Nearby Lake Research Articles

Wappapello Dam Spillway Overtopping Event of 2011

Abstract The one-dimensional HEC-RAS multi-purpose open channel flow modeling software was successfully used, with ArcMap and HEC-GeoRAS, to simulate flow over the Wappapello Dam limited-use Ogee spillway (Wappapello, Missouri). Initial computational hydraulic modeling results predicted a lake elevation of 132.9 m (405.0 ft) [NAVD 1988] would be required for the resulting floodwaters overtopping the spillway to reach the nearby Wappapello Lake Management Office. An intense rainfall event during 2011 led to the spillway being overtopped for the first time since 1945. Spillway performance during the 2011 event was analyzed afterwards. Results indicated that the spillway crest was not submerged by backwater. A technique was employed which successfully estimated the design energy head of 7.160 m (23.49 ft) for the spillway. Hydraulic modeling developed after the 2011 event incorporated this estimated design energy head, allowing the spillway discharge coefficient to vary with discharge in the course of an unsteady modeling run. Results indicated that, while the spillway did perform as designed, the performance is limited by the shallow approach depth.

Unsanitary Landfill Fires as a Source of a PCDD/Fs Contamination

The aim of this study was to determine whether a combustion process (open burning) on an unsanitary landfill produces polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), for which several media were analysed (smoked air, landfill soil, and lake sediment). The concentration of PCDD/Fs detected in the air increased over 4000 times during the landfill fire, from 0.480 fg m–3 to 1940.4 fg m–3 or expressed as Toxic Equivalency (TEQ) from 0.004 fg TEQ m–3 to 25.72 fg TEQ m–3. Increased values of PCDD/Fs were also determined in the soil from the landfill site (2597.6 ng kg-1, 48.11 ng TEQ kg-1), and the influence of combustion process occurring on the landfill was also registered in the nearby lake sediment (23.17 ng kg–1, 0.03 ng TEQ kg–1). Due to the high sedimentation rate (6.4 mm y–1), a significant contaminant dilution in the lake sediment can be expected. The results of this preliminary study point to the need of implementing a continuous long-term monitoring of PCDD/PCDFs in the landfill surrounding environment.

Opportunistic disease in yellow perch in response to decadal changes in the chemistry of oil sands-affected waters.

Oil sands-affected water from mining must eventually be incorporated into the reclaimed landscape or treated and released. However, this material contains petrogenic organic compounds, such as naphthenic acids and traces of polycyclic aromatic hydrocarbons. This has raised concerns for impacts of oil sands process-affected waters on the heath of wildlife and humans downstream of receiving environments. The objective of this study was to evaluate the temporal association of disease states in fish with water chemistry of oil sands-affected waters over more than a decade and determine the pathogens associated with disease pathologies. Yellow perch (Perca flavescens) captured from nearby lakes were stocked into two experimental ponds during 1995-1997 and 2008-2010. South Bison Pond is a drainage basin that has received unextracted oil sands-contaminated material. Demonstration Pond is a constructed pond containing mature fine tailings capped with fresh water. Two disease pathologies, fin erosion for which a suspected bacterial pathogen (Acinetobacter Iwoffi) is identified, and lymphocystis (confirmed using a real-time PCR) were associated with oil sands-affected water exposure. From 1995 to 1997 pathologies were most prevalent in the South Bison Pond; however, from 2008 to 2009, disease was more frequently observed in the Demonstration Pond. CYP1A activity was 3-16 fold higher in fish from experimental ponds as compared to reference populations and this pattern was consistent across all sampling years. Bile fluorescence displayed a gradient of exposure with experimental ponds being elevated over local perch populations. Naphthenic acids decreased in the Bison Pond from approximately 12mg/L to <4mg/L while naphthenic acids increased in the Demonstration Pond from 6mg/L to 12mg/L due to tailings densification. Temporal changes in naphthenic acid levels, CYP1A activity and bile fluorescent metabolites correlate positively with incidence of disease pathologies whereas all inorganic water quality changes (major ions, pH, metals) were not associated with disease responses.

‘The happiest time of my life …’: Emotive visitor books and early mission tourism to Victoria’s Aboriginal reserves

On the afternoon of 16 January 1895, a group of visitors to the Gippsland Lakes, Victoria, gathered to perform songs and hymns with the Aboriginal residents of Lake Tyers Aboriginal Mission. Several visitors from the nearby Lake Tyers House assisted with the preparations and an audience of Aboriginal mission residents and visitors spent a pleasant summer evening performing together and enjoying refreshments. The 'program' included an opening hymn by 'the Aborigines' followed by songs and hymns sung by friends of the mission, the missionary's daughter and a duet by two Aboriginal women, Mrs E. O'Rourke and Mrs Jennings, who in particular received hearty applause for their performance of 'Weary Gleaner'. The success of this shared performance is recorded by an anonymous hand in the Lake Tyers visitor book, noting that 9 pounds 6 shillings was collected from the enthusiastic audience. The missionary's wife, Caroline Bulmer, was most likely responsible for this note celebrating the success of an event that stands out among the comments of visitors to Lake Tyers. One such visitor was a woman named Miss Florrie Powell who performed the song 'The Old Countess' after the duet by Mrs O'Rourke and Mrs Jennings. She wrote effusively in the visitor book that 'to give you an idea of enjoyment down here would be impossible. Everyone must find out for him or herself. The happiest time of my life was spent here. The kindness of Mrs and Mr Bulmer is past description'.

Temporal and Spatial Variations of Microbial Carbon Utilization in Water Bodies from the Dajiuhu Peatland, Central China

To investigate the microbial utilization of organic carbon in peatland ecosystem, water samples were collected from the Dajiuhu Peatland and nearby lakes, central China across the year of 2014. The acridine orange (AO) staining and Biolog Eco microplates were used to numerate microbial counts and determine the carbon utilization of microbial communities. Meanwhile, physicochemical characteristics were measured for subsequent analysis of the correlation between microbial carbon utilization and environmental factors. Results indicated that total microbial counts were between 106–107 cells/L. Microbial diversities and carbon utilization rates showed a similar pattern, highest in September and lowest in November. Microbial communities in the peat pore waters preferred to utilize N-bearing carbon sources such as amines and amino acids compared with microbial communities in lakes. The network analysis of microbial utilization of 31 carbon substrates clearly distinguished microbial communities from peat pore waters and those from lakes. Redundancy analysis (RDA) showed the total organic nitrogen content (P=0.03, F=2.5) and daily average temperature (P=0.034, F=2.4) significantly controlled microbial carbon utilization throughout the sampling period. Our report is the first one to address the temporal and spatial variations of carbon utilization of microbial communities which are closely related to the decomposition of organic matter in the Dajiuhu Peatland in context of climate warming.

Investigating the genetic structure of trout from the Garden of Ninfa (central Italy): Suggestions for conservation and management

AbstractMediterranean populations of brown trout (Salmo trutta L. complex) have lost a large part of their genetic distinctiveness, mostly due to massive restocking, and the waters of the Gardens of Ninfa (province of Latina, central Italy, Site of Community Importance since 2013) are regarded as one of a few potential reservoirs of autochthonous trout lineages in the Tyrrhenian drainage of the Italian peninsula. In this study, nuclear and mitochondrial markers were used on brown trout samples from Ninfa to estimate non‐Mediterranean influence in the population gene pool, potential changes of genetic structure over time and genetic relationships with other sites known (or suspected) to host native trout gene pools. Striking changes in both microsatellite and mtDNA allele frequencies over a 9‐year time span were found and provided evidence of unrecorded stocking from the nearby Lake Fibreno. Results are analysed in the light of potential ecological consequences of such events on a longer time scale and provide a scientific background for fisheries management and conservation programmes in the area.

Biological Nitrogen Fixation Prevents the Response of a Eutrophic Lake to Reduced Loading of Nitrogen: Evidence from a 46-Year Whole-Lake Experiment

A whole-ecosystem experiment in Lake 227 (L227) at the Experimental Lakes Area, ongoing since 1969, examined the roles of carbon (C), nitrogen (N), and phosphorus (P) in controlling eutrophication. During 2011, we conducted a series of sub-experiments and more intensive monitoring to improve estimates of N fixation and its ability to meet algal growth demands in the decades following the cessation of artificial N loading, while maintaining long-term high artificial P loading. Stoichiometric nutrient ratios indicated both moderate N and P limitation of the phytoplankton during spring, preceding a shift in phytoplankton community structure toward dominance by N fixing cyanobacteria. During bloom development, and for the remainder of the stratified period, stoichiometric nutrient ratios indicated moderate to strong P limitation. N fixation rates, corrected using 15N2 methods, increased 2× after 1990, when N loading ceased. Ambient dissolved inorganic nitrogen prior to the bloom represented less than 3% of N demands of the phytoplankton. N fixation accounted for between 69–86% of total N loading to the epilimnion during the period of rapid bloom development, and 72–86% of total N loading during the May–October period. Phytoplankton biomass did not decline in L227 during the 40 years since artificial N loading was reduced, or the nearly 25 years since artificial N loads ceased entirely (1990–2013), and remained approximately 20× higher than four nearby reference lakes. These results suggest that despite constraints on biological N fixation, it retains a large capacity to offset potential N loading reductions in freshwaters.

Rapid atmospheric transport and large-scale deposition of recently synthesized plant waxes

Sedimentary plant wax 2H/1H ratios are important tools for understanding hydroclimate and environmental changes, but large spatial and temporal uncertainties exist about transport mechanisms from ecosystem to sediments. To assess atmospheric pathways, we collected aerosol samples for two years at four locations within a ∼60 km radius in northern Switzerland. We measured n-alkane distributions and 2H/1H ratios in these samples, and from local plants, leaf litter, and soil, as well as surface sediment from six nearby lakes. Increased concentrations and 2H depletion of long odd chain n-alkanes in early summer aerosols indicate that most wax aerosol production occurred shortly after leaf unfolding, when plants synthesize waxes in large quantities. During autumn and winter, aerosols were characterized by degraded n-alkanes lacking chain length preferences diagnostic of recent biosynthesis, and 2H/1H values that were in some cases more than 100‰ higher than growing season values. Despite these seasonal shifts, modeled deposition-weighted average 2H/1H values of long odd chain n-alkanes primarily reflected summer values. This was corroborated by n-alkane 2H/1H values in lake sediments, which were similar to deposition-weighted aerosol values at five of six sites. Atmospheric deposition rates for plant n-alkanes on land were ∼20% of accumulation rates in lakes, suggesting a role for direct deposition to lakes or coastal oceans near similar production sources, and likely a larger role for deposition on land and transport in river systems. This mechanism allows mobilization and transport of large quantities of recently produced waxes as fine-grained material to low energy sedimentation sites over short timescales, even in areas with limited topography. Widespread atmospheric transfer well before leaf senescence also highlights the importance of the isotopic composition of early season source water used to synthesize waxes for the geologic record.

Analysis of the correlations between environmental factors and rare cranes in the Poyang Lake region of China

Abstract Using survey data during 2001–2013 from a total of 38 lakes in the Poyang Lake region of China, we analyzed the inter-annual change in crane populations and the spatial distribution of crane species. Across the study sites, the total crane population was 6400 ± 2620 individuals during the period 2001–2013. Crane populations varied widely across the study sites: the largest crane population was observed on Bang Lake with an annual average of 2373, followed by Qi Lake, Dacha Lake, and Zhu Lake. The four main crane species, which were active on 50–80% of study lakes during the period of investigation, were G. leucogeranus, G. monacha, G. vipio, and G. grus. In particular, G. leucogeranus, G. monacha, and G. vipio were observed mainly in Poyang Lake National Nature Reserve and nearby lakes. G. grus was mostly observed in Poyang County. The largest populations of G. leucogeranus, G. vipio, and G. monacha were observed on Bang Lake, with annual averages of 1229, 985, and 88 birds, respectively. The largest G. grus population was observed on Qi Lake, with an annual average of 756 birds. We found that habitats for G. leucogeranus, G. monacha, and G. vipio were defined by similar environmental factors. In particular, increasing distance from roads had a positive impact on populations of these three species. By contrast, sedimentary total phosphorus content showed negative correlations with populations of all four main crane species, which implied that eutrophication could pose a threat to these rare crane species.

Monitoring the long term vegetation phenology change in Northeast China from 1982 to 2015

Global warming has contributed to the extension of the growing season in North Hemisphere. In this paper, we investigated the spatial characteristics of the date of the start of the season (SOS), the date of the end of the season (EOS) and the length of the season (LOS) and their change trends from 1982 to 2015 in Northeast China. Our results showed that there was a significant advance of SOS and a significant delay of EOS, especially in the north part of Northeast China. For the average change slope of EOS in the study area, the delay trend was 0.25 d/y, which was more obvious than the advance trend of −0.13 d/y from the SOS. In particular, the LOS of deciduous needleleaf forest (DNF) and grassland increased with a trend of 0.63 d/y and 0.66 d/y from 1982 to 2015, indicating the growth season increased 21.42 and 22.44 days in a 34-year period, respectively. However, few negative signals were detected nearby Hulun Lake, suggesting that the continuous climate warming in the future may bring no longer growing periods for the grass in the semiarid areas as the drought caused by climate warming may limit the vegetation growth.

Low sedimentary accumulation of lead caused by weak downward export of organic matter in Hudson Bay, northern Canada

Atmospheric input of anthropogenic lead increased globally over the last centuries. The present study shows that the concentrations of lead in sediment cores from low-productivity Hudson Bay, northern Canada, remained relatively constant over the last centuries. The lack of imprint of the increased anthropogenic lead input in this marine environment is not consistent with the increased lead concentrations in nearby lakes over the same period. In addition, the observed trend in lead isotopic composition in our cores suggests an apparent progressive overprint of anthropogenic lead during the 1900s. In other words, isotopes clearly registered the increasingly anthropogenic nature of lead in the sedimentary record, but total lead concentrations remained constant, indicating that some process limited the export of lead to the sediment. These observations point to a long-term limitation of the downward export of particles in Hudson Bay. Given that the source of lead was the same for both Hudson Bay and neighboring high-productivity lakes, we hypothesize that the very low primary productivity of Hudson Bay waters was responsible for the low vertical export of lead to marine sediments. We further propose that primary productivity is the most important factor that generally drives the vertical export of particulate matter, and thus hydrophobic contaminants, in near-oligotrophic marine environments.

Analysis of the Potential for Use of Floating PV Power Plant on the Skadar Lake for Electricity Supply of Aluminium Plant in Montenegro

This paper deals with a conceptual solution for the supply of a part of electrical energy for the needs of Aluminium Plant Podgorica (KAP) in Montenegro from a large Floating Photovoltaic Power Plant (FPPP), that would be installed on the nearby lake. The recommended FPPP, with an innovative azimuth angle control method and total installed power of 90 MWp, would consist of 18 power plants having an installed power of 5 MWp each. An analysis using the NREL solar insolation database ascertained that the recommended FPPP power plant can achieve a significantly higher production in comparison with previous solutions. An economic analysis has shown that the recommended power plant would yield positive economic indicators. Additionally, such a power plant would significantly contribute to the reduction of CO2 emissions.

Glacial chronology of the Sierra Nevada, California, from the Last Glacial Maximum to the Holocene

During the Last Glacial Maximum the Sierra Nevada in California, USA, supported a mountain glacier/ice cap complex that covered over 20,000 km2. The history of this ice cover can be reconstructed using 14C and cosmogenic-nuclide surface-exposure dating. These show that the glaciers reached their maximum extent for the last glacial cycle between 21 and 18 ka, i.e., during the global Last Glacial Maximum. This is termed the Tioga 3 advance. A slow retreat began at 18 ka and accelerated rapidly at about 17 ka. After retreating an unknown distance, the glaciers began to readvance at about 16.7 ka, reaching the Tioga 4 limit at 16.2 ka. They then rapidly retreated to the crest of the range, probably within 500 to 1000 years. There is no indication of subsequent glacial expansion until the Recess Peak advance between 14.0 and 12.5 ka. Unfortunately, chronological control is not adequate to determine whether this advance was during the early Younger Dryas or slightly preceded it. The equilibrium-line-altitude reduction during the Tioga 3 was about 1200 m, that during the Tioga 4 about 800 m, and during the Recess Peak 100 to 200 m. The Tioga 4 advance coincided with the expansion of nearby pluvial Lake Lahontan to its maximum size. The Sierra Nevada advances correlate well with the glacial chronology of the Alps during the same period, and also with the episodes of melting and advance of the European and Laurentide Ice Sheets. Times of glacial advance in the Sierra Nevada may be connected to the melting history of the ice sheets, and to Heinrich events, by expansion and contraction of sea ice in the southern North Atlantic.

Diversity and succession of pelagic microorganism communities in a newly restored Illinois River floodplain lake

While the success of restoration efforts frequently depends on reconstructing ecological communities, time series observations of community structure over the course of restoration are rare. Here, frequent sampling of bacterioplankton, phytoplankton, planktonic protozoa (ciliates and testaceans), and zooplankton was done along with measurements of select physical and chemical parameters during the first year of ecological restoration of Thompson Lake (TL), an Illinois River floodplain lake not connected to the river. The primary objective was to describe the microbial composition, diversity, and seasonal dynamics in TL and compare these results to similar measurements made in a nearby reference lake, river flood-pulsed Lake Chautauqua (LC). Strong seasonal patterns in bacterioplankton diversity were observed for both lakes. While TL phytoplankton diversity was lower and blooms more erratic than in LC, ciliate richness and abundance patterns were similar in both lakes. Rotifers and microcrustaceans were about 5× more abundant in TL than LC, with copepods and cladocerans exhibiting a fall abundance peak only in TL. When compared to temporal patterns of planktonic microorganisms in the reference lake (LC), the microbial dynamics in a lake recovering from decades of agriculture and drainage (TL) reflect the instability associated with early stages of ecological restoration.

Food Web Responses to Artificial Mixing in a Small Boreal Lake

In order to simulate food web responses of small boreal lakes to changes in thermal stratification due to global warming, a 4 year whole-lake manipulation experiment was performed. Within that time, period lake mixing was intensified artificially during two successive summers. Complementary data from a nearby lake of similar size and basic water chemistry were used as a reference. Phytoplankton biomass and chlorophyll a did not respond to the greater mixing depth but an increase was observed in the proportional abundance of diatoms, and the proportional abundance of cryptophytes also increased immediately after the onset of mixing. Obligate anoxic green sulphur bacteria vanished at the onset of mixing but gradually recovered after re-establishment of hypolimnetic anoxic conditions. No major effect on crustacean zooplankton was found, but their diversity increased in the metalimnion. During the mixing, the density of rotifers declined but protozoan density increased in the hypolimnion. Littoral benthic invertebrate density increased during the mixing due to Ephemeroptera, Asellus aquaticus and Chironomidae, whereas the density of Chaoborus larvae declined during mixing and lower densities were still recorded one year after the treatment. No structural changes in fish community were found although gillnet catches increased after the onset of the study. The early growth of perch (Perca fluviatilis) increased compared to the years before the mixing and in comparison to the reference lake, suggesting improved food availability in the experimental lake. Although several food web responses to the greater mixing depth were found, their persistence and ecological significance were strongly dependent on the extent of the disturbance. To better understand the impacts of wind stress on small lakes, long term whole-lake experiments are needed.

Backcountry Limnology: Engaging Citizen Scientists to Collect Data on High Country Lakes, Reservoirs, and Ponds to Develop a Database for Climate Change Research

Backcountry Limnology: Engaging Citizen Scientists to Collect Data on High Country Lakes, Reservoirs, and Ponds to Develop a Database for Climate Change Research

“It makes us really look inferior to outsiders”: Coping with psychosocial experiences associated with the lack of access to safe water and sanitation

This paper explores daily experiences and coping resources related to the lack of access to safe water and adequate sanitation in Usoma, a lakeshore community in Western Kenya. A qualitative approach that involved 10 focus group discussions and 9 key informant interviews with community leaders, volunteers and professionals was used to explore the research objectives. Data were collected from June to August 2013. Daily practices and experiences around water and sanitation, such as water collection, open defecation and shared toilets, were a major concern to residents. In the absence of safe water, residents used social networks and support, financial resources and the nearby Lake Victoria as coping resources. Findings from this study are important for mobilizing resources in vulnerable settings as a first step towards designing community-based interventions. For public health practice, practitioners must work with - and collaborate across - sectors to enhance and strengthen social networks and cohesion, and protect the natural environment while working toward addressing water-related challenges in deprived settings.

Freshwater turtle or tortoise? The exploitation of testudines at the Mousterian site of Nahal Mahanayeem Outlet, Hula Valley, Israel

Numerous sites showing human occupation during the Pleistocene were discovered at the Hula Valley — in the northern segment of the Jordan Valley, Israel. At the Middle Paleolithic site of Nahal Mahanayeem Outlet (NMO; OSL dated to ca. 65,000B.P.), two testudine species were recovered, a freshwater turtle — the Western Caspian Turtle (Mauremys cf. rivulata), and a tortoise — the Mediterranean Spur-thighed Tortoise (Testudo graeca). The faunal and lithic assemblages were deposited during repeated short-term occupation events. The site was fast covered by mud deposited by rising water in the nearby paleo-Hula Lake, resulting in excellent preservation that provides a rare opportunity to reconstruct the process of procurement, use and eventual disposal of the testudines step-by-step. Evidence of consumption of the Mediterranean Spur-thighed and its carapace exists from the late Lower Paleolithic onward, however, no systematic exploitation of the Western Caspian Turtle has been reported to date from any Pleistocene archaeological sites in the Levant. This is the first and earliest evidence of butchering of the freshwater turtle, M. cf. rivulata, at a Levantine Paleolithic site. Based on detailed taxonomic identification and taphonomic analysis, we suggest that both species were exploited in a similar way at NMO. Their limbs were torn apart, and then the bridge connecting the carapace and plastron was broken. Stone tools were used to separate visceral tissues from the peripheral bones in order to detach the meat. However, due to the different shell thickness, the survival rate of the bridge area varies slightly between the two species. Finally we would like to draw attention to the presence of pits mimicking man-made percussion notches on the shells of extant specimen of both species, advocating caution when identifying percussion signs in the fossil record.

Growth and survival rate of endemic trees of Ethiopia: Olea africana and Hagenia abysinicca in the degraded lake of Haramaya Watershed, Ethiopia

The study was conducted to explore the growth and survival rate of the native tree species of Ethiopia, Olea africana and Hagenia abysinicca in the degraded Lake Haramaya Watershed, eastern Ethiopia. Three sub watersheds of Lake Haramaya Watershed, namely: Bachake, Damota, and Tinike were selected purposefully on the basis of their extreme degradation and nearby vanished Lake Haramaya. In each sub watersheds, a total of about 12 main standard quadrats have been applied and the required data has been recorded. The result of the study indicated that Olea africana performs well at Damota sub watershed, accounting 38% of survival rate followed by Tinike sub watershed having a survival rate of 37%. Only 29% of the total planted Olea africana were survived at Bachake sub watershed. Furthermore, it has been revealed via this study that about 55.6% of Hagenia abysinicca were survived at Damota sub watershed. Comparing the survival rate of the two species, Hagenia abysinicca were better withstand and grow under an extreme pressure of local peoples intervention at all sub watersheds. Therefore, the study indicated that growing and maintaining of these two endemic trees in all sub watersheds were difficult task unless much awareness will be made at grass root level. Lastly, the study encourages mega projects on growth and survival rate of other native trees species in the degraded areas of Ethiopia.

English

The study was conducted to explore the growth and survival rate of the native tree species of Ethiopia, Olea africana and Hagenia abysinicca in Lake Haramaya Watershed, Eastern Ethiopia. Three sub watersheds of Lake Haramaya Watershed, namely, Bachake, Damota, and Tinike were selected purposefully on the basis of their extreme degradation and nearby vanished Lake Haramaya. In each sub watersheds, a total of about 12 main standard quadrats have been applied and the required data has been recorded. The result of the study indicated that O. africana performs well at Damota sub watershed, accounting 38% of survival rate followed by Tinike sub watershed having a survival rate of 37%. Only 29% of the total planted O. africana were survived at Bachake sub watershed. Furthermore, it has been revealed via this study that about 55.6% of H. abysinicca survived at Damota sub watershed. Comparing the survival rate of the two species, H. abysinicca better withstand and grow under an extreme pressure of local peoples intervention at all sub watersheds. Therefore, the study shows that growing and maintaining of these two endemic trees in all sub watersheds were difficult task unless much awareness will be made. Lastly, the study encourages mega projects on growth and survival rate of other native trees species and explores the challenges associated with growing these trees in the study area in specific and in Ethiopia in general. Key words: Survival rate, endemic trees, sub watershed.