by abundant, mostly prokaryotic, microbial communities. This review summarizes results of studies of main functional groups of the soda lake prokaryotes responsible for carbon, nitrogen and

  5. Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

    Science.gov (United States)

    Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

    2016-06-01

    Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Sanctuaries for lake trout in the Great Lakes

    Science.gov (United States)

    Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

    1987-01-01

    Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

  7. Water quality of Lake Austin and Town Lake, Austin, Texas

    Science.gov (United States)

    Andrews, Freeman L.; Wells, Frank C.; Shelby, Wanda J.; McPherson, Emma

    1988-01-01

    Lake Austin and Town Lake are located on the Colorado River in Travis County, central Texas, and serve as a source of water for municipal and industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Lake Austin, located immediately downstream of Lake Travis, extends for more than 20 miles into the western edge of the city of Austin. Town Lake extends through the downtown area of the city of Austin for nearly 6 miles where the Colorado River is impounded by Longhorn Dam.

  8. Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  9. Transient Tsunamis in Lakes

    Science.gov (United States)

    Couston, L.; Mei, C.; Alam, M.

    2013-12-01

    A large number of lakes are surrounded by steep and unstable mountains with slopes prone to failure. As a result, landslides are likely to occur and impact water sitting in closed reservoirs. These rare geological phenomena pose serious threats to dam reservoirs and nearshore facilities because they can generate unexpectedly large tsunami waves. In fact, the tallest wave experienced by contemporary humans occurred because of a landslide in the narrow bay of Lituya in 1958, and five years later, a deadly landslide tsunami overtopped Lake Vajont's dam, flooding and damaging villages along the lakefront and in the Piave valley. If unstable slopes and potential slides are detected ahead of time, inundation maps can be drawn to help people know the risks, and mitigate the destructive power of the ensuing waves. These maps give the maximum wave runup height along the lake's vertical and sloping boundaries, and can be obtained by numerical simulations. Keeping track of the moving shorelines along beaches is challenging in classical Eulerian formulations because the horizontal extent of the fluid domain can change over time. As a result, assuming a solid slide and nonbreaking waves, here we develop a nonlinear shallow-water model equation in the Lagrangian framework to address the problem of transient landslide-tsunamis. In this manner, the shorelines' three-dimensional motion is part of the solution. The model equation is hyperbolic and can be solved numerically by finite differences. Here, a 4th order Runge-Kutta method and a compact finite-difference scheme are implemented to integrate in time and spatially discretize the forced shallow-water equation in Lagrangian coordinates. The formulation is applied to different lake and slide geometries to better understand the effects of the lake's finite lengths and slide's forcing mechanism on the generated wavefield. Specifically, for a slide moving down a plane beach, we show that edge-waves trapped by the shoreline and free

  10. Technologies for lake restoration

    Directory of Open Access Journals (Sweden)

    Helmut KLAPPER

    2003-09-01

    Full Text Available Lakes are suffering from different stress factors and need to be restored using different approaches. The eutrophication remains as the main water quality management problem for inland waters: both lakes and reservoirs. The way to curb the degradation is to stop the nutrient sources and to accelerate the restoration with help of in-lake technologies. Especially lakes with a long retention time need (eco- technological help to decrease the nutrient content in the free water. The microbial and other organic matter from sewage and other autochthonous biomasses, causes oxygen depletion, which has many adverse effects. In less developed countries big reservoirs function as sewage treatment plants. Natural aeration solves problems only partly and many pollutants tend to accumulate in the sediments. The acidification by acid rain and by pyrite oxidation has to be controlled by acid neutralizing technologies. Addition of alkaline chemicals is useful only for soft waters, and technologies for (microbial alkalinization of very acidic hardwater mining lakes are in development. The corrective measures differ from those in use for eutrophication control. The salinization and water shortage mostly occurs if more water is used than available. L. Aral, L. Tschad, the Dead Sea or L. Nasser belong to waters with most severe environmental problems on a global scale. Their hydrologic regime needs to be evaluated. The inflow of salt water at the bottom of some mining lakes adds to stability of stratification, and thus accumulation of hydrogen sulphide in the monimolimnion of the meromictic lakes. Destratification, which is the most used technology, is only restricted applicable because of the dangerous concentrations of the byproducts of biological degradation. The contamination of lakes with hazardous substances from industry and agriculture require different restoration technologies, including subhydric isolation and storage, addition of nutrients for better self

  11. Lakes on Mars

    CERN Document Server

    Cabrol, Nathalie A

    2014-01-01

    On Earth, lakes provide favorable environments for the development of life and its preservation as fossils. They are extremely sensitive to climate fluctuations and to conditions within their watersheds. As such, lakes are unique markers of the impact of environmental changes. Past and current missions have now demonstrated that water once flowed at the surface of Mars early in its history. Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown; upcoming missions may find critic

  12. Haitian Americans.

    Science.gov (United States)

    Catanese, Anthony V.

    1998-01-01

    Uses 1990 U.S. Census data to show the changing demographic profile of Haitian Americans. Haitian Americans are likely to live along the Atlantic seaboard and to have relatively low, although not the lowest, incomes. However, the demographic mosaic of Haitian Americans is diverse, showing the effects of Haitian national and ethnic history. (SLD)

  13. Terrestrial CDOM in Lakes of Yamal Peninsula: Connection to Lake and Lake Catchment Properties

    Directory of Open Access Journals (Sweden)

    Yury Dvornikov

    2018-01-01

    Full Text Available In this study, we analyze interactions in lake and lake catchment systems of a continuous permafrost area. We assessed colored dissolved organic matter (CDOM absorption at 440 nm (a(440CDOM and absorption slope (S300–500 in lakes using field sampling and optical remote sensing data for an area of 350 km2 in Central Yamal, Siberia. Applying a CDOM algorithm (ratio of green and red band reflectance for two high spatial resolution multispectral GeoEye-1 and Worldview-2 satellite images, we were able to extrapolate the a(λCDOM data from 18 lakes sampled in the field to 356 lakes in the study area (model R2 = 0.79. Values of a(440CDOM in 356 lakes varied from 0.48 to 8.35 m−1 with a median of 1.43 m−1. This a(λCDOM dataset was used to relate lake CDOM to 17 lake and lake catchment parameters derived from optical and radar remote sensing data and from digital elevation model analysis in order to establish the parameters controlling CDOM in lakes on the Yamal Peninsula. Regression tree model and boosted regression tree analysis showed that the activity of cryogenic processes (thermocirques in the lake shores and lake water level were the two most important controls, explaining 48.4% and 28.4% of lake CDOM, respectively (R2 = 0.61. Activation of thermocirques led to a large input of terrestrial organic matter and sediments from catchments and thawed permafrost to lakes (n = 15, mean a(440CDOM = 5.3 m−1. Large lakes on the floodplain with a connection to Mordy-Yakha River received more CDOM (n = 7, mean a(440CDOM = 3.8 m−1 compared to lakes located on higher terraces.

  14. The pygmy whitefish, Coregonus coulteri, in Lake Superior

    Science.gov (United States)

    Eschmeyer, Paul H.; Bailey, Reeve M.

    1955-01-01

    Bottom trawling by the U. S. Fish and Wildlife Service motor vessel Cisco in Lake Superior in 1952–1953 revealed a large population of a tiny whitefish, Coregonus (Prosopium) coulteri, which has been reported previously only from northwestern North America. The hiatus in range, from Lake Superior to the Columbia River basin, is the greatest known for a North American freshwater fish. Although minor structural differences characterize the disjunct populations of the pygmy whitefish, these are not deemed worthy of nomenclatorial recognition. Comparisons with related species indicate that the pygmy whitefish is distinctive in the small size, large scales, few vertebrae, few pyloric caeca, and in other characters.

  15. The Hyalella (Crustacea: Amphipoda) species cloud of the ancient Lake Titicaca originated from multiple colonizations.

    Science.gov (United States)

    Adamowicz, Sarah J; Marinone, María Cristina; Menu-Marque, Silvina; Martin, Jeffrey W; Allen, Daniel C; Pyle, Michelle N; De Los Ríos, Patricio; Sobel, Crystal N; Ibañez, Carla; Pinto, Julio; Witt, Jonathan D S

    2018-08-01

    Ancient lakes are renowned for their exceptional diversity of endemic species. As model systems for the study of sympatric speciation, it is necessary to understand whether a given hypothesized species flock is of monophyletic or polyphyletic origin. Here, we present the first molecular characterization of the Hyalella (Crustacea: Amphipoda) species complex of Lake Titicaca, using COI and 28S DNA sequences, including samples from the connected Small and Large Lakes that comprise Lake Titicaca as well as from a broader survey of southern South American sites. At least five evolutionarily distant lineages are present within Lake Titicaca, which were estimated to have diverged from one another 12-20 MYA. These major lineages are dispersed throughout the broader South American Hyalella phylogeny, with each lineage representing at least one independent colonization of the lake. Moreover, complex genetic relationships are revealed between Lake Titicaca individuals and those from surrounding water bodies, which may be explained by repeated dispersal into and out of the lake, combined with parallel intralacustrine diversification within two separate clades. Although further work in deeper waters will be required to determine the number of species present and modes of diversification, our results strongly indicate that this amphipod species cloud is polyphyletic with a complex geographic history. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Poet Lake Crystal Approval

    Science.gov (United States)

    This September 19, 2016 letter from EPA approves the petition from Poet Biorefining-Lake Crystal, regarding non-grandfathered ethanol produced through a dry mill process, qualifying under the Clean Air Act for renewable fuel (D-code 6) RINs under the RFS

  17. Lake Kariba, Zimbabwe

    African Journals Online (AJOL)

    1984-02-01

    Feb 1, 1984 ... rings word opgesom terwyl sommige van die lesse wat by Kariba geleer is en 'n ... one area of the lake must have an effect, directly or indirectly, on other consumer organisms in the aquatic environment. Con- sidering ... are liable to attain their high density at the price of other taxa. ... be measured. Data on ...

  18. IN LAKE TANA, ETHIOPIA

    African Journals Online (AJOL)

    Turbidity showed depressed effect on biomass ... Key words/phrases: Biomass, duration of development, Lake Tana, large-turbid ... 36°45'-38°14'E and at an altitude of 1830 In, a.s.l. ... 30 cm mouth opening, 1.2 m cod end), which was ... times of the three copepods were measured under .... The greatest density values were.

  19. Lake whitefish diet, condition, and energy density in Lake Champlain and the lower four Great Lakes following dreissenid invasions

    Science.gov (United States)

    Herbst, Seth J.; Marsden, J. Ellen; Lantry, Brian F.

    2013-01-01

    Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining energy density. In contrast to Lake Whitefish from some of the Great Lakes, those from Lake Champlain Lake Whitefish did not show a dietary shift towards dreissenid mussels, but instead fed primarily on fish eggs in spring, Mysis diluviana in summer, and gastropods and sphaeriids in fall and winter. Along with these dietary differences, the condition and energy density of Lake Whitefish from Lake Champlain were high compared with those of Lake Whitefish from Lakes Michigan, Huron, and Ontario after the dreissenid invasion, and were similar to Lake Whitefish from Lake Erie; fish from Lakes Michigan, Huron, and Ontario consumed dreissenids, whereas fish from Lake Erie did not. Our comparisons of Lake Whitefish populations in Lake Champlain to those in the Great Lakes indicate that diet and condition of Lake Champlain Lake Whitefish were not negatively affected by the dreissenid mussel invasion.

  20. Microbiology of Lonar Lake and other soda lakes

    Science.gov (United States)

    Paul Antony, Chakkiath; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

    2013-01-01

    Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. PMID:23178675

  1. Lake trout rehabilitation in Lake Erie: a case history

    Science.gov (United States)

    Cornelius, Floyd C.; Muth, Kenneth M.; Kenyon, Roger

    1995-01-01

    Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population. In the early 1980s, New York's Department of Environmental Conservation, Pennsylvania's Fish and Boat Commission, and the U.S. Fish and Wildlife Service entered into a cooperative program to rehabilitate lake trout in the eastern basin of Lake Erie. After 11 years of stocking selected strains of lake trout in U.S. waters, followed by effective sea lamprey control, lake trout appear to be successfully recolonizing their native habitat. Adult stocks have built up significantly and are expanding their range in the lake. Preliminary investigations suggest that lake trout reproductive habitat is still adequate for natural reproduction, but natural recruitment has not been documented. Future assessments will be directed toward evaluation of spawning success and tracking age-class cohorts as they move through the fishery.

  2. [Limnology of high mountain tropical lake, in Ecuador: characteristics of sediments and rate of sedimentation].

    Science.gov (United States)

    Gunkel, Günter

    2003-06-01

    Equatorial high mountain lakes are a special type of lake occurring mainly in the South American Andes as well as in Central Africa and Asia. They occur at altitudes of a few thousand meters above sea level and are cold-water lakes (limnological study was therefore undertaken at Lake San Pablo, Ecuador, to analyze the basic limnological processes of the lake, which has a tendency for eutrophication. Sediment quality of San Pablo Lake is given under consideration of horizontal and vertical distribution using sediment cores. Significance of sediments for eutrophication process of lakes is demonstrated using phosphorus concentration of sediments as well as the phosphorus retention capacity of the sediments by ratio Fe/P. Dating of the sediments is done using 137Cs and 210Pb, but the activity of 137Cs in the sediment was very low nearly at the detection level. Sedimentation rate is determined to be 3.5 mm/year and the sediment cores represent about 110 years. P concentration of the sediments is high (approximately 5 g/kg dry substance), and P retention capacity by Fe is insufficient (Fe/P = 4). The sediment quality did not change significantly during the past decades, and the trophic state of San Pablo Lake was already less or more eutrophic 110 years ago. The contamination of the lake sediments by heavy metals is insignificant.

  3. Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor

    Science.gov (United States)

    Kessel, Steven T.; Hondorp, Darryl W.; Holbrook, Christopher; Boase, James C.; Chiotti, Justin A.; Thomas, Michael V.; Wills, Todd C.; Roseman, Edward; Drouin, Richard; Krueger, Charles C.

    2018-01-01

    Population structure, distribution, abundance, and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations is an important aspect of the ecology of highly-mobile animals, allowing populations to exploit spatially- or temporally-distributed food and space resources.This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes.Over six years (2011 – 2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 yr battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use.Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assign to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 “contingents” (spatiotemporally segregated subgroups).Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

  4. Evolution of alkaline lakes - Lake Van case study

    Science.gov (United States)

    Tillman Meyer, Felix; Viehberg, Finn; Bahroun, Sonya; Wolf, Annabel; Immenhauser, Adrian; Kwiecien, Ola

    2017-04-01

    Lake Van in Eastern Anatolia (Turkey) is the largest terminal soda lake on Earth. The lake sedimentary profile covers ca. 600 ka (Stockhecke et al. 2014) Based on lithological changes, the presence of freshwater microfossils and close-to-freshwater pH value in the pore water, members of ICDP PALEOVAN concluded that Lake Van might have started as an open lake. Here we show paleontological and geochemical evidence in favour of this idea and constrain the time, when Lake Van likely transformed into a closed lake. Additionally we provide the first conceptual model of how this closure may have happened. Our archives of choice are inorganic and biogenic carbonates, separated by wet sieving. We identified microfossil assemblages (fraction > 125 µm) and performed high-resolution oxygen isotope (delta18O) and elemental (Mg/Ca, Sr/Ca) analyses of the fraction plants growing in the photic zone as food supply. These two aspects point to an increasing salinity in a shallowing lake. The delta18O values of inorganic carbonates are relatively low during the initial phase of Lake Van and increase abruptly (ca. 7‰) after 530 ka BP. At approximately the same time combination of Sr/Ca and Mg/Ca data suggest first occurrence of aragonite. Again, these findings suggest geochemical changes of the lake water concurrent with transition documented by microfossils. Comparison between Lake Van and Lake Ohrid (Lacey et al. 2016) delta18O data, precludes regional climate change (e.g.: increased evaporation) as the main driver of observed changes. With no evidence for increased volcanic or tectonic activity (e.g.: tephra layers, deformation structures, slumping) in the Lake Van sedimentary profile around 530 ka, it seems unlikely that a pyroclastic flow blocked the outflow of the lake. Alternatively, a portion of inflow has been diverged which might have caused a change in the hydrological balance and lake level falling below its outlet. However, as no geomorphological data confirming this

  5. Redox stratification of an ancient lake in Gale crater, Mars.

    Science.gov (United States)

    Hurowitz, J A; Grotzinger, J P; Fischer, W W; McLennan, S M; Milliken, R E; Stein, N; Vasavada, A R; Blake, D F; Dehouck, E; Eigenbrode, J L; Fairén, A G; Frydenvang, J; Gellert, R; Grant, J A; Gupta, S; Herkenhoff, K E; Ming, D W; Rampe, E B; Schmidt, M E; Siebach, K L; Stack-Morgan, K; Sumner, D Y; Wiens, R C

    2017-06-02

    In 2012, NASA's Curiosity rover landed on Mars to assess its potential as a habitat for past life and investigate the paleoclimate record preserved by sedimentary rocks inside the ~150-kilometer-diameter Gale impact crater. Geological reconstructions from Curiosity rover data have revealed an ancient, habitable lake environment fed by rivers draining into the crater. We synthesize geochemical and mineralogical data from lake-bed mudstones collected during the first 1300 martian solar days of rover operations in Gale. We present evidence for lake redox stratification, established by depth-dependent variations in atmospheric oxidant and dissolved-solute concentrations. Paleoclimate proxy data indicate that a transition from colder to warmer climate conditions is preserved in the stratigraphy. Finally, a late phase of geochemical modification by saline fluids is recognized. Copyright © 2017, American Association for the Advancement of Science.

  6. Predicting Maximum Lake Depth from Surrounding Topography

    Science.gov (United States)

    Lake volume aids understanding of the physical and ecological dynamics of lakes, yet is often not readily available. The data needed to calculate lake volume (i.e. bathymetry) are usually only collected on a lake by lake basis and are difficult to obtain across broad regions. ...

  7. Lake-level frequency analysis for Devils Lake, North Dakota

    Science.gov (United States)

    Wiche, Gregg J.; Vecchia, Aldo V.

    1996-01-01

    Two approaches were used to estimate future lake-level probabilities for Devils Lake. The first approach is based on an annual lake-volume model, and the second approach is based on a statistical water mass-balance model that generates seasonal lake volumes on the basis of seasonal precipitation, evaporation, and inflow. Autoregressive moving average models were used to model the annual mean lake volume and the difference between the annual maximum lake volume and the annual mean lake volume. Residuals from both models were determined to be uncorrelated with zero mean and constant variance. However, a nonlinear relation between the residuals of the two models was included in the final annual lakevolume model.Because of high autocorrelation in the annual lake levels of Devils Lake, the annual lake-volume model was verified using annual lake-level changes. The annual lake-volume model closely reproduced the statistics of the recorded lake-level changes for 1901-93 except for the skewness coefficient. However, the model output is less skewed than the data indicate because of some unrealistically large lake-level declines. The statistical water mass-balance model requires as inputs seasonal precipitation, evaporation, and inflow data for Devils Lake. Analysis of annual precipitation, evaporation, and inflow data for 1950-93 revealed no significant trends or long-range dependence so the input time series were assumed to be stationary and short-range dependent.Normality transformations were used to approximately maintain the marginal probability distributions; and a multivariate, periodic autoregressive model was used to reproduce the correlation structure. Each of the coefficients in the model is significantly different from zero at the 5-percent significance level. Coefficients relating spring inflow from one year to spring and fall inflows from the previous year had the largest effect on the lake-level frequency analysis.Inclusion of parameter uncertainty in the model

  8. Lake-wide distribution of Dreissena in Lake Michigan, 1999

    Science.gov (United States)

    Fleischer, Guy W.; DeSorcie, Timothy J.; Holuszko, Jeffrey D.

    2001-01-01

    The Great Lakes Science Center has conducted lake-wide bottom trawl surveys of the fish community in Lake Michigan each fall since 1973. These systematic surveys are performed at depths of 9 to 110 m at each of seven index sites around Lake Michigan. Zebra mussel (Dreissena polymorpha) populations have expanded to all survey locations and at a level to sufficiently contribute to the bottom trawl catches. The quagga (Dreissena bugensis), recently reported in Lake Michigan, was likely in the catches though not recognized. Dreissena spp. biomass ranged from about 0.6 to 15 kg/ha at the various sites in 1999. Dreissenid mussels were found at depths of 9 to 82 m, with their peak biomass at 27 to 46 m. The colonization of these exotic mussels has ecological implications as well as potential ramifications on the ability to sample fish consistently and effectively with bottom trawls in Lake Michigan.

  9. The diversity of benthic mollusks of Lake Victoria and Lake Burigi ...

    African Journals Online (AJOL)

    Molluscan diversity, abundance and distribution in sediments of Lake Victoria and its satellite lake, Lake Burigi, were investigated. The survey was carried out in January and February 2002 for Lake Victoria and in March and April 2002 for Lake Burigi. Ten genera were recorded from four zones of Lake Victoria while only ...

  10. An Overview of Sediment Organic Matter Records of Human Eutrophication in the Laurentian Great Lakes Region

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, Philip A. [University of Michigan, Department of Geological Sciences (United States)], E-mail: pameyers@umich.ed

    2006-12-15

    The isotopic and molecular compositions of organic matter buried in lake sediments provide information that helps to reconstruct past environmental conditions and to assess impacts of humans on local ecosystems. This overview of sedimentary records from the North American Great Lakes region describes examples of applications of organic geochemistry to paleolimnological reconstructions. These lakes experienced a succession of human-induced environmental changes that started after completion of the Erie Canal in 1825. Agricultural deforestation in the mid-nineteenth century released soil nutrients that increased algal productivity and caused an associated increase in algal biomarkers in sediment records. Eutrophication that accompanied magnified delivery of municipal nutrients to the lakes in the 1960s and 1970s created excursions to less negative {delta}{sup 13}C values in sediment organic matter. Increased organic carbon mass accumulation rates mirror the isotopic evidence of eutrophication in the Great Lakes.

  11. New data on mitochondrial diversity and origin of Hemimysis anomala in the Laurentian Great Lakes

    Science.gov (United States)

    Questel, Jennifer M.; Walsh, Maureen G.; Smith, Randall J.; Welsh, Amy B.

    2012-01-01

    The most recent Ponto-Caspian species to invade the Laurentian Great Lakes is the crustacean Hemimysis anomala, first reported in 2006. A previous study described three haplotype groups (A, B, C) of H. anomala in native and invaded areas within Europe, but only one haplotype (A1) in a sample from Lake Michigan. Our study expands these results to additional populations in the Great Lakes basin, and evaluates relationships among North American and European populations. A 549-bp fragment of themitochondrial cytochrome oxidase I (COI) gene was analyzed from populations of H. anomala in Lakes Ontario, Erie, Huron, and the St. Lawrence River.Two different haplotypes, A1 and B1,were observed in the sampled populations of H. anomala and in a previous analysis from H. anomala in Oneida Lake (New York). Our results, in contrast with a previous study, detect an additional haplotype in North America.

  12. Marine leech Ozobranchus margoi parasitizing loggerhead turtle (Caretta caretta in Rio Grande do Sul, Brazil Sanguessugas Ozobranchus margoi parasitando uma tartaruga cabeçuda (Caretta caretta no Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Carla Rosane Rodenbusch

    2012-09-01

    Full Text Available This paper reports the finding of several Ozobranchus margoi (Annelida: Hirudinea parasitizing a loggerhead turtle (Caretta caretta that was found in the municipality of Tavares, state of Rio Grande do Sul, southern Brazil. Since this parasite is considered to be a vector of chelonid herpesvirus 5 (ChHV-5, the leeches collected were tested for the presence of this virus. All the specimens were negative on PCR analysis. Although O. margoi is considered to be a common sea turtle parasite, this is the first official record describing collection of this parasite from a loggerhead turtle in southern Brazil, within the country's subtropical zone. This finding draws attention to the presence of this parasite and to the risk of leech-borne infectious diseases among turtles found along the coast of southern Brazil.Este artigo relata a descoberta de vários exemplares de Ozobranchus margoi (Annelida Hirudínea parasitando uma tartaruga cabeçuda (Caretta caretta encontrada no município de Tavares, Rio Grande do Sul, sul do Brasil. Uma vez que esse parasito é considerado vetor do chelonid herpesvirus 5 (ChHV 5, as sanguessugas foram testadas para a presença deste vírus. Todas as amostras foram negativas pela análise de PCR. Embora o O. margoi seja considerado um parasito comum de tartarugas marinhas, este é o primeiro registro oficial que descreve a coleta deste parasita em uma tartaruga cabeçuda no sul do Brasil, dentro da zona subtropical do país. Este achado chama a atenção para a presença deste parasita e para o risco de sanguessugas transmitirem doenças infecciosas em tartarugas no litoral sul do Brasil.

  13. Elliot Lake progress report

    International Nuclear Information System (INIS)

    Findlay, W.; Scott, A.S.

    1980-01-01

    The intent of the Elliot Lake remedial program is to identify houses in Elliot Lake with annual average WL's in excess of 0.02, discover the routes of radon entry into identified houses and close enough of them to reduce the annual average WL to an acceptable level, and to demonstrate that the annual average WL is below 0.02 in houses where remedial work was not thought necessary as well as in houses where remedial work has been completed. The remedial program is organized into two subprograms, the survey program and the remedial action program. By December 31, 1979 more than 17000 survey measurements had been carried out, identifying 157 houses where remedial action was required and confirming that no action was needed in 413 houses. Remedial work had been completed on 98 houses

  14. Angora Fire, Lake Tahoe

    Science.gov (United States)

    2007-01-01

    On the weekend of June 23, 2007, a wildfire broke out south of Lake Tahoe, which stretches across the California-Nevada border. By June 28, the Angora Fire had burned more than 200 homes and forced some 2,000 residents to evacuate, according to The Seattle Times and the Central Valley Business Times. On June 27, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the burn scar left by the Angora fire. The burn scar is dark gray, or charcoal. Water bodies, including the southern tip of Lake Tahoe and Fallen Leaf Lake, are pale silvery blue, the silver color a result of sunlight reflecting off the surface of the water. Vegetation ranges in color from dark to bright green. Streets are light gray, and the customary pattern of meandering residential streets and cul-de-sacs appears throughout the image, including the area that burned. The burn scar shows where the fire obliterated some of the residential areas just east of Fallen Leaf Lake. According to news reports, the U.S. Forest Service had expressed optimism about containing the fire within a week of the outbreak, but a few days after the fire started, it jumped a defense, forcing the evacuation of hundreds more residents. Strong winds that had been forecast for June 27, however, did not materialize, allowing firefighters to regain ground in controlling the blaze. On June 27, authorities hoped that the fire would be completely contained by July 3. According to estimates provided in the daily report from the National Interagency Fire Center, the fire had burned 3,100 acres (about 12.5 square kilometers) and was about 55 percent contained as of June 28. Some mandatory evacuations remained in effect. NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  15. Great Lakes Energy Institute

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J. Iwan [Case Western Reserve Univ., Cleveland, OH (United States)

    2012-11-18

    The vision of the Great Lakes Energy Institute is to enable the transition to advanced, sustainable energy generation, storage, distribution and utilization through coordinated research, development, and education. The Institute will place emphasis on translating leading edge research into next generation energy technology. The Institute’s research thrusts focus on coordinated research in decentralized power generation devices (e.g. fuel cells, wind turbines, solar photovoltaic devices), management of electrical power transmission and distribution, energy storage, and energy efficiency.

  16. Limnology of Lake Midmar

    CSIR Research Space (South Africa)

    Breen, CM

    1983-12-01

    Full Text Available goals. Those which seem important to us are: the identification of the limnological responses affecting water quality which are of universal application. Some such as phosphorus load are well known whereas others may still require to be identified... Figure 17 Pattern of release of total nitrogen and phosphorus from decomposing vegetation ............................. 56 Figure 18 Changes in the amounts of total phosphorus within the lake, the inflow and the outflow on a weekly basis....... 59...

  17. Restoring life to acidified lakes

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, M

    1986-05-01

    In 1983 EPRI initiated the lake acidification mitigation project (LAMP) in order to examine the long-term ecosystem effects of liming lakes, and to develop a model for calculating optimal liming doses. Investigations were carried out at lakes under 3 sets of conditions: reacidification, maintenance liming and preventive maintenance liming. The research so far has indicated that liming is a safe and effective technique.

  18. Radioecological characteristics of Lake Zarnowieckie

    International Nuclear Information System (INIS)

    Soszka, G.J.; Grzybowska, D.; Rostek, J.; Pietruszewski, A.; Wardaszko, T.; Kalinowska, A.; Tomczak, J.

    1986-01-01

    Results are presented of the radioecological studies carried out in Lake Zarnowieckie as a part of pre-operational investigations related to the construction of a nuclear power station at this lake. Concentrations of essential radionuclides were determined in water, bottom sediments and selected plants and animals. Analyses were made of the distribution and spreading of 90 Sr and 137 Cs in the lake ecosystem and in the near-by meadows. 28 refs., 6 figs., 6 tabs. (author)

  19. Environmental Monitoring, Water Quality - Lakes Assessments - Attaining

    Data.gov (United States)

    NSGIC Education | GIS Inventory — This layer shows only attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water Act...

  20. Managing inherent complexity for sustainable walleye fisheries in Lake Erie

    Science.gov (United States)

    Roseman, Edward F.; Drouin, Richard; Gaden, Marc; Knight, Roger; Tyson, Jeff; Zhao, Yingming; Taylor, William W.; Lynch, Abigail J.; Léonard, Nancy J.

    2012-01-01

    In Lake Erie, Walleye (Sander vitreus vitreus) is king. The naturally occurring species is the foundation of commercial fishing operations on the Canadian side of the lake and is a much-prized sport fish on the American side. Management of Lake Erie walleye fisheries is complex and takes place in an inter-jurisdictional setting composed of resource agencies from the states of Michigan (MDNR), Ohio (ODNR), Pennsylvania (PFBC), and New York (NYDEC) and the province of Ontario (OMNR). The complexity of walleye management is exacerbated by interactions among environmental and ecological changes in Lake Erie, complex life-history characteristics of the species, public demand for walleye, and cultural/governance differences among managing groups and their respective constituents. Success of future management strategies will largely hinge upon our ability to understand these inherent complexities and to employ tactics that successfully accommodate stock productivity and human demand in a highly dynamic environment. In this report, we review the history of Lake Erie walleye management, outline the multi-jurisdictional process for international management of walleye, and discuss strategies to address challenges facing managers.

  1. Algae Bloom in a Lake

    Directory of Open Access Journals (Sweden)

    David Sanabria

    2008-01-01

    Full Text Available The objective of this paper is to determine the likelihood of an algae bloom in a particular lake located in upstate New York. The growth of algae in this lake is caused by a high concentration of phosphorous that diffuses to the surface of the lake. Our calculations, based on Fick's Law, are used to create a mathematical model of the driving force of diffusion for phosphorous. Empirical observations are also used to predict whether the concentration of phosphorous will diffuse to the surface of this lake within a specified time and under specified conditions.

  2. Submerged Grove in Lake Onogawa

    OpenAIRE

    Sato, Yasuhiro; Nakamura, Soken; Ochiai, Masahiro

    1996-01-01

    Abstract : The first record by ultrasonic echo sounding on the distribution of the submerged standing trees on the bottom of Lake Onogawa is presented. Lake Onogawa is a dammed lake formed at the time of the eruption of the volcano Mt.Bandai in 1888. Since then the original vegetation of the dammed valley has remained submerged. Many submerged standing trees are distributed on the bottom within about 600m from the northeast end of the lake. The density of the trees in this area is sufficient ...

  3. Lake Charles CCS Project

    Energy Technology Data Exchange (ETDEWEB)

    Leib, Thomas [Leucadia Energy, LLC, Salt Lake City, UT (United States); Cole, Dan [Denbury Onshore, LLC, Plano, TX (United States)

    2015-06-30

    In late September 2014 development of the Lake Charles Clean Energy (LCCE) Plant was abandoned resulting in termination of Lake Charles Carbon Capture and Sequestration (CCS) Project which was a subset the LCCE Plant. As a result, the project was only funded through Phase 2A (Design) and did not enter Phase 2B (Construction) or Phase 2C (Operations). This report was prepared relying on information prepared and provided by engineering companies which were engaged by Leucadia Energy, LLC to prepare or review Front End Engineering and Design (FEED) for the Lake Charles Clean Energy Project, which includes the Carbon Capture and Sequestration (CCS) Project in Lake Charles, Louisiana. The Lake Charles Carbon Capture and Sequestration (CCS) Project was to be a large-scale industrial CCS project intended to demonstrate advanced technologies that capture and sequester carbon dioxide (CO2) emissions from industrial sources into underground formations. The Scope of work was divided into two discrete sections; 1) Capture and Compression prepared by the Recipient Leucadia Energy, LLC, and 2) Transport and Sequestration prepared by sub-Recipient Denbury Onshore, LLC. Capture and Compression-The Lake Charles CCS Project Final Technical Report describes the systems and equipment that would be necessary to capture CO2 generated in a large industrial gasification process and sequester the CO2 into underground formations. The purpose of each system is defined along with a description of its equipment and operation. Criteria for selection of major equipment are provided and ancillary utilities necessary for safe and reliable operation in compliance with environmental regulations are described. Construction considerations are described including a general arrangement of the CCS process units within the overall gasification project. A cost estimate is provided, delineated by system area with cost breakdown showing equipment, piping and materials

  4. Holocene Lake-Level Fluctuations of Lake Aricota, Southern Peru

    Science.gov (United States)

    Placzek, Christa; Quade, Jay; Betancourt, Julio L.

    2001-09-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17° 22‧S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 14C yr B.P. and ended ∼2700 14C yr B.P. Moderately high lake levels occurred at 1700 and 1300 14C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16°S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes.

  5. Swimming black-crowned night-herons (Nycticorax nycticorax) Kleptoparasitize American coots (Fulica americana)

    DEFF Research Database (Denmark)

    Graves, Gary R.

    2015-01-01

    I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid.......I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid....

  6. Evaluation of groundwater discharge into small lakes based on the temporal distribution of radon-222

    Science.gov (United States)

    Dimova, N.T.; Burnett, W.C.

    2011-01-01

    In order to evaluate groundwater discharge into small lakes we constructed a model that is based on the budget of 222Rn (radon t1/2 5 3.8 d) as a tracer. The main assumptions in our model are that the lake's waters are wellmixed horizontally and vertically; the only significant 222Rn source is via groundwater discharge; and the only losses are due to decay and atmospheric evasion. In order to evaluate the groundwater-derived 222Rn flux, we monitored the 222Rn concentration in lake water over periods long enough (usually 1-3 d) to observe changes likely caused by variations in atmospheric exchange (primarily a function of wind speed and temperature). We then attempt to reproduce the observed record by accounting for decay and atmospheric losses and by estimating the total 222Rn input flux using an iterative approach. Our methodology was tested in two lakes in central Florida: one of which is thought to have significant groundwater inputs (Lake Haines) and another that is known not to have any groundwater inflows but requires daily groundwater augmentation from a deep aquifer (Round Lake). Model results were consistent with independent seepage meter data at both Lake Haines (positive seepage of ??? 1.6 ?? 104 m3 d-1 in Mar 2008) and at Round Lake (no net groundwater seepage). ?? 2011, by the American Society of Limnology and Oceanography, Inc.

  7. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    Energy Technology Data Exchange (ETDEWEB)

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  8. Choking Lake Winnipeg

    Science.gov (United States)

    Byrne, J. M.; Little, L. J.; Dodgson, K. A.; MacDonald, R. J.; Graham, J.

    2009-12-01

    The problems of waterway eutrophication and coastal zone hypoxia are reaching epidemic proportions. Fresh water and coastal marine environments around the world are suffering unprecedented pollution loadings. We are developing an education program to address the dramatic need for public, community and K-12 education about the harsh impacts of elevated nutrient loads on fresh and marine water environments. The Lake Winnipeg watershed is adopted as the poster child of fresh water eutrophication in western North America. The watershed, one of the largest on the continent, is in rapid decline due to pollution, population pressures and water diversion. A concerted education program is needed to change personal and society actions that negatively impact the Winnipeg watershed; and the confluence of the watershed - Lake Winnipeg. But the education program goes beyond Lake Winnipeg. Negative impacts of nutrient loads are adversely affecting environments right to the oceans. Major dead zones that are expanding on our continental shelves due to nutrient overloading threaten to coalesce into extensive regions of marine life die-off. This presentation outlines the documentary education production process under development. We are building a series of Public Service Announcements (PSAs) for national television networks. The PSAs will direct educators, stakeholders and citizens to an associated website with educational video clips detailing the issues of eutrophication and hypoxia. The video clips or webisodes, present interviews with leading scientists. The discussions address the causes of the problems, and presents workable solutions to nutrient overloads from a variety of sources. The webisodes are accompanied by notes and advice to teachers on ways and means to use the webisodes in classrooms. The project is fully funed by a group of Canadian Community Foundations, with the understanding the work wil be available free to educators anywhere in the world. Our education

  9. Lake Carnegie, Western Australia

    Science.gov (United States)

    2002-01-01

    Ephemeral Lake Carnegie, in Western Australia, fills with water only during periods of significant rainfall. In dry years, it is reduced to a muddy marsh. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on May 19, 1999. This is a false-color composite image made using shortwave infrared, infrared, and red wavelengths. The image has also been sharpened using the sensor's panchromatic band. Image provided by the USGS EROS Data Center Satellite Systems Branch. This image is part of the ongoing Landsat Earth as Art series.

  10. L-Lake macroinvertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

  11. L-Lake macroinvertebrate community

    International Nuclear Information System (INIS)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake's macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors

  12. Lake-level increasing under the climate cryoaridization conditions during the Last Glacial Maximum

    Science.gov (United States)

    Amosov, Mikhail; Strelkov, Ivan

    2017-04-01

    A lake genesis and lake-level increasing during the Last Glacial Maximum (LGM) are the paramount issues in paleoclimatology. Investigating these problems reveals the regularities of lake development and figures out an arid territory conditions at the LGM stage. Pluvial theory is the most prevalent conception of lake formation during the LGM. This theory is based on a fact that the water bodies emerged and their level increased due to torrential rainfalls. In this study, it is paid attention to an alternative assumption of lake genesis at the LGM stage, which is called climate cryoaridization. In accordance with this hypothesis, the endorheic water basins had their level enlarged because of a simultaneous climate aridity and temperature decrease. In this research, a lake-level increasing in endorheic regions of Central Asia and South American Altiplano of the Andes is described. The lake investigation is related to its conditions during the LGM. The study also includes a lake catalogue clearly presenting the basin conditions at the LGM stage and nowadays. The data compilation partly consists of information from an earlier work of Mikhail Amosov, Lake-levels, Vegetation And Climate In Central Asia During The Last Glacial Maximum (EGU2014-3015). According to the investigation, a lake catalogue on 27 lakes showed that most of the water bodies had higher level. This feature could be mentioned for the biggest lakes of the Aral Sea, Lake Balkhash, Issyk-Kul etc. and for the small ones located in the mountains, such as Pamir, Tian-Shan and Tibet. Yet some lakes that are situated in Central Asian periphery (Lake Qinghai and lakes in Inner Mongolia) used to be lower than nowadays. Also, the lake-level increasing of Altiplano turned to be a significant feature during the LGM in accordance with the data of 5 lakes, such as Titicaca, Coipasa-Uyuni, Lejia, Miscanti and Santa-Maria. Most of the current endorheic basins at the LGM stage were filled with water due to abundant

  13. 75 FR 34934 - Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA

    Science.gov (United States)

    2010-06-21

    ...-AA00 Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA AGENCY... Fireworks for the Virginia Lake Festival event. This action is intended to restrict vessel traffic movement... Virginia Lake Festival, Buggs Island Lake, Clarksville, VA (a) Regulated Area. The following area is a...

  14. Holocene lake-level fluctuations of Lake Aricota, Southern Peru

    Science.gov (United States)

    Placzek, C.; Quade, Jay; Betancourt, J.L.

    2001-01-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17?? 22???S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (Titicaca (16?? S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes. ?? 2001 University of Washington.

  15. Milankovitch Modulation of the Ecosystem Dynamics of Fossil Great Lakes

    Science.gov (United States)

    Whiteside, J. H.; Olsen, P. E.; Eglinton, T. I.; Cornet, B.; Huber, P.; McDonald, N. G.

    2008-12-01

    Triassic and Early Jurassic lacustrine deposits of eastern North American rift basins preserve a spectacular record of precession-related Milankovitch forcing in the Pangean tropics. The abundant and well-preserved fossil fish assemblages from these great lakes demonstrate a sequence of cyclical changes that track the permeating hierarchy of climatic cycles. To detail ecosystem processes correlating with succession of fish communities, we measured bulk δ13Corg through a 100 ky series of Early Jurassic climatic precession-forced lake level cycles in the lower Shuttle Meadow Formation of the Hartford rift basin, CT. The deep-water phase of one of these cycles, the Bluff Head bed, has produced thousands of articulated fish. We observe fluctuations in the bulk δ13Corg of the cyclical strata that reflect differing degrees of lake water stratification, nutrient levels, and relative proportion of algal vs. plant derived organic matter that trace fish community changes. We can exclude extrinsic changes in the global exchangeable reservoirs as an origin of this variability because molecule-level δ13C of n-alkanes of plant leaf waxes from the same strata show no such variability. While at higher taxonomic levels the fish communities responded largely by sorting of taxa by environmental forcing, at the species level the holostean genus Semionotus responded by in situ evolution, and ultimately extinction, of a species flock. Fluctuations at the higher frequency, climatic precessional scale are mirrored at lower frequency, eccentricity modulated, scales, all following the lake-level hierarchical pattern. Thus, lacustrine isotopic ratios amplify the Milankovitch climate signal that was already intensified by sequelae of the end-Triassic extinctions. The degree to which the ecological structure of modern lakes responds to similar environmental cyclicity is largely unknown, but we suspect similar patterns and processes within the Neogene history of the East African great lakes

  16. Flood-inundation maps for Lake Champlain in Vermont and in northern Clinton County, New York

    Science.gov (United States)

    Flynn, Robert H.; Hayes, Laura

    2016-06-30

    extents against the inundation area extents determined for the May 2011 flood (which incorporated documented high-water marksfrom the flood of May 201) (Bjerklie and others, 2014).A digital elevation model (DEM) was created by USGS, within a geographic information system (GIS), from the recently flown and processed light detection and ranging(lidar) data (2013–2014) in Vermont and the lake shore area of northern Clinton County in New York. The lidar data have a vertical accuracy of 0.3 to 0.6-ft (9.6 to 18.0-centimeters [cm]) and a horizontal resolution of 2.3 to 4.6 ft (0.7 to 1.4 meters). This DEM was used in determining the floodboundary for 11 flood stages at 0.5-ft intervals from 100.0 to104.0 ft (NGVD 29) and 1-ft intervals from 104.0 to 106.0 ft (NGVD 29) as referenced to the USGS lake gage 04295000, Richelieu River (Lake Champlain) at Rouses Point, N.Y. In addition, the May 2011 flood-inundation area for elevation103.20 ft (NGVD 29) (102.77 ft, North American Vertical Datum [NAVD] 88) was determined from this DEM. The May 2011 flood is the highest recorded lake water level (stage)at the Rouses Point, N.Y., lake gage. Flood stages greater than 101.5 ft (NGVD 29) exceed the “major flood stage”as defined by the NationalWeather Service for USGS lake gage 04295000.The availability of these maps, along with Internet information regarding current stage from the USGS lake gage and forecasted high-flow stages from the NationalWeather Service, will provide emergency management personnel and residents with information that is critical for flood responseactivities such as evacuations and road closures, as well as for post-flood recovery eforts.

  17. Forest blowdown and lake acidification

    International Nuclear Information System (INIS)

    Dobson, J.E.; Rush, R.M.; Peplies, R.W.

    1990-01-01

    The authors examine the role of forest blowdown in lake acidification. The approach combines geographic information systems (GIS) and digital remote sensing with traditional field methods. The methods of analysis consist of direct observation, interpretation of satellite imagery and aerial photographs, and statistical comparison of two geographical distributions-one representing forest blow-down and another representing lake chemistry. Spatial and temporal associations between surface water pH and landscape disturbance are strong and consistent in the Adirondack Mountains of New York. In 43 Adirondack Mountain watersheds, lake pH is associated with the percentage of the watershed area blown down and with hydrogen ion deposition (Spearman rank correlation coefficients of -0.67 and -0.73, respectively). Evidence of a temporal association is found at Big Moose Lake and Jerseyfield Lake in New York and the Lygners Vider Plateau of Sweden. They conclude that forest blowdown facilities the acidification of some lakes by altering hydrologic pathways so that waters (previously acidified by acid deposition and/or other sources) do not experience the neutralization normally available through contact with subsurface soils and bedrock. Increased pipeflow is suggested as a mechanism that may link the biogeochemical impacts of forest blowdown to lake chemistry

  18. Microplastics in Taihu Lake, China.

    Science.gov (United States)

    Su, Lei; Xue, Yingang; Li, Lingyun; Yang, Dongqi; Kolandhasamy, Prabhu; Li, Daoji; Shi, Huahong

    2016-09-01

    In comparison with marine environments, the occurrence of microplastics in freshwater environments is less understood. In the present study, we investigated microplastic pollution levels during 2015 in Taihu Lake, the third largest Chinese lake located in one of the most developed areas of China. The abundance of microplastics reached 0.01 × 10(6)-6.8 × 10(6) items/km(2) in plankton net samples, 3.4-25.8 items/L in surface water, 11.0-234.6 items/kg dw in sediments and 0.2-12.5 items/g ww in Asian clams (Corbicula fluminea). The average abundance of microplastics was the highest in plankton net samples from the southeast area of the lake and in the sediments from the northwest area of the lake. The northwest area of the lake was the most heavily contaminated area of the lake, as indicated by chlorophyll-α and total phosphorus. The microplastics were dominated by fiber, 100-1000 μm in size and cellophane in composition. To our best knowledge, the microplastic levels measured in plankton net samples collected from Taihu Lake were the highest found in freshwater lakes worldwide. The ratio of the microplastics in clams to each sediment sample ranged from 38 to 3810 and was negatively correlated to the microplastic level in sediments. In brief, our results strongly suggest that high levels of microplastics occurred not only in water but also in organisms in Taihu Lake. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Tissue contaminants and associated transcriptional response in trout liver from high elevation lakes of Washington

    Science.gov (United States)

    Moran, P.W.; Aluru, N.; Black, R.W.; Vijayan, M.M.

    2007-01-01

    The consistent cold temperatures and large amount of precipitation in the Olympic and Cascade ranges of Washington State are thought to enhance atmospheric deposition of contaminants. However, little is known about contaminant levels in organisms residing in these remote high elevation lakes. We measured total mercury and 28 organochlorine compounds in trout collected from 14 remote lakes in the Olympic, Mt. Rainer, and North Cascades National Parks. Mercury was detected in trout from all lakes sampled (15 to 262 ??g/kg ww), while two organochlorines, total polychlorinated biphenyls (tPCB) and dichlorodiphenyldichloroethylene (DDE), were also detected in these fish tissues (<25 ??g/kg ww). In sediments, organochlorine levels were below detection, while median total and methyl mercury were 30.4 and 0.34 ??g/ kg dry weight (ww), respectively. Using fish from two lakes, representing different contaminant loading levels (Wilcox lake: high; Skymo lake: low), we examined transcriptional response in the liver using a custom-made low-density targeted rainbow trout cDNA microarray. We detected significant differences in liver transcriptional response, including significant changes in metabolic, endocrine, and immune-related genes, in fish collected from Wilcox Lake compared to Skymo Lake. Overall, our results suggest that local urban areas contribute to the observed contaminant patterns in these high elevation lakes, while the transcriptional changes point to a biological response associated with exposure to these contaminants in fish. Specifically, the gene expression pattern leads us to hypothesize a role for mercury in disrupting the metabolic and reproductive pathways in fish from high elevation lakes in western Washington. ?? 2007 American Chemical Society.

  20. Key Lake spill. Final report

    International Nuclear Information System (INIS)

    1984-03-01

    On January 5, 1984 contaminated water overflowed a storage reservoir at the Key Lake uranium mill onto the ice on a neighboring lake, into a muskeg area and onto a road. Outflow continued for two days, partially undercutting a retaining dyke. This report concludes the spill was the result of poor operation by the Key Lake Mining Corp.. The environmental impact will be minimal after cleanup. Improvements can be made in the regulatory process, and it is necessary to prepare for possible future mishaps

  1. 2010 Great Lakes Restoration Initiative Bathymetric Lidar: Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data contained in this file contain hydrographic and topographic data collected by the Fugro LADS Mk II system along the Lake Superior coast of Minnessota,...

  2. American Illuminations

    DEFF Research Database (Denmark)

    Nye, David

    Illuminated fêtes and civic celebrations began in Renaissance Italy and spread through the courts of Europe. Their fireworks, torches, lamps, and special effects glorified the monarch, marked the birth of a prince, or celebrated military victory. Nineteenth-century Americans rejected such monarch...

  3. Jordan Lake Watershed Protection District

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Polygon representing the area of the Jordan Lake Watershed Protection District. The Watershed Protection District (PDF) is a sensitive area of land that drains to...

  4. Great Lakes Environmental Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NOAA-GLERL and its partners conduct innovative research on the dynamic environments and ecosystems of the Great Lakes and coastal regions to provide information for...

  5. Gasoline-related organics in Lake Tahoe before and after prohibition of carbureted two-stroke engines

    Science.gov (United States)

    Lico, M.S.

    2004-01-01

    On June 1, 1999, carbureted two-stroke engines were banned on waters within the Lake Tahoe Basin of California and Nevada. The main gasoline components MTBE (methyl tert-butyl ether) and BTEX (benzene, toluene, ethylbenzene, and xylenes) were present at detectable concentrations in all samples taken from Lake Tahoe during 1997-98 prior to the ban. Samples taken from 1999 through 2001 after the ban contained between 10 and 60 percent of the pre-ban concentrations of these compounds, with MTBE exhibiting the most dramatic change (a 90 percent decrease). MTBE and BTEX concentrations in water samples from Lake Tahoe and Lower Echo Lake were related to the amount of boat use at the sampling sites. Polycyclic aromatic hydrocarbon (PAH) compounds are produced by high-temperature pyrolytic reactions. They were sampled using semipermeable membrane sampling devices in Lake Tahoe and nearby Donner Lake, where carbureted two-stroke engines are legal. PAHs were detected in all samples taken from Lake Tahoe and Donner Lake. The number of PAH compounds and their concentrations are related to boat use. The highest concentrations of PAH were detected in samples from two heavily used boating areas, Tahoe Keys Marina and Donner Lake boat ramp. Other sources of PAH, such as atmospheric deposition, wood smoke, tributary streams, and automobile exhaust do not contribute large amounts of PAH to Lake Tahoe. Similar numbers of PAH compounds and concentrations were found in Lake Tahoe before and after the ban of carbureted two-stroke engines. ?? by the North American Lake Management Society 2004.

  6. Spatial distribution of seepage at a flow-through lake: Lake Hampen, Western Denmark

    DEFF Research Database (Denmark)

    Kidmose, Jacob Baarstrøm; Engesgaard, Peter Knudegaard; Nilsson, Bertel

    2011-01-01

    recharge patiern of the lake and relating these to the geologic history of the lake. Recharge of the surrounding aquifer by lake water occurs off shore in a narrow zone, as measured from lake–groundwater gradients. A 33-m-deep d18O profi le at the recharge side shows a lake d18O plume at depths...... that corroborates the interpretation of lake water recharging off shore and moving down gradient. Inclusion of lake bed heterogeneity in the model improved the comparison of simulated and observed discharge to the lake. The apparent age of the discharging groundwater to the lake was determined by CFCs, resulting...

  7. Can small zooplankton mix lakes?

    OpenAIRE

    Simoncelli, S.; Thackeray, S.J.; Wain, D.J.

    2017-01-01

    The idea that living organisms may contribute to turbulence and mixing in lakes and oceans (biomixing) dates to the 1960s, but has attracted increasing attention in recent years. Recent modeling and experimental studies suggest that marine organisms can enhance turbulence as much as winds and tides in oceans, with an impact on mixing. However, other studies show opposite and contradictory results, precluding definitive conclusions regarding the potential importance of biomixing. For lakes, on...

  8. Lake Turkana National Parks Kenya.

    OpenAIRE

    2005-01-01

    Lake Turkana is the largest, most northerly and most saline of Africa's Rift Valley lakes and an outstanding laboratory for the study of plant and animal communities. The three National Parks are a stopover for migrant waterfowl and are major breeding grounds for the Nile crocodile and hippopotamus. The Koobi Fora deposits are rich in pre-human, mammalian, molluscan and other fossil remains and have contributed more to the understanding of Quaternary palaeoenvironments than any other site on ...

  9. Radiocarbon dating of lake sediments

    OpenAIRE

    Pocevičius, Matas

    2016-01-01

    Matas Pocevičius, Radiocarbon dating of lake sediments, bachelor thesis, Vilnius University, Faculty of Physics, Department of General Physics and Spectroscopy, physics, Vilnius, 45 p., 2016. The aim of this study is to evaluate the possibility of radiocarbon dating application for Tapeliai lake bottom sediments. The literature review discusses topics related to accelerator mass spectrometry, principles of radiocarbon formation, importance of nuclear fallout for 14C, possible applications of ...

  10. 77 FR 50923 - Safety Zone; Jet Express Triathlon, Sandusky Bay, Lake Erie, Lakeside, OH

    Science.gov (United States)

    2012-08-23

    ... fireworks display. B. Basis and Purpose The organization Endurance Sports Productions is sponsoring a... waters of Lake Erie within a direct line from 41[deg]33'49'' N, 082[deg]47'8'' W to 41[deg]33'25'' N, 82[deg]48'8'' W and 15 yards on either side of direct line. All geographic coordinates are North American...

  11. Aquatic macrophyte richness in Danish lakes in relation to alkalinity, transparency, and lake area

    DEFF Research Database (Denmark)

    Vestergaard, Ole Skafte; Sand-Jensen, Kaj

    2000-01-01

    We examined the relationship between environmental factors and the richness of submerged macrophytes species in 73 Danish lakes, which are mainly small, shallow, and have mesotrophic to hypertrophic conditions. We found that mean species richness per lake was only 4.5 in acid lakes of low...... alkalinity but 12.3 in lakes of high alkalinity due to a greater occurrence of the species-rich group of elodeids. Mean species richness per lake also increased significantly with increasing Secchi depth. No significant relationship between species richness and lake surface area was observed among the entire...... group of lakes or a subset of eutrophic lakes, as the growth of submerged macrophytes in large lakes may be restricted by wave action in shallow water and light restriction in deep water. In contrast, macrophyte species richness increased with lake surface area in transparent lakes, presumably due...

  12. Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

    Science.gov (United States)

    Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.

    2016-01-01

    Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

  13. Changes in Rongbuk lake and Imja lake in the Everest region of Himalaya

    Science.gov (United States)

    Chen, W.; Doko, T.; Liu, C.; Ichinose, T.; Fukui, H.; Feng, Q.; Gou, P.

    2014-12-01

    The Himalaya holds the world record in terms of range and elevation. It is one of the most extensively glacierized regions in the world except the Polar Regions. The Himalaya is a region sensitive to climate change. Changes in the glacial regime are indicators of global climate changes. Since the second half of the last century, most Himalayan glaciers have melted due to climate change. These changes directly affected the changes of glacial lakes in the Himalayan region due to the glacier retreat. New glacial lakes are formed, and a number of them have expanded in the Everest region of the Himalayas. This paper focuses on the two glacial lakes which are Imja Lake, located at the southern slope, and Rongbuk Lake, located at the northern slope in the Mt. Everest region, Himalaya to present the spatio-temporal changes from 1976 to 2008. Topographical conditions between two lakes were different (Kruskal-Wallis test, p < 0.05). Rongbuk Lake was located at 623 m higher than Imja Lake, and radiation of Rongbuk Lake was higher than the Imja Lake. Although size of Imja Lake was larger than the Rongbuk Lake in 2008, the growth speed of Rongbuk Lake was accelerating since 2000 and exceeds Imja Lake in 2000-2008. This trend of expansion of Rongbuk Lake is anticipated to be continued in the 21st century. Rongbuk Lake would be the biggest potential risk of glacial lake outburst flood (GLOF) at the Everest region of Himalaya in the future.

  14. Spruce Lake Dam reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, G. [SGE Acres Ltd., Fredericton, NB (Canada); Barnard, J. [SGE Acres Ltd., St. John' s, NF (Canada); Vriezen, C. [City of Saint John, NF (Canada); Stephenson, M. [Jacques Whitford Environment Ltd., Fredericton, NB (Canada)

    2004-09-01

    Spruce Lake Dam was constructed in 1898 as part of the water supply system for Saint John, New Brunswick. The original dam was a 6 meter high, 140 meter long concrete gravity dam with an intake structure at its mid point and an overflow spillway at the left abutment. A rehabilitation project was launched in 2001 to bring the deteriorated dam into conformance with the dam safety guidelines of the Canadian Dam Association. The project criteria included minimal disruption to normal operation of water supply facilities and no negative effect on water quality. The project involved installation of a new low level outlet, removal of a gate house and water intake pipes, replacement of an access road culvert in the spillway channel, and raising the earth dam section by 1.8 meters to allow for increased water storage. The new raised section has an impervious core. The project also involved site and geotechnical investigations as well as hydrotechnical and environmental studies. This presentation described the final design of the remedial work and the environmental permitting procedures. Raising the operating level of the system proved successful as demonstrated by the fewer number of pumping days required after dam rehabilitation. The dam safety assessment under the Canadian Environmental Assessment Act began in April 2001, and the rehabilitation was completed by the end of 2002. 1 tab., 8 figs.

  15. Spray Lakes reclamation project

    International Nuclear Information System (INIS)

    Zacaruk, M.R.

    1996-01-01

    When the level of the Spray Lakes (Alberta) reservoir was lowered by four metres, 208 ha of shoreline was exposed offering little to no wildlife benefit and only limited recreation potential. A reclamation plan for 128 ha of shoreline was therefore developed. A wild life-palatable, self-sustaining vegetation cover was established. Approximately 90 ha was scarified, and/or had tree stumps removed prior to seeding, while approximately 40 ha was seeded and fertilized only. The remaining 80 ha of shoreline was not revegetated due to limited access; these areas will be allowed to re-establish naturally from the forested edge. The species were selected based on their adaptation to alkaline soils, drought tolerance, persistence in a stand and rooting characteristics, as well as palatability to wildlife. Alfalfa, white clover and fall rye were seeded. In general, all areas of the reclamation plan are successfully revegetated. Areas which were recontoured are stable and non-eroding. Success was most significant in areas which had been scarified, then seeded and trackpacked. Areas that were seeded and fertilized only were less well established at the end of the first year, but showed improvement in the second and third years. The area will be monitored to ensure the reclaimed vegetation is self-sustaining

  16. American Studies

    Directory of Open Access Journals (Sweden)

    V. O. Pechatnov

    2014-01-01

    Full Text Available The "Founding fathers" of American Studies at MGIMO are considered to be A.V. Efimov and L.I. Clove. Alexey Efimov - Corresponding Member of the USSR Academy of Sciences since 1938, Head of the Department of Modern and Contemporary History and Dean of the Historical School at the Moscow State University - one of the first professors of the Faculty of International Relations MGIMO. Efimov distinguished himself by a broad vision and scope of scientific interests. Back in 1934 he published a monograph "On the history of capitalism in the United States," which initiated a series of research culminating in the fundamental work "The United States. The path of capitalist development (pre-imperialist era". Alexey was not only a great scientist but also a great teacher, whose lectures was popular throughout Moscow. His lecture courses, given at the end of the 1940s at MGIMO, became the basis for the first post-war history textbooks USA - "Essays on the history of the United States." At least as colorful a figure was Professor Leo Izrailevich Zubok - a man of unusual destiny. As a teenager he emigrated to the United States with his parents, where he soon joined the American revolutionary movement in the 1920s and was forced to leave the country. He came to MGIMO being already an experienced scientists. His research interests were very wide: from the study of American foreign policy expansion to the history of the labor movement in the United States. Zubok's fundamental works still have not lost its scientific significance. He has successfully combined scientific work with teaching. Tutorials that are based on his lectures were very popular not only among students of MGIMO.

  17. The reproduction of lake trout in southern Lake Superior

    Science.gov (United States)

    Eschmeyer, Paul H.

    1955-01-01

    The principal spawning grounds of lake trout (Salvelinus namaycush namaycush) in United States waters of southern Lake Superior are on rocky shoals at depths of less than 20 fathoms. Most spawning occurs in October and early November. Of the mature fish collected on or near the spawning grounds, 60 to 69 percent were males. Among mature fish the average length of females was greater than that of males; few males less than 24 inches or females less than 26 inches in total length were caught. Recoveries of lake trout tagged on the spawning grounds showed that some males remained in the immediate area for a period of several weeks during the spawning season. Marked fish showed a tendency to return during later years to spawning grounds on which they had been tagged, even though many of them ranged long distances between spawning seasons.

  18. Recent warming of lake Kivu.

    Science.gov (United States)

    Katsev, Sergei; Aaberg, Arthur A; Crowe, Sean A; Hecky, Robert E

    2014-01-01

    Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient.

  19. Recent warming of lake Kivu.

    Directory of Open Access Journals (Sweden)

    Sergei Katsev

    Full Text Available Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient.

  20. 33 CFR 162.134 - Connecting waters from Lake Huron to Lake Erie; traffic rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; traffic rules. 162.134 Section 162.134 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.134 Connecting waters from Lake Huron to Lake Erie; traffic rules. (a) Detroit River. The...

  1. 33 CFR 162.132 - Connecting waters from Lake Huron to Lake Erie; communications rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; communications rules. 162.132 Section 162.132 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.132 Connecting waters from Lake Huron to Lake Erie; communications rules. (a...

  2. 33 CFR 162.130 - Connecting waters from Lake Huron to Lake Erie; general rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; general rules. 162.130 Section 162.130 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.130 Connecting waters from Lake Huron to Lake Erie; general rules. (a) Purpose. The...

  3. 33 CFR 162.138 - Connecting waters from Lake Huron to Lake Erie; speed rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; speed rules. 162.138 Section 162.138 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.138 Connecting waters from Lake Huron to Lake Erie; speed rules. (a) Maximum speed limit for...

  4. 33 CFR 162.136 - Connecting waters from Lake Huron to Lake Erie; anchorage grounds.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; anchorage grounds. 162.136 Section 162.136 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.136 Connecting waters from Lake Huron to Lake Erie; anchorage grounds. (a) In the Detroit...

  5. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. 162.140 Section 162.140 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.140 Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. (a...

  6. Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

    Science.gov (United States)

    Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

    2006-01-01

    We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

  7. Hierarchical multi-scale classification of nearshore aquatic habitats of the Great Lakes: Western Lake Erie

    Science.gov (United States)

    McKenna, J.E.; Castiglione, C.

    2010-01-01

    Classification is a valuable conservation tool for examining natural resource status and problems and is being developed for coastal aquatic habitats. We present an objective, multi-scale hydrospatial framework for nearshore areas of the Great Lakes. The hydrospatial framework consists of spatial units at eight hierarchical scales from the North American Continent to the individual 270-m spatial cell. Characterization of spatial units based on fish abundance and diversity provides a fish-guided classification of aquatic areas at each spatial scale and demonstrates how classifications may be generated from that framework. Those classification units then provide information about habitat, as well as biotic conditions, which can be compared, contrasted, and hierarchically related spatially. Examples within several representative coastal or open water zones of the Western Lake Erie pilot area highlight potential application of this classification system to management problems. This classification system can assist natural resource managers with planning and establishing priorities for aquatic habitat protection, developing rehabilitation strategies, or identifying special management actions.

  8. Preparation of aluminium lakes by electrocoagulation

    OpenAIRE

    Prapai Pradabkham

    2008-01-01

    Aluminium lakes have been prepared by electrocoagulation employing aluminium as electrodes. The electrocoagulation is conducted in an aqueous alcoholic solution and is completed within one hour. The dye content in the lake ranges approximately between 4-32%.

  9. Global Lake and River Ice Phenology Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Lake and River Ice Phenology Database contains freeze and thaw/breakup dates as well as other descriptive ice cover data for 865 lakes and rivers in the...

  10. Lake Tahoe Water Quality Improvement Programs

    Science.gov (United States)

    Information on the Lake Tahoe watershed, EPA's protection efforts, water quality issues, effects of climate, change, Lake Tahoe Total Maximum Daily Load (TMDL), EPA-sponsored projects, and list of partner agencies.

  11. Biota - 2011 Vegetation Inventory - Marsh Lake, MN

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — 2011 Vegetation Classification for Marsh Lake, MN Vegetation Project Report, OMBIL Environmental Stewardship - Level 1 Inventory. Marsh Lake is located on the...

  12. Profile: Asian Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Asian American Profile: Asian Americans Asian American Profile (Map of the US with the top 10 states displaying the largest Asian American population according to the Census Bureau) CA - ...

  13. Immunizations and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Immunizations Immunizations and African Americans African American adults are less ... 19 to 35 months had comparable rates of immunization. African American women are as likely to have ...

  14. Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

    Directory of Open Access Journals (Sweden)

    Gerhard MAIER

    2005-08-01

    Full Text Available The zooplankton communities of two basins of a large lake, Lake Constance, were compared during the years 2002 and 2003. The two basins differ in morphology, physical and chemical conditions. The Upper Lake basin has a surface area of 470 km2, a mean depth of 100 and a maximum depth of 250 m; the Lower Lake basin has a surface area of 62 km2, a mean depth of only 13 and a maximum depth of 40 m. Nutrient, chlorophyll-a concentrations and mean temperatures are somewhat higher in the Lower than in the Upper Lake. Total abundance of rotifers (number per m2 lake surface was higher and rotifer development started earlier in the year in the Lower than in the Upper Lake. Total abundance of crustaceans was higher in the Upper Lake in the year 2002; in the year 2003 no difference in abundance could be detected between the lake basins, although in summer crustacean abundance was higher in the Lower than in the Upper Lake. Crustacean communities differed significantly between lake basins while there was no apparent difference in rotifer communities. In the Lower Lake small crustaceans, like Bosmina spp., Ceriodaphnia pulchella and Thermocyclops oithonoides prevailed. Abundance (number per m2 lake surface of predatory cladocerans, large daphnids and large copepods was much lower in the Lower than in the Upper Lake, in particular during the summer months. Ordination with nonmetric multidimensional scaling (NMS separated communities of both lakes along gradients that correlated with temperature and chlorophyll a concentration. Clutches of copepods were larger in the Lower than in the Upper Lake. No difference could be detected in clutch size of large daphnids between lake basins. Our results show that zooplankton communities in different basins of Lake Constance can be very different. They further suggest that the lack of large crustaceans in particular the lack of large predatory cladocerans in the Lower Lake can have negative effects on growth and

  15. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

  16. lakemorpho: Calculating lake morphometry metrics in R.

    Science.gov (United States)

    Hollister, Jeffrey; Stachelek, Joseph

    2017-01-01

    Metrics describing the shape and size of lakes, known as lake morphometry metrics, are important for any limnological study. In cases where a lake has long been the subject of study these data are often already collected and are openly available. Many other lakes have these data collected, but access is challenging as it is often stored on individual computers (or worse, in filing cabinets) and is available only to the primary investigators. The vast majority of lakes fall into a third category in which the data are not available. This makes broad scale modelling of lake ecology a challenge as some of the key information about in-lake processes are unavailable. While this valuable in situ information may be difficult to obtain, several national datasets exist that may be used to model and estimate lake morphometry. In particular, digital elevation models and hydrography have been shown to be predictive of several lake morphometry metrics. The R package lakemorpho has been developed to utilize these data and estimate the following morphometry metrics: surface area, shoreline length, major axis length, minor axis length, major and minor axis length ratio, shoreline development, maximum depth, mean depth, volume, maximum lake length, mean lake width, maximum lake width, and fetch. In this software tool article we describe the motivation behind developing lakemorpho , discuss the implementation in R, and describe the use of lakemorpho with an example of a typical use case.

  17. Study of pollution in Rawal lake

    International Nuclear Information System (INIS)

    Ahmad, M.; Khan, M.I.A.; Nisar, M.; Kaleem, M.Y.

    1999-01-01

    It was intended to establish effects of pollution on quality of water of Rawal Lake, Islamabad. Six stations were located for collection of water. The data collected and analyzed so far indicated increasing pollution in the lake Increase in growth of hydrophytes in quite evident, leading towards process of eutrophication of the lake. (author)

  18. Decline of the world's saline lakes

    Science.gov (United States)

    Wayne A. Wurtsbaugh; Craig Miller; Sarah E. Null; R. Justin DeRose; Peter Wilcock; Maura Hahnenberger; Frank Howe; Johnnie Moore

    2017-01-01

    Many of the world’s saline lakes are shrinking at alarming rates, reducing waterbird habitat and economic benefits while threatening human health. Saline lakes are long-term basin-wide integrators of climatic conditions that shrink and grow with natural climatic variation. In contrast, water withdrawals for human use exert a sustained reduction in lake inflows and...

  19. A reactive nitrogen budget for Lake Michigan

    Science.gov (United States)

    The reactive nitrogen budget for Lake Michigan was reviewed and updated, making use of recent estimates of watershed and atmospheric nitrogen loads. The updated total N load to Lake Michigan was approximately double the previous estimate from the Lake Michigan Mass Balance study ...

  20. Historical changes to Lake Washington and route of the Lake Washington Ship Canal, King County, Washington

    Science.gov (United States)

    Chrzastowski, Michael J.

    1983-01-01

    Lake Washington, in the midst of the greater Seattle metropolitan area of the Puget Sound region (fig. 1), is an exceptional commercial, recreational, and esthetic resource for the region . In the past 130 years, Lake Washington has been changed from a " wild " lake in a wilderness setting to a regulated lake surrounded by a growing metropolis--a transformation that provides an unusual opportunity to study changes to a lake's shoreline and hydrologic characteristics -resulting from urbanization.

  1. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    Science.gov (United States)

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  2. Broad-scale lake expansion and flooding inundates essential wood bison habitat in northwestern Canada.

    Science.gov (United States)

    Blais, J. M.; Korosi, J.; Thienpont, J. R.; Pisaric, M. F.; Kokelj, S.; Smol, J. P.; Simpson, M. J.

    2017-12-01

    Climate change-induced landscape alterations have consequences for vulnerable wildlife. In high-latitude regions, dramatic changes in water levels have been linked to climate warming. While most attention has focused on shrinking Arctic lakes, here, we document the opposite scenario: extensive lake expansion in Canada's Northwest Territories that has implications for the conservation of ecologically-important wood bison. We quantified lake area changes since 1986 using remote sensing techniques, and recorded a net gain of > 500 km2, from 5.7% to 11% total water coverage. Inter-annual variability in water level was significantly correlated to the Pacific/North American pattern teleconnection and the summer sea surface temperature anomaly. Historical reconstructions using proxy data archived in dated sediment cores showed that recent lake expansion is outside the range of natural variability of these ecosystems over at least the last 300 years. Lake expansion resulted in increased allochthonous carbon transport, as shown unequivocally by increases in lignin-derived phenols, but with a greater proportional increase in the contribution of organic matter from phytoplankton, as a result of increased open-water habitat. We conclude that complex hydrological changes occurring as a result of recent climatic change have resulted in rapid and widespread lake expansion that may significantly affect at-risk wildlife populations. This study is based on results we reported in Nature Communications in 2017 (DOI: 10.1038/ncomms14510).

  3. Horizontal drilling under Lake Erie

    Energy Technology Data Exchange (ETDEWEB)

    Meller, R.

    2001-07-01

    Drilling oil wells under Lake Erie calls for horizontal drilling wells to be drilled from shore out into the pay-zone under the lake. The nature and characteristics of horizontal wells as compared to vertical wells are explored. Considerations that have to be taken into account in drilling horizontal wells are explained (the degree of curvature, drilling fluid quality, geosteering in the pay-zone, steering instrumentation, measurements while drilling (MWD), logging while drilling (LWD)). The concept and reasons for extended reach wells are outlined, along with characteristic features of multilateral wells.

  4. The Lake and the City

    Directory of Open Access Journals (Sweden)

    Konstantin Lidin

    2013-09-01

    Full Text Available The article considers relations between the city of Irkutsk and Lake Baikal in terms of cultural geography. Baikal is included in the UNESCO world heritage list. Unlike the majority of lakes also included in this list, Baikal’s coast is inhabited, especially its southern part. Similar situation is, for example, in the cluster “the city of Bergen – Geiranger village – Geirangerfjord” in Norway. The comparative analysis shows how Norway’s positive experience of the system “a city – a village – a natural phenomenon” could be used in order to make Irkutsk more attractive for tourists and citizens.

  5. Protecting the endangered lake salmon

    International Nuclear Information System (INIS)

    Soimakallio, H.; Oesch, P.

    1997-01-01

    In addition to the Ringed Seal, the labyrinthine Saimaa lake system created after the Ice Age also trapped a species of salmon, whose entire life cycle became adapted to fresh water. In order to improve the living conditions of this lake salmon which - like the ringed seal - is today classified as an endangered species, an intensive research programme has been launched. The partners include the Finnish Game and Fisheries Research Institute, fishing and environmental authorities and - in collaboration with UPM-Kymmene Oy and Kuurnan Voima Oy - the IVO subsidiary Pamilo Oy

  6. LAKE BAIKAL: Underwater neutrino detector

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    A new underwater detector soon to be deployed in Lake Baikal in Siberia, the world's deepest lake with depths down to 1.7 kilometres, could help probe the deepest mysteries of physics. One of the big unsolved problems of astrophysics is the origin of very energetic cosmic rays. However there are many ideas on how particles could be accelerated by exotic concentrations of matter and provide the majority of the Galaxy's high energy particles. Clarification would come from new detectors picking up the energetic photons and neutrinos from these sources

  7. Protecting the endangered lake salmon

    Energy Technology Data Exchange (ETDEWEB)

    Soimakallio, H.; Oesch, P. [ed.

    1997-11-01

    In addition to the Ringed Seal, the labyrinthine Saimaa lake system created after the Ice Age also trapped a species of salmon, whose entire life cycle became adapted to fresh water. In order to improve the living conditions of this lake salmon which - like the ringed seal - is today classified as an endangered species, an intensive research programme has been launched. The partners include the Finnish Game and Fisheries Research Institute, fishing and environmental authorities and - in collaboration with UPM-Kymmene Oy and Kuurnan Voima Oy - the IVO subsidiary Pamilo Oy

  8. Post Audit of Lake Michigan Lake Trout PCB Model Forecasts

    Science.gov (United States)

    The Lake Michigan (LM) Mass Balance Study was conducted to measure and model polychlorinated biphenyls (PCBs) and other anthropogenic substances to gain a better understanding of the transport, fate, and effects of these substances within the system and to aid managers in the env...

  9. Feeding ecology of lake whitefish larvae in eastern Lake Ontario

    Science.gov (United States)

    Johnson, James H.; McKenna, James E.; Chalupnicki, Marc A.; Wallbridge, Tim; Chiavelli, Rich

    2009-01-01

    We examined the feeding ecology of larval lake whitefish (Coregonus clupeaformis) in Chaumont Bay, Lake Ontario, during April and May 2004-2006. Larvae were collected with towed ichthyoplankton nets offshore and with larval seines along the shoreline. Larval feeding periodicity was examined from collections made at 4-h intervals over one 24-h period in 2005. Inter-annual variation in diet composition (% dry weight) was low, as was spatial variation among collection sites within the bay. Copepods (81.4%), primarily cyclopoids (59.1%), were the primary prey of larvae over the 3-year period. Cladocerans (8.1%; mainly daphnids, 6.7%) and chironomids (7.3%) were the other major prey consumed. Larvae did not exhibit a preference for any specific prey taxa. Food consumption of lake whitefish larvae was significantly lower at night (i.e., 2400 and 0400 h). Substantial variation in diet composition occurred over the 24-h diel study. For the 24-h period, copepods were the major prey consumed (50.4%) and their contribution in the diet ranged from 29.3% (0400 h) to 85.9% (1200 h). Chironomids made up 33.4% of the diel diet, ranging from 8.0% (0800 h) to 69.9% (0400 h). Diel variation in the diet composition of lake whitefish larvae may require samples taken at several intervals over a 24-h period to gain adequate representation of their feeding ecology.

  10. Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor.

    Science.gov (United States)

    Kessel, Steven T; Hondorp, Darryl W; Holbrook, Christopher M; Boase, James C; Chiotti, Justin A; Thomas, Michael V; Wills, Todd C; Roseman, Edward F; Drouin, Richard; Krueger, Charles C

    2018-01-01

    Population structure, distribution, abundance and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations are an important aspect of the ecology of highly mobile animals, allowing populations to exploit spatially or temporally distributed food and space resources. This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes. Over 6 years (2011-2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 years battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use. Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assigned to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 "contingents" (spatiotemporally segregated subgroups). Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

  11. Isotope techniques in lake water studies

    International Nuclear Information System (INIS)

    Gourcy, L.

    1999-01-01

    Freshwater lakes are among the most easily exploitable freshwater resources. Lakes are also recognized as major sedimentological features in which stored material can be used to study recent climate and pollution evolution. To adequately preserve these important landscape features, and to use them as climatic archives, an improved understanding of processes controlling their hydrologic and bio-geochemical environments if necessary. This article briefly describes the IAEA activities related to the study of lakes in such areas as lake budget, lake dynamics, water contamination, and paleolimnological investigations

  12. Distributional patterns of the South American species of Hyalella (Amphipoda: Hyalellidae)

    OpenAIRE

    De los Ríos-Escalante, Patricio; Morrone, Juan J; Rivera, Reinaldo

    2012-01-01

    Distributional patterns of the South American species of the freshwater amphipod genus Hyalella were analysed using a panbiogeographic approach. Five generalized tracks were found: (1) northern Andes to Lake Titicaca (H. dielaii, H. meinerti, H. dybowskii, H.jelskii, H. lubominsky, and H. pauperocavae; (2) lake Titicaca (H. armata, H. cuprea, H. latinamus, H. lucifugax, H. montforti, H. neveulemairei, H. robusta, H. tiwanaku, H. simplex simplex, and H. solida); (3) central Andes (H. fossamanc...

  13. Decline of the world's saline lakes

    Science.gov (United States)

    Wurtsbaugh, Wayne A.; Miller, Craig; Null, Sarah E.; Derose, R. Justin; Wilcock, Peter; Hahnenberger, Maura; Howe, Frank; Moore, Johnnie

    2017-11-01

    Many of the world's saline lakes are shrinking at alarming rates, reducing waterbird habitat and economic benefits while threatening human health. Saline lakes are long-term basin-wide integrators of climatic conditions that shrink and grow with natural climatic variation. In contrast, water withdrawals for human use exert a sustained reduction in lake inflows and levels. Quantifying the relative contributions of natural variability and human impacts to lake inflows is needed to preserve these lakes. With a credible water balance, causes of lake decline from water diversions or climate variability can be identified and the inflow needed to maintain lake health can be defined. Without a water balance, natural variability can be an excuse for inaction. Here we describe the decline of several of the world's large saline lakes and use a water balance for Great Salt Lake (USA) to demonstrate that consumptive water use rather than long-term climate change has greatly reduced its size. The inflow needed to maintain bird habitat, support lake-related industries and prevent dust storms that threaten human health and agriculture can be identified and provides the information to evaluate the difficult tradeoffs between direct benefits of consumptive water use and ecosystem services provided by saline lakes.

  14. Ohio Lake Erie Commission Homepage

    Science.gov (United States)

    management of Lake Erie: including, water quality protection, fisheries management, wetlands restoration over 365 projects since 1993. Projects have focused on an array of issues critical to the effective quality of its waters and ecosystem, and to promote economic development of the region by ensuring the

  15. Schistosomiasis in Lake Malawi villages

    DEFF Research Database (Denmark)

    Madsen, Henry; Bloch, Paul; Makaula, Peter

    2011-01-01

    Historically, open shorelines of Lake Malawi were free from schistosome, Schistosoma haematobium, transmission, but this changed in the mid-1980s, possibly as a result of over-fishing reducing density of molluscivore fishes. Very little information is available on schistosome infections among...

  16. Pollutant transformations over Lake Michigan

    International Nuclear Information System (INIS)

    Alkezweeny, A.J.; Arbuthnot, D.R.; Busness, K.M.; Easter, R.C.; Hales, J.M.; Lee, R.N.; Young, J.M.

    1979-01-01

    An aircraft, a chartered boat, and a constant altitude balloon were used to study pollutant transformations over Lake Michigan in a Lagrangian frame of reference. The experiments were conducted during the summer under strong atmospheric stability where diffusion and dry deposition of pollutants can be neglected

  17. The lakes of the Jordan Rift Valley

    International Nuclear Information System (INIS)

    Gat, J.R.

    2001-01-01

    This paper presents a summary of the proceedings of a workshop on the Lakes of the Jordan Rift Valley that was held in conjunction with the CRP on The Use of Isotope Techniques in Lake Dynamics Investigations. The paper presents a review of the geological, hydrogeological and physical limnological setting of the lakes in the Jordan Rift Valley, Lake Hula, Lake Kinneret and the Dead Sea. This is complemented by a description of the isotope hydrology of the system that includes the use of a wide range of isotopes: oxygen-18, deuterium, tritium, carbon-14, carbon-13, chlorine isotopes, boron-11 and helium-3/4. Environmental isotope aspects of the salt balances of the lakes, their palaeolimnology and biogeochemical tracers are also presented. The scope of application of isotopic tracers is very broad and provides a clear insight into many aspects of the physical, chemical and biological limnology of the Rift Valley Lakes. (author)

  18. Eutrophication potential of Payette Lake, Idaho

    Science.gov (United States)

    Woods, Paul F.

    1997-01-01

    Payette Lake was studied during water years 1995-96 to determine the 20.5-square-kilometer lake's assimilative capacity for nutrients and, thus, its eutrophication potential. The study included quantification of hydrologic and nutrient budgets, characterization of water quality in the limnetic and littoral zones, development of an empirical nutrient load/lake response model, and estimation of the limnological effects of a large-scale forest fire in the lake's 373-square-kilometer watershed during the autumn of 1994. Streamflow from the North Fork Payette River, the lake's primary tributary, delivered about 73 percent of the lake's inflow over the 2 years. Outflow from the lake, measured since 1908, was 128 and 148 percent of the long-term average in 1995 and 1996, respectively. The larger volumes of outflow reduced the long-term average water-

  19. AMERICAN EXCEPTIONALISM

    Directory of Open Access Journals (Sweden)

    Oana-Andreea Pirnuta

    2017-11-01

    Full Text Available In an interconnected world where foreign relations matter not only for resources or military alliances but also for cultural relationships, it is highly important to have a better understanding of the power relations among nations. The information carries certain meanings that have important outcomes thus defining the power of a given nation. Foreign policy is the channel through which global politics is exercised. International politics is a hierarchy of power being determined by important cultural, economic as well as geographical aspects. The reasons and strategies that are used in order to reach the outcomes in global politics represent the focus of the present paper. The United States has been the leader in international politics since the early 20th century due to its vast resources and wealth as well as its cultural output. America’s interest in preserving a democratic and free world has its foundation in the beliefs and values it stands for the aim of this paper is to question whether or not there is a concrete premise for the idea of American exceptionalism.

  20. Contaminant Monitoring Strategy for Henrys Lake, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    John S. Irving; R. P. Breckenridge

    1992-12-01

    Henrys Lake, located in southeastern Idaho, is a large, shallow lake (6,600 acres, {approx} 17.1 feet maximum depth) located at 6,472 feet elevation in Fremont Co., Idaho at the headwaters of the Henrys Fork of the Snake River. The upper watershed is comprised of high mountains of the Targhee National Forest and the lakeshore is surrounded by extensive flats and wetlands, which are mostly privately owned. The lake has been dammed since 1922, and the upper 12 feet of the lake waters are allocated for downriver use. Henrys Lake is a naturally productive lake supporting a nationally recognized ''Blue Ribbon'' trout fishery. There is concern that increasing housing development and cattle grazing may accelerate eutrophication and result in winter and early spring fish kills. There has not been a recent thorough assessment of lake water quality. However, the Department of Environmental Quality (DEQ) is currently conducting a study of water quality on Henrys Lake and tributary streams. Septic systems and lawn runoff from housing developments on the north, west, and southwest shores could potentially contribute to the nutrient enrichment of the lake. Many houses are on steep hillsides where runoff from lawns, driveways, etc. drain into wetland flats along the lake or directly into the lake. In addition, seepage from septic systems (drainfields) drain directly into the wetlands enter groundwater areas that seep into the lake. Cattle grazing along the lake margin, riparian areas, and uplands is likely accelerating erosion and nutrient enrichment. Also, cattle grazing along riparian areas likely adds to nutrient enrichment of the lake through subsurface flow and direct runoff. Stream bank and lakeshore erosion may also accelerate eutrophication by increasing the sedimentation of the lake. Approximately nine streams feed the lake (see map), but flows are often severely reduced or completely eliminated due to irrigation diversion. In addition, subsurface

  1. Life history of lake herring of Green Bay, Lake Michigan

    Science.gov (United States)

    Smith, Stanford H.

    1956-01-01

    Although the lake herring has been an important contributor to the commercial fish production of Green Bay, little has been known about it. This study is based on field observations and data from about 6,500 lake herring collected over the period 1948 to 1952. Relatively nonselective commercial pound nets were a primary source of material for the study of age and growth. Commercial and experimental gill nets were used to obtain data on gear selectivity and vertical distribution. Scales were employed to investigate age and growth. Age group IV normally dominated commercial catches during the first half of the calendar year and age group III the last half. At these ages the fish averaged about 10.5 inches in length. The season's growth started in May, was most rapid in July, and terminated near the end of October. The sexes grew at the same rate. Selectivity of fishing gear was found to influence the estimation of growth. Geographical and annual differences in growth are shown. Factors that might contribute to discrepancies in calculated growth are evaluated. Possible real and apparent causes of growth compensation are given. The relation between length and weight is shown to vary with sex, season, year, and method of capture. Females were relatively more plentiful in commercial catches in February than in May through December. The percentage of females decreased with increase in age in pound-net catches but increased with age in gill-net samples. Within a year class the percentage of females decreased with increase in age. Most Green Bay lake herring mature during their second or third year of life. They are pelagic spawners with most intensive spawning over shallow areas. Spawning takes place between mid-November and mid-December, and eggs hatch in April and May. Lake herring ovaries contained from 3,500 to 11,200 eggs (averaged 6,375). Progress of spawning by age, sex, and length is given. Lake herring were distributed at all depths in Green Bay in early May, were

  2. Spatial and temporal genetic diversity of lake whitefish (Coregonus clupeaformis (Mitchill)) from Lake Huron and Lake Erie

    Science.gov (United States)

    Stott, Wendylee; Ebener, Mark P.; Mohr, Lloyd; Hartman, Travis; Johnson, Jim; Roseman, Edward F.

    2013-01-01

    Lake whitefish (Coregonus clupeaformis (Mitchill)) are important commercially, culturally, and ecologically in the Laurentian Great Lakes. Stocks of lake whitefish in the Great Lakes have recovered from low levels of abundance in the 1960s. Reductions in abundance, loss of habitat and environmental degradation can be accompanied by losses of genetic diversity and overall fitness that may persist even as populations recover demographically. Therefore, it is important to be able to identify stocks that have reduced levels of genetic diversity. In this study, we investigated patterns of genetic diversity at microsatellite DNA loci in lake whitefish collected between 1927 and 1929 (historical period) and between 1997 and 2005 (contemporary period) from Lake Huron and Lake Erie. Genetic analysis of lake whitefish from Lakes Huron and Erie shows that the amount of population structuring varies from lake to lake. Greater genetic divergences among collections from Lake Huron may be the result of sampling scale, migration patterns and demographic processes. Fluctuations in abundance of lake whitefish populations may have resulted in periods of increased genetic drift that have resulted in changes in allele frequencies over time, but periodic genetic drift was not severe enough to result in a significant loss of genetic diversity. Migration among stocks may have decreased levels of genetic differentiation while not completely obscuring stock boundaries. Recent changes in spatial boundaries to stocks, the number of stocks and life history characteristics of stocks further demonstrate the potential of coregonids for a swift and varied response to environmental change and emphasise the importance of incorporating both spatial and temporal considerations into management plans to ensure that diversity is preserved.

  3. Experiências sôbre a transmissão do Trypanosoma cruzi por sanguessugas e de tripanosomas de vertebrados de sangue frio por triatomíneos Experiments of the transmission of Trypanosoma cruzi by leechs and cold blooded vertebrate trypanosomas by triatominae

    Directory of Open Access Journals (Sweden)

    Samuel B. Pessôa

    1969-06-01

    Full Text Available Observou-se que o Trypanosoma cruzi não se multiplica na sanguessuga (Haementeria lutzi Pinto; os tripanosomas sugados degeneram após algum tempo; outros permanecem aparentemente normais, porém 48 horas após a ingestão infectante acabam morrendo. Observou-se ainda que os tripanosomas parasitas da rã (T. rotatorium e T. leptodactyli bem como o T. hogei, parasita da serpente Rachidelus brazili, não se multiplicam no intestino dos triatomíneos. O mais resistente (o T. leptodactyli, permanece vivo até 72 horas após a ingestão infectante, porém as outras duas espécies (T. rotatorium e T. hogei não resistem mais de 24 horas após serem sugadas pelos triatomíneos.Trypanosoma cruzi does not reproduce itself in the leech (Haementerm lutzi Pinto; the ingested trypanosomes degenerate after some time; other organisms remain apparently normal, however dying 48 hours after the feeding of the leechs. The parasite trypanosomas of the frog (T. rotatorium and T. leptodactyli as well as those parasiting the ophidian Rachidelus brazili (T. hogei do not multiply in the intestine of the triatominae. The most resistent species (T. leptocbactyli remains alive 72 hours after the feeding of the triatominae; the other two, however, do not survive more than 24 hours.

  4. Distribution and Modeled Transport of Plastic Pollution in the Great Lakes, the World's Largest Freshwater Resource

    Directory of Open Access Journals (Sweden)

    Rachel N. Cable

    2017-07-01

    Full Text Available Most plastic pollution originates on land. As such, freshwater bodies serve as conduits for the transport of plastic litter to the ocean. Understanding the concentrations and fluxes of plastic litter in freshwater ecosystems is critical to our understanding of the global plastic litter budget and underpins the success of future management strategies. We conducted a replicated field survey of surface plastic concentrations in four lakes in the North American Great Lakes system, the largest contiguous freshwater system on the planet. We then modeled plastic transport to resolve spatial and temporal variability of plastic distribution in one of the Great Lakes, Lake Erie. Triplicate surface samples were collected at 38 stations in mid-summer of 2014. Plastic particles >106 μm in size were quantified. Concentrations were highest near populated urban areas and their water infrastructure. In the highest concentration trawl, nearly 2 million fragments km−2 were found in the Detroit River—dwarfing previous reports of Great Lakes plastic abundances by over 4-fold. Yet, the accuracy of single trawl counts was challenged: within-station plastic abundances varied 0- to 3-fold between replicate trawls. In the smallest size class (106–1,000 μm, false positive rates of 12–24% were determined analytically for plastic vs. non-plastic, while false negative rates averaged ~18%. Though predicted to form in summer by the existing Lake Erie circulation model, our transport model did not predict a permanent surface “Lake Erie Garbage Patch” in its central basin—a trend supported by field survey data. Rather, general eastward transport with recirculation in the major basins was predicted. Further, modeled plastic residence times were drastically influenced by plastic buoyancy. Neutrally buoyant plastics—those with the same density as the ambient water—were flushed several times slower than plastics floating at the water's surface and exceeded the

  5. Effects of hurricanes Katrina and Rita on the chemistry of bottom sediments in Lake Pontchartrain, Louisiana, USA

    Science.gov (United States)

    Van Metre, P.C.; Horowitz, A.J.; Mahler, B.J.; Foreman, W.T.; Fuller, C.C.; Burkhardt, M.R.; Elrick, K.A.; Furlong, E.T.; Skrobialowski, S.C.; Smith, J.J.; Wilson, J.T.; Zaugg, S.D.

    2006-01-01

    The effects of Hurricanes Katrina and Rita and the subsequent unwatering of New Orleans, Louisiana, on the sediment chemistry of Lake Pontchartrain were evaluated by chemical analysis of samples of street mud and suspended and bottom sediments. The highest concentrations of urban-related elements and compounds (e.g., Pb, Zn, polycyclic aromatic hydrocarbons, and chlordane) in bottom sediments exceeded median concentrations in U.S. urban lakes and sediment-quality guidelines. The extent of the elevated concentrations was limited, however, to within a few hundred meters of the mouth of the 17th Street Canal, similar to results of historical assessments. Chemical and radionuclide analysis of pre- and post-Hurricane Rita samples indicates that remobilization of near-shore sediment by lake currents and storms is an ongoing process. The effects of Hurricanes Katrina and Rita on the sediment chemistry of Lake Pontchartrain are limited spatially and are most likely transitory. ?? 2006 American Chemical Society.

  6. Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

    Science.gov (United States)

    McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

    2013-01-01

    Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

  7. Deposition, exhumation, and paleoclimate of an ancient lake deposit, Gale crater, Mars.

    Science.gov (United States)

    Grotzinger, J P; Gupta, S; Malin, M C; Rubin, D M; Schieber, J; Siebach, K; Sumner, D Y; Stack, K M; Vasavada, A R; Arvidson, R E; Calef, F; Edgar, L; Fischer, W F; Grant, J A; Griffes, J; Kah, L C; Lamb, M P; Lewis, K W; Mangold, N; Minitti, M E; Palucis, M; Rice, M; Williams, R M E; Yingst, R A; Blake, D; Blaney, D; Conrad, P; Crisp, J; Dietrich, W E; Dromart, G; Edgett, K S; Ewing, R C; Gellert, R; Hurowitz, J A; Kocurek, G; Mahaffy, P; McBride, M J; McLennan, S M; Mischna, M; Ming, D; Milliken, R; Newsom, H; Oehler, D; Parker, T J; Vaniman, D; Wiens, R C; Wilson, S A

    2015-10-09

    The landforms of northern Gale crater on Mars expose thick sequences of sedimentary rocks. Based on images obtained by the Curiosity rover, we interpret these outcrops as evidence for past fluvial, deltaic, and lacustrine environments. Degradation of the crater wall and rim probably supplied these sediments, which advanced inward from the wall, infilling both the crater and an internal lake basin to a thickness of at least 75 meters. This intracrater lake system probably existed intermittently for thousands to millions of years, implying a relatively wet climate that supplied moisture to the crater rim and transported sediment via streams into the lake basin. The deposits in Gale crater were then exhumed, probably by wind-driven erosion, creating Aeolis Mons (Mount Sharp). Copyright © 2015, American Association for the Advancement of Science.

  8. Establishment patterns of water-elm at Catahoula Lake, Louisiana

    Science.gov (United States)

    Karen S. Doerr; Sanjeev Joshi; Richard F. Keim

    2015-01-01

    At Catahoula Lake in central Louisiana, an internationally important lake for water fowl, hydrologic alterations to the surrounding rivers and the lake itself have led to an expansion of water-elm (Planera aquatic J.F. Gmel.) into the lake bed. In this study, we used dendrochronology and aerial photography to quantify the expansion of water-elm in the lake and identify...

  9. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... youthonline . [Accessed 08/18/2017] HEALTH IMPACT OF OBESITY People who are overweight are more likely to ...

  10. Native Americans with Diabetes

    Science.gov (United States)

    ... Read the MMWR Science Clips Native Americans with Diabetes Better diabetes care can decrease kidney failure Language: ... between 1996 and 2013. Problem Kidney failure from diabetes was highest among Native Americans. Native Americans are ...

  11. 75 FR 22620 - Upper Klamath, Lower Klamath, Tule Lake, Bear Valley, and Clear Lake National Wildlife Refuges...

    Science.gov (United States)

    2010-04-29

    ...] Upper Klamath, Lower Klamath, Tule Lake, Bear Valley, and Clear Lake National Wildlife Refuges, Klamath..., Bear Valley, and Clear Lake National Wildlife Refuges (Refuges) located in Klamath County, Oregon, and..., Tule Lake, Bear Valley, and Clear Lake Refuges located in Klamath County, Oregon, and Siskiyou and...

  12. Large Lakes Dominate CO2 Evasion From Lakes in an Arctic Catchment

    Science.gov (United States)

    Rocher-Ros, Gerard; Giesler, Reiner; Lundin, Erik; Salimi, Shokoufeh; Jonsson, Anders; Karlsson, Jan

    2017-12-01

    CO2 evasion from freshwater lakes is an important component of the carbon cycle. However, the relative contribution from different lake sizes may vary, since several parameters underlying CO2 flux are size dependent. Here we estimated the annual lake CO2 evasion from a catchment in northern Sweden encompassing about 30,000 differently sized lakes. We show that areal CO2 fluxes decreased rapidly with lake size, but this was counteracted by the greater overall coverage of larger lakes. As a result, total efflux increased with lake size and the single largest lake in the catchment dominated the CO2 evasion (53% of all CO2 evaded). By contrast, the contribution from the smallest ponds (about 27,000) was minor (evasion at the landscape scale.

  13. Great Lakes Restoration Initiative Great Lakes Mussel Watch(2009-2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Following the inception of the Great Lakes Restoration Initiative (GLRI) to address the significant environmental issues plaguing the Great Lakes region, the...

  14. From Greenland to green lakes: Cultural eutrophication and the loss of benthic pathways in lakes

    DEFF Research Database (Denmark)

    Vadeboncoeur, Y.; Jeppesen, E.; Zanden, M. J. V.

    2003-01-01

    Benthic community responses to lake eutrophication are poorly understood relative to pelagic responses. We compared phytoplankton and periphyton productivity along a eutrophication gradient in Greenland, U.S., and Danish lakes. Phytoplankton productivity increased along the phosphorus gradient (t...

  15. Lake Morphometry for NHD Lakes in Upper Colorado Region 14 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  16. Lake Morphometry for NHD Lakes in North East Region 1 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  17. Lake Morphometry for NHD Lakes in Souris Red Rainy Region 9 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  18. Lake Morphometry for NHD Lakes in Lower Colorado Region 15 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  19. Lake Morphometry for NHD Lakes in Upper Mississippi Region 7 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  20. Lake Morphometry for NHD Lakes in the Upper Portion of the Missouri Region 10 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  1. Lake Morphometry for NHD Lakes in Rio Grande Region 13 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  2. Lake Morphometry for NHD Lakes in Arkansas White Red Region 11 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  3. Lake Morphometry for NHD Lakes in Pacific Northwest Region 17 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  4. Lake Morphometry for NHD Lakes in Lower Mississippi Region 8 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  5. Lake Morphometry for NHD Lakes in Texas-Gulf Region 12 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  6. Lake Morphometry for NHD Lakes in the Lower Portion of the Missouri Region 10 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  7. Expanding models of lake trophic state to predict cyanobacteria in lakes

    Science.gov (United States)

    Background/Question/Methods: Cyanobacteria are a primary taxonomic group associated with harmful algal blooms in lakes. Understanding the drivers of cyanobacteria presence has important implications for lake management and for the protection of human and ecosystem health. Chlor...

  8. Bubbles in a freshwater lake.

    Science.gov (United States)

    Thorpe, S A; Stubbs, A R

    1979-05-31

    WHEN the wind is strong enough to produce whitecaps on Loch Ness, patchy 'clouds' of acoustic reflectors are detected well below the surface, the depth to which they penetrate increasing with wind speed (Fig. 1). No seasonal variation in the occurrence of the reflectors has been detected. A biological explanation is therefore discounted and we suggest here that they are bubbles caused by waves breaking and forming whitecaps in deep water. Similar bubble clouds may occur in other lakes and in the sea.

  9. Lake Nasser evaporation reduction study

    Directory of Open Access Journals (Sweden)

    Hala M.I. Ebaid

    2010-10-01

    Full Text Available This study aims to evaluate the reduction of evaporation of Lake Nasser’s water caused by disconnecting (fully or partially some of its secondary channels (khors. This evaluation integrates remote sensing, Geographic Information System (GIS techniques, aerodynamic principles, and Landsat7 ETM+ images. Three main procedures were carried out in this study; the first derived the surface temperature from Landsat thermal band; the second derived evaporation depth and approximate evaporation volume for the entire lake, and quantified evaporation loss to the secondary channels’ level over one month (March by applied aerodynamic principles on surface temperature of the raster data; the third procedure applied GIS suitability analysis to determine which of these secondary channels (khors should be disconnected. The results showed evaporation depth ranging from 2.73 mm/day at the middle of the lake to 9.58 mm/day at the edge. The evaporated water-loss value throughout the entire lake was about 0.86 billion m3/month (March. The analysis suggests that it is possible to save an approximate total evaporation volume loss of 19.7 million m3/month (March, and thus 2.4 billion m3/year, by disconnecting two khors with approximate construction heights of 8 m and 15 m. In conclusion, remote sensing and GIS are useful for applications in remote locations where field-based information is not readily available and thus recommended for decision makers remotely planning in water conservation and management.

  10. Climate and climate variability of the wind power resources in the Great Lakes region of the United States

    Science.gov (United States)

    X. Li; S. Zhong; X. Bian; W.E. Heilman

    2010-01-01

    The climate and climate variability of low-level winds over the Great Lakes region of the United States is examined using 30 year (1979-2008) wind records from the recently released North American Regional Reanalysis (NARR), a three-dimensional, high-spatial and temporal resolution, and dynamically consistent climate data set. The analyses focus on spatial distribution...

  11. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  12. Decomposition of lake phytoplankton. 1

    International Nuclear Information System (INIS)

    Hansen, L.; Krog, G.F.; Soendergaard, M.

    1986-01-01

    Short-time (24 h) and long-time (4-6 d) decomposition of phytoplankton cells were investigasted under in situ conditions in four Danish lakes. Carbon-14-labelled, dead algae were exposed to sterile or natural lake water and the dynamics of cell lysis and bacterial utilization of the leached products were followed. The lysis process was dominated by an initial fast water extraction. Within 2 to 4 h from 4 to 34% of the labelled carbon leached from the algal cells. After 24 h from 11 to 43% of the initial particulate carbon was found as dissolved carbon in the experiments with sterile lake water; after 4 to 6 d the leaching was from 67 to 78% of the initial 14 C. The leached compounds were utilized by bacteria. A comparison of the incubations using sterile and natural water showed that a mean of 71% of the lysis products was metabolized by microorganisms within 24 h. In two experiments the uptake rate equalled the leaching rate. (author)

  13. Mapping Lake Michigan Fish Catch Data

    OpenAIRE

    Wodd, Jacob; Doucette, Jarrod; Höök, Tomas O.

    2014-01-01

    The only Great Lake completely contained in the U.S., Lake Michigan offers an abundance of recreational fishing. This project takes 20 years’ worth of salmonid fish catch data, and uses GIS to organize and visually represent the data in a way that is meaningful and helpful to local fisherman and researchers. Species represented included Brown Trout, Lake Trout, Rainbow Trout, Chinook Salmon, and Coho Salmon. The species are organized by both decadal and yearly spans, as well as catch per t...

  14. Pacific salmonines in the Great Lakes Basin

    Science.gov (United States)

    Claramunt, Randall M.; Madenjian, Charles P.; Clapp, David; Taylor, William W.; Lynch, Abigail J.; Léonard, Nancy J.

    2012-01-01

    Pacific salmon (genus Oncorhynchus) are a valuable resource, both within their native range in the North Pacific rim and in the Great Lakes basin. Understanding their value from a biological and economic perspective in the Great Lakes, however, requires an understanding of changes in the ecosystem and of management actions that have been taken to promote system stability, integrity, and sustainable fisheries. Pacific salmonine introductions to the Great Lakes are comprised mainly of Chinook salmon, coho salmon, and steelhead and have accounted for 421, 177, and 247 million fish, respectively, stocked during 1966-2007. Stocking of Pacific salmonines has been effective in substantially reducing exotic prey fish abundances in several of the Great Lakes (e.g., lakes Michigan, Huron, and Ontario). The goal of our evaluation was to highlight differences in management strategies and perspectives across the basin, and to evaluate policies for Pacific salmonine management in the Great Lakes. Currently, a potential conflict exists between Pacific salmonine management and native fish rehabilitation goals because of the desire to sustain recreational fisheries and to develop self-sustaining populations of stocked Pacific salmonines in the Great Lakes. We provide evidence that suggests Pacific salmonines have not only become naturalized to the food webs of the Great Lakes, but that their populations (specifically Chinook salmon) may be fluctuating in concert with specific prey (i.e., alewives) whose populations are changing relative to environmental conditions and ecosystem disturbances. Remaining questions, however, are whether or not “natural” fluctuations in predator and prey provide enough “stability” in the Great Lakes food webs, and even more importantly, would a choice by managers to attempt to reduce the severity of predator-prey oscillations be antagonistic to native fish restoration efforts. We argue that, on each of the Great Lakes, managers are pursuing

  15. Environmental Monitoring, Water Quality - Lakes Assessments - Non Attaining

    Data.gov (United States)

    NSGIC Education | GIS Inventory — This layer shows only non attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water...

  16. Antarctic Active Subglacial Lake Inventory from ICESat Altimetry, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains lake boundaries, volume changes, and gridded elevations for 124 active subglacial lakes beneath the Antarctic ice sheet. Lakes were identified...

  17. 75 FR 6354 - NOAA Great Lakes Habitat Restoration Program Project Grants under the Great Lakes Restoration...

    Science.gov (United States)

    2010-02-09

    ...-04] RIN 0648-ZC10 NOAA Great Lakes Habitat Restoration Program Project Grants under the Great Lakes... Atmospheric Administration (NOAA), Department of Commerce. ACTION: Notice of funding availability; Date... on January 19, 2010. That notice announced the NOAA Great Lakes Habitat Restoration Program Project...

  18. Crustacean plankton communities in forty-five lakes in the experimental lakes area, northwestern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Patalas, K

    1971-01-01

    Zooplankton communities were characterized on the basis of samples taken in summer as vertical net hauls in the central part of lakes. Twenty-eight species of crustaceans were found in the 45 lakes studied. The highest number of species as well as the highest numbers of individuals (per unit of area) usually occurred in the largest deepest lakes with most transparent water.

  19. Human impact on lake ecosystems: the case of Lake Naivasha, Kenya

    African Journals Online (AJOL)

    Lake Naivasha is a wetland of national and international importance. However, it is under constant anthropogenic pressures, which include the quest for socioeconomic development within the lake ecosystem itself as well as other activities within the catchment. The lake is an important source of fresh water in an otherwise ...

  20. Clearing lakes : an ecosystem approach to the restoration and management of shallow lakes in the Netherlands

    NARCIS (Netherlands)

    Hosper, H.

    1997-01-01

    In the 1950 s and 1960 s, most shallow lakes in the Netherlands shifted from macrophyte-dominated clear water lakes, towards algae-dominated turbid water lakes. Eutrophication, i.e. increased nutrient loading, is the main cause of the deterioration

  1. Lake Michigan lake trout PCB model forecast post audit (oral presentation)

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents an...

  2. Environmentally relevant chemical mixtures of concern in waters of United States tributaries to the Great Lakes

    Science.gov (United States)

    Elliott, Sarah M.; Brigham, Mark E.; Kiesling, Richard L.; Schoenfuss, Heiko L.; Jorgenson, Zachary G.

    2018-01-01

    The North American Great Lakes are a vital natural resource that provide fish and wildlife habitat, as well as drinking water and waste assimilation services for millions of people. Tributaries to the Great Lakes receive chemical inputs from various point and nonpoint sources, and thus are expected to have complex mixtures of chemicals. However, our understanding of the co‐occurrence of specific chemicals in complex mixtures is limited. To better understand the occurrence of specific chemical mixtures in the US Great Lakes Basin, surface water from 24 US tributaries to the Laurentian Great Lakes was collected and analyzed for diverse suites of organic chemicals, primarily focused on chemicals of concern (e.g., pharmaceuticals, personal care products, fragrances). A total of 181 samples and 21 chemical classes were assessed for mixture compositions. Basin wide, 1664 mixtures occurred in at least 25% of sites. The most complex mixtures identified comprised 9 chemical classes and occurred in 58% of sampled tributaries. Pharmaceuticals typically occurred in complex mixtures, reflecting pharmaceutical‐use patterns and wastewater facility outfall influences. Fewer mixtures were identified at lake or lake‐influenced sites than at riverine sites. As mixture complexity increased, the probability of a specific mixture occurring more often than by chance greatly increased, highlighting the importance of understanding source contributions to the environment. This empirically based analysis of mixture composition and occurrence may be used to focus future sampling efforts or mixture toxicity assessments. 

  3. Lake Titicaca: History and current studies

    International Nuclear Information System (INIS)

    Paredes Riveros, M.A.; Gonfiantini, R.

    1999-01-01

    This article summarizes results of Titicaca lake water balance studies including the findings of the IAEA Technical Cooperation Project RLA/08/022. Direct precipitation over the lake accounts for about 55% of the water inflow and rivers and streams provide about 45% of the water inflow. Diffuse groundwater leakage into the lake from coastal aquifers is believed to represent a negligible term of water balance. Evaporation from the lake is strong and accounts for more than 95% of the water losses. The isotopic and chemical composition data obtained within the frameworks of the IAEA Technical Cooperation Project RLA/08/022 are discussed

  4. Lake Titicaca: History and current studies

    Energy Technology Data Exchange (ETDEWEB)

    Paredes Riveros, M A [PELT, Puno (Peru); Gonfiantini, R [Istituto di Geocronologia e Geochimica Isotopica del CNR, Pisa (Italy)

    1999-12-01

    This article summarizes results of Titicaca lake water balance studies including the findings of the IAEA Technical Cooperation Project RLA/08/022. Direct precipitation over the lake accounts for about 55% of the water inflow and rivers and streams provide about 45% of the water inflow. Diffuse groundwater leakage into the lake from coastal aquifers is believed to represent a negligible term of water balance. Evaporation from the lake is strong and accounts for more than 95% of the water losses. The isotopic and chemical composition data obtained within the frameworks of the IAEA Technical Cooperation Project RLA/08/022 are discussed.

  5. Diatoms in Liyu Lake, Eastern Taiwan

    Directory of Open Access Journals (Sweden)

    Liang-Chi Wang

    2010-09-01

    Full Text Available This study described the diatoms appeared in the sediments of Liyu Lake, a lowland natural lake situated at Hualen, eastern Taiwan. A total of 50 species was found in the sediments of this eutrophic lake. In them, 8 species were reported for the first time in Taiwan. They are: Cymbella thienemannii, Navicula absoluta, Navicula bacillum, Frustulia rhomboides var. crassinervia, Gyrosigma procerum, Nitzschia paleacea Epithemia smithii and Eunotia subarcuatioides. The ultrastructures of each species were described on the basis of observations under a scanning electron microscope. The ecological implications of the occurrence of these diatom species in this lake were inferred.

  6. Fish impingement at Lake Michigan power plants

    International Nuclear Information System (INIS)

    Sharma, R.K.; Freeman, R.F.; Spigarelli, S.A.

    1976-01-01

    A study was initiated in 1974 to survey the magnitude and to evaluate the impact of fish impingement at 20 power plants on the Great Lakes. Data on impingement rates, site characteristics, intake designs and operational features have been collected and analyzed. Interpretive analyses of these data are in progress. The objectives of this study were: to summarize fish impingement data for Lake Michigan (16/20 plants surveyed are on Lake Michigan); to assess the significance of total and source-related mortalities on populations of forage and predator species; and to expand the assessment of power plant impingement to include all water intakes on Lake Michigan. Data are tabulated

  7. Residence time and physical processes in lakes

    Directory of Open Access Journals (Sweden)

    Nicoletta SALA

    2003-09-01

    Full Text Available The residence time of a lake is highly dependent on internal physical processes in the water mass conditioning its hydrodynamics; early attempts to evaluate this physical parameter emphasize the complexity of the problem, which depends on very different natural phenomena with widespread synergies. The aim of this study is to analyse the agents involved in these processes and arrive at a more realistic definition of water residence time which takes account of these agents, and how they influence internal hydrodynamics. With particular reference to temperate lakes, the following characteristics are analysed: 1 the set of the lake's caloric components which, along with summer heating, determine the stabilizing effect of the surface layers, and the consequent thermal stratification, as well as the winter destabilizing effect; 2 the wind force, which transfers part of its momentum to the water mass, generating a complex of movements (turbulence, waves, currents with the production of active kinetic energy; 3 the water flowing into the lake from the tributaries, and flowing out through the outflow, from the standpoint of hydrology and of the kinetic effect generated by the introduction of these water masses into the lake. These factors were studied in the context of the general geographical properties of the lake basin and the watershed (latitude, longitude, morphology, also taking account of the local and regional climatic situation. Also analysed is the impact of ongoing climatic change on the renewal of the lake water, which is currently changing the equilibrium between lake and atmosphere, river and lake, and relationships

  8. Hydrological network and classification of lakes on the Third Pole

    Science.gov (United States)

    Gao, Yang; Wang, Weicai; Yao, Tandong; Lu, Ning; Lu, Anxin

    2018-05-01

    The intensity and form of changes in closed lakes, upstream lakes and outflow lakes on the Third Pole (TP) differ based on their drainage mode. Researchers' insufficient understanding of the hydrological networks associated with lakes hampers studies of the relationship between lakes and climate. In this study, we establish a comprehensive hydrological network for each lake (>1 km2) on the TP using 106 Landsat images, 236 Chinese topographic maps, and SRTM DEM. Three-hundred-ninety-seven closed lakes, 488 upstream lakes and 317 outflow lakes totaling 3,5498.49 km2, 7,378.82 km2, and 3,382.29 km2, respectively, were identified on the TP using 2010 data. Two-hundred-thirty-four closed lakes were found to not be linked to upstream lakes. The remaining 163 closed lakes were connected to and fed by the 488 upstream lakes. The object-oriented analyses within this study indicated that more rapid changes occurred in the surface extent of closed lakes than in upstream lakes or outflow lakes on the TP from 1970 s to 2010. Furthermore, the water volume of the examined closed lakes was almost nine times greater than that of the upstream lakes from 2003 to 2009. All the examined closed lakes exhibited an obvious water volume change compared to the corresponding upstream lakes in the same basin. Furthermore, two case studies illustrate that the annual and seasonal dynamics associated with the changes in closed lakes may reflect climate change patterns, while the upstream lake dynamics may be more controlled by the lakeshore terrain and drainage characteristics. The lake inventory and hydrological network catalogued in this study provide a basis for developing a better understanding of lake response to climate change on the TP.

  9. 'Infantile convulsions' in the early nineteenth century. Abnormal brain blood flow and leeches, teething and gums' scarification and food and purgatives: the historical contribution of John Clarke (1760-1815).

    Science.gov (United States)

    Brigo, Francesco; Lattanzi, Simona; Trinka, Eugen; Nardone, Raffaele; Bragazzi, Nicola Luigi; Ruggieri, Martino; Vecchio, Ignazio; Martini, Mariano

    2018-03-20

    In this article, we discuss on the role of the British physician and midwifery practitioner John Clarke (1760-1815) in the characterisation of the various types of seizures and epilepsy and related phenomena ('convulsions') occurring in children. In his unfinished work Commentaries on Some of the Most Important Diseases of Children (1815), Clarke discussed the pathophysiology of convulsions and was the first to describe, 12 years before the French neurologist Louis Francois Bravais (1801-1843) and more than 30 years before the Irish-born physician Robert Bentley Todd (1809-1860), the postictal paresis. He believed that convulsions originated from changes in pressure within the ventricles as a consequence of abnormal blood flow to the cerebral vessels. In keeping with the theories of his time (e.g. Baumes 1789, 1805; Brachet 1824), Clarke believed that teething was a major cause of 'infantile convulsions'. His proposed remedies ranged from scarification of the gums to ammonia, application of leeches, cold water, and purgatives. The use of antispasmodics, quite popular at the time, was instead questioned. In his Practical Observations on the Convulsions of Infants (1826), the London practitioner and midwifery John North (1790-1873) deeply criticised Clarke's view that convulsions arise inevitably as a consequence of organic brain lesions. North inferred that the results of autopsies of children who had died of convulsions revealed no brain damages, and claimed that cerebral irritation could also occur as the effect of distant lesions. Other Clarke's contemporaries (e.g. Jean Baptiste Timothée Baumes-1756-1828) inferred that all convulsions reflected a hereditary diathesis, which rendered children (especially those with softer and limper nervous and muscular tissues!) extremely sensitive to all sorts of provocation that could trigger convulsions, including bad digestion (more pronounced at the time of teething), loud noise, and bright light. Although almost every

  10. Obesity and Hispanic Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Hispanic/Latino > Obesity Obesity and Hispanic Americans Among Mexican American women, 77 percent are overweight ... inhqrdr/data/query At a Glace – Risk Factors: Obesity is a risk ... Americans Heart Disease – See Heart Disease and Hispanic Americans ...

  11. A Dynamical Downscaling study over the Great Lakes Region Using WRF-Lake: Historical Simulation

    Science.gov (United States)

    Xiao, C.; Lofgren, B. M.

    2014-12-01

    As the largest group of fresh water bodies on Earth, the Laurentian Great Lakes have significant influence on local and regional weather and climate through their unique physical features compared with the surrounding land. Due to the limited spatial resolution and computational efficiency of general circulation models (GCMs), the Great Lakes are geometrically ignored or idealized into several grid cells in GCMs. Thus, the nested regional climate modeling (RCM) technique, known as dynamical downscaling, serves as a feasible solution to fill the gap. The latest Weather Research and Forecasting model (WRF) is employed to dynamically downscale the historical simulation produced by the Geophysical Fluid Dynamics Laboratory-Coupled Model (GFDL-CM3) from 1970-2005. An updated lake scheme originated from the Community Land Model is implemented in the latest WRF version 3.6. It is a one-dimensional mass and energy balance scheme with 20-25 model layers, including up to 5 snow layers on the lake ice, 10 water layers, and 10 soil layers on the lake bottom. The lake scheme is used with actual lake points and lake depth. The preliminary results show that WRF-Lake model, with a fine horizontal resolution and realistic lake representation, provides significantly improved hydroclimates, in terms of lake surface temperature, annual cycle of precipitation, ice content, and lake-effect snowfall. Those improvements suggest that better resolution of the lakes and the mesoscale process of lake-atmosphere interaction are crucial to understanding the climate and climate change in the Great Lakes region.

  12. Refuge Lake Reclassification in 620 Minnesota Cisco Lakes under Future Climate Scenarios

    Directory of Open Access Journals (Sweden)

    Liping Jiang

    2017-09-01

    Full Text Available Cisco (Coregonus artedi is the most common coldwater stenothermal fish in Minnesota lakes. Water temperature (T and dissolved oxygen (DO in lakes are important controls of fish growth and reproduction and likely change with future climate warming. Built upon a previous study, this study uses a modified method to identify which of 620 cisco lakes in Minnesota can still support cisco populations under future climate and therefore be classified as cisco refuge lakes. The previous study used oxythermal stress parameter TDO3, the temperature at DO of 3 mg/L, simulated only from deep virtual lakes to classify 620 cisco lakes. Using four categories of virtual but representative cisco lakes in modified method, a one-dimensional water quality model MINLAKE2012 was used to simulate daily T and DO profiles in 82 virtual lakes under the past (1961–2008 and two future climate scenarios. A multiyear average of 31-day largest TDO3 over variable benchmark (VB periods, AvgATDO3VB, was calculated from simulated T and DO profiles using FishHabitat2013. Contour plots of AvgATDO3VB for four categories of virtual lakes were then developed to reclassify 620 cisco lakes into Tier 1 (AvgATDO3VB < 11 °C or Tier 2 refuge lakes, and Tier 3 non-refuge lakes (AvgATDO3VB > 17 °C. About 20% of 620 cisco lakes are projected to be refuge lakes under future climate scenarios, which is a more accurate projection (improving the prediction accuracy by ~6.5% from the previous study since AvgATDO3VB was found to vary by lake categories.

  13. Environmental isotope signatures of the largest freshwater lake in Kerala

    International Nuclear Information System (INIS)

    Unnikrishnan Warrier, C.

    2007-01-01

    Sasthamkotta lake, the largest freshwater lake in Kerala, serves as a source for drinking water for more than half a million people. Environmental 137 Cs analysis done on undisturbed sediment core samples reveals that the recent rate of sedimentation is not uniform in the lake. The useful life of lake is estimated as about 800 years. The δD and δ 18 O values of the lake waters indicate that the lake is well mixed with a slight variation horizontally. The stable isotope studies on well waters from the catchment indicate hydraulic communication with the lake and lake groundwater system is flow-through type. Analytical model also supports this view. (author)

  14. Anaerobic Psychrophiles from Lake Zub and Lake Untersee, Antarctica

    Science.gov (United States)

    Townsend, Alisa; Pikuta, Elena V.; Guisler, Melissa; Stahl, Sarah; Hoover, Richard B.

    2009-01-01

    The study of samples from Antarctica 2008 and 2009 expeditions organized and successfully conducted by Richard Hoover led to the isolation of diverse anaerobic strains with psychrotolerant and psychrophilic physiology. Due to the fact that Lake Untersee has never been subject to microbiological study, this work with the samples has significant and pioneering impact to the knowledge about the biology of this unique ecosystem. Also, the astrobiological significance for the study of these ecosystems is based on new findings of ice covered water systems on other bodies of our solar system. Anaerobic psychrotolerant strain LZ-22 was isolated from a frozen sample of green moss with soils around the rhizosphere collected near Lake Zub in Antarctica. Morphology of strain LZ-22 was observed to be motile, rod shaped and spore-forming cells with sizes 1 x 5-10 micron. This new isolate is a mesophile with the maximum temperature of growth at 40C. Strain LZ-22 is able to live on media without NaCl and in media with up to 7% (w/v) NaCl. It is catalase negative and grows only on sugars with the best growth rate being on lactose. The strain is a neutrophile and grows between pH 5 and 9.0 with the optimum at 7.8. Another two strains UL7-96mG and LU-96m7P were isolated from deep water samples of Lake Untersee. Proteolytic strain LU-96m7P had a truly psychrophilic nature and refused to grow at room temperature. Sugarlytic strain UL7-96mG was found to be psychrotolerant, but its rate of growth at 3C was very high compared with other mesophiles. Two homoacetogenic psychrophilic strains A7AC-96m and AC-DS7 were isolated and purified from samples of Lake Untersee; both of them are able to grow chemolithotrophically on H2+CO2. In the presence of lactate, these strains are able to grow only at 0-18C, and growth at 22C was observed only with yeast extract stimulation. In this paper, physiological and morphological characteristics of novel psychrophilic and psychrotolerant isolates from

  15. Stable isotope and hydrogeochemical studies of Beaver Lake and Radok Lake, MacRobertson Land, East Antarctica

    International Nuclear Information System (INIS)

    Wand, U.; Hermichen, W.D.

    1988-01-01

    Beaver Lake and Radok Lake, the largest known epishelf lake and the deepest freshwater lake on the Antarctic continent, respectively, were isotopically (δ 2 H, δ 18 O) and hydrogeochemically studied. Radok Lake is an isothermal and nonstratified, i.e. homogeneous water body, while Beaver Lake is stratified with respect to temperature, salinity and isotopic composition. The results for the latter attest to freshwater (derived from snow and glacier melt) overlying seawater. (author)

  16. Watershed vs. within-lake drivers of nitrogen: phosphorus dynamics in shallow lakes.

    Science.gov (United States)

    Ginger, Luke J; Zimmer, Kyle D; Herwig, Brian R; Hanson, Mark A; Hobbs, William O; Small, Gaston E; Cotner, James B

    2017-10-01

    Research on lake eutrophication often identifies variables affecting amounts of phosphorus (P) and nitrogen (N) in lakes, but understanding factors influencing N:P ratios is important given its influence on species composition and toxin production by cyanobacteria. We sampled 80 shallow lakes in Minnesota (USA) for three years to assess effects of watershed size, proportion of watershed as both row crop and natural area, fish biomass, and lake alternative state (turbid vs. clear) on total N : total P (TN : TP), ammonium, total dissolved phosphorus (TDP), and seston stoichiometry. We also examined N:P stoichiometry in 20 additional lakes that shifted states during the study. Last, we assessed the importance of denitrification by measuring denitrification rates in sediment cores from a subset of 34 lakes, and by measuring seston δ 15 N in four additional experimental lakes before and after they were experimentally manipulated from turbid to clear states. Results showed alternative state had the largest influence on overall N:P stoichiometry in these systems, as it had the strongest relationship with TN : TP, seston C:N:P, ammonium, and TDP. Turbid lakes had higher N at given levels of P than clear lakes, with TN and ammonium 2-fold and 1.4-fold higher in turbid lakes, respectively. In lakes that shifted states, TN was 3-fold higher in turbid lakes, while TP was only 2-fold higher, supporting the notion N is more responsive to state shifts than is P. Seston δ 15 N increased after lakes shifted to clear states, suggesting higher denitrification rates may be important for reducing N levels in clear states, and potential denitrification rates in sediment cores were among the highest recorded in the literature. Overall, our results indicate lake state was a primary driver of N:P dynamics in shallow lakes, and lakes in clear states had much lower N at a given level of P relative to turbid lakes, likely due to higher denitrification rates. Shallow lakes are often

  17. American wild celery (Vallisneria americana): Ecological considerations for restoration

    Science.gov (United States)

    Korschgen, C.E.; Green, W.L.

    1988-01-01

    The success of vegetation management programs for waterfowl is dependent on knowing the physical and physiological requirements of target species. Lakes and riverine impoundments that contain an abundance of the American wildcelery (Vallisneria americana ) have traditionally been favored by canvasbacks (Aythya valisineria ) and other waterfowl as feeding areas during migration. Information on the ecology of American wildcelery is summarized to serve as a guide for potential wetland restoration projects. Techniques are described for transplanting winter buds. Management programs that employ these techniques should define objectives clearly and evaluate the water regime carefully before initiating major restoration.

  18. A new leech species of Helobdella (Hirudinea, Glossiphoniidae from San Carlos de Bariloche, Río Negro, Argentina Una especie nueva de sanguijuela del género Helobdella (Hirudinea, Glossiphoniidae de San Carlos de Bariloche, Río Negro, Argentina

    Directory of Open Access Journals (Sweden)

    Bettina S. Gullo

    2009-04-01

    Full Text Available A new freshwater leech species Helobdella fantasmae n. sp. is described. This description is based on the examination of 12 specimens collected in Laguna Fantasma, Bariloche (41° 05'S 71° 28'W, during December 2002. Leeches were found attached to submerged plants. They were relaxed with gradual addition of 70% ethanol, fixed in 10% formalin, stored in 70% ethanol and stained with borax carmine. Examination of external morphology, dissections and microphotographs were accomplished with a Leica Wild M3Z stereo microscope aided with an Olympus C-4000 digital camera. H. fantasmae n. sp. differs from other species of the genus by the presence of 1 pair of eyes on somite III, crop without gastric chambers, digitiform caeca and postcaeca., short sperm ducts reaching the back of somite XV, atrium pyriform, short ovisacs reaching somite XIII. This is the first record of leeches from an ephemeral wetland in North Patagonia. This finding expands current knowledge of the biodiversity of Hirudinea in South America, increasing the number of known Helobdella spp. from the Río Negro province (North Patagonia to 10 species.Se describe una especie de sanguijuela dulceacuícola Helobdella fantasmae n. sp. Esta descripción se basa en el examen de 12 ejemplares recolectados en la Laguna Fantasma, Bariloche (41° 05'S 71° 28'O durante diciembre de 2002. Los individuos se hallaron asociados a la vegetación sumergida. Fueron relajados con la adición gradual de etanol 70%, fijados en formalina al 10%, preservados en etanol 70% y teñidos con carmín borácico. El examen de la morfología externa, disecciones y microfotografías fueron realizados con la ayuda de un estereomicroscopio Leica Wild M3Z con cámara digital Olympus C-4000. H. fantasmae n. sp. difiere de otras especies del género por los siguientes caracteres: un par de ojos en el somito III, estómago recto sin cámaras, ciegos laterales ni postciegos, espermiductos cortos que descienden hasta el

  19. Hazards of volcanic lakes: analysis of Lakes Quilotoa and Cuicocha, Ecuador

    Directory of Open Access Journals (Sweden)

    G. Gunkel

    2008-01-01

    Full Text Available Volcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakesLakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. – have been the focus of these investigations. Both volcanoes are geologically young or historically active, and have formed large and deep calderas with lakes of 2 to 3 km in diameter, and 248 and 148 m in depth, respectively. In both lakes, visible gas emissions of CO2 occur, and an accumulation of CO2 in the deep water body must be taken into account.

    Investigations were carried out to evaluate the hazards of these volcanic lakes, and in Lake Cuicocha intensive monitoring was carried out for the evaluation of possible renewed volcanic activities. At Lake Quilotoa, a limnic eruption and diffuse CO2 degassing at the lake surface are to be expected, while at Lake Cuicocha, an increased risk of a phreatic-magmatic eruption exists.

  20. Rubidium-strontium ages from the Oxford Lake-Knee Lake greenstone belt, northern Manitoba

    International Nuclear Information System (INIS)

    Clark, G.S.; Cheung, S.-P.

    1980-01-01

    Rb-Sr whole-rock ages have been determined for rocks from the Oxford Lake-Knee Lake-Gods Lake geenstone belt in the Superior Province of northeastern Manitoba. The age of the Magill Lake Pluton is 2455 +- 35 Ma(lambda 87 Rb = 1.42 x 10 -11 yr -1 ), with an initial 87 Sr/ 86 Sr ratio of 0.7078 +- 0.0043. This granite stock intrudes the Oxford Lake Group, so it is post-tectonic and probably related to the second, weaker stage of metamorphism. The age of the Bayly Lake Pluton is 2424 +- 74 Ma, with an initial 87 Sr/ 86 Sr ratio of 0.7029 +- 0.0001. This granodioritic batholith complex does not intrude the Oxford Lake Group. It is syn-tectonic and metamorphosed. The age of volcanic rocks of the Hayes River Group, from Goose Lake (30 km south of Gods Lake Narrows), is 2680 +- 125 Ma, with an initial 87 Sr/ 86 Sr ratio of 0.7014 +- 0.0009. The age for the Magill Lake and Bayly Lake Plutons can be interpreted as the minimum ages of granite intrusion in the area. The age for the Hayes River Group volcanic rocks is consistent with Rb-Sr ages of volcanic rocks from other Archean greenstone belts within the northwestern Superior Province. (auth)

  1. Changing values of lake ecosystem services as a result of bacteriological contamination on Lake Trzesiecko and Lake Wielimie, Poland

    Directory of Open Access Journals (Sweden)

    Cichoń Małgorzata

    2017-12-01

    Full Text Available Lake ecosystems, on the one hand, are affected by tourism, and on the other by development for tourism. Lake ecosystem services include: water with its self-cleaning processes, air with climate control processes, as well as flora and fauna. Utilisation of services leads to interventions in the structure of ecosystems and their processes. Only to a certain extent, this is specific to each type of environmental interference, remains within the limits of ecosystem resilience and does not lead to its degradation. One of the threats is bacteriological contamination, for which the most reliable sanitation indicator is Escherichia coli. In lake water quality studies it is assumed that the lakeshore cannot be a source of bacteria. It has been hypothesised that the problem of bacterial contamination can be serious for the places that do not have any infrastructure, especially sanitation. Consequently, the purpose of the study was to determine the extent to which lakeshore sanitation, in particular the level of bacteriological contamination, has an impact on the value of services provided by the selected lake ecosystems (Lake Trzesiecko and Lake Wielimie – Szczecinek Lake District. Five selected services related to lake ecosystems are: water, control over the spread of contagious diseases, aesthetic values, tourism and recreation, as well as the hydrological cycle with its self-cleaning function. Services, as well as the criteria adopted for evaluation, allow us to conclude that the services provided by the lake ecosystems are suitable to fulfill a recreation function. However, the inclusion of quality criteria for sanitary status has shown that the value of system services has dropped by as much as 50%. Value changes are visible primarily for water and aesthetic qualities. Such a significant decrease in the value of services clearly indicates the importance of the sanitary conditions of lakes and their appropriate infrastructure. In view of the

  2. Anaglyph, Salt Lake City, Utah

    Science.gov (United States)

    2002-01-01

    The 2002 Winter Olympics are hosted by Salt Lake City at several venues within the city, in nearby cities, and within the adjacent Wasatch Mountains. This anaglyph image provides a stereoscopic map view of north central Utah that includes all of these Olympic sites. In the south, next to Utah Lake, Provo hosts the ice hockey competition. In the north, northeast of the Great Salt Lake, Ogden hosts curling and the nearby Snowbasin ski area hosts the downhill events. In between, southeast of the Great Salt Lake, Salt Lake City hosts the Olympic Village and the various skating events. Further east, across the Wasatch Mountains, the Park City ski resort hosts the bobsled, ski jumping, and snowboarding events. The Winter Olympics are always hosted in mountainous terrain. This view shows the dramatic landscape that makes the Salt Lake City region a world-class center for winter sports.The stereoscopic effect of this anaglyph was created by first draping a Landsat satellite image over a Shuttle Radar Topography Mission digital elevation model and then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed

  3. The Lake Charles CCS Project

    Energy Technology Data Exchange (ETDEWEB)

    Doug Cathro

    2010-06-30

    The Lake Charles CCS Project is a large-scale industrial carbon capture and sequestration (CCS) project which will demonstrate advanced technologies that capture and sequester carbon dioxide (CO{sub 2}) emissions from industrial sources into underground formations. Specifically the Lake Charles CCS Project will accelerate commercialization of large-scale CO{sub 2} storage from industrial sources by leveraging synergy between a proposed petroleum coke to chemicals plant (the LCC Gasification Project) and the largest integrated anthropogenic CO{sub 2} capture, transport, and monitored sequestration program in the U.S. Gulf Coast Region. The Lake Charles CCS Project will promote the expansion of EOR in Texas and Louisiana and supply greater energy security by expanding domestic energy supplies. The capture, compression, pipeline, injection, and monitoring infrastructure will continue to sequester CO{sub 2} for many years after the completion of the term of the DOE agreement. The objectives of this project are expected to be fulfilled by working through two distinct phases. The overall objective of Phase 1 was to develop a fully definitive project basis for a competitive Renewal Application process to proceed into Phase 2 - Design, Construction and Operations. Phase 1 includes the studies attached hereto that will establish: the engineering design basis for the capture, compression and transportation of CO{sub 2} from the LCC Gasification Project, and the criteria and specifications for a monitoring, verification and accounting (MVA) plan at the Hastings oil field in Texas. The overall objective of Phase 2, provided a successful competitive down-selection, is to execute design, construction and operations of three capital projects: (1) the CO{sub 2} capture and compression equipment, (2) a Connector Pipeline from the LLC Gasification Project to the Green Pipeline owned by Denbury and an affiliate of Denbury, and (3) a comprehensive MVA system at the Hastings oil field.

  4. Current and temperature structure of Rihand Lake

    Digital Repository Service at National Institute of Oceanography (India)

    Suryanarayana, A.; Swamy, G.N.; Sadhuram, Y.

    The environmental parameters such as wind, water and air temperatures, and currents were measured in Rihand Lake, Madhya Pradesh, India during the hotest months, May-June of 1983. Rihand is an artificial lake having an area of 300 km super(2...

  5. Preparation of aluminium lakes by electrocoagulation

    Directory of Open Access Journals (Sweden)

    Prapai Pradabkham

    2008-07-01

    Full Text Available Aluminium lakes have been prepared by electrocoagulation employing aluminium as electrodes. The electrocoagulation is conducted in an aqueous alcoholic solution and is completed within one hour. The dye content in the lake ranges approximately between 4-32%.

  6. Lake-tilting investigations in southern Sweden

    International Nuclear Information System (INIS)

    Paasse, T.

    1996-04-01

    The main aim of lake-tilting investigations is to determine the course of the glacio-isostatic uplift, i.e. to find a formula for the uplift. Besides the lake-tilting graphs, knowledge of the recent relative uplift and the gradient of some marine shorelines are used for solving this problem. This paper summarizes four investigations. 23 refs, 10 figs

  7. Lake Chapala change detection using time series

    Science.gov (United States)

    López-Caloca, Alejandra; Tapia-Silva, Felipe-Omar; Escalante-Ramírez, Boris

    2008-10-01

    The Lake Chapala is the largest natural lake in Mexico. It presents a hydrological imbalance problem caused by diminishing intakes from the Lerma River, pollution from said volumes, native vegetation and solid waste. This article presents a study that allows us to determine with high precision the extent of the affectation in both extension and volume reduction of the Lake Chapala in the period going from 1990 to 2007. Through satellite images this above-mentioned period was monitored. Image segmentation was achieved through a Markov Random Field model, extending the application towards edge detection. This allows adequately defining the lake's limits as well as determining new zones within the lake, both changes pertaining the Lake Chapala. Detected changes are related to a hydrological balance study based on measuring variables such as storage volumes, evapotranspiration and water balance. Results show that the changes in the Lake Chapala establish frail conditions which pose a future risk situation. Rehabilitation of the lake requires a hydrologic balance in its banks and aquifers.

  8. Cryptanalysis of the LAKE Hash Family

    DEFF Research Database (Denmark)

    Biryukov, Alex; Gauravaram, Praveen; Guo, Jian

    2009-01-01

    We analyse the security of the cryptographic hash function LAKE-256 proposed at FSE 2008 by Aumasson, Meier and Phan. By exploiting non-injectivity of some of the building primitives of LAKE, we show three different collision and near-collision attacks on the compression function. The first attac...

  9. Combining lake and watershed characteristics with Landsat TM data for remote estimation of regional lake clarity

    Science.gov (United States)

    McCullough, Ian M.; Loftin, Cyndy; Sader, Steven A.

    2012-01-01

    Water clarity is a reliable indicator of lake productivity and an ideal metric of regional water quality. Clarity is an indicator of other water quality variables including chlorophyll-a, total phosphorus and trophic status; however, unlike these metrics, clarity can be accurately and efficiently estimated remotely on a regional scale. Remote sensing is useful in regions containing a large number of lakes that are cost prohibitive to monitor regularly using traditional field methods. Field-assessed lakes generally are easily accessible and may represent a spatially irregular, non-random sample of a region. We developed a remote monitoring program for Maine lakes >8 ha (1511 lakes) to supplement existing field monitoring programs. We combined Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) brightness values for TM bands 1 (blue) and 3 (red) to estimate water clarity (secchi disk depth) during 1990–2010. Although similar procedures have been applied to Minnesota and Wisconsin lakes, neither state incorporates physical lake variables or watershed characteristics that potentially affect clarity into their models. Average lake depth consistently improved model fitness, and the proportion of wetland area in lake watersheds also explained variability in clarity in some cases. Nine regression models predicted water clarity (R2 = 0.69–0.90) during 1990–2010, with separate models for eastern (TM path 11; four models) and western Maine (TM path 12; five models that captured differences in topography and landscape disturbance. Average absolute difference between model-estimated and observed secchi depth ranged 0.65–1.03 m. Eutrophic and mesotrophic lakes consistently were estimated more accurately than oligotrophic lakes. Our results show that TM bands 1 and 3 can be used to estimate regional lake water clarity outside the Great Lakes Region and that the accuracy of estimates is improved with additional model variables that reflect

  10. Stennis visits Lake Cormorant school

    Science.gov (United States)

    2010-01-01

    Alexis Harry, assistant director of Astro Camp at NASA's John C. Stennis Space Center, talks with students at Lake Cormorant (Miss.) Elementary School during a 'Living and Working in Space' presentation March 30. Stennis hosted the school presentation during a visit to the Oxford area. Harry, who also is a high school biology teacher in Slidell, La., spent time discussing space travel with students and answering questions they had about the experience, including queries about how astronauts eat, sleep and drink in space. The presentation was sponsored by the NASA Office of External Affairs and Education at Stennis. For more information about NASA education initiatives, visit: http://education.ssc.nasa.gov/.

  11. Pleistocene lake level changes in Western Mongolia

    Science.gov (United States)

    Borodavko, P. S.

    2009-04-01

    Global cooling in the Early Pleistocene caused extensive continental glaciation in the northern hemisphere including the arid areas of Central Asia. The reduction of temperatures (particularly summer temperatures) reduced evaporation and strengthened the importance of precipitation. The simultaneity of "lakes periods" (pluvials) and stages of glaciation is established experience confirmed by investigations in the west of North America and Russia. In the Mongolian Great Lakes Depression new evidence for similar conditions is found. The Great Lakes Depression is one of the largest in Central Asia, and is divided into 2 main Lakes basins: Hyargas Lake Basin and Uvs Lake Basin. The basin is 600-650 km in length with a width of 200-250 km in the north and 60-100 km in the south. Total catchment area is about 186600 km2. The elevation of the basin floor is from 1700 m a.s.l. to 760 m a.s.l., decreasing to the north and south-east. The depression extends south-north and is bounded by mountains: Tannu-Ola to the north, Hangai to the east; Gobi Altai to the south and Mongolian Altay to the west. The maximum elevation of the mountains is 4000 m a.s.l. There are some mountains with an elevation between 2000 and 3000 m a.s.l in the lake catchment. These mountains are not glaciated today. The geological record [1] suggests the Great Lakes Depression already existed in the Mesozoic, but assumed its modern form only during the Pliocene-Quaternary when tectonic movements caused the uplift of the surrounding mountains. A phase of tectonic stability occurred during the Late Quaternary. The depression is filled by Quaternary fluvial, aeolian and lacustrine deposits (e.g. sand, pebbles). The Neogene deposits are represented by coloured clay, marl, sand and sandstone [1]. Hyargas Lake is the end base level of erosion of the lake group consisting of the Hara-Us Nur, Dorgon, Hara Nur and Airag lakes. Hyargas is one of the largest lakes in Mongolia, with a water surface of 1,407 km2. The

  12. Investigation of landscape and lake acidification relationships

    Energy Technology Data Exchange (ETDEWEB)

    Rush, R.M.; Honea, R.B.; Krug, E.C.; Peplies, R.W.; Dobson, J.E.; Baxter, F.P.

    1985-10-01

    This interim report presents the rationale and initial results for a program designed to gather and analyze information essential to a better understanding of lake acidification in the northeastern United States. The literature pertinent to a study of landscape and lake acidification relationships is reviewed and presented as the rationale for a landscape/lake acidification study. The results of a study of Emmons Pond in northwestern Connecticut are described and lead to the conclusion that a landscape change was a contributor to the acidification of this pond. A regional study of sixteen lakes in southern New England using Landsat imagery is described, and preliminary observations from a similar study in the Adirondack Mountains are given. These results indicate that satellite imagery can be useful in identifying types of ground cover important to landscape/lake acidification relationships.

  13. Residues of Organochlorine Pesticides in Lake Mariut

    International Nuclear Information System (INIS)

    Saad, M.A.H.; Abu-Elamayem, M.M.; El-Sebae, A.B.; Sharaf, I.P.

    1981-01-01

    Lake Mariut, a brackish water lake adjoining the Mediterranean Coast of Egypt, has suffered much from intensive pollution in recent years due to the successive increase of human population and industry around it (Saad, 1980). The occurrence and distribution of organochlorine pesticides in the water of Lake Mariut during a period of one year were studied. This study represents an essential part of a pilot project on pollution of Lake Mariut supported by IAEA. The major organochlorine pesticides detected in the water of Lake Mariut were Lindane, p, p'-DDE, o,p'-DDT and p, p'-DDT. The mean concentrations of these pesticides were 2.091, 4.493, 0.009 and 0.134 ppb, respectively. The mean concentration of the calculated total DDT (Σ DDT) was 5.1 PPb

  14. Comparative limnology of strip-mine lakes

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, J D

    1964-01-01

    Lakes were classified according to chemical properties. The concentration of the ferric iron oxides was responsible for a reddish-black turbidity which, in turn, played a major role in the thermal stratification of red strip-mine lakes. Owing to the lack of measurable turbidity and as a result of selective absorption of visible solar radiation, other strip-mine lakes appeared blue in color. The annual heat budget and the summer heat budget are essentially equivalent under saline conditions. Regardless of the physical and chemical conditions of the strip-mine lakes, heat income was a function of the circulating water mass. The progressive oxidation and precipitation of the iron oxides is the key to the classification of strip-mine lakes.

  15. International Planning for Subglacial Lake Exploration

    Science.gov (United States)

    Kennicutt, M.; Priscu, J.

    2003-04-01

    As one of the last unexplored frontiers on our planet, subglacial lakes offer a unique and exciting venue for exploration and research. Over the past several years, subglacial lakes have captured the imagination of the scientific community and public, evoking images of potential exotic life forms surviving under some of the most extreme conditions on earth. Various planning activities have recognized that due to the remote and harsh conditions, that a successful subglacial lake exploration program will entail a concerted effort for a number of years. It will also require an international commitment of major financial and human resources. To begin a detailed planning process, the Scientific Committee on Antarctic Research (SCAR) convened the Subglacial Antarctic Lake Exploration Group of Specialists (SALEGOS) in Tokyo in 2000. The group was asked to build on previous workshops and meetings to develop a plan to explore subglacial lake environments. Its mandate adopted the guiding principles as agreed in Cambridge in 1999 that the program would be interdisciplinary in scope, be designed for minimum contamination and disturbance of the subglacial lake environment, have as a goal lake entry and sample retrieval, and that the ultimate target of the program should be Lake Vostok exploration. Since its formation SALEGOS has met three times and addressed some of the more intractable issues related to subglacial lake exploration. Topics under discussion include current state-of-the-knowledge of subglacial environments, technological needs, international management and organizational strategies, a portfolio of scientific projects, "clean" requirements, and logistical considerations. In this presentation the actvities of SALEGOS will be summarized and recommendations for an international subglacial lake exploration program discussed.

  16. Pronounced occurrence of long-chain alkenones and dinosterol in a 25,000-year lipid molecular fossil record from Lake Titicaca, South America

    Science.gov (United States)

    Theissen, Kevin M.; Zinniker, David A.; Moldowan, J. Michael; Dunbar, Robert B.; Rowe, Harold D.

    2005-02-01

    Our analysis of lipid molecular fossils from a Lake Titicaca (16° S, 69° W) sediment core reveals distinct changes in the ecology of the lake over an ˜25,000-yr period spanning latest Pleistocene to late Holocene time. Previous investigations have shown that over this time period Lake Titicaca was subject to large changes in lake level in response to regional climatic variability. Our results indicate that lake algal populations were greatly affected by the changing physical and chemical conditions in Lake Titicaca. Hydrocarbons are characterized by a combination of odd-numbered, mid- to long-chain (C 21-C 31) normal alkanes and alkenes. During periods when lake level was higher (latest Pleistocene, early Holocene, and late Holocene), the C 21n-alkane, and the C 25 and C 27 alkenes dominate hydrocarbon distributions and indicate contribution from an algal source, potentially the freshwater alga Botryococcus braunii. The C 30 4 α-methyl sterol (dinosterol) increases sharply during the mid-Holocene, suggesting a greatly increased dinoflagellate presence at that time. Long-chain alkenones (LCAs) become significant during the early Holocene and are highly abundant in mid-Holocene samples. There are relatively few published records of LCA detection in lake sediments but their occurrence is geographically widespread (Antarctica, Asia, Europe, North America). Lake Titicaca represents the first South American lake and the first low-latitude lake in which LCAs have been reported. LCA abundance and distribution may be related to the temperature-dependent response of an unidentified algal precursor. Although the LCA unsaturation indices cannot be used to determine absolute Lake Titicaca temperatures, we suspect that the published LCA U37K unsaturation calibrations can be applied to infer relative temperatures for early to mid-Holocene time when LCA concentrations are high. Using these criteria, the U37K unsaturation indices suggest relatively warmer temperatures in the

  17. Using Satellite Imagery to Monitor the Major Lakes; Case Study Lake Hamun

    Science.gov (United States)

    Norouzi, H.; Islam, R.; Bah, A.; AghaKouchak, A.

    2015-12-01

    Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes would provide invaluable information for policy-makers and local people. As part of a comprehensive study, we aim to monitor the land-cover/ land-use changes in the world's major lakes using satellite observations. As a case study, Hamun Lake which is a pluvial Lake, also known as shallow Lake, located on the south-east of Iran and adjacent to Afghanistan, and Pakistan borders is investigated. The Lake is the main source of resources (agriculture, fishing and hunting) for the people around it and politically important in the region since it is shared among three different countries. The purpose of the research is to find the Lake's area from 1972 to 2015 and to see if any drought or water resources management has affected the lake. Analyzing satellites imagery from Landsat shows that the area of the Lake changes seasonally and intra-annually. Significant seasonal effects are found in 1975,1977, 1987, 1993, 1996, 1998, 2000, 2009 and 2011, as well as, substantial amount of shallow water is found throughout the years. The precipitation records as well as drought historical records are studied for the lake's basin. Meteorological studies suggest that the drought, decrease of rainfalls in the province and the improper management of the Lake have caused environmental, economic and geographical consequences. The results reveal that lake has experienced at least two prolong dryings since 1972 which drought cannot solely be blamed as main forcing factor.Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes

  18. Decomposition of lake phytoplankton. 2

    International Nuclear Information System (INIS)

    Hansen, L.; Krog, G.F.; Soendergaard, M.

    1986-01-01

    The lysis process of phytoplankton was followed in 24 h incubations in three Danish lakes. By means of gel-chromatography it was shown that the dissolved carbon leaching from different algal groups differed in molecular weight composition. Three distinct molecular weight classes (>10,000; 700 to 10,000 and < 700 Daltons) leached from blue-green algae in almost equal proportion. The lysis products of spring-bloom diatoms included only the two smaller size classes, and the molecules between 700 and 10,000 Daltons dominated. Measurements of cell content during decomposition of the diatoms revealed polysaccharides and low molecular weight compounds to dominate the lysis products. No proteins were leached during the first 24 h after cell death. By incubating the dead algae in natural lake water, it was possible to detect a high bacterial affinity towards molecules between 700 and 10,000 Daltons, although the other size classes were also utilized. Bacterial transformation of small molecules to larger molecules could be demonstrated. (author)

  19. Lake Roosevelt fisheries monitoring program

    International Nuclear Information System (INIS)

    Griffith, J.R.; Scholz, A.T.

    1991-01-01

    The purpose of this study was to provide baseline data that could be used to evaluate the effectiveness of two kokanee salmon hatcheries that will produce 8 million kokanee salmon (Oncorhynchus nerka) fry or 3.2 million adults for stocking into Lake Roosevelt. The hatcheries will also produce 500,000 rainbow trout (Oncorhynchus mykiss) fingerlings to support the Lake Roosevelt net-pen programs. The baseline data will also be used to evaluate the effectiveness of the habitat improvement projects ongoing on a separate contract. At the present time, the principle sport fish in the reservoir are net-pen rainbow trout and walleye (Stizostedion vitreum). The objectives of the second year of the monitoring program were: (1) to determine angling pressure, catch per unit effort, total harvest and the economic value; (2) to determine relative abundance of fish species in the reservoir by conducting electrofishing and gillnet surveys at nine index stations during May, August, and October; (3) to determine growth rates of kokanee, rainbow trout, and walleye based upon backcalculations from scales collected during May, August and October and creel surveys; (4) to determine density, size, and biomass of zooplankton and how reservoir operations affect their population dynamics; (5) to determine feeding habits of kokanee, rainbow trout, and walleye and their preferred prey densities; and (6) to determine migration patterns of tagged walleye and net-pen rainbow trout. 118 refs., 20 figs., 98 tabs

  20. Changes in the dreissenid community in the lower Great Lakes with emphasis on southern Lake Ontario

    Science.gov (United States)

    Mills, Edward L.; Chrisman, Jana R.; Baldwin, Brad; Owens, Randall W.; O'Gorman, Robert; Howell, Todd; Roseman, Edward F.; Raths, Melinda K.

    1999-01-01

    A field study was conducted in the lower Great Lakes to assess changes in spatial distribution and population structure of dreissenid mussel populations. More specifically, the westward range expansion of quagga mussel into western Lake Erie and toward Lake Huron was investigated and the shell size, density, and biomass of zebra and quagga mussel with depth in southern Lake Ontario in 1992 and 1995 were compared. In Lake Erie, quagga mussel dominated the dreissenid community in the eastern basin and zebra mussel dominated in the western basin. In southern Lake Ontario, an east to west gradient was observed with the quagga mussel dominant at western sites and zebra mussel dominant at eastern locations. Mean shell size of quagga mussel was generally larger than that of zebra mussel except in western Lake Erie and one site in eastern Lake Erie. Although mean shell size and our index of numbers and biomass of both dreissenid species increased sharply in southern Lake Ontario between 1992 and 1995, the increase in density and biomass was much greater for quagga mussels over the 3-year period. In 1995, zebra mussels were most abundant at 15 to 25 m whereas the highest numbers and biomass of quagga mussel were at 35 to 45 m. The quagga mussel is now the most abundant dreissenid in areas of southern Lake Ontario where the zebra mussel was once the most abundant dreissenid; this trend parallels that observed for dreissenid populations in the Dneiper River basin in the Ukraine.

  1. Hydro biological investigations of lake Drukshiai

    International Nuclear Information System (INIS)

    Mazheikaite, S.; Sinkevichiene, Z.; Marchiulioniene, D.; Astrauskas, A.; Barshiene, J.

    1998-01-01

    Purposes of this research were to investigate changes in the physical, chemical and tropic conditions of Lake Drukshiai caused by the combined effect of Ignalina NPP and how it effects on structures and function of biocenoses; to estimate the influence of phytocenoses, zoocenoses and bacteriocenoses on the quality of water in Lake Drukshiai; to estimate the eco toxicological state of Lake Drukshiai. According to the complex hydro biological investigations on Lake Drukshiai - Ignalina NPP cooler great changes in planktonic organism community, tendencies of those changes in different ecological zones were evaluated in 1993 - 1997. The amount of species of most dominant planktonic organisms in 1993 - 1997 decreased 2-3 times in comparison with that before Ignalina NPP operation: phytoplankton from 116 to 40 - 50, zooplankton - from 233 to 139. The organic matter increasing tendency was determined in bottom sediments of the lake. The highest amount of it was evaluated in the south - eastern part of the lake. 69 water macrophyte species were found in bottom sediments during the investigation period. 16 species were not found in this lake earlier. Abundance of filamentous green algae was registered.The rates of fish communities successional transformation were ten times in excess of those of the given processes in natural lakes. Moreover the comparison of results on Lake Drukshiai bioindication analysis with changes of comparable bio markers which were obtained from other water systems of Lithuania, Switzerland, Sweden and Poland, including those with active nuclear power plants in their environment was carried out. It was determined that the functional and structural changes in Lake Drukshiai biota are mostly caused by chemical pollution. It was found out that the frequency of cytogenetic damage emerged as a specific radionuclide - caused effect in aquatic organisms inhabiting Lake Drukshiai, is slightly above the background level and is 5 times lower than the same

  2. Outflows of groundwater in lakes: case study of Lake Raduńske Górne

    Directory of Open Access Journals (Sweden)

    Cieśliński Roman

    2014-12-01

    Full Text Available The aim of the study was to locate and describe groundwater outflows in a selected lake basin. The study hypothesis was based on the fact that, according to the specialist literature, one of the forms of lake water supply is through groundwater outflows. It was also assumed that the lakes of the Kashubian Lake District are characterised by such a form of lake water supply. The time scope of the work included the period from January 2011 to September 2012. The spatial scope of the work included the area of Lake Raduńskie Górne, located in the Kashubian Lake District in north Poland. The research plot was in the north-eastern part of the lake. Office works were aimed at gathering and studying source materials and maps. Cartographic materials were analysed with the use of the MapInfo Professional 9.5. The purpose of the field work was to find the groundwater outflows in the basin of Lake Raduńskie Górne. During the field research diving was carried out in the lake. During the dive audiovisual documentation was conducted using a Nikon D90 camera with Ikelite underwater housing for Nikon D90 and an Ikelite DS 161 movie substrobe, as well as a GoPro HD HERO 2 Outdoor camera. During the project, four groundwater outflows were found. In order to examine these springs audiovisual and photographic documentation was made. To systematise the typology of the discovered springs, new nomenclature was suggested, namely under-lake springs with subtypes: an under-lake slope spring and under-lake offshore spring

  3. 76 FR 23276 - Lake Tahoe Basin Federal Advisory Committee (LTFAC)

    Science.gov (United States)

    2011-04-26

    ... Interagency Partnership on the Lake Tahoe Region and other matters raised by the Secretary. DATES: The meeting... preliminary recommendation of Lake Tahoe Southern Nevada Public Land Management Act (SNPLMA) Round 12 capital... Lake Tahoe SNPLMA Round 12 capital projects and science themes, and 3) public comment. All Lake Tahoe...

  4. Acidity of Lakes and Impoundments in North-Central Minnesota

    Science.gov (United States)

    Elon S. Verry

    1981-01-01

    Measurements of lake and impoundment pH for several years, intensive sampling within years, and pH-calcium plots verify normal pH levels and do not show evidence of changes due to acid precipitation. These data in comparison with general lake data narrow the northern Lake States area in which rain or snow may cause lake acidification.

  5. BATHYMETRIC STUDY OF WADI EL-RAYAN LAKES, EGYPT

    Directory of Open Access Journals (Sweden)

    Radwan Gad Elrab ABD ELLAH

    2016-12-01

    Full Text Available Bathymetry is a technique of measuring depths to determine the morphometry of water bodies. The derivation of bathymetry from the surveys is one of the basic researches of the aquatic environment, which has several practical implications to on the lake environment and it's monitoring. Wadi El-Rayan, as Ramsar site, is a very important wetland, in Egypt, as a reservoir for agricultural drainage water, fisheries and tourism. The Lakes are man-made basins in the Fayoum depression. Wadi El-Rayan Lakes are two reservoirs (upper Lake and Lower Lake, at different elevations. The Upper Lake is classified as open basin, while the Lower Lake is a closed basin, with no significant obvious water outflow. During recent decades, human impact on Wadi El-Rayan Lakes has increased due to intensification of agriculture and fish farming. Analyses of bathyemtric plans from 1996, 2010 and 2016 showed, the differences between morphometric parameters of the Upper Lake were generally small, while the Lower Lake changes are obvious at the three periods. The small fluctuate, in the features of Upper Lake is due to the water balance between the water inflow and water. The Lower Lake has faced extreme water loss through last twenty years is due to the agricultural lands and fish farms extended in the depression. The Upper Lake is rich in Lakeshores macrophyets, while decline the water plants in the Lower Lake. With low water levels, in the Lower Lake, the future continuity of the Lake system is in jeopardy

  6. ENVIRONMENT PROTECTION AND ENVIRONMENT MONITORING ISSUES IN THE PROJECTS OF SUBGLACIAL LAKES STUDIES IN ANTARCTICA

    Directory of Open Access Journals (Sweden)

    I. A. Alekhina

    2012-01-01

    Full Text Available Antarctic subglacial lakes can represent extreme natural habitats for microorganisms from the position of their evolution and adaptation, as well as they can contain the information on Antarctic ice sheet history and climatic changes in their sediments. Now only direct measurements and sampling from these habitats can answer on many fundamental questions. Special precaution should be complied at penetration into these unique relic environments without unfavorable impacts and contamination. A number of recommendations were developed on levels of cleanliness and sterility during direct exploration and research of subglacial environments. Documents considered in the article are the first and necessary steps for appropriate and long-term ecological management of subglacial Antarctic environments. Today there are three projects of subglacial aquatic environment research which are in preparation and realization – the Russian project of Lake Vostok, the similar British project of Lake Ellsworth and the American project on Whillans Ice Stream. The programs of ecological stewardship for direct exploration of these lakes are discussed. All these subglacial aquatic objects of further exploration and research are so various on their structure, age and regime, that only results of all programs as a whole can help to draw us a uniform picture of a subglacial ecological system. Ecological stewardship of these should provide the minimal ecological impact with maximal scientific results. On the basis of existing documents and recommendations the general approaches and the program of ecological stewardship for Lake Vostok research are discussed. Study of drilling fluid, drilling chips, Vostok ice core and the fresh frozen water will allow to make an assessment of biological and chemical contamination as a result of the first penetration and to modify the further stewardship program for the second penetration and direct exploration of lake water.

  7. Obesity and Asian Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Asian American > Obesity Obesity and Asian Americans Non-Hispanic whites are 60% ... youthonline . [Accessed 08/18/2017] HEALTH IMPACT OF OBESITY People who are overweight are more likely to ...

  8. American Society of Echocardiography

    Science.gov (United States)

    American Society of Echocardiography Join Ase Renew Member Portal Log In Membership Member Portal Log In Join ASE Renew Benefits Rates FASE – Fellow of the American Society of Echocardiography Member Referral Program FAQs Initiatives Advocacy Awards, Grants, ...

  9. Asthma and Hispanic Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Hispanic/Latino > Asthma Asthma and Hispanic Americans In 2015, 2.2 million Hispanics reported that they currently have asthma. Puerto Rican Americans have almost twice the asthma ...

  10. Trophic diversity of Poznań Lakeland lakes

    Directory of Open Access Journals (Sweden)

    Dzieszko Piotr

    2015-06-01

    Full Text Available The main goal of the presented work is to determine the current trophic state of 31 lakes located in Poznań Lakeland. These lakes are included in the lake monitoring programme executed by the Voivodship Environmental Protection Inspectorate in Poznań. The place in the trophic classification for investigated lakes was determined as well as the relationships between their trophic state indices. The trophic state of investigated lakes in the research area is poor. More than a half of the investigated lakes are eutrophic. Depending on the factor that is taken into account the trophic state of investigated lakes differs radically.

  11. Ice formation in subglacial Lake Vostok, Central Antarctica

    Science.gov (United States)

    Souchez, R.; Petit, J. R.; Tison, J.-L.; Jouzel, J.; Verbeke, V.

    2000-09-01

    The investigation of chemical and isotopic properties in the lake ice from the Vostok ice core gives clues to the mechanisms involved in ice formation within the lake. A small lake water salinity can be reasonably deduced from the chemical data. Possible implications for the water circulation of Lake Vostok are developed. The characteristics of the isotopic composition of the lake ice indicate that ice formation in Lake Vostok occurred by frazil ice crystal generation due to supercooling as a consequence of rising waters and a possible contrast in water salinity. Subsequent consolidation of the developed loose ice crystals results in the accretion of ice to the ceiling of the lake.

  12. Geophysical investigation of sentinel lakes in Lake, Seminole, Orange, and Volusia Counties, Florida

    Science.gov (United States)

    Reich, Christopher; Flocks, James; Davis, Jeffrey

    2012-01-01

    This study was initiated in cooperation with the St. Johns River Water Management District (SJRWMD) to investigate groundwater and surface-water interaction in designated sentinel lakes in central Florida. Sentinel lakes are a SJRWMD established set of priority water bodies (lakes) for which minimum flows and levels (MFLs) are determined. Understanding both the structure and lithology beneath these lakes can ultimately lead to a better understanding of the MFLs and why water levels fluctuate in certain lakes more so than in other lakes. These sentinel lakes have become important water bodies to use as water-fluctuation indicators in the SJRWMD Minimum Flows and Levels program and will be used to define long-term hydrologic and ecologic performance measures. Geologic control on lake hydrology remains poorly understood in this study area. Therefore, the U.S. Geological Survey investigated 16 of the 21 water bodies on the SJRWMD priority list. Geologic information was obtained by the tandem use of high-resolution seismic profiling (HRSP) and direct-current (DC) resistivity profiling to isolate both the geologic framework (structure) and composition (lithology). Previous HRSP surveys from various lakes in the study area have been successful in identifying karst features, such as subsidence sinkholes. However, by using this method only, it is difficult to image highly irregular or chaotic surfaces, such as collapse sinkholes. Resistivity profiling was used to complement HRSP by detecting porosity change within fractured or collapsed structures and increase the ability to fully characterize the subsurface. Lake Saunders (Lake County) is an example of a lake composed of a series of north-south-trending sinkholes that have joined to form one lake body. HRSP shows surface depressions and deformation in the substrate. Resistivity data likewise show areas in the southern part of the lake where resistivity shifts abruptly from approximately 400 ohm meters (ohm-m) along the

  13. Rehabilitation of Mohawk Lake: Brantford's crown jewel

    International Nuclear Information System (INIS)

    Farrell, C.W.; Kube, D.J.

    1994-01-01

    Mohawk Lake in Brantford, Ontario had been receiving contaminants from various industrial and municipal sources since the late 1800s. The lake suffered a slow death with the absence of any watershed management plan. A citizen committee was established in 1990 to rehabilitate the lake so that its recreational and resource potential could be fully realized. In 1993, the committee obtained government funding to carry out a detailed baseline environmental study of the lake. Lake sediments were found to consist of an upper horizon of poorly consolidated, organic-rich, odoriferous material overlying a more compact sandy layer. Lake water was characterized by high concentrations of nutrients and metals, and high biological oxygen demand. Sediments also had high concentrations of heavy metals and low concentrations of such organic contaminants as pyrene, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls. The most distinct contaminant appeared to be petroleum hydrocarbons at 0.5-1% concentration. It was determined that lake rehabilitation would require removal of these sediments. Tests indicated that the sediments were non-hazardous non-registrable solid waste, and the preferred removal option was hydraulic dredging into settlement ponds along the undeveloped south shore of the lake. A sediment trap was recommended to be installed at the entrance of the lake, along with a constructed wetland to remove a variety of water pollutants. The sediment dredging, dewatering, trap and wetland installation, and land remediation of the sediment disposal area are estimated to cost ca $3.75 million, and the work will require at least 18 months to complete. 1 fig

  14. Forecasting cyanobacteria dominance in Canadian temperate lakes.

    Science.gov (United States)

    Persaud, Anurani D; Paterson, Andrew M; Dillon, Peter J; Winter, Jennifer G; Palmer, Michelle; Somers, Keith M

    2015-03-15

    Predictive models based on broad scale, spatial surveys typically identify nutrients and climate as the most important predictors of cyanobacteria abundance; however these models generally have low predictive power because at smaller geographic scales numerous other factors may be equally or more important. At the lake level, for example, the ability to forecast cyanobacteria dominance is of tremendous value to lake managers as they can use such models to communicate exposure risks associated with recreational and drinking water use, and possible exposure to algal toxins, in advance of bloom occurrence. We used detailed algal, limnological and meteorological data from two temperate lakes in south-central Ontario, Canada to determine the factors that are closely linked to cyanobacteria dominance, and to develop easy to use models to forecast cyanobacteria biovolume. For Brandy Lake (BL), the strongest and most parsimonious model for forecasting % cyanobacteria biovolume (% CB) included water column stability, hypolimnetic TP, and % cyanobacteria biovolume two weeks prior. For Three Mile Lake (TML), the best model for forecasting % CB included water column stability, hypolimnetic TP concentration, and 7-d mean wind speed. The models for forecasting % CB in BL and TML are fundamentally different in their lag periods (BL = lag 1 model and TML = lag 2 model) and in some predictor variables despite the close proximity of the study lakes. We speculate that three main factors (nutrient concentrations, water transparency and lake morphometry) may have contributed to differences in the models developed, and may account for variation observed in models derived from large spatial surveys. Our results illustrate that while forecast models can be developed to determine when cyanobacteria will dominate within two temperate lakes, the models require detailed, lake-specific calibration to be effective as risk-management tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Unlearning American Patriotism

    Science.gov (United States)

    Miller, Richard W.

    2007-01-01

    Immoral excesses of American foreign policy are so severe and so deep-rooted that American patriotism is now a moral burden. This love, which pulls toward amnesia, wishful thinking and inattention to urgent foreign interests, should be replaced by commitment to a global social movement that seeks to hem in the American empire. Teachers can advance…

  16. Circulation and sedimentation in a tidal-influenced fjord lake: Lake McKerrow, New Zealand

    Science.gov (United States)

    Pickrill, R. A.; Irwin, J.; Shakespeare, B. S.

    1981-01-01

    Lake McKerrow is a tide-influenced fjord lake, separated from the open sea by a Holocene barrier spit. Fresh, oxygenated waters of the epilimnion overlie saline, deoxygenated waters of the hypolimnion. During winter, water from the Upper Hollyford River interflows along the pycnocline, depositing coarse silt on the steep delta and transporting finer sediment down-lake. An extensive sub-lacustrine channel system on the foreset delta slope is possibly maintained by turbidity currents. Saline waters of the hypolimnion are periodically replenished. During high tides and low lake levels saline water flows into the lake and downslope into the lake basin as a density current in a well defined channel.

  17. Heavy Metals Pollution in Lake Mariut

    International Nuclear Information System (INIS)

    Saad, M.A.H.; Ezzat, A.A.E.; El-Rayis, O.A.; Hafez, H.

    1981-01-01

    The occurrence and distribution of heavy metals in the water of the heavily polluted Lake Mariut (Egypt) during August 1978 to September 1979 as well as the accumulation of these metals in the different parts of the common fish, Tilapia species, were studied. The study represents a second part of a pilot project on pollution of Lake Mariut supported by IAEA. The mean concentrations of the measured Zn, Gu, Fe, Mn and Cd in the lake water were 10.9, 4.2, 19.1, 26.2 and 0.62 μg/l, respectively

  18. Changes in depth occupied by Great Lakes lake whitefish populations and the influence of survey design

    Science.gov (United States)

    Rennie, Michael D.; Weidel, Brian C.; Claramunt, Randall M.; Dunlob, Erin S.

    2015-01-01

    Understanding fish habitat use is important in determining conditions that ultimately affect fish energetics, growth and reproduction. Great Lakes lake whitefish (Coregonus clupeaformis) have demonstrated dramatic changes in growth and life history traits since the appearance of dreissenid mussels in the Great Lakes, but the role of habitat occupancy in driving these changes is poorly understood. To better understand temporal changes in lake whitefish depth of capture (Dw), we compiled a database of fishery-independent surveys representing multiple populations across all five Laurentian Great Lakes. By demonstrating the importance of survey design in estimating Dw, we describe a novel method for detecting survey-based bias in Dw and removing potentially biased data. Using unbiased Dw estimates, we show clear differences in the pattern and timing of changes in lake whitefish Dw between our reference sites (Lake Superior) and those that have experienced significant benthic food web changes (lakes Michigan, Huron, Erie and Ontario). Lake whitefish Dw in Lake Superior tended to gradually shift to shallower waters, but changed rapidly in other locations coincident with dreissenid establishment and declines in Diporeia densities. Almost all lake whitefish populations that were exposed to dreissenids demonstrated deeper Dw following benthic food web change, though a subset of these populations subsequently shifted to more shallow depths. In some cases in lakes Huron and Ontario, shifts towards more shallow Dw are occurring well after documented Diporeia collapse, suggesting the role of other drivers such as habitat availability or reliance on alternative prey sources.

  19. Geochemical monitoring of volcanic lakes. A generalized box model for active crater lakes

    Directory of Open Access Journals (Sweden)

    Franco Tassi

    2011-06-01

    Full Text Available

    In the past, variations in the chemical contents (SO42−, Cl−, cations of crater lake water have not systematically demonstrated any relationships with eruptive activity. Intensive parameters (i.e., concentrations, temperature, pH, salinity should be converted into extensive parameters (i.e., fluxes, changes with time of mass and solutes, taking into account all the internal and external chemical–physical factors that affect the crater lake system. This study presents a generalized box model approach that can be useful for geochemical monitoring of active crater lakes, as highly dynamic natural systems. The mass budget of a lake is based on observations of physical variations over a certain period of time: lake volume (level, surface area, lake water temperature, meteorological precipitation, air humidity, wind velocity, input of spring water, and overflow of the lake. This first approach leads to quantification of the input and output fluxes that contribute to the actual crater lake volume. Estimating the input flux of the "volcanic" fluid (Qf- kg/s –– an unmeasurable subsurface parameter –– and tracing its variations with time is the major focus during crater lake monitoring. Through expanding the mass budget into an isotope and chemical budget of the lake, the box model helps to qualitatively characterize the fluids involved. The (calculated Cl− content and dD ratio of the rising "volcanic" fluid defines its origin. With reference to continuous monitoring of crater lakes, the present study provides tips that allow better calculation of Qf in the future. At present, this study offers the most comprehensive and up-to-date literature review on active crater lakes.

  20. Molecular characterization of the Great Lakes viral hemorrhagic septicemia virus (VHSV isolate from USA

    Directory of Open Access Journals (Sweden)

    Vakharia Vikram N

    2009-10-01

    Full Text Available Abstract Background Viral hemorrhagic septicemia virus (VHSV is a highly contagious viral disease of fresh and saltwater fish worldwide. VHSV caused several large scale fish kills in the Great Lakes area and has been found in 28 different host species. The emergence of VHS in the Great Lakes began with the isolation of VHSV from a diseased muskellunge (Esox masquinongy caught from Lake St. Clair in 2003. VHSV is a member of the genus Novirhabdovirus, within the family Rhabdoviridae. It has a linear single-stranded, negative-sense RNA genome of approximately 11 kbp, with six genes. VHSV replicates in the cytoplasm and produces six monocistronic mRNAs. The gene order of VHSV is 3'-N-P-M-G-NV-L-5'. This study describes molecular characterization of the Great Lakes VHSV strain (MI03GL, and its phylogenetic relationships with selected European and North American isolates. Results The complete genomic sequences of VHSV-MI03GL strain was determined from cloned cDNA of six overlapping fragments, obtained by RT-PCR amplification of genomic RNA. The complete genome sequence of MI03GL comprises 11,184 nucleotides (GenBank GQ385941 with the gene order of 3'-N-P-M-G-NV-L-5'. These genes are separated by conserved gene junctions, with di-nucleotide gene spacers. The first 4 nucleotides at the termini of the VHSV genome are complementary and identical to other novirhadoviruses genomic termini. Sequence homology and phylogenetic analysis show that the Great Lakes virus is closely related to the Japanese strains JF00Ehi1 (96% and KRRV9822 (95%. Among other novirhabdoviruses, VHSV shares highest sequence homology (62% with snakehead rhabdovirus. Conclusion Phylogenetic tree obtained by comparing 48 glycoprotein gene sequences of different VHSV strains demonstrate that the Great Lakes VHSV is closely related to the North American and Japanese genotype IVa, but forms a distinct genotype IVb, which is clearly different from the three European genotypes. Molecular

  1. A Systematic Study of Zerbar Lake Restoration

    Science.gov (United States)

    Hosseini, Reza; Oveis Torabi, Seyed; Forman Asgharzadeh, Deonna

    2017-04-01

    The beautiful lake of Zerbar, located near Marivan City at the west of Iran, is a freshwater lake with an area of 20 km2 and average depth of 5 meters. The lake is created by regional tectonic activities and is mainly fed with natural spring water from bottom. During the past three decades, regional development has caused much disturbance to the natural environment of the lake and its watershed. Rescuing the lake is crucial to the sustainability of the whole region. The study of Zerbar Restoration was performed with the aim to restore its health indicators. Variety of human activities in the watershed, as well as the multidisciplinary nature of lake restoration studies, made it necessary to develop a systematic approach to conduct the study. In Step I of restoration studies, satellite images were investigated to identify the historical changes of watershed during the past 30 years. Meanwhile, documents since 50 years ago were studied. Results indicate that farmland and graze land areas have been relatively constant during the past 50 years. Also, the area of lake, its riparian canes and floating plants have not changed much. In fact, the only significant land use change observed was the significant spread of Marivan City that has stretched toward the lake. The main physical variation to the lake has been elevating the southern edge of the lake by a constructing a landfill dam which was done to control the lake's overflow discharge for irrigation of downstream farmland development. Step II consists of studies performed by disciplines of water resources, hydrogeology, water quality, wetland and watershed ecology, agriculture, animal farming and fishery. Study results indicate that eutrophication (TSL>100), mainly caused by sewage from Marivan City and the surrounding rural areas has been the main reason for lake ecosystem degradation. DPSIR framework, as a novel approach in lake restoration, was applied to synthesize the study results of different disciplines in a

  2. Crotch Lake dam rehabilitation project

    International Nuclear Information System (INIS)

    Brunet, G.; Dobrowolski, E.

    1999-01-01

    Replacement of the existing wood crib dam structure on Crotch Lake on the Mississippi River in eastern Ontario that provided water storage for the power production at High Falls Generating Station, became necessary when it was determined that the dam did not meet Ontario-Hydro's safety standards. This paper describes the project of replacing the existing structure with a PVC coated gabion wall with waterproofing. The entire structure was covered with three layers of wire mesh, laced together, and criss-crossed for superior strength and rigidity. The work was completed in 28 days with no environmental impact . Life expectancy of the new structure is in excess of 40 years. With periodic maintenance of the gabion mat cover, life span could be extended an additional 20 to 40 years. 5 figs

  3. Sources and distribution of microplastics in China's largest inland lake - Qinghai Lake.

    Science.gov (United States)

    Xiong, Xiong; Zhang, Kai; Chen, Xianchuan; Shi, Huahong; Luo, Ze; Wu, Chenxi

    2018-04-01

    Microplastic pollution was studied in China's largest inland lake - Qinghai Lake in this work. Microplastics were detected with abundance varies from 0.05 × 10 5 to 7.58 × 10 5 items km -2 in the lake surface water, 0.03 × 10 5 to 0.31 × 10 5 items km -2 in the inflowing rivers, 50 to 1292 items m -2 in the lakeshore sediment, and 2 to 15 items per individual in the fish samples, respectively. Small microplastics (0.1-0.5 mm) dominated in the lake surface water while large microplastics (1-5 mm) are more abundant in the river samples. Microplastics were predominantly in sheet and fiber shapes in the lake and river water samples but were more diverse in the lakeshore sediment samples. Polymer types of microplastics were mainly polyethylene (PE) and polypropylene (PP) as identified using Raman Spectroscopy. Spatially, microplastic abundance was the highest in the central part of the lake, likely due to the transport of lake current. Based on the higher abundance of microplastics near the tourist access points, plastic wastes from tourism are considered as an important source of microplastics in Qinghai Lake. As an important area for wildlife conservation, better waste management practice should be implemented, and waste disposal and recycling infrastructures should be improved for the protection of Qinghai Lake. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Hydrological and solute budgets of Lake Qinghai, the largest lake on the Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Zhangdong [Chinese Academy of Sciences (CAS), Beijing (China); National Cheng Kung Univ., Tainan City (Taiwan); You, Chen-Feng [National Cheng Kung Univ., Tainan City (Taiwan); Wang, Yi [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shi, Yuewei [Bureau of Hydrology and Water Resources of Qinghai Province, Xining (China)

    2009-12-04

    Water level and chemistry of Lake Qinghai are sensitive to climate changes and are important for paleoclimatic implications. An accurate understanding of hydrological and chemical budgets is crucial for quantifying geochemical proxies and carbon cycle. Published results of water budget are firstly reviewed in this paper. Chemical budget and residence time of major dissolved constituents in the lake are estimated using reliable water budget and newly obtained data for seasonal water chemistry. The results indicate that carbonate weathering is the most important riverine process, resulting in dominance of Ca 2+ and DIC for river waters and groundwater. Groundwater contribution to major dissolved constituents is relatively small (4.2 ± 0.5%). Wet atmospheric deposition contributes annually 7.4–44.0% soluble flux to the lake, resulting from eolian dust throughout the seasons. Estimates of chemical budget further suggest that (1) the Buha-type water dominates the chemical components of the lake water, (2) Na+, Cl-, Mg 2+ , and K+ in lake water are enriched owing to their conservative behaviors, and (3) precipitation of authigenic carbonates (low-Mg calcite, aragonite, and dolomite) transits quickly dissolved Ca 2+ into the bottom sediments of the lake, resulting in very low Ca 2+ in the lake water. Therefore, authigenic carbonates in the sediments hold potential information on the relative contribution of different solute inputs to the lake and the lake chemistry in the past.

  5. L-Lake zooplankton: L-Lake/Steel Creek Biological Monitoring Program, November 1985--December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, J.A. [Westinghouse Savannah River Co., Aiken, SC (United States); Bowen, M. [Normandeau Associates, Inc., New Ellenton, SC (United States)

    1992-03-01

    The L- Lake Biological Monitoring Program was designed to meet environmental regulatory requirements associated with the restart of L-Reactor and address portions of Section 316(a) of the Clean Water Act, which requires an applicant for a discharge permit to provide scientific evidence that the discharge causes no significant impact on the indigenous ecosystem. The Department of Energy (DOE) must demonstrate that the discharge of L-Reactor affluent into L Lake will not inhibit the eventual establishment of a ``Balanced Biological Community`` (BBC) in at least 50% of the lake. This report details results of monitoring zooplankton populations in L-Lake.

  6. L-Lake zooplankton: L-Lake/Steel Creek Biological Monitoring Program, November 1985--December 1991

    International Nuclear Information System (INIS)

    Bowers, J.A.; Bowen, M.

    1992-03-01

    The L- Lake Biological Monitoring Program was designed to meet environmental regulatory requirements associated with the restart of L-Reactor and address portions of Section 316(a) of the Clean Water Act, which requires an applicant for a discharge permit to provide scientific evidence that the discharge causes no significant impact on the indigenous ecosystem. The Department of Energy (DOE) must demonstrate that the discharge of L-Reactor affluent into L Lake will not inhibit the eventual establishment of a ''Balanced Biological Community'' (BBC) in at least 50% of the lake. This report details results of monitoring zooplankton populations in L-Lake

  7. Mummy Lake: An unroofed ceremonial structure within a large-scale ritual landscape

    Science.gov (United States)

    Benson, Larry V.; Griffin, Eleanor R.; Stein, J.R.; Friedman, R. A.; Andrae, S. W.

    2014-01-01

    The structure at Mesa Verde National Park known historically as Mummy Lake and more recently as Far View Reservoir is not part of a water collection, impoundment, or redistribution system. We offer an alternative explanation for the function of Mummy Lake. We suggest that it is an unroofed ceremonial structure, and that it serves as an essential component of a Chacoan ritual landscape. A wide constructed avenue articulates Mummy Lake with Far View House and Pipe Shrine House. The avenue continues southward for approximately 6 km where it apparently divides connecting with Spruce Tree House and Sun Temple/Cliff Palace. The avenue has previously been interpreted as an irrigation ditch fed by water impounded at Mummy Lake; however, it conforms in every respect to alignments described as Chacoan roads. Tree-ring dates indicate that the construction of Spruce Tree House and Cliff Palace began about A.D. 1225, roughly coincident with the abandonment of the Far View community. This pattern of periodically relocating the focus of an Anasazi community by retiring existing ritual structures and linking them to newly constructed facilities by means of broad avenues was first documented by Fowler and Stein (1992) in Manuelito Canyon, New Mexico. Periods of intense drought appear to have contributed to the relocation of prehistoric Native Americans from the Far View group to Cliff Palace/Spruce Tree House in the mid-13th century and eventually to the abandonment of all Anasazi communities in southwestern Colorado in the late-13th century.

  8. Accumulation and hazard assessment of mercury to waterbirds at Lake Chapala, Mexico.

    Science.gov (United States)

    Torres, Zaria; Mora, Miguel A; Taylor, Robert J; Alvarez-Bernal, Dioselina; Buelna, Hector R; Hyodo, Ayumi

    2014-06-03

    Lake Chapala is the largest tropical lake in Mexico. The objectives of this study were to determine bioaccumulation of Hg in fish and to evaluate the potential impacts of Hg in the diet of aquatic birds, particularly the American white pelican (AWPE), in Lake Chapala. Hg concentrations in three fish species ranged from 0.021 to 0.568 μg/g wet weight. Mercury in fish was positively and significantly correlated with total fish length (R2=0.44, Pbird feathers were not significantly different between years, among locations, or among species. Hg concentrations in fish from Lake Chapala were within values reported in many parts of the world. The Hg (mean range of 2.75 to 4.54 μg/g dw) and δD (mean range of -62‰ to -11‰) values in bird feathers suggested a wide pattern of exposure for highly migratory AWPE and egrets, although birds with lower δD values in feathers appeared to have greater concentrations of Hg than those with higher δD values. Contaminant exposure in aquatic birds in Chapala during the breeding season should be monitored next to better determine the potential effects of Hg on resident aquatic birds.

  9. Arsenic, Fluoride and Vanadium in surface water (Chasicó Lake, Argentina

    Directory of Open Access Journals (Sweden)

    Maria laura ePuntoriero

    2014-06-01

    Full Text Available Chasicó Lake is the main water body in the southwest of the Chaco-Pampean plain. It shows some differences from the typical Pampean shallow lakes, such as high salinity and high arsenic and fluoride levels. The aim of this paper is to analyze the trace elements [arsenic (As, fluoride (F- and vanadium (V] present in Chasicó Lake. Surface and groundwater were sampled in dry and wet periods, during 2010 and 2011. Fluoride was determined with a selective electrode. As and V were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES. Significant correlation in surface water was only found for As and F- (r=0.978, p<0.01. The As, F- and V concentration values were higher and more widely dispersed in surface water than in groundwater, as a consequence of evaporation. The fact that these elements do not correlate in surface water may also indicates that groundwater would not be the main source of origin of As, F- and V in surface water. The origin of these trace elements is from volcanic glass from Pampean loess. As, F- and V concentration were higher than in national and international guideline levels for the protection of aquatic biota. Hence, this issue is relevant since the silverside (Odontesthes bonariensis is the most important commercial species in Chasicó Lake. This fish is both consumed locally and exported to other South-American countries through commercial and sport fishing.

  10. Stable isotope and hydrogeochemical studies of Beaver Lake and Lake Radok, MacRobertson Land, East Antarctica

    International Nuclear Information System (INIS)

    Wand, U.; Hermichen, W.D.; Hoefling, R.; Muehle, K.

    1987-01-01

    Beaver Lake and Lake Radok, the largest known epishelf and the deepest freshwater lake on the Antarctic continent, respectively, were isotopically (δ 2 H, δ 18 O) and hydrogeochemically studied. Lake Radok is an isothermal and non-stratified, i.e. homogeneous water body, while Beaver Lake is stratified with respect to temperature, salinity and isotopic composition. The results for the latter attest to freshwater (derived from snow and glacier melt) overlying seawater. (author)

  11. Palaeolimnological evidence of vulnerability of Lake Neusiedl (Austria) toward climate related changes since the last "vanished-lake" stage.

    Science.gov (United States)

    Tolotti, Monica; Milan, Manuela; Boscaini, Adriano; Soja, Gerhard; Herzig, Alois

    2013-04-01

    The palaeolimnological reconstruction of secular evolution of Euroepan Lakes with key socio-economical relevance respect to large (climate change) and local scale (land use, tourism) environmental changes, represents one of the objectives of the project EuLakes (European Lakes Under Environmental Stressors, Supporting lake governance to mitigate the impact of climate change, Reg. N. 2CE243P3), launched in 2010 within the Central European Inititiative. The project consortium comprises lakes of different morphology and prevalent human uses, including the meso-eutrophic Lake Neusiedl, the largest Austrian lake (total area 315 km2), and the westernmost shallow (mean depth 1.2 m) steppe lake of the Euro-Asiatic continent. The volume of Lake Neusiedl can potentially change over the years, in relation with changing balance between atmospheric precipitation and lake water evapotranspiration. Changing water budget, together with high lake salinity and turbidity, have important implications over the lake ecosystem. This contribution illustrates results of the multi-proxi palaeolimnological reconstruction of ecologial changes occurred in Lake Neusiedl during the last ca. 140 years, i.e. since the end of the last "vanished-lake" stage (1865-1871). Geochemical and biological proxies anticipate the increase in lake productivity of ca. 10 years (1950s) respect to what reported in the literature. Diatom species composition indicate a biological lake recovery in the late 1980s, and suggest a second increment in lake productivity since the late 1990s, possibly in relation with the progressive increase in the nitrogen input from agriculture. Abundance of diatoms typical of brackish waters indicated no significant long-term change in lake salinity, while variations in species toleranting dessiccation confirm the vulnerability of Lake Neusiedl toward climate-driven changes in the lake water balance. This fragility is aggravated by the the semi-arid climate conditions of the catchemnt

  12. Investigation of Residence and Travel Times in a Large Floodplain Lake with Complex Lake-River Interactions: Poyang Lake (China

    Directory of Open Access Journals (Sweden)

    Yunliang Li

    2015-04-01

    Full Text Available Most biochemical processes and associated water quality in lakes depends on their flushing abilities. The main objective of this study was to investigate the transport time scale in a large floodplain lake, Poyang Lake (China. A 2D hydrodynamic model (MIKE 21 was combined with dye tracer simulations to determine residence and travel times of the lake for various water level variation periods. The results indicate that Poyang Lake exhibits strong but spatially heterogeneous residence times that vary with its highly seasonal water level dynamics. Generally, the average residence times are less than 10 days along the lake’s main flow channels due to the prevailing northward flow pattern; whereas approximately 30 days were estimated during high water level conditions in the summer. The local topographically controlled flow patterns substantially increase the residence time in some bays with high spatial values of six months to one year during all water level variation periods. Depending on changes in the water level regime, the travel times from the pollution sources to the lake outlet during the high and falling water level periods (up to 32 days are four times greater than those under the rising and low water level periods (approximately seven days.

  13. Estimation of lake water - groundwater interactions in meromictic mining lakes by modelling isotope signatures of lake water.

    Science.gov (United States)

    Seebach, Anne; Dietz, Severine; Lessmann, Dieter; Knoeller, Kay

    2008-03-01

    A method is presented to assess lake water-groundwater interactions by modelling isotope signatures of lake water using meteorological parameters and field data. The modelling of delta(18)O and deltaD variations offers information about the groundwater influx into a meromictic Lusatian mining lake. Therefore, a water balance model is combined with an isotope water balance model to estimate analogies between simulated and measured isotope signatures within the lake water body. The model is operated with different evaporation rates to predict delta(18)O and deltaD values in a lake that is only controlled by weather conditions with neither groundwater inflow nor outflow. Comparisons between modelled and measured isotope values show whether the lake is fed by the groundwater or not. Furthermore, our investigations show that an adaptation of the Craig and Gordon model [H. Craig, L.I. Gordon. Deuterium and oxygen-18 variations in the ocean and the marine atmosphere. In Stable Isotopes in Oceanographic Studies and Paleotemperature, Spoleto, E. Tongiorgi (Ed.), pp. 9-130, Consiglio Nazionale delle Ricerche, Laboratorio di Geologia Nucleare, Pisa (1965).] to specific conditions in temperate regions seems necessary.

  14. Oxygen uptake by excised gills of Procambarus clarkii (Girard) from Albufera Lake of Valencia, Spain, under heavy metal treatments

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Mayans, J.; Torreblanca, A.; Del Ramo, J.; Nunez, A.

    1986-06-01

    The American red crayfish Procambarus clarkii, originally from Louisiana (USA) was introduced in Spain in the 70's in the Guadalquivir River swamps. It appeared first randomly and in a more regular basis afterwards since 1978 in the Albufera Lake south of Valencia and in the surrounding rice fields. Albufera lake and surrounding rice fields waters are being subject since the last three decades to very heavy load of sewage, toxic industrial residues including heavy metals and pesticides from the many urban and industrial settlements in the zone. In the present study, the authors have investigated the effect that heavy metals (Chromium, Cadmium and Mercury) have on the oxygen uptake by excised bills of Procambarus clarkii (Girard) coming from the Albufera Lake (Valencia).

  15. Predicting the locations of naturally fishless lakes

    Science.gov (United States)

    Schilling, Emily Gaenzle; Loftin, C.S.; Degoosh, K.E.; Huryn, Alexander D.; Webster, K.E.

    2008-01-01

    1. Fish have been introduced into many previously fishless lakes throughout North America over the past 100+ years. It is difficult to determine the historical distribution of fishless lakes, however, because these introductions have not always been well-documented. 2. Due to its glacial history and low human population density, the state of Maine (U.S.A.) may host the greatest number of naturally fishless lakes in the northeastern United States. However, less than one-quarter of Maine's 6000+ lakes have been surveyed for fish presence, and no accurate assessments of either the historical or current abundance and distribution of fishless lakes exist. 3. We developed methods to assess the abundance and distribution of Maine's naturally fishless lakes (0.6-10.1 ha). We hypothesized that the historical distribution of fishless lakes across a landscape is controlled by geomorphic and geographic conditions. 4. We used ArcGIS to identify landscape-scale geomorphic and geographic factors (e.g. connectivity, surrounding slope) correlated with fish absence in two geomorphic regions of Maine - the western and interior mountains and the eastern lowlands and foothills. By using readily available geographic information systems data our method was not limited to field-visited sites. We estimated the likelihood that a particular lake is fishless with a stepwise logistic regression model developed for each region. 5. The absence of fish from western lakes is related to altitude (+), minimum percent slope in the 500 m buffer (+), maximum percent slope in the 500 m buffer (+) and percent cover of herbaceous-emergent wetland in 1000 m buffer (-). The absence of fish from eastern lakes is related to the lack of a stream within 50 m of the lake. 6. The models predict that a total of 4% (131) of study lakes in the two regions were historically fishless, with the eastern region hosting a greater proportion than the western region. 7. We verified the model predictions with two

  16. VT Lake Champlain (extracted from VHDCARTO) - polygon

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) LKCH5K is an extract of Lake Champlain that is derived from VHDCARTO. The following metadata is from VHDCARTO.VHDCARTO is a simplified version of...

  17. DNR 100K Lakes and Rivers

    Data.gov (United States)

    Minnesota Department of Natural Resources — Polygons representing hydrographic features (lakes, ponds, some rivers, and open water areas) originating from the USGS 1:100,000 (100K)DLG (Digital Line Graph)...

  18. Lake Naivasha Sustainability : Ecosystem Improvement for Health ...

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

    Lake Naivasha Sustainability : Ecosystem Improvement for Health and ... The overall goal is to make recommendations for the sustainable management of natural ... to improve livestock vaccine development and production to benefit farmers ...

  19. Targets set to reduce Lake Erie algae

    Science.gov (United States)

    Evans, Mary

    2016-01-01

    In February 2016, the Great Lakes Executive Committee, which oversees the implementation of the Great Lakes Water Quality Agreement (GLWQA) between the U.S. and Canada, approved phosphorus loading targets for Lake Erie to reduce the size of harmful algal blooms (HABs), reduce the presence of the low oxygen zone in the central basin, and protect nearshore water quality. The targets are set with respect to the nutrient loads calculated for 2008. To reduce the impacts of HABs on Lake Erie a target was set of a 40 percent reduction in total and soluble reactive phosphorus loads in the spring from two Canadian rivers and several Michigan and Ohio rivers, especially the Maumee River (https://binational.net/2016/02/22/ finalptargets-ciblesfinalesdep/). States and the province of Ontario are already developing Domestic Action Plans to accomplish the reductions and scientists are developing research and monitoring plans to assess progress.

  20. Pulpwood Production in the Lake States

    Science.gov (United States)

    James E. Blyth; Jerold T. Hahn

    1977-01-01

    This 31st annual report shows 1976 pulpwood production by county and species group in Michigan, Minnesota, and Wisconsin. Production in these three Lake States climbed to 4.7 million cords from 4.1 million cords in 1975

  1. Lake Beach Monitoring Locations in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Monitored state lake beach locations in Iowa. The Watershed Monitoring & Assessment Section of the Iowa DNR takes regular water samples at these listed beaches...

  2. Great Lakes CoastWatch Node

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CoastWatch is a nationwide National Oceanic and Atmospheric Administration (NOAA) program within which the Great Lakes Environmental Research Laboratory (GLERL)...

  3. Biota - 2009 Vegetation Inventory - Lake Ashtabula, ND

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — 2009 Vegetation Classification for Lake Ashtabula, ND Vegetation Project Report, OMBIL Environmental Stewardship - Level 1 Inventory, U.S. Army Corps of Engineers...

  4. Network Skewness Measures Resilience in Lake Ecosystems

    Science.gov (United States)

    Langdon, P. G.; Wang, R.; Dearing, J.; Zhang, E.; Doncaster, P.; Yang, X.; Yang, H.; Dong, X.; Hu, Z.; Xu, M.; Yanjie, Z.; Shen, J.

    2017-12-01

    Changes in ecosystem resilience defy straightforward quantification from biodiversity metrics, which ignore influences of community structure. Naturally self-organized network structures show positive skewness in the distribution of node connections. Here we test for skewness reduction in lake diatom communities facing anthropogenic stressors, across a network of 273 lakes in China containing 452 diatom species. Species connections show positively skewed distributions in little-impacted lakes, switching to negative skewness in lakes associated with human settlement, surrounding land-use change, and higher phosphorus concentration. Dated sediment cores reveal a down-shifting of network skewness as human impacts intensify, and reversal with recovery from disturbance. The appearance and degree of negative skew presents a new diagnostic for quantifying system resilience and impacts from exogenous forcing on ecosystem communities.

  5. Niskey Lake Middle School. Atlanta, Georgia

    Science.gov (United States)

    Stevens, Preston, Jr.

    1976-01-01

    The proposed Niskey Lake Middle School is designed to have solar heating in half of the building, solar water heating for the entire facility, and solar cooling for the administration area. (Author/MLF)

  6. Lake Bathymetric DEM Shaded Relief Image

    Data.gov (United States)

    Minnesota Department of Natural Resources — Geo-referenced, shaded relief image of lake bathymetry classified at 5-foot depth intervals. This dataset has a cell resolution of 5 meters (occasionally 10m) as...

  7. The Neogene lakes on the Balkan land

    Directory of Open Access Journals (Sweden)

    Krstić Nadežda

    2012-01-01

    Full Text Available Palaeogeographic maps of the lacustrine Miocene and Pliocene have been constructed according to all the known geological data. The Lakes of the Balkan Land, depending on the tectonics, migrated due to causes from the deep subsurface. There are several phases of the Miocene lakes: the lowermost Miocene transiting from marine Oligocene, Lower, Middle, Upper Miocene covering, in patches, the main part of the Land. The Pliocene lakes spread mostly to the north of the Balkan Land and covered only its marginal parts. Other lake-like sediments, in fact freshened parts of the Black Sea Kuialnician (Upper Pliocene, stretched along the middle and southern portions of the Balkan Peninsula (to the south of the Balkan Mt.. Subsequently, the Balkan Peninsula was formed.

  8. Sulphate deposition by precipitation into Lake Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, R W; Whelpdale, D M

    1973-01-01

    Measurements of sulphate concentration in precipitation from individual snow storms of several hours duration in the western Lake Ontario region indicate that approximately 9-66 mg/M/sub 2/ of SO/sub 4//sup 2 -/ is being deposited into the lake per storm. This amount is up to several times more than daily average values over long periods found by other workers. Using a mean sulphate concentration of 4 mg/l and an annual accumulation of precipitation of 760 mm, the yearly sulphate deposition by precipitation is about 0.1% of the total mass of sulphate in the lake; however, more significantly, it is of the same order of magnitude as that discharged directly into the lake by industry.

  9. Anthropopression markers in lake bottom sediments

    Science.gov (United States)

    Nadolna, Anna; Nowicka, Barbara

    2014-05-01

    Lakes are vulnerable to various types of anthropogenic disturbances. Responses of lake ecosystems to environmental stressors are varied and depend not only on the type of a factor but also on the lake natural resistance to degradation. Within the EULAKES project an evaluation of anthropogenic stress extent in a flow-through, postglacial, ribbon lake (Lake Charzykowskie) was carried out. It was assumed, that this impact manifests unevenly, depending on a type and degree of the pressure on the shore zones, water quality of tributaries, lake basin shape and dynamics of a water movement. It was stated, that anthropogenic markers are substances accumulated in bottom sediments as a result of allochthonous substances inflow from the catchment and atmosphere. Along the selected transects 105 samples from the top layer of sediments (about 20 cm) was collected representing the contemporary accumulation (about 15 years). The content of selected chemical elements and compounds was examined, including nutrients (TN and TP), heavy metals (arsenic, cadmium, lead, chromium, nickel, copper, zinc, mercury, iron, and manganese) and pesticides (DDT, DDD, DDE, DMDT , γ-HCH). The research was conducted in the deepest points of each lake basin and along the research transects - while choosing the spots, the increased intensity of anthropogenic impact (ports, roads with heavy traffic, wastewater discharge zones, built-up areas) was taken into consideration. The river outlets to the lake, where there are ecotonal zones between limnic and fluvial environment, were also taken into account. Analysis of the markers distribution was carried out against the diversity of chemical characteristics of limnic sediments. Ribbon shape of the lake basin and the dominant wind direction provide an opportunity of easy water mixing to a considerable depth. Intensive waving processes cause removal of the matter from the littoral zone towards lake hollows (separated by the underwater tresholds), where the

  10. Lake Ontario benthic prey fish assessment, 2015

    Science.gov (United States)

    Weidel, Brian C.; Walsh, Maureen; Holden, Jeremy P.; Connerton, Michael J.

    2016-01-01

    Benthic prey fishes are a critical component of the Lake Ontario food web, serving as energy vectors from benthic invertebrates to native and introduced piscivores. Since the late 1970’s, Lake Ontario benthic prey fish status was primarily assessed using bottom trawl observations confined to the lake’s south shore, in waters from 8 – 150 m (26 – 492 ft). In 2015, the Benthic Prey Fish Survey was cooperatively adjusted and expanded to address resource management information needs including lake-wide benthic prey fish population dynamics. Effort increased from 55 bottom trawl sites to 135 trawl sites collected in depths from 8 - 225m (26 – 738 ft). The spatial coverage of sampling was also expanded and occurred in all major lake basins. The resulting distribution of tow depths more closely matched the available lake depth distribution. The additional effort illustrated how previous surveys were underestimating lake-wide Deepwater Sculpin, Myoxocephalus thompsonii, abundance by not sampling in areas of highest density. We also found species richness was greater in the new sampling sites relative to the historic sites with 11 new fish species caught in the new sites including juvenile Round Whitefish, Prosopium cylindraceum, and Mottled sculpin, Cottus bairdii. Species-specific assessments found Slimy Sculpin, Cottus cognatus abundance increased slightly in 2015 relative to 2014, while Deepwater Sculpin and Round Goby, Neogobius melanostomus, dramatically increased in 2015, relative to 2014. The cooperative, lake-wide Benthic Prey Fish Survey expanded our understanding of benthic fish population dynamics and habitat use in Lake Ontario. This survey’s data and interpretations influence international resource management decision making, such as informing the Deepwater Sculpin conservation status and assessing the balance between sport fish consumption and prey fish populations. Additionally a significant Lake Ontario event occurred in May 2015 when a single

  11. [Ecosystem services valuation of Qinghai Lake].

    Science.gov (United States)

    Jiang, Bo; Zhang, Lu; Ouyang, Zhi-yun

    2015-10-01

    Qinghai Lake is the largest inland and salt water lake in China, and provides important ecosystem services to beneficiaries. Economic valuation of wetland ecosystem services from Qinghai Lake can reveal the direct contribution of lake ecosystems to beneficiaries using economic data, which can advance the incorporation of wetland protection of Qinghai Lake into economic tradeoffs and decision analyses. In this paper, we established a final ecosystem services valuation system based on the underlying ecological mechanisms and regional socio-economic conditions. We then evaluated the eco-economic value provided by the wetlands at Qinghai Lake to beneficiaries in 2012 using the market value method, replacement cost method, zonal travel cost method, and contingent valuation method. According to the valuation result, the total economic values of the final ecosystem services provided by the wetlands at Qinghai Lake were estimated to be 6749.08 x 10(8) yuan RMB in 2012, among which the value of water storage service and climate regulation service were 4797.57 x 10(8) and 1929.34 x 10(8) yuan RMB, accounting for 71.1% and 28.6% of the total value, respectively. The economic value of the 8 final ecosystem services was ranked from greatest to lowest as: water storage service > climate regulation service > recreation and tourism service > non-use value > oxygen release service > raw material production service > carbon sequestration service > food production service. The evaluation result of this paper reflects the substantial value that the wetlands of Qinghai Lake provide to beneficiaries using monetary values, which has the potential to help increase wetland protection awareness among the public and decision-makers, and inform managers about ways to create ecological compensation incentives. The final ecosystem service evaluation system presented in this paper will offer guidance on separating intermediate services and final services, and establishing monitoring programs for

  12. PREDICTED SEDIMENTARY SECTION OF SUBGLACIAL LAKE VOSTOK

    Directory of Open Access Journals (Sweden)

    G. I. Leychenkov

    2012-01-01

    Full Text Available In early February 2012, the drill hole at the Vostok Station encountered theLakeVostokwater. This step is important to study the lake composition including possible microbial life and to model subglacial environments however, the next ambitious target of the Vostok Drilling Project is sampling of bottom sediments, which contain the unique record of ice sheet evolution and environmental changes in centralAntarcticafor millions of years. In this connection, the forecast of sedimentary succession based on existing geophysical data, study of mineral inclusions in the accretion ice cores and tectonic models is important task. Interpretation of Airborne geophysical data suggests thatLakeVostokis the part of spacious rift system, which exists at least from Cretaceous. Reflection and refraction seismic experiments conducted in the southern part ofLakeVostokshow very thin (200–300 m stratified sedimentary cover overlying crystalline basement with velocity of 6.0–6.2 km/s. At present, deposition in southernLakeVostokis absent and similar conditions occurred likely at least last3 m.y. when ice sheet aboveLakeVostokchanged insignificantly. It can be also inferred that from the Late Miocene the rate of deposition inLakeVostokwas extremely low and so the most of sedimentary section is older being possibly of Oligocene to early to middle Miocene age when ice sheet oscillated and deposition was more vigorous. If so, the sampling of upper few meters of this condensed section is very informative in terms of history of Antarctic glaciation. Small thickness of sedimentary cover raises a question about existence of lake (rift depression during preglacial and early glacial times.

  13. Subaquatic moraine amphitheatre in Lake Thun

    OpenAIRE

    Fabbri, Stefano Claudio; Weiss, Benedikt J.; Hübscher, Christian; Horstmeyer, Heinrich; Schmelzbach, Cédric; Büchi, Marius; Herwegh, Marco; Schlunegger, Fritz; Anselmetti, Flavio

    2016-01-01

    The combination of a recently acquired high-resolution multibeam bathymetric dataset with 2D multichannel reflection seismic data from perialpine Lake Thun reveals new insights into the evolution of the lake basin upon deglaciation and a so far unknown subaquatic moraine. These new data improve our socomprehension of the landforms associated with the ice-contact zone, the facies architecture of the sub- to proglacial units, the related depositional processes, and thus the retreat mechanisms o...

  14. Noble Gases in Lakes and Ground Waters

    OpenAIRE

    Kipfer, Rolf; Aeschbach-Hertig, Werner; Peeters, Frank; Stute, Marvin

    2002-01-01

    In contrast to most other fields of noble gas geochemistry that mostly regard atmospheric noble gases as 'contamination,' air-derived noble gases make up the far largest and hence most important contribution to the noble gas abundance in meteoric waters, such as lakes and ground waters. Atmospheric noble gases enter the meteoric water cycle by gas partitioning during air / water exchange with the atmosphere. In lakes and oceans noble gases are exchanged with the free atmosphere at the surface...

  15. Heart Disease and African Americans

    Science.gov (United States)

    ... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

  16. [Characterizing chromophoric dissolved organic matter (CDOM) in Lake Honghu, Lake Donghu and Lake Liangzihu using excitation-emission matrices (EEMs) fluorescence and parallel factor analysis (PARAFAC)].

    Science.gov (United States)

    Zhou, Yong-Qiang; Zhang, Yun-Lin; Niu, Cheng; Wang, Ming-Zhu

    2013-12-01

    Little is known about DOM characteristics in medium to large sized lakes located in the middle and lower reaches of Yangtze River, like Lake Honghu, Lake Donghu and Lake Liangzihu. Absorption, fluorescence and composition characteristics of chromophoric dissolved organic matter (CDOM) are presented using the absorption spectroscopy, the excitation-emission ma trices (EEMs) fluorescence and parallel factor analysis (PARAFAC) model based on the data collected in Sep-Oct. 2007 including 15, 9 and 10 samplings in Lake Honghu, Lake Donghu and Lake Liangzihu, respectively. CDOM absorption coefficient at 350 nm a(350) coefficient in Lake Honghu was significantly higher than those in Lake Donghu and Lake Liangzihu (t-test, pCDOM spectral slope in the wavelength range of 280-500 nm (S280-500) and a(350) (R2 =0. 781, p<0. 001). The mean value of S280-500 in Lake Honghu was significantly lower than those in Lake Donghu (t-test, pLake Liangzihu (t-test, p<0. 001). The mean value of spectral slope ratio SR in Lake Honghu was also significantly lower than those in Lake Donghu and Lake Liangzihu (t-test, p<0. 05). Two humic-like (C1, C2) and two protein-like fluorescent components (C3, C4) were identified by PARAFAC model, among which significant positive correlations were found between C1 and C2 (R2 =0. 884, p<0. 001), C3 and C4 (R2 =0. 677, p<0.001), respectively, suggesting that the sources of the two humic-like components as well as the two protein-like components were similar. However, no significant correlation has been found between those 4 fluorescent components and DOC concentration. Th e fluorescenceindices of FI255 (HIX), Fl265, FI310 (BIX) and Fl370 in Lake Donghu were all significantly higher than those in Lake Liangzihu (t-test, p <0.05) and Lake Honghu (t-test, p<0. 01), indicating that the eutrophication status in Lake Donghu was higher than Lake Honghu and Lake Liangzihu.

  17. Survey and assessment of post volcanic activities of a young caldera lake, Lake Cuicocha, Ecuador

    Directory of Open Access Journals (Sweden)

    G. Gunkel

    2009-05-01

    Full Text Available Cuicocha is a young volcano adjacent to the inactive Pleistocene Cotacachi volcano complex, located in the western cordilleras of the Ecuadorian Andes. A series of eruptions with intensive ash emission and collapse of the caldera occurred around 4500–3000 y BP. A crater 3.2 km in diameter and a maximum depth of 450 m was formed. Further eruptions of the volcano occurred 1300 y BP and formed four smaller domes within the caldera. Over the last few hundred years, a caldera lake has developed, with a maximum depth of 148 m. The lake water is characterized by sodium carbonate with elevated concentrations of manganese, calcium and chloride. Nowadays, an emission of gases, mainly CO2, and an input of warm spring water occur in Lake Cuicocha. The zone of high activity is in the western basin of the lake at a depth of 78 m, and continuous gas emissions with sediment resuspension were observed using sonar. In the hypolimnion of the lake, CO2 accumulation occurs up to 0.2% saturation, but the risk of a limnic eruption can be excluded at present. The lake possesses monomictic stratification behaviour, and during overturn an intensive gas exchange with the atmosphere occurs. Investigations concerning the sedimentation processes of the lake suggest only a thin sediment layer of up to 10–20 cm in the deeper lake basin; in the western bay, in the area of gas emissions, the lake bottom is partly depleted of sediment in the form of holes, and no lake colmation exists. Decreases in the lake water level of about 30 cm y−1 indicate a percolation of water into fractures and fissures of the volcano, triggered by a nearby earthquake in 1987.

  18. A Synoptic Climatology of Heavy Rain Events in the Lake Eyre and Lake Frome Catchments

    Directory of Open Access Journals (Sweden)

    Michael John Pook

    2014-11-01

    Full Text Available The rare occasions when Lake Eyre in central, southern Australia fills with water excite great interest and produce major ecological responses. The filling of other smaller lakes such as Lake Frome, have less impact but can contribute important information about the current and past climates of these arid regions. Here, the dominant synoptic systems responsible for heavy rainfall over the catchments of Lake Eyre and Lake Frome since 1950 are identified and compared. Heavy rain events are defined as those where the mean catchment rainfall for 24 hours reaches a prescribed threshold. There were 25 such daily events at Lake Eyre and 28 in the Lake Frome catchment. The combination of a monsoon trough at mean sea level and a geopotential trough in the mid-troposphere was found to be the synoptic system responsible for the majority of the heavy rain events affecting Lake Eyre and one in five of the events at Lake Frome. Complex fronts where subtropical interactions occurred with Southern Ocean fronts also contributed over 20% of the heavy rainfall events in the Frome catchment. Surface troughs without upper air support were found to be associated with 10% or fewer of events in each catchment, indicating that mean sea level pressure analyses alone do not adequately capture the complexity of the heavy rainfall events. At least 80% of the heavy rain events across both catchments occurred when the Southern Oscillation Index (SOI was in its positive phase, and for Lake Frome, the SOI exceeded +10 on 60% of occasions, suggesting that the background atmospheric state in the Pacific Ocean was tilted towards La Niña. Hydrological modeling of the catchments suggests that the 12-month running mean of the soil moisture in a sub-surface layer provides a low frequency filter of the precipitation and matches measured lake levels relatively well.

  19. Contaminant trends in lake trout and walleye from the Laurentian Great Lakes

    Science.gov (United States)

    DeVault, David S.; Hesselberg, Robert J.; Rodgers, Paul W.; Feist, Timothy J.

    1996-01-01

    Trends in PCBs, DDT, and other contaminants have been monitored in Great Lakes lake trout and walleye since the 1970s using composite samples of whole fish. Dramatic declines have been observed in concentrations of PCB, ΣDDT, dieldrin, and oxychlordane, with declines initially following first order loss kinetics. Mean PCB concentrations in Lake Michigan lake trout increased from 13 μg/g in 1972 to 23 μg/g in 1974, then declined to 2.6 μg/g by 1986. Between 1986 and 1992 there was little change in concentration, with 3.5 μg/g observed in 1992. ΣDDT in Lake Michigan trout followed a similar trend, decreasing from 19.2 μg/g in 1970 to 1.1 μg/g in 1986, and 1.2 μg/g in 1992. Similar trends were observed for PCBs and ΣDDT in lake trout from Lakes Superior, Huron and Ontario. Concentrations of both PCB and ΣDDT in Lake Erie walleye declined between 1977 and 1982, after which concentrations were relatively constant through 1990. When originally implemented it was assumed that trends in the mean contaminant concentrations in open-lake fish would serve as cost effective surrogates to trends in the water column. While water column data are still extremely limited it appears that for PCBs in lakes Michigan and Superior, trends in lake trout do reasonably mimic those in the water column over the long term. Hypotheses to explain the trends in contaminant concentrations are briefly reviewed. The original first order loss kinetics used to describe the initial decline do not explain the more recent leveling off of contaminant concentrations. Recent theories have examined the possibilities of multiple contaminant pools. We suggest another hypothesis, that changes in the food web may have resulted in increased bioaccumulation. However, a preliminary exploration of this hypothesis using a change point analysis was inconclusive.

  20. Recruitment variability of alewives in Lake Michigan

    Science.gov (United States)

    Madenjian, C.P.; Hook, T.O.; Rutherford, E.S.; Mason, D.M.; Croley, T.E.; Szalai, E.B.; Bence, J.R.

    2005-01-01

    We used a long-term series of observations on alewife Alosa pseudoharengus abundance that was based on fall bottom-trawl catches to assess the importance of various abiotic and biotic factors on alewife recruitment in Lake Michigan during 1962–2002. We first fit a basic Ricker spawner–recruit model to the lakewide biomass estimates of age-3 recruits and the corresponding spawning stock size; we then fit models for all possible combinations of the following four external variables added to the basic model: an index of salmonine predation on an alewife year-class, an index for the spring–summer water temperatures experienced by alewives during their first year in the lake, an index of the severity of the first winter experienced by alewives in the lake, and an index of lake productivity during an alewife year-class's second year in the lake. Based on an information criterion, the best model for alewife recruitment included indices of salmonine predation and spring–summer water temperatures as external variables. Our analysis corroborated the contention that a decline in alewife abundance during the 1970s and early 1980s in Lake Michigan was driven by salmonine predation. Furthermore, our findings indicated that the extraordinarily warm water temperatures during the spring and summer of 1998 probably led to a moderately high recruitment of age-3 alewives in 2001, despite abundant salmonines.

  1. Wapan Sakahikan : the making of a lake

    Energy Technology Data Exchange (ETDEWEB)

    Jaremko, D.

    2009-08-15

    This article discussed an ecosystem project built on reclaimed oil sands lands. The oil sands mine originally required the removal of sections of the Tar and Calumet rivers, tributaries of the Athabasca River. A 76.7 hectare lake was constructed in order to salvage over 100,000 fish. The reclamation included the development of a traditional gathering area for local First Nations and Metis. The lake included a variety of fish habitats and was supported by 5 years of monitoring. The lake will be home to 8 fish species and is 23 meters in depth with shallow areas of 5 meters. Biologists helped to build the habitats, which include deep channels with varying depth and widths; shoals; overhead vegetation; and a rearing habitat area. The lake's littoral zone is approximately 30 per cent of the lake's total area. The involvement of First Nations and Metis included a traditional ceremony on the empty lake bottom. 1 fig.

  2. Plutonium and americium in Lake Michigan sediments

    International Nuclear Information System (INIS)

    Edgington, D.N.; Alberts, J.J.; Wahlgren, M.A.; Karttunen, J.O.; Reeve, C.A.

    1975-01-01

    The vertical distributions of 239 , 240 Pu, 238 Pu, and 137 Cs have been measured in sediment cores taken from Lake Michigan. Sections from a limited number of cores have been analyzed for 241 Am. In addition, grab samples from ten locations in the southern basin of the lake have been analyzed for phase distribution of 239 , 240 Pu using a sequential extraction technique. The results indicate that the 239 , 240 Pu, 238 Pu, and 137 Cs from weapons testing, and the 241 Am formed in situ are concentrated in the sediments. A comparison of the total deposition of 239 , 240 Pu and 137 Cs indicates that 137 Cs may be valuable as a monitor for 239 , 240 Pu deposition in the sediments. Values of the 238 Pu/ 239 , 240 Pu ratio are in agreement with values reported in Lake Ontario sediments (and Lake Michigan plankton) and show little variation with depth. 241 Am data support the concept of in situ production with little preferential mobility after formation. Studies of sedimentary phase distributions show that 239 , 240 Pu is associated with hydrous oxide phases which are chemically stable under the prevailing conditions in lake sediments. Since Lake Michigan sediments remain aerobic, relatively little 239 , 240 Pu is available for chemical mobilization from the hydrous oxide or organic phases present in the sediments

  3. [Imperial Oil's Cold Lake oil sands operations

    International Nuclear Information System (INIS)

    Dingle, H. B.

    1999-01-01

    Imperial Oil Limited's Cold Lake oil sands resources, production and operations in Alberta are discussed. Cold Lake is the company's largest single asset and its largest source of crude oil production. In 1998, Cold Lake accounted for just under half of Imperial's total liquid production, averaging more than 135,000 barrels of bitumen a day. Despite the very difficult operating conditions experienced by the oil sands industry in 1998, Imperial Oil's Cold Lake operations generated a positive cash flow and earnings. Just as important, the near and long-term potential of Cold Lake property continues to be strong, even with the tough market conditions today and the foreseeable future. Proved reserves at the end of 1997 were 1.3 billions barrels, equal to about 24 years of current production, but even more important is Imperial's resource base in the Athabasca region, which represents 150 years of production at current rates. Although production forecasts for the near future are are revised downward because of production shut-in due to low prices, the company is confident of its long-term prospects mainly because of existing infrastructure, superior reservoir quality, 30 years worth of operating improvements and established bitumen-blend markets. Details of the company's future Cold Lake development plans are discussed. The need to continue technology development, which has been at the core of the industry's growth in the past and will continue to be the key to the future, are emphasized

  4. Solar and atmospheric forcing on mountain lakes.

    Science.gov (United States)

    Luoto, Tomi P; Nevalainen, Liisa

    2016-10-01

    We investigated the influence of long-term external forcing on aquatic communities in Alpine lakes. Fossil microcrustacean (Cladocera) and macrobenthos (Chironomidae) community variability in four Austrian high-altitude lakes, determined as ultra-sensitive to climate change, were compared against records of air temperature, North Atlantic Oscillation (NAO) and solar forcing over the past ~400years. Summer temperature variability affected both aquatic invertebrate groups in all study sites. The influence of NAO and solar forcing on aquatic invertebrates was also significant in the lakes except in the less transparent lake known to have remained uniformly cold during the past centuries due to summertime snowmelt input. The results suggest that external forcing plays an important role in these pristine ecosystems through their impacts on limnology of the lakes. Not only does the air temperature variability influence the communities but also larger-scale external factors related to atmospheric circulation patterns and solar activity cause long-term changes in high-altitude aquatic ecosystems, through their connections to hydroclimatic conditions and light environment. These findings are important in the assessment of climate change impacts on aquatic ecosystems and in greater understanding of the consequences of external forcing on lake ontogeny. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Community energy plan : village of Burns Lake

    International Nuclear Information System (INIS)

    Rivard, B.

    2008-09-01

    Climate change has a significant impact on the lives of Canadians and their economies. In northern British Columbia, the ability to grow, process and transport food will likely change. The rising cost of fuel and other natural resources will create a need for more resilient communities. This report presented a community energy plan for Burns Lake in order to provide the first steps toward building on an already resilient community. The report answered questions about Burns Lake's energy consumption and greenhouse gas (GHG) emissions as well as the community's views on energy issues. The report provided background information on the Village of Burns Lake and discussed climate change in Burns Lake, energy use, and greenhouse gas emissions. The report also described community engagement by way of a questionnaire on fuel prices, homes and public opinion in Burns Lake. A strategy was also outlined. It was concluded that the village of Burns Lake is well positioned to face challenges regarding future energy use. The community is looking to the municipality for support and leadership, in order to deliver through active opportunities to reduce greenhouse gas emissions. 6 figs., 4 appendices.

  6. Hulun Lake's ecological health and evaluation of its' eutrophication

    Science.gov (United States)

    Li, W.; Yang, W.; Wang, X.; Huang, J.; Sun, B.; Li, X.

    2013-12-01

    Hulun Lake is the largest lake in the north of china. The special geological location determines its important position in regional environmental protection. In terms of Hulun Lake's current situation, this paper chooses the indexes of lake system, lake structure and lake condition. Based on the calculation of these indexes and related theory , the evaluation standards of Hulun Lake's ecological healthy system are worked out. The author used Analytic Hierarchy Process to determine the weight of each indicator layer and criteria layer, and then applied fuzzy-pattern recognition model to calculate, finally, identifying the status of Hulun Lake according to the degrees of all levels. At the same time, the author used an integrated nutrition state index method to do the eutrophication assessment. Evaluation results show that the current status of Hulun Lake is healthy and it is in the moderate level of eutrophication.

  7. Mirror Lake: Past, present and future: Chapter 6

    Science.gov (United States)

    Likens, Gene E.; LaBaugh, James W.; Winter, Thomas C.; Likens, Gene E.

    2009-01-01

    This chapter discusses the hydrological and biogeochemical characteristics of Mirror Lake and the changes that resulted from air-land-water interactions and human activities. Since the formation of Mirror Lake, both the watershed and the lake have undergone many changes, such as vegetation development and basin filling. These changes are ongoing, and Mirror Lake is continuing along an aging pathway and ultimately, it will fill with sediment and no longer be a lake. The chapter also identifies major factors that affected the hydrology and biogeochemistry of Mirror Lake: acid rain, atmospheric deposition of lead and other heavy metals, increased human settlement around the lake, the construction of an interstate highway through the watershed of the Northeast Tributary, the construction of an access road through the West and Northeast watersheds to the lake, and climate change. The chapter also offers future recommendations for management and protection of Mirror Lake.

  8. Lake Granbury and Lake Whitney Assessment Initiative Final Scientific/Technical Report Summary

    Energy Technology Data Exchange (ETDEWEB)

    Harris, B. L. [Texas AgriLife Research, College Station, TX (United States); Roelke, Daniel [Texas AgriLife Research, College Station, TX (United States); Brooks, Bryan [Texas AgriLife Research, College Station, TX (United States); Grover, James [Texas AgriLife Research, College Station, TX (United States)

    2010-10-11

    A team of Texas AgriLife Research, Baylor University and University of Texas at Arlington researchers studied the biology and ecology of Prymnesium parvum (golden algae) in Texas lakes using a three-fold approach that involved system-wide monitoring, experimentation at the microcosm and mesocosm scales, and mathematical modeling. The following are conclusions, to date, regarding this organism's ecology and potential strategies for mitigation of blooms by this organism. In-lake monitoring revealed that golden algae are present throughout the year, even in lakes where blooms do not occur. Compilation of our field monitoring data with data collected by Texas Parks and Wildlife and Brazos River Authority (a period spanning a decade) revealed that inflow and salinity variables affect bloom formations. Thresholds for algae populations vary per lake, likely due to adaptations to local conditions, and also to variations in lake-basin morphometry, especially the presence of coves that may serve as hydraulic storage zones for P. parvum populations. More specifically, our in-lake monitoring showed that the highly toxic bloom that occurred in Lake Granbury in the winter of 2006/2007 was eliminated by increased river inflow events. The bloom was flushed from the system. The lower salinities that resulted contributed to golden algae not blooming in the following years. However, flushing is not an absolute requirement for bloom termination. Laboratory experiments have shown that growth of golden algae can occur at salinities ~1-2 psu but only when temperatures are also low. This helps to explain why blooms are possible during winter months in Texas lakes. Our in-lake experiments in Lake Whitney and Lake Waco, as well as our laboratory experiments, revealed that cyanobacteria, or some other bacteria capable of producing algicides, were able to prevent golden algae from blooming. Identification of this organism is a high priority as it may be a key to managing golden algae

  9. Many Drops Make a Lake

    Directory of Open Access Journals (Sweden)

    Chaitanya S. Mudgal

    2014-03-01

    greater knowledge, better skills and disseminate this knowledge through this journal to influence as many physicians and their patients as possible. They have taken the knowledge of their teachers, recognized their giants and are now poised to see further than ever before. My grandmother often used to quote to me a proverb from India, which when translated literally means “Many drops make a lake”. I cannot help but be amazed by the striking similarities between the words of Newton and this Indian saying. Therefore, while it may seem intuitive, I think it must be stated that it is vital for the betterment of all our patients that we recognize our own personal lakes to put our drops of knowledge into. More important is that we recognize that it is incumbent upon each and every one of us to contribute to our collective lakes of knowledge such as ABJS. And finally and perhaps most importantly we need to be utterly cognizant of never letting such lakes of knowledge run dry.... ever.

  10. Basic limnology of fifty-one lakes in Costa Rica.

    Science.gov (United States)

    Haberyan, Kurt A; Horn, Sally P; Umaña, Gerardo

    2003-03-01

    We visited 51 lakes in Costa Rica as part of a broad-based survey to document their physical and chemical characteristics and how these relate to the mode of formation and geographical distribution of the lakes. The four oxbow lakes were low in elevation and tended to be turbid, high in conductivity and CO2, but low in dissolved O2; one of these, L. Gandoca, had a hypolimnion essentially composed of sea water. These were similar to the four wetland lakes, but the latter instead had low conductivities and pH, and turbidity was often due to tannins rather than suspended sediments. The thirteen artificial lakes formed a very heterogenous group, whose features varied depending on local factors. The thirteen lakes dammed by landslides, lava flows, or lahars occurred in areas with steep slopes, and were more likely to be stratified than most other types of lakes. The eight lakes that occupy volcanic craters tended to be deep, stratified, clear, and cool; two of these, L. Hule and L. Río Cuarto, appeared to be oligomictic (tending toward meromictic). The nine glacial lakes, all located above 3440 m elevation near Cerro Chirripó, were clear, cold, dilute, and are probably polymictic. Cluster analysis resulted in three significant groups of lakes. Cluster 1 included four calcium-rich lakes (average 48 mg l-1), Cluster 2 included fourteen lakes with more Si than Ca+2 and higher Cl- than the other clusters, and Cluster 3 included the remaining thirty-three lakes that were generally less concentrated. Each cluster included lakes of various origins located in different geographical regions; these data indicate that, apart from the high-altitude glacial lakes and lakes in the Miravalles area, similarity in lake chemistry is independent of lake distribution.

  11. Are all temperate lakes eutrophying in a warmer world?

    Science.gov (United States)

    Paltsev, A.; Creed, I. F.

    2017-12-01

    Freshwater lakes are at risk of eutrophication due to climate change and intensification of human activities on the planet. In relatively undisturbed areas of the temperate forest biome, lakes are "sentinels" of the effects of rising temperatures. We hypothesise that rising temperatures are driving a shift from nutrient-poor oligotrophic states to nutrient-rich eutrophic states. To test this hypothesis, we examined a time series of satellite based chlorophyll-a (a proxy of algal biomass) of 12,000+ lakes over 30 years in the Canadian portion of the Laurentian Great Lakes basin. From the time series, non-stationary trends (detected by Mann-Kendall analysis) and stationary cycles (revealed through Morlet wavelet analysis) were removed, and the standard deviation (SD) of the remaining residuals was used as an indicator of lake stability. Four classes of lake stability were identified: (1) stable (SD is consistently low); (2) destabilizing (SD increases over time); (3) unstable (SD is consistently high); and (4) stabilizing lakes (SD decreases over time). Stable lakes were either oligotrophic or eutrophic indicating the presence of two stable states in the region. Destabilizing lakes were shifting from oligotrophic to lakes with a higher trophic status (indicating eutrophication), unstable lakes were mostly mesotrophic, and stabilizing lakes were shifting from eutrophic to the lakes with lower trophic status (indicating oligotrophication). In contrast to common expectations, while many lakes (2142) were shifting from oligotrophic to eutrophic states, more lakes (3199) were showing the opposite trend and shifting from eutrophic to oligotrophic states. This finding reveals a complexity of lake responses to rising temperatures and the need to improve understanding of why some lakes shift while others do not. Future work is focused on exploring the interactive effects of global, regional, and local drivers of lake trophic states.

  12. Lake whitefish and Diporeia spp. in the Great lakes: an overview

    Science.gov (United States)

    Nalepa, Thomas F.; Mohr, Lloyd C.; Henderson, Bryan A.; Madenjian, Charles P.; Schneeberger, Philip J.

    2005-01-01

    Because of growing concern in the Great Lakes over declines in abundance and growth of lake whitefish (Coregonus clupeaformis) and declines in abundance of the benthic amphipod Diporeia spp., a workshop was held to examine past and current trends, to explore trophic links, and to discuss the latest research results and needs. The workshop was divided into sessions on the status of populations in each of the lakes, bioenergetics and trophic dynamics, and exploitation and management. Abundance, growth, and condition of whitefish populations in Lakes Superior and Erie are stable and within the range of historical means, but these variables are declining in Lakes Michigan and Ontario and parts of Lake Huron. The loss of Diporeia spp., a major food item of whitefish, has been a factor in observed declines, particularly in Lake Ontario, but density-dependent factors also likely played a role in Lakes Michigan and Huron. The loss of Diporeia spp. is temporally linked to the introduction and proliferation of dreissenid mussels, but a direct cause for the negative response of Diporeia spp. has not been established. Given changes in whitefish populations, age-structured models need to be re-evaluated. Other whitefish research needs to include a better understanding of what environmental conditions lead to strong year-classes, improved aging techniques, and better information on individual population (stock) structure. Further collaborations between assessment biologists and researchers studying the lower food web would enhance an understanding of links between trophic levels.

  13. Development and evaluation of the Lake Multi-biotic Integrity Index for Dongting Lake, China

    Directory of Open Access Journals (Sweden)

    Xing Wang

    2015-06-01

    Full Text Available A Lake Multi-biotic Integrity Index (LMII for the China’s second largest interior lake (Dongting Lake was developed to assess the water quality status using algal and macroinvertebrate metrics. Algae and benthic macroinvertebrate assemblages were sampled at 10 sections across 3 subregions of Dongting Lake. We used a stepwise process to evaluate properties of candidate metrics and selected ten for the LMII: Pampean diatom index, diatom quotient, trophic diatom index, relative abundance diatoms, Margalef index of algae, percent sensitive diatoms, % facultative individuals, % Chironomidae individuals, % predators individuals, and total number of macroinvertebrate taxa. We then tested the accuracy and feasibility of the LMII by comparing the correlation with physical-chemical parameters. Evaluation of the LMII showed that it discriminated well between reference and impaired sections and was strongly related to the major chemical and physical stressors (r = 0.766, P<0.001. The re-scored results from the 10 sections showed that the water quality of western Dongting Lake was good, while that of southern Dongting Lake was relatively good and whereas that of eastern Dongting Lake was poor. The discriminatory biocriteria of the LMII are suitable for the assessment of the water quality of Dongting Lake. Additionally, more metrics belonging to habitat, hydrology, physics and chemistry should be considered into the LMII, so as to establish comprehensive assessment system which can reflect the community structure of aquatic organisms, physical and chemical characteristics of water environment, human activities, and so on.

  14. Early steroid sulfurisation in surface sediments of a permanebtly stratified lake (Ace Lake, Antarctica)

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Rijpstra, W.I.C.; Robertson, L.; Volkman, J.K.

    2000-01-01

    Surface sediments (0 25 cm) from Ace Lake (eastern Antarctica), a saline euxinic lake, were analyzed to study the early incorporation of reduced inorganic sulfur species into organic matter. The apolar fractions were shown to consist predominantly of dimeric (poly)sulfide linked C27-C29 steroids.

  15. Anaerobic methane oxidation and aerobic methane production in an east African great lake (Lake Kivu)

    DEFF Research Database (Denmark)

    Roland, Fleur A.E.; Morana, Cédric; Darchambeau, François

    2018-01-01

    We investigated CH4 oxidation in the water column of Lake Kivu, a deep meromictic tropical lake with CH4-rich anoxic deep waters. Depth profiles of dissolved gases (CH4 and N2O) and a diversity of potential electron acceptors for anaerobic CH4 oxidation (NO3 −, SO4 2−, Fe and Mn oxides) were dete...

  16. 77 FR 39638 - Safety Zone; Barbara Harder Wedding Fireworks, Lake Erie, Lake View, NY

    Science.gov (United States)

    2012-07-05

    ... environmental risk to health or risk to safety that may disproportionately affect children. 10. Indian Tribal... be held on Lake Erie near Lake View, NY. The Captain of the Port Buffalo has determined that fireworks launched proximate to a gathering of watercraft pose a significant risk to public safety and...

  17. Long-Term Variability of Satellite Lake Surface Water Temperatures in the Great Lakes

    Science.gov (United States)

    Gierach, M. M.; Matsumoto, K.; Holt, B.; McKinney, P. J.; Tokos, K.

    2014-12-01

    The Great Lakes are the largest group of freshwater lakes on Earth that approximately 37 million people depend upon for fresh drinking water, food, flood and drought mitigation, and natural resources that support industry, jobs, shipping and tourism. Recent reports have stated (e.g., the National Climate Assessment) that climate change can impact and exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of certain fish species, increased invasive species and harmful algal blooms, declining beach health, and lengthened commercial navigation season. In this study, we will examine the impact of climate change on the Laurentian Great Lakes through investigation of long-term lake surface water temperatures (LSWT). We will use the ATSR Reprocessing for Climate: Lake Surface Water Temperature & Ice Cover (ARC-Lake) product over the period 1995-2012 to investigate individual and interlake variability. Specifically, we will quantify the seasonal amplitude of LSWTs, the first and last appearances of the 4°C isotherm (i.e., an important identifier of the seasonal evolution of the lakes denoting winter and summer stratification), and interpret these quantities in the context of global interannual climate variability such as ENSO.

  18. Effects of acidity on primary productivity in lakes: phytoplankton. [Lakes Panther, Sagamore, and Woods

    Energy Technology Data Exchange (ETDEWEB)

    Hendrey, G R

    1979-01-01

    Relationships between phytoplankton communities and lake acidity are being studied at Woods Lake (pH ca. 4.9), Sagamore Lake (pH ca. 5.5), and Panther Lake (pH ca. 7.0). Numbers of phytoplankton species observed as of July 31, 1979 are Woods 27, Sagamore 38, and Panther 64, conforming to other observations that species numbers decrease with increasing acidity. Patterns of increasing biomass and productivity found in Woods Lake may be atypical of similar oligotrophic lakes in that they develop rather slowly instead of occuring very close to ice-out. Contributions of netplankton (net > 48 ..mu..m), nannoplankton (48 > nanno > 20 ..mu..m) and ultraplankton (20 > ultra >0.45 ..mu..m) to productivity per m/sup -2/ show that the smaller plankton are relatively more important in the more acid lakes. This pattern could be determined by nutrient availability (lake acidification leading to decreased availability of phosphorus). The amount of /sup 14/C-labelled dissolved photosynthate (/sup 14/C-DOM), as a percent of total productivity, is ordered Woods > Sagamore > Panther. This is consistent with a hypothesis that microbial heterotrophic activity is reduced with increasing acidity, but the smaller phytoplankton may be more leaky at low pH. (ERB)

  19. Continuous water-quality monitoring to improve lake management at Lake Mattamuskeet National Wildlife Refuge

    Science.gov (United States)

    Michelle Moorman; Tom Augspurger

    2016-01-01

    The U.S. Fish and Wildlife Service has partnered with U.S. Geological Survey to establish 2 continuous water-quality monitoring stations at Lake Mattamuskeet. Stations on the east and west side of the lake measure water level, clarity, dissolved oxygen, pH, temperature, salinity, and conductivity.

  20. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.

    Science.gov (United States)

    Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.; Brown, S.B.

    2009-01-01

    We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

  1. Integrating three lake models into a Phytoplankton Prediction System for Lake Taihu (Taihu PPS) with Python

    NARCIS (Netherlands)

    Huang, J.; Gao, J.; Hörmann, G.; Mooij, W.M.

    2012-01-01

    In the past decade, much work has been done on integrating different lake models using general frameworks to overcome model incompatibilities. However, a framework may not be flexible enough to support applications in different fields. To overcome this problem, we used Python to integrate three lake

  2. Determining lake surface water temperatures worldwide using a tuned one-dimensional lake model (FLake, v1)

    Science.gov (United States)

    Layden, Aisling; MacCallum, Stuart N.; Merchant, Christopher J.

    2016-06-01

    A tuning method for FLake, a one-dimensional (1-D) freshwater lake model, is applied for the individual tuning of 244 globally distributed large lakes using observed lake surface water temperatures (LSWTs) derived from along-track scanning radiometers (ATSRs). The model, which was tuned using only three lake properties (lake depth, snow and ice albedo and light extinction coefficient), substantially improves the measured mean differences in various features of the LSWT annual cycle, including the LSWTs of saline and high altitude lakes, when compared to the observed LSWTs. Lakes whose lake-mean LSWT persists below 1 °C for part of the annual cycle are considered to be seasonally ice-covered. For trial seasonally ice-covered lakes (21 lakes), the daily mean and standard deviation (2σ) of absolute differences between the modelled and observed LSWTs are reduced from 3.07 °C ± 2.25 °C to 0.84 °C ± 0.51 °C by tuning the model. For all other trial lakes (14 non-ice-covered lakes), the improvement is from 3.55 °C ± 3.20 °C to 0.96 °C ± 0.63 °C. The post tuning results for the 35 trial lakes (21 seasonally ice-covered lakes and 14 non-ice-covered lakes) are highly representative of the post-tuning results of the 244 lakes. For the 21 seasonally ice-covered lakes, the modelled response of the summer LSWTs to changes in snow and ice albedo is found to be statistically related to lake depth and latitude, which together explain 0.50 (R2adj, p = 0.001) of the inter-lake variance in summer LSWTs. Lake depth alone explains 0.35 (p = 0.003) of the variance. Lake characteristic information (snow and ice albedo and light extinction coefficient) is not available for many lakes. The approach taken to tune the model, bypasses the need to acquire detailed lake characteristic values. Furthermore, the tuned values for lake depth, snow and ice albedo and light extinction coefficient for the 244 lakes provide some guidance on improving FLake LSWT modelling.

  3. A pharyngeal jaw evolutionary innovation facilitated extinction in Lake Victoria cichlids.

    Science.gov (United States)

    McGee, Matthew D; Borstein, Samuel R; Neches, Russell Y; Buescher, Heinz H; Seehausen, Ole; Wainwright, Peter C

    2015-11-27

    Evolutionary innovations, traits that give species access to previously unoccupied niches, may promote speciation and adaptive radiation. Here, we show that such innovations can also result in competitive inferiority and extinction. We present evidence that the modified pharyngeal jaws of cichlid fishes and several marine fish lineages, a classic example of evolutionary innovation, are not universally beneficial. A large-scale analysis of dietary evolution across marine fish lineages reveals that the innovation compromises access to energy-rich predator niches. We show that this competitive inferiority shaped the adaptive radiation of cichlids in Lake Tanganyika and played a pivotal and previously unrecognized role in the mass extinction of cichlid fishes in Lake Victoria after Nile perch invasion. Copyright © 2015, American Association for the Advancement of Science.

  4. Lake Wobegon’s Guns: Overestimating Our Gun-Related Competences

    Directory of Open Access Journals (Sweden)

    Emily Stark

    2016-02-01

    Full Text Available The Lake Wobegon Effect is a general tendency for people to overestimate their own abilities. In this study, the authors conducted a large, nationally-representative survey of U.S. citizens to test whether Americans overestimate their own gun-relevant personality traits, gun safety knowledge, and ability to use a gun in an emergency. The authors also tested how gun control attitudes, political identification, gender, and gun experience affect self-perceptions. Consistent with prior research on the Lake Wobegon Effect, participants overestimated their gun-related competencies. Conservatives, males, and pro-gun advocates self-enhanced somewhat more than their counterparts but this effect was primarily due to increased gun experience among these participants. These findings are important to policymakers in the area of gun use, because overconfidence in one’s gun-related abilities may lead to a reduced perceived need for gun training.

  5. Assessment of the Great Lakes Marine Renewable Energy Resources: Characterizing Lake Erie Surge, Seiche and Waves

    Science.gov (United States)

    Farhadzadeh, A.; Hashemi, M. R.

    2016-02-01

    Lake Erie, the fourth largest in surface area, smallest in volume and shallowest among the Great Lakes is approximately 400 km long and 90 km wide. Short term lake level variations are due to storm surge generated by high winds and moving pressure systems over the lake mainly in the southwest-northeast direction, along the lakes longitudinal axis. The historical wave data from three active offshore buoys shows that significant wave height can exceed 5 m in the eastern and central basins. The long-term lake level data show that storm surge can reach up to 3 m in eastern Lake Erie. Owing its shallow depth, Lake Erie frequently experiences seiching motions, the low frequency oscillations that are initiated by storm surge. The seiches whose first mode of oscillations has a period of nearly 14.2 hours can last from several hours to days. In this study, the Lake Erie potential for power generation, primarily using storm surge and seiche and also waves are assessed. Given the cyclic lake level variations due to storm-induced seiching, a concept similar to that of tidal range development is utilized to assess the potential of storm surge and seiche energy harvesting mechanisms for power generation. In addition, wave energy resources of the Lake is characterized -. To achieve these objectives, the following steps are taken : (1) Frequency of occurrence for extreme storm surge and wave events is determined using extreme value analysis such as Peak-Over-Threshold method for the long-term water level and wave data; (2) Spatial and temporal variations of wave height, storm surge and seiche are characterized. The characterization is carried out using the wave and storm surge outputs from numerical simulation of a number of historical extreme events. The coupled ADCIRC and SWAN model is utilized for the modeling; (3) Assessment of the potentials for marine renewable power generation in Lake Erie is made. The approach can be extended to the other lakes in the Great Lakes region.

  6. Regional Climate Models as a Tool for Assessing Changes in the Laurentian Great Lakes Net Basin Supply

    Science.gov (United States)

    Music, B.; Mailhot, E.; Nadeau, D.; Irambona, C.; Frigon, A.

    2017-12-01

    Over the last decades, there has been growing concern about the effects of climate change on the Great Lakes water supply. Most of the modelling studies focusing on the Laurentian Great Lakes do not allow two-way exchanges of water and energy between the atmosphere and the underlying surface, and therefore do not account for important feedback mechanisms. Moreover, energy budget constraint at the land surface is not usually taken into account. To address this issue, several recent climate change studies used high resolution Regional Climate Models (RCMs) for evaluating changes in the hydrological regime of the Great Lakes. As RCMs operate on the concept of water and energy conservation, an internal consistency of the simulated energy and water budget components is assured. In this study we explore several recently generated Regional Climate Model (RCM) simulations to investigate the Great Lakes' Net Basin Supply (NBS) in a changing climate. These include simulations of the Canadian Regional Climate Model (CRCM5) supplemented by simulations from several others RCMs participating to the North American CORDEX project (CORDEX-NA). The analysis focuses on the NBS extreme values under nonstationary conditions. The results are expected to provide useful information to the industries in the Great Lakes that all need to include accurate climate change information in their long-term strategy plans to better anticipate impacts of low and/or high water levels.

  7. Mercury and selenium contamination in waterbird eggs and risk to avian reproduction at Great Salt Lake, Utah

    Science.gov (United States)

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, Christopher A.; Isanhart, John P.; Herring, Garth; Vaughn, Sharon; Cavitt, John F.; Eagles-Smith, Collin A.; Browers, Howard; Cline, Chris; Vest, Josh

    2015-01-01

    The wetlands of the Great Salt Lake ecosystem are recognized regionally, nationally, and hemispherically for their importance as breeding, wintering, and migratory habitat for diverse groups of waterbirds. Bear River Migratory Bird Refuge is the largest freshwater component of the Great Salt Lake ecosystem and provides critical breeding habitat for more than 60 bird species. However, the Great Salt Lake ecosystem also has a history of both mercury and selenium contamination, and this pollution could reduce the health and reproductive success of waterbirds. The overall objective of this study was to evaluate the risk of mercury and selenium contamination to birds breeding within Great Salt Lake, especially at Bear River Migratory Bird Refuge, and to identify the waterbird species and areas at greatest risk to contamination. We sampled eggs from 33 species of birds breeding within wetlands of Great Salt Lake during 2010 ̶ 2012 and focused on American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster’s terns (Sterna forsteri), white-faced ibis (Plegadis chihi), and marsh wrens (Cistothorus palustris) for additional studies of the effects of contaminants on reproduction.

  8. The American Dream

    OpenAIRE

    Önnerth, Lars; Neubert, Mikkel; Omerbasic, Dejan; Heyman, Minch; Kimberly, Marie; Nielsen, Lyngbo; Mynte, Anne; Hørlyck Kaastrup, Markus

    2015-01-01

    This study examines the phenomenon that is the American Dream and its effect on the working and upper class citizens in American society. To give context to the American dream and its origin, we have made use of professor Jim Cullen’s book “The American Dream: A Short Story of an Idea that Shaped a Nation” from 2003. We have identified what we decided to call the “the traditional dream” and “the modern dream”, both representing different outlooks on lives and ethical standards. We have done t...

  9. Lake Erie and Lake Michigan zebra mussel settlement monitoring and implications for chlorination treatment

    International Nuclear Information System (INIS)

    Demoss, D.; Mendelsberg, J.I.

    1992-01-01

    This paper reports on the 1991 zebra mussel veliger settlement monitoring program undertaken to record and evaluate zebra mussel veliger settlement in Lake Erie and Lake Michigan. Studies by Dr. Gerald Mackie of Canada in 1990 indicated veliger settlement may be occurring primarily during short time periods every season corresponding with warmer water temperatures. Veliger settlement monitoring was performed using a plexiglass sampler apparatus. The samplers were simple in design and consisted of a 20-inch-square plexiglass base panel with thirty-six 1 inch x 3 inch clear plexiglass microscope slides attached. The results of the monitoring program indicate the existence of preferential settlement periods for veligers correlating with sustained lake water temperatures above 70 degrees F. Veliger settlement concentrations in the south basin of Lake Michigan appear to be similar to those in western Lake Erie

  10. Help-Seeking Experiences and Attitudes among African American, Asian American, and European American College Students

    Science.gov (United States)

    Masuda, Akihiko; Anderson, Page L.; Twohig, Michael P.; Feinstein, Amanda B.; Chou, Ying-Yi; Wendell, Johanna W.; Stormo, Analia R.

    2009-01-01

    The study examined African American, Asian American, and European American college students' previous direct and indirect experiences of seeking professional psychological services and related attitudes. Survey data were collected from 254 European American, 182 African American and 82 Asian American college students. Results revealed that fewer…

  11. Close relationships between asian american and european american college students

    OpenAIRE

    Chen, C; Edwards, K; Young, B; Greenberger, E

    2001-01-01

    The authors examined attitudes and behaviors regarding close relationships between European and Asian Americans, with a particular emphasis on 5 major subgroups of Asian Americans (Chinese, Japanese, Korean, Vietnamese, and Filipino Americans). Participants were 218 Asian American college students and 171 European American college students attending a culturally diverse university. The European Americans did not differentiate among the various subgroups of Asian Americans. Their attitudes reg...

  12. Inventory of montane-nesting birds in Katmai and Lake Clark national parks and preserves

    Science.gov (United States)

    Ruthrauff, Daniel R.; Tibbitts, Lee; Gill, Robert E.; Handel, Colleen M.

    2007-01-01

    As part of the National Park Service’s Inventory and Monitoring Program, biologists from the U. S. Geological Survey’s Alaska Science Center conducted an inventory of birds in montane regions of Katmai and Lake Clark National Parks and Preserves during 2004–2006. We used a stratified random survey design to allocate samples by ecological subsection. To survey for birds, we conducted counts at 468 points across 29, 10-km x 10-km (6.2-mi x 6.2-mi) sample plots in Katmai and 417 points across 25, 10-km x 10-km sample plots in Lake Clark. We detected 92 and 104 species in Katmai and Lake Clark, respectively, including 40 species of conservation concern. We detected three species not previously recorded in Katmai (Ring-necked Duck [Aythya collaris], Lesser Scaup [Aythya affinis], and White-tailed Ptarmigan [Lagopus leucurus]) and two species not previously recorded in Lake Clark (Northern Flicker [Colaptes auratus ] and Olive-sided Flycatcher [Contopus cooperi]). The most commonly detected species in both parks was Golden-crowned Sparrow (Zonotrichia atricapilla); Fox Sparrow (Passerella iliaca) and American Pipit (Anthus rubescens) were abundant and widely-distributed as well. We defined sites as low (100–350 m), middle (351–600 m), or high (601–1,620 m) elevation based on the distribution of vegetation cover, and similarly categorized the 34 most-commonly detected species based on the mean elevation of sample points at which they were detected. High elevation (i.e., alpine) sites were characterized by high percent cover of dwarf shrub and bare ground habitat and supported species like Rock Ptarmigan (L. mutus), American Golden-Plover (Pluvialis dominica), Wandering Tattler (Tringa incana), Surfbird (Aphriza virgata), and Snow Bunting (Plectrophenax nivalis), all species of conservation concern. This inventory represents the first systematic survey of birds nesting in montane regions of both parks. Results from this inventory can form the foundation of

  13. Lake Mead Intake No. 3

    Directory of Open Access Journals (Sweden)

    Jon Hurt

    2017-12-01

    Full Text Available As a result of a sustained drought in the Southwestern United States, and in order to maintain existing water capacity in the Las Vegas Valley, the Southern Nevada Water Authority constructed a new deep-water intake (Intake No. 3 located in Lake Mead. The project included a 185 m deep shaft, 4.7 km tunnel under very difficult geological conditions, and marine works for a submerged intake. This paper presents the experience that was gained during the design and construction and the innovative solutions that were developed to handle the difficult conditions that were encountered during tunneling with a dual-mode slurry tunnel-boring machine (TBM in up to 15 bar (1 bar = 105 Pa pressure. Specific attention is given to the main challenges that were overcome during the TBM excavation, which included the mode of operation, face support pressures, pre-excavation grouting, and maintenance; to the construction of the intake, which involved deep underwater shaft excavation with blasting using shaped charges; to the construction of the innovative over 1200 t concrete-and-steel intake structure; to the placement of the intake structure in the underwater shaft; and to the docking and connection to an intake tunnel excavated by hybrid TBM. Keywords: Sub-aqueous tunneling, Tunnel-boring machine excavation, Water intakes

  14. In-Lake Processes Offset Increased Terrestrial Inputs of Dissolved Organic Carbon and Color to Lakes

    Science.gov (United States)

    Köhler, Stephan J.; Kothawala, Dolly; Futter, Martyn N.; Liungman, Olof; Tranvik, Lars

    2013-01-01

    Increased color in surface waters, or browning, can alter lake ecological function, lake thermal stratification and pose difficulties for drinking water treatment. Mechanisms suggested to cause browning include increased dissolved organic carbon (DOC) and iron concentrations, as well as a shift to more colored DOC. While browning of surface waters is widespread and well documented, little is known about why some lakes resist it. Here, we present a comprehensive study of Mälaren, the third largest lake in Sweden. In Mälaren, the vast majority of water and DOC enters a western lake basin, and after approximately 2.8 years, drains from an eastern basin. Despite 40 years of increased terrestrial inputs of colored substances to western lake basins, the eastern basin has resisted browning over this time period. Here we find the half-life of iron was far shorter (0.6 years) than colored organic matter (A420 ; 1.7 years) and DOC as a whole (6.1 years). We found changes in filtered iron concentrations relate strongly to the observed loss of color in the western basins. In addition, we observed a substantial shift from colored DOC of terrestrial origin, to less colored autochthonous sources, with a substantial decrease in aromaticity (-17%) across the lake. We suggest that rapid losses of iron and colored DOC caused the limited browning observed in eastern lake basins. Across a wider dataset of 69 Swedish lakes, we observed greatest browning in acidic lakes with shorter retention times (< 1.5 years). These findings suggest that water residence time, along with iron, pH and colored DOC may be of central importance when modeling and projecting changes in brownification on broader spatial scales. PMID:23976946

  15. Effectiveness of a refuge for Lake Trout in Western Lake Superior II: Simulation of future performance

    Science.gov (United States)

    Akins, Andrea L; Hansen, Michael J.; Seider, Michael J.

    2015-01-01

    Historically, Lake Superior supported one of the largest and most diverse Lake Trout Salvelinus namaycush fisheries in the Laurentian Great Lakes, but Lake Trout stocks collapsed due to excessive fishery exploitation and predation by Sea Lampreys Petromyzon marinus. Lake Trout stocking, Sea Lamprey control, and fishery regulations, including a refuge encompassing Gull Island Shoal (Apostle Islands region), were used to enable recovery of Lake Trout stocks that used this historically important spawning shoal. Our objective was to determine whether future sustainability of Lake Trout stocks will depend on the presence of the Gull Island Shoal Refuge. We constructed a stochastic age-structured simulation model to assess the effect of maintaining the refuge as a harvest management tool versus removing the refuge. In general, median abundances of age-4, age-4 and older (age-4+), and age-8+ fish collapsed at lower instantaneous fishing mortality rates (F) when the refuge was removed than when the refuge was maintained. With the refuge in place, the F that resulted in collapse depended on the rate of movement into and out of the refuge. Too many fish stayed in the refuge when movement was low (0–2%), and too many fish became vulnerable to fishing when movement was high (≥22%); thus, the refuge was more effective at intermediate rates of movement (10–11%). With the refuge in place, extinction did not occur at any simulated level of F, whereas refuge removal led to extinction at all combinations of commercial F and recreational F. Our results indicate that the Lake Trout population would be sustained by the refuge at all simulated F-values, whereas removal of the refuge would risk population collapse at much lower F (0.700–0.744). Therefore, the Gull Island Shoal Refuge is needed to sustain the Lake Trout population in eastern Wisconsin waters of Lake Superior.

  16. Energy and water in the Great Lakes.

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, Vincent Carroll

    2011-11-01

    The nexus between thermoelectric power production and water use is not uniform across the U.S., but rather differs according to regional physiography, demography, power plant fleet composition, and the transmission network. That is, in some regions water demand for thermoelectric production is relatively small while in other regions it represents the dominate use. The later is the case for the Great Lakes region, which has important implications for the water resources and aquatic ecology of the Great Lakes watershed. This is today, but what about the future? Projected demographic trends, shifting lifestyles, and economic growth coupled with the threat of global climate change and mounting pressure for greater U.S. energy security could have profound effects on the region's energy future. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decisionmaking is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place. Based on these confounding needs, the objective of this effort is to develop Great Lakes-specific methods and tools to integrate energy and water resource planning and thereby support the dual goals of smarter energy planning and development, and protection of Great Lakes water resources. Guiding policies for this planning are the Great Lakes and St. Lawrence River Basin Water Resources Compact and the Great Lakes Water Quality Agreement. The desired outcome of integrated energy-water-aquatic resource planning is a more sustainable regional energy mix for the Great Lakes basin ecosystem.

  17. Episodes of low dissolved oxygen indicated by ostracodes and sediment geochemistry at Crystal Lake, Illinois, USA

    Science.gov (United States)

    Curry, B. Brandon; Filippelli, G.M.

    2010-01-01

    Low dissolved oxygen during the summer and early fall controls profundal continental ostracode distribution in Crystal Lake (McHenry County), Illinois, favoring Cypria ophthalmica and Physocypria globula at water depths from 6 to 13 m. These species also thrived in the lake's profundal zone from 14,165 to 9600 calendar year before present (cal yr b.p.) during the late Boiling, Allerod, and Younger Dryas chronozones, and early Holocene. Characterized by sand, cemented tubules, large aquatic gastropod shells, and littoral ostracode valves, thin (1-6 cm) tempestite deposits punctuate thicker deposits of organic gyttja from 16,080 to 11,900 cal yr b.p. The succeeding 2300 yr (11,900-9600 cal yr b.p.) lack tempestites, and reconstructed water depths were at their maximum. Deposition of marl under relatively well-oxygenated conditions occurred during the remainder of the Holocene until the arrival of Europeans, when the lake returned to a pattern of seasonally low dissolved oxygen. Such conditions are also indicated in the lake sediment by the speciation of phosphorus, high concentrations of organic carbon, and abundant iron and manganese occluded to mineral grains. Initial low dissolved oxygen was probably caused by the delivery of dissolved P and Fe in shallow groundwater, the chemistry of which was influenced by Spodosol pedogenesis under a spruce forest. The triggering may have been regionally warm and wet conditions associated with retreat of the Lake Michigan lobe (south-central Laurentide Ice Sheet). ?? 2010, by the American Society of Limnology and Oceanography Inc.

  18. Simulating Lake-Groundwater Interactions During Decadal Climate Cycles: Accounting For Variable Lake Area In The Watershed

    Science.gov (United States)

    Virdi, M. L.; Lee, T. M.

    2009-12-01

    The volume and extent of a lake within the topo-bathymetry of a watershed can change substantially during wetter and drier climate cycles, altering the interaction of the lake with the groundwater flow system. Lake Starr and other seepage lakes in the permeable sandhills of central Florida are vulnerable to climate changes as they rely exclusively on rainfall and groundwater for inflows in a setting where annual rainfall and recharge vary widely. The groundwater inflow typically arrives from a small catchment area bordering the lake. The sinkhole origin of these lakes combined with groundwater pumping from underlying aquifers further complicate groundwater interactions. Understanding the lake-groundwater interactions and their effects on lake stage over multi-decadal climate cycles is needed to manage groundwater pumping and public expectation about future lake levels. The interdependence between climate, recharge, changing lake area and the groundwater catchment pose unique challenges to simulating lake-groundwater interactions. During the 10-year study period, Lake Starr stage fluctuated more than 13 feet and the lake surface area receded and expanded from 96 acres to 148 acres over drier and wetter years that included hurricanes, two El Nino events and a La Nina event. The recently developed Unsaturated Zone Flow (UZF1) and Lake (LAK7) packages for MODFLOW-2005 were used to simulate the changing lake sizes and the extent of the groundwater catchment contributing flow to the lake. The lake area was discretized to occupy the largest surface area at the highest observed stage and then allowed to change size. Lake cells convert to land cells and receive infiltration as receding lake area exposes the underlying unsaturated zone to rainfall and recharge. The unique model conceptualization also made it possible to capture the dynamic size of the groundwater catchment contributing to lake inflows, as the surface area and volume of the lake changed during the study

  19. Predicting the effects of climate change on trophic status of three morphologically varying lakes: Implications for lake restoration and management

    DEFF Research Database (Denmark)

    Trolle, Dennis; Hamilton, David P.; Pilditch, Conrad A.

    2011-01-01

    To quantify the effects of a future climate on three morphologically different lakes that varied in trophic status from oligo-mesotrophic to highly eutrophic, we applied the one-dimensional lake ecosystem model DYRESM-CAEDYM to oligo-mesotrophic Lake Okareka, eutrophic Lake Rotoehu, both in the t....... Therefore, future climate effects should be taken into account in the long-term planning and implementation of lake management as strategies may need to be refined and adapted to preserve or improve the present-day lake water quality....

  20. Bathymetric Contour Maps of Lakes Surveyed in Iowa in 2005

    Science.gov (United States)

    Linhart, S.M.; Lund, K.D.

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Iowa Department of Natural Resources, conducted bathymetric surveys on seven lakes in Iowa during 2005 (Arrowhead Pond, Central Park Lake, Lake Keomah, Manteno Park Pond, Lake Miami, Springbrook Lake, and Yellow Smoke Lake). The surveys were conducted to provide the Iowa Department of Natural Resources with information for the development of total maximum daily load limits, particularly for estimating sediment load and deposition rates. The bathymetric surveys provide a baseline for future work on sediment loads and deposition rates for these lakes. All of the lakes surveyed in 2005 are man-made lakes with fixed spillways. Bathymetric data were collected using boat-mounted, differential global positioning system, echo depth-sounding equipment, and computer software. Data were processed with commercial hydrographic software and exported into a geographic information system for mapping and calculating area and volume. Lake volume estimates ranged from 47,784,000 cubic feet (1,100 acre-feet) at Lake Miami to 2,595,000 cubic feet (60 acre-feet) at Manteno Park Pond. Surface area estimates ranged from 5,454,000 square feet (125 acres) at Lake Miami to 558,000 square feet (13 acres) at Springbrook Lake.