966 resultados para Lake Geneva
Resumo:
Natural selection drives local adaptation, potentially even at small temporal and spatial scales. As a result, adaptive genetic and phenotypic divergence can occur among populations living in different habitats. We investigated patterns of differentiation between contrasting lake and stream habitats in the cyprinid fish European minnow (Phoxinus phoxinus) at both the morphological and genomic levels using geometric morphometrics and AFLP markers, respectively. We also used a spatial correlative approach to identify AFLP loci associated with environmental variables representing potential selective forces responsible for adaptation to divergent habitats. Our results identified different morphologies between lakes and streams, with lake fish presenting a deeper body and caudal peduncle compared to stream fish. Body shape variation conformed to a priori predictions concerning biomechanics and swimming performance in lakes vs. streams. Moreover, morphological differentiation was found to be associated with several environmental variables, which could impose selection on body and caudal peduncle shape. We found adaptive genetic divergence between these contrasting habitats in the form of 'outlier' loci (2.9%) whose genetic divergence exceeded neutral expectations. We also detected additional loci (6.6%) not associated with habitat type (lake vs. stream), but contributing to genetic divergence between populations. Specific environmental variables related to trophic dynamics, landscape topography and geography were associated with several neutral and outlier loci. These results provide new insights into the morphological divergence and genetic basis of adaptation to differentiated habitats.
Resumo:
Lake Neuchatel is a medium sized, hard-water lake, lacking varved sediments, situated in the western Swiss Lowlands at the foot of the Jura Mountains. Stable isotope data (delta(18)O and delta(13)C) from both bulk carbonate and ostracode calcite in an 81 cm long, radiocarbon-dated sediment core represent the last 1500 years of Lake Neuchatel's environmental history. Comparison between this isotopic and other palaeolimnologic data (mineralogical, geochemical, palynological, etc.) helps to differentiate between anthropogenic and natural factors most recently affecting the lake. An increase in lacustrine productivity (450-650AD ca), inferred from the positive trend in delta(13)C values of bulk carbonate, is related to medieval forest clearances and the associated nutrient budget changes. A negative trend in both the bulk carbonate and ostracode calcite delta(18)O values between approximately 1300 and 1500AD, is tentatively interpreted as due to a cooling in mean air temperature at the transition from the Medieval Warm Period to the Little Ice Age. Negative trends in bulk carbonate delta(18)O and delta(13)C values through the uppermost sediments, which have no equivalent in ostracode calcite isotopic values, are concomitant with the recent onset of eutrophication in the lake. Isotopic disequilibrium during calcite precipitation, probably due to kinetic factors in periods of high productivity is postulated as the mechanism to explain the associated negative isotopic trends, although the effect of a shift of the calcite precipitation towards the warmer months cannot be excluded.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
The Department of Natural Resources (IDNR) Lake Restoration Program focuses on restoring impaired lakes to improve the quality of life for Iowans. Communities are rallying around their water resources as they seek population growth and economic success. Communities of the Iowa Great Lakes Region, Storm Lake, Crystal Lake, Creston and Clear Lake are obvious examples, but other communities including Lake View and Brighton are identifying the importance of lakes for their futures as well. The distribution and nature of Vision Iowa grants, Community Attraction and Tourism grants, and now, Great Places, all further emphasize the importance of water to community, quality of life and economic growth.
Resumo:
Twelve-Mile Lake is an 800-acre man-made lake in central Union County. The watershed has 13,964 land acres that are used by farmers for row crops and pasture. This lake is used as a water supply source for the City of Creston and the Southern Iowa Rural Water Association. In total approximately 40,000 people are affected by this project. Developed over 20 years ago, the lake and fishery was renovated and restocked and much of the shoreline was riprapped about six years ago. During its history, extensive watershed efforts have been ongoing. However, as farmland for cropland has become more valuable and demand has increased, hilly land once used for dairy farming, grazing, and CRP has been put into row crop production. Consequently, sediment loss has become an increasing issue for farmers, conservation professionals, and the Creston Waterworks Department, which owns the water treatment facility at the lake. In 2011, the Creston Water Board received a WIRB grant to implement a sedimentation structure at the north end of the main channel flowing into the lake. The WIRB funds were used for land acquisition, with the IDNR actually constructing the facility. This report depicts work performed as part of the WIRB project.
Resumo:
The Rathbun Land and Water Alliance and partners have undertaken a highly effective approach to water quality protection through the Rathbun Lake Special Project. This approach is achieving a significant reduction in the sediment and phosphorus that impair water quality in Rathbun Lake and its tributaries as a result of the targeted application of best management practices (BMPs) for priority land in the watershed. This application proposes to assist landowners to apply BMPs that will reduce sediment and phosphorus delivery from priority land in targeted sub-watersheds as part of the Rathbun Lake Special Project. Features of this project are: (1) use of geographic information system (GIS) analysis to identify priority land that requires BMPs; (2) assistance for landowners to apply BMPs for 4,000 acres that will reduce the annual delivery of sediment by 6,000 tons and phosphorus by 20,000 pounds; (3) evaluation of the benefits from BMP application using GIS analysis and water quality monitoring; and (4) watershed outreach activities that encourage landowners to apply BMPs for priority land to protect water quality.
Resumo:
Summary of Iowa's lake monitoring which was completed as part of a national study of lake water quality.
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Summary of lake water quality data collected from 2000 through 2011.
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Summary of lake water quality data collected in 2011.