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The Diversity Of Benthic Mollusks Of Lake Victoria And Lake Burigi, Ja Mwambungu

Tanzania Journal of Science

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 three genera were recorded from Lake Burigi. In Lake Victoria the most diverse zone was Mara zone. The mollusca communities comprised of Bellamya, Gabbiella, Melanoides, Bulinus, Biomphalaria and Cleopatra (Gastropoda) and Corbicula, Eupera (Byssanodonta), Caelatura and Sphaerium (Bivalvia). Lake Burigi comprised of Melanoides, Bulinus and Biomphalaria. Melanoides tuberculata …

Phytoplankton And Nutrients Studies In Magu Bay, Speke Gulf, Lake Victoria, (Tanzania) Following The 2001 Principal Rain Season, Jf Machiwa, C Lugomela, Ann Muzuka

Tanzania Journal of Science

Phytoplankton abundance and species composition in relation to some physico-chemical parameters were studied in Magu Bay, Lake Victoria, in May 2001. Investigations on the influence of Simiyu River on the biological and physical characteristics of the Bay were carried out. Surface and bottom currents flowed in the northeast direction close to the river mouth but were completely reversed after about 1.5 km from the river mouth. Most suspended particles brought in by the river were deposited within 0.5 km after entering the lake. Nutrient concentrations were generally high towards the eastern part of the bay as compared to the rest …

Species Composition And Biomass Estimates Of Zooplankton In Some Water Bodies Within Lake Victoria Basin, Rk Waya, Ai Chande

Tanzania Journal of Science

Zooplankton communities were identified and their abundance and biomass estimated in some selected satellite lakes and Mara River in Lake Victoria basin, during wet and dry seasons in 2002. Samples were collected from eight water bodies. Three stations were sampled from each water body using a plankton net (40 µm mesh size) hauled vertically through the water column. The zooplankton community comprised mainly crustacea and rotifers. The results show that the number of species collected during the wet and dry seasons was 31 species and 28 species, respectively. The Shannon wiener diversity indices were not significantly different (Mann-Whitney U Test …

Relationship Between Water Transparency And Species Richness Of Surviving Haplochromines In Selected Habitats In Mwanza Gulf - Lake Victoria, Hdj Mrosso, Bs Msuku, O Seehausen

Tanzania Journal of Science

Several of the surviving haplochromine species have been recorded in habitats of different water transparencies within the Mwanza Gulf. Sampling for the haplochromines was carried out in muddy, rocky, sandy and vegetated habitats. All of the recorded species had been reported previously. Fewer species were encountered than previously reported in the same sampling stations. There was evidence for positive correlation between species richness and water transparency that was reinforced with data on ecological differentiation. Further exploration and conservation measures of diversity have been suggested for Lake Victoria haplochromines.

Fish Species Composition, Size Structure And Distribution In Non-Trawlable Areas Of Lake Victoria (Tanzania) With Emphasis On Mwanza Gulf And Mori Bay, Jdr Bayona, B Msuku, S Mzighani

Tanzania Journal of Science

Fish diversity studies in littoral non-trawlable areas of Lake Victoria (Tanzania) were undertaken during six systematic surveys (November 2000 to December 2002). Information on fish species composition, size structure as well as spatial and temporal distribution was generated from gill-netting, beach-seining and electric fishing. Lates niloticus, indicated a declining trend in composition from 78.9% in March 2001 to 5.1% in July 2002. The species, however, increased to 40.6 % in catch composition as of December 2002, exhibiting somewhat inverse trends in distribution with Oreochromis niloticus and haplochromines in the lake fisheries. The surveys identified over 50 species for which 42 …

Spatial Distribution Of Parasites Along The Gut Of The Catfish Clarias Gariepinus (Burchell, 1822) (Clariidae) From The Mwanza Gulf, Lake Victoria, G Nkwengulila, C Mwita

Tanzania Journal of Science

The diversity, abundance and spatial distribution of parasites in the alimentary tract of Clarias gariepinus from the Mwanza Gulf were investigated. Ten parasite species were recovered; the Trematoda, Cestoda and Nematoda were each represented by three species while Dolops ranarum was the only crustacean recovered from the posterior part of the buccal cavity. Parasites diversity was highest in the small intestine and the stomach. Although the gut community of C. gariepinus studied was rich in intensity and individual numbers of helminth species, helminth infection in most sections of the gut comprised of monospecific infection and thus cohabiting interspecific interaction was …

Studies On The Fisheries And Biology Of Oreochromis Urolepsis (Pisces: Cichilidae) In The Mtera Resorvoir (Tanzania), F M M Chale

Tanzania Journal of Science

The fisheries and some aspects of the biology of Oreochromis urolepis of the Mtera Reservoir (Tanzania) were examined in August 2002. It was observed that there was no proper management of the reservoir's fisheries. Beach seine fishing dominated the fishery. Nearly all the O. urolepis caught by this type of gear were juveniles. The number of fish caught by the beach seines was very high, some times up to 4,000 fish per haul. The beach seines also destroy the spawning sites for the tilapias. Mean total lengths of O. urolepis caught in gillnets of legal mesh sizes (ranging from 88 …

Physical And Chemical Characteristics Of Water In Selected Locations In Lake Victoria, Tanzania, M A Kishe

Tanzania Journal of Science

A study conducted during the period of March/April 2002 aimed at measuring physical and chemical parameters in Tanzanian portion of Lake Victoria. Temperature and conductivity values were homogeneous among and within the study stations. Levels of dissolved oxygen (DO) ranged from 4 - 9 mgl-1 and there was significant difference between stations (P < 0.05). Water transparency was poor (< 2 m secchi depth) and differed from one sampling station to another. Ammonium nitrogen (NH4+-N), with few exceptions, showed the highest concentrations both at the bottom and near-surface followed by total phosphates (TP), nitrate nitrogen (NO2+NO3--N), nitrite nitrogen (NO2--N) and Soluble Reactive Silicon (SRSi). Concentrations of NH4+-N, TP and SRSi were high at bottom waters and the reverse was true for NO2+NO3--N and NO2--N. Differences in nutrients and physical water parameters among sampling stations were statistically significant (P < 0.05). However, temperature and nutrient levels at studied areas were higher than that of 50 years ago and the trend reversed for DO and transparency. This indicates that Lake Victoria is receiving organic materials from the catchment area leading to the decline of water quality. Long-term efforts for rehabilitation, conservation and sustainable management of the lake are suggested.

Agenda: Introduction To The Legal Foundation Of Federal Land Management, University Of Colorado Boulder. Natural Resources Law Center

Introduction to the Legal Foundation of Federal Land Management (December 1-3)

Materials prepared for the course held at the National Center for Atmospheric Research in Boulder, Colorado on December 1-3, 2004

Course instructors: Charles Wilkinson; Sarah Krakoff; Kathryn Mutz; Ann Morgan; Maggie Fox

Contents:

Introduction -- Agenda -- Summaries of laws -- Case studies. Travel management; Oil and gas development; Timber/fuels reduction -- How to influence agency decision makers -- Natural resource related legal and policy resources for the non-legal professional

Introduction To The Legal Foundation Of Federal Land Management, University Of Colorado Boulder. Natural Resources Law Center

Introduction to the Legal Foundation of Federal Land Management (December 1-3)

1 v. (various pagings) : ill., maps ; 28 cm

Materials prepared for the course held at the National Center for Atmospheric Research in Boulder, Colorado on December 1-3, 2004

Course instructors: Charles Wilkinson; Sarah Krakoff; Kathryn Mutz; Ann Morgan; Maggie Fox

Contents:

Introduction -- Agenda -- Summaries of laws -- Case studies. Travel management; Oil and gas development; Timber/fuels reduction -- How to influence agency decision makers -- Natural resource related legal and policy resources for the non-legal professional

Evidence For Microbial Enhanced Electrical Conductivity In Hydrocarbon-Contaminated Sediments, Estella A. Atekwana, Eliot A. Atekwana, D. Dale Werkema, Jonathan P. Allen, Laura A. Smart, Joseph W. Duris, Daniel P. Cassidy, William A. Sauck, Silvia Rossbach

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Bulk electrical conductivity of sediments during microbial mineralization of diesel was investigated in a mesoscale laboratory experiment consisting of biotic contaminated and uncontaminated columns. Population numbers of oil degrading microorganisms increased with a clear pattern of depth zonation within the contaminated column not observed in the uncontaminated column. Microbial community structure determined from ribosomal DNA intergenic spacer analysis showed a highly specialized microbial community in the contaminated column. The contaminated column showed temporal increases in bulk conductivity, dissolved inorganic carbon, and calcium, suggesting that the high bulk conductivity is due to enhanced mineral weathering from microbial activity. The greatest change …

Hydrologic And Geochemical Cycling Within Karst Versus Non-Karst Basins Within The Interior Low Plateau Province Of South-Central Kentucky, David Ek

Masters Theses & Specialist Projects

This thesis summarizes my research in which I investigated differences and characteristics in hydrologic, nutrient and geochemical cycling between karst versus nonkarst basins within the Interior Low Plateau Province. Field data including stream discharge, evapotranspiration, and dissolved major ion concentrations were collected for a period of one year for two basins within Mammoth Cave National Park. Twelve percent carbonate rocks underlie one basin, while the other consists of 48 percent carbonate rocks. The carbonate rock exposures within both basins exhibit karstification. The hydrologic and geochemical differences between these basins were compared to determine to what extent that cycles are modified …

Unconformities And Age Relationships, Tongue River And Older Members Of The Fort Union Formation (Paleocene), Western Williston Basin, U.S.A., Edward S. Belt, Joseph H. Hartman, John A. Diemer, Timothy J. Kroeger, Neil E. Tibert, H. Allen Curran

Geosciences: Faculty Publications

An unconformable relationship is observed within the Paleocene Fort Union Formation in the western Williston Basin at the contact between the Tongue River Member and the underlying Lebo and Ludlow Members. Isotopic dates and pollen biozone data reported here are integrated with previously published data. A new correlation of these facies results in a revised history of localized depositional and tectonic events. One unconformity occurs at this lithological contact in the Pine Hills (PH), Terry Badlands (TB), and Ekalaka (E) areas west of the Cedar Creek anticline (CCA), and another unconformity occurs at the same lithological contact in the Little …

Hydrogeologic Model Of A Leachate Plume In An Unconfined Coastal Plain Aquifer And Chemical Transport Mechanisms Of Metals And Dense Non-Aqueous Phase Liquids, Thomas Lindblad

Theses and Dissertations

Groundwater contamination is of increasing environmental concern as many aquifers across the globe have experienced a decrease in water quality in recent time. The growth of the world's population over the last couple of decades has caused a dramatic increase in the rate of groundwater use. One potential source of groundwater contamination is waste material in landfills. The 1 st Division Road Sanitary landfill at Fort Benning Military Reservation was studied to evaluate the potential effect on local groundwater and a leachate plume was recognized using data from 16 groundwater monitoring wells located around the facility. The study site is …

Tracking The Sea-Level Signature Of The 8.2 Ka Cooling Event: New Constraints From The Mississippi Delta, Torbjörn E. Törnqvist, Scott J. Bick, Juan L. Gonzalez, Klaas Van Der Borg, Arie F. M. De Jong

School of Earth, Environmental, & Marine Sciences Faculty Publications

The ever increasing need for accurate predictions of global environmental change under greenhouse conditions has sparked immense interest in an abrupt, century‐scale cooling around 8200 years ago, with a focal point in the North Atlantic and with hemispheric teleconnections. Despite considerable progress in the unraveling of this striking feature, including a conceivable driving mechanism (rapid drainage of proglacial Lake Agassiz/Ojibway and a resulting reduced strength of North Atlantic thermohaline circulation), several key questions remain unanswered. One salient aspect concerns the total amount of freshwater released during this catastrophic event, likely echoed by a near‐instantaneous eustatic sea‐level rise. So far, no …

Field Evidence For Geophysical Detection Of Subsurface Zones Of Enhanced Microbial Activity, Eliot A. Atekwana, Estella A. Atekwana, Franklyn D. Legall, R. V. Krishnamurthy

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Geochemical data from closely spaced vertical intervals in a hydrocarbon-impacted aquifer were used to assess the relationship between bulk conductivity and zones of enhanced microbial activity. The bulk conductivity was measured using in situ vertical resistivity probes. Microbial activity was verified using terminal electron acceptors (nitrate, sulfate, iron, and manganese), dissolved inorganic carbon (DIC), and major ion chemistry. Peaks in bulk conductivity in the aquifer overlapped with zones where nitrates and sulfates were depleted, total petroleum hydrocarbon, iron, manganese, dissolved ions, and DIC were elevated, suggesting a link between higher electrical conductivity and zones of enhanced microbial activity stimulated by …

A Watershed-Based Classification System For Lakes In Agriculturally-Dominated Ecosystems: A Case Study Of Nebraska Reservoirs, Henry N. N. Bulley

Department of Geography: Dissertations, Theses, and Student Research

In recent decades substantial progress has been made in improving the quality of surface waters in the United States (Hawkins et al., 2000; EPA, 2000; EPA, 2001); nevertheless, much work remains to be done in assessing the state of impairment of lake waters. Impairment implies that the existing water quality of a lake, as measured by selected criteria (e.g., nitrogen, phosphorus, chlorophyll-a, Secchi depth), exceeds a threshold value or standard that presumably reflects optimal attainable lake water quality conditions (or "reference" conditions) (Hughes, 1995; EPA, 2000; EPA, 2001). Such impaired waters are not suitable for designated uses such as drinking, …

Patterns Of Early Lake Evolution In Boreal Landscapes: A Comparison Of Stratigraphic Inferences With A Modern Chronosequence In Glacier Bay, Alaska, Sherilyn C. Fritz, Daniel R. Engstrom, Stephen Juggins

Department of Earth and Atmospheric Sciences: Faculty Publications

The chronosequence approach, which infers temporal patterns of environmental change from a spatial array of modern sites, has been a major tool for studying successional processes. A model of early lake ontogeny in boreal landscapes, developed from a chronosequence of lakes in Alaska, suggests that long-term soil development and related hydrological change produce a loss of alkalinity and base cations, a decrease in pH, an increase in DOC and a transient increase followed by a decrease in lakewater nitrogen concentrations over time. We compare this model of lake ontogeny with patterns of change reconstructed from diatom assemblages in 10 sediment …

Geosciences Newsletter - 2004, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 1, No. 29

• Mohamed Sultan, Chairperson
• Faculty News
• Emeriti News
• Department News
• Graduate Student News
• Awards & Graduations
• Alumni News
• Field Trips
• Outstanding Alumni Academy
• Special Honor
• New Faces in the Geosciences

Low Marine Sulphate And Protracted Oxygenation Of The Proterozoic Biosphere, Linda C. Kah, Timothy W. Lyons, Tracy D. Frank

Department of Earth and Atmospheric Sciences: Faculty Publications

Progressive oxygenation of the Earth’s early biosphere is thought to have resulted in increased sulphide oxidation during continental weathering, leading to a corresponding increase in marine sulphate concentration. Accurate reconstruction of marine sulphate reservoir size is therefore important for interpreting the oxygenation history of early Earth environments. Few data, however, specifically constrain how sulphate concentrations may have changed during the Proterozoic era (2.5–0.54 Gyr ago). Prior to 2.2 Gyr ago, when oxygen began to accumulate in the Earth’s atmosphere, sulphate concentrations are inferred to have been <200 >μM, on the basis of limited isotopic variability preserved in sedimentary sulphides4 and experimental …

High Dispersal In A Frog Species Suggests That It Is Vulnerable To Habitat Fragmentation, W. Chris Funk, Allison E. Greene, Paul Stephen Corn, Fred W. Allendorf

United States Geological Survey: Staff Publications

Global losses of amphibian populations are a major conservation concern and their causes have generated substantial debate. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among contiguous amphibian populations using formal movement estimators. In contrast, if dispersal is naturally low in amphibians, fragmentation can be disregarded as a cause of amphibian declines and conservation efforts can be focused elsewhere. We examined dispersal rates in Columbia spotted frogs (Rana luteiventris) using capture–recapture analysis of over …

Geogram 2004, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.

Hydrologic Variations Within Created And Natural Wetlands In Southeastern Virginia, Aaron Dyer Despres

OES Theses and Dissertations

The hydrology of wetlands, particularly how wetland soils collect, store, and redistribute water strongly affects how wetland systems function. In created wetlands, construction processes and materials influence the hydrology and consequently, the potential for successful reestablishment of target vegetation communities. During .2002- 2004, the Virginia Department of Transportation constructed large mitigation wetlands on two different Quaternary aged surfaces with very similar hydrogeomorphic conditions. The Sandy Bottom Nature Park site (SBNP) located in Hampton, VA and rests on the sandy loam Tabb Formation while the Charles City Wetland site (CCW) lies on the older and clay-rich Shirley Formation. This study documents …

Earth News, V28, Fall 2004, Department Of Earth Science, University Of Northern Iowa.

Earth News

Inside this issue:

--- Earth Science Staff Activities
--- Earth Science Majors
--- Student Internships
--- From Ocean to Ice: GSI 2004 Spring Field Trip Highlights
--- National Earth Science Week Quarry Open House
--- Sigma Gamma Epsilon - Gamma Sigma Chapter
--- Student Research Presentation
--- 2004-2005 Scholarship and Award Recipients
--- 2004 Earth Science Graduates
--- Earth Science Seminar Series
--- Gifts to the Department of Earth Science
--- Earth Science Alumni News

Technical Assessment Of Natural Resource Management Threats And Options In The Northern Agricultural Region Of Western Australia, Lorinda Hunt, G Patterson, Northern Agricultural Catchments Council (Wa)

Resource management technical reports

Analysis of the risk of soil, land and water degradation within the Northern Agricultural Region of Western Australia. Natural resource issues discussed include: acid groundwater, acid sulfate soils, climate change, dryland salinity, flooding, herbicide resistance, non-wetting (water repellence), nutrient loss and eutrophication, remnant vegetation decline, soil acidity, soil fertility decline, soil structure decline, subsurface compaction, waterlogging, wind erosion and soil contamination.

Three-Dimensional Modeling Of Lacustrine Diatom Habitat Areas: Improving Paleolimnological Interpretation Of Planktic : Benthic Ratios, Jeffery R. Stone, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

Three-dimensional modeling of lake morphometry enables the calculation of lake volume, planar surface area, and basin surface area, which are critical components of a conceptual model of how planktic and benthic habitat areas change with changing lake level. We have applied three-dimensional modeling to Foy Lake, Montana, and compared model results of changing ratios of planktic and benthic habitat areas at all possible lake levels to sediment cores recovered from the lake. The model allows us to produce semiquantitative depth reconstructions and greatly improves lake-level reconstruction of this morphometrically complex basin. The conceptual model also was modified to examine the …

Accuracy Of Neural Network Classifiers In Humid Tropical Areas, Genong Yu

All-Inclusive List of Electronic Theses and Dissertations

This research develops a better understanding of the use of neural networks in the context of tropical land cover characterization using multiple scale remotely sensed data. Results of the research contributed to developing a robust neural network classifier suitable to use for humid tropical land cover classification in areas such as Altamira, Brazil. Research was focused upon the following: (1) performance ofneural networks with different ancillary data- such as DEM (digital elevation model) and its derivatives; (2) effect of spatial scale on neural network classifiers using remote sensing data from IKONOS, Landsat TM, ASTER, and MODIS; (3) accuracy of neural …

Efficacy Of Offshore Breakwater Structures In A Eutrophic Midwestern Reservoir, Larry D. Pape

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Impact Of Heterogeneity, Bed Forms, And Stream Curvature On Subchannel Hyporheic Exchange, M. Bayani Cardenas, J. L. Wilson, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

Advection through hyporheic zones (HZ) consisting of heterogeneous channel bend streambed deposits and their equivalent homogenous medium was investigated using finite difference groundwater flow and transport simulations and forward particle tracking. The top prescribed head boundary was varied in order to mimic various stream channel head distributions resulting from the presence of bed forms and channel curvature. Flux calculations show that heterogeneity causes significant additional HZ flux compared to an equivalent homogenous medium. However, the major cause of HZ flux is a spatially periodic (sinusoidal) head distribution along the boundary, representing the effect of bed forms. The additional influence of …

Sediments, Facies Tracts, And Variations In Sedimentation Rates Of Holocene Platform Carbonate Sediments And Associated Deposits, Northern Belize -- Implications For "Representative" Sedimentation Rates, Wan Yang, Salvatore J. Mazzullo, Chellie S. Teal

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In stratigraphic analysis and simulation, sedimentation rates are typically assumed to be constant for meter-scale sedimentation units of similar lithology. The rates of Holocene, shallow-marine carbonate and associated sediments within an 820 km² area of Chetumal Bay in northern Belize were evaluated to test this assumption. Rates were determined from thickness data from 363 locations, durations derived from ¹⁴C age dates of mangrove peat on Pleistocene bedrock limestone and of overlying cerithid gravels, and reference to a sea-level curve for this area. The rate of entire Holocene sections (basal transgressive mangrove peat, shelly gravel, and overlying carbonate) varies …