Mercury bioaccumulation in fish: Effects of intensive fishing in three natural lakes of Northern Québec, Canada

2003 ◽  
Vol 107 ◽  
pp. 1443-1443 ◽  
Author(s):  
C. Surette ◽  
M. Lucotte ◽  
J. Doire ◽  
A. Tremblay
Keyword(s):  
Natural Lakes ◽  
Mercury Bioaccumulation ◽  
Intensive Fishing

Regional variation in mercury bioaccumulation among NW Atlantic Golden (Lopholatilus chamaeleonticeps) and Blueline (Caulolatilus microps) Tilefish

2021 ◽  
pp. 117177
Author(s):  
Hunter Roose ◽  
Gordon Paterson ◽  
Michael G. Frisk ◽  
Robert M. Cerrato ◽  
Paul Nitschke ◽  
...  
Keyword(s):  
Regional Variation ◽  
Mercury Bioaccumulation

scholarly journals Watershed Suspended Sediment Supply and Potential Impacts of Dam Removals for an Estuary

2021 ◽  
Author(s):  
David K. Ralston ◽  
Brian Yellen ◽  
Jonathan D. Woodruff
Keyword(s):  
Suspended Sediment ◽  
River Estuary ◽  
Dam Removal ◽  
Hudson River ◽  
Sediment Traps ◽  
Sediment Supply ◽  
Watershed Area ◽  
Natural Lakes ◽  
Sediment Deposits ◽  
Dam Removals

AbstractObservations and modeling are used to assess potential impacts of sediment releases due to dam removals on the Hudson River estuary. Watershed sediment loads are calculated based on sediment-discharge rating curves for gauges covering 80% of the watershed area. The annual average sediment load to the estuary is 1.2 Mt, of which about 0.6 Mt comes from side tributaries. Sediment yield varies inversely with watershed area, with regional trends that are consistent with substrate erodibility. Geophysical and sedimentological surveys in seven subwatersheds of the Lower Hudson were conducted to estimate the mass and composition of sediment trapped behind dams. Impoundments were classified as (1) active sediment traps, (2) run-of-river sites not actively trapping sediment, and (3) dammed natural lakes and spring-fed ponds. Based on this categorization and impoundment attributes from a dam inventory database, the total mass of impounded sediment in the Lower Hudson watershed is estimated as 4.9 ± 1.9 Mt. This represents about 4 years of annual watershed supply, which is small compared with some individual dam removals and is not practically available given current dam removal rates. More than half of dams impound drainage areas less than 1 km2, and play little role in downstream sediment supply. In modeling of a simulated dam removal, suspended sediment in the estuary increases modestly near the source during discharge events, but otherwise effects on suspended sediment are minimal. Fine-grained sediment deposits broadly along the estuary and coarser sediment deposits near the source, with transport distance inversely related to settling velocity.

scholarly journals Long-Term Changes in Floristic Diversity as an Effect of Transforming the Lake into a Retention Reservoir

2021 ◽  
Vol 13 (14) ◽  
pp. 7642
Author(s):  
Joanna Sender ◽  
Danuta Urban ◽  
Monika Różańska-Boczula ◽  
Antoni Grzywna
Keyword(s):  
Drainage System ◽  
High Water ◽  
Diversity Indices ◽  
Habitat Diversity ◽  
Peat Bogs ◽  
Ecological Index ◽  
Natural Lakes ◽  
Lighting Conditions ◽  
Low Reaction Temperature

The Łęczna-Włodawa Lake District is one of the most valuable natural regions in Europe. It is an area of numerous lakes, peat bogs, swamps and forests, which has been undergoing intensive transformation for decades. Among the largest projects were the creation of the Wieprz Krzna Canal system along with the drainage system and the transformation of natural lakes into retention reservoirs. Among the transformed lakes is Lake Wytyckie. The land was used for analyses near the lake, and floristic and habitat analyses were carried out within the boundaries of the contemporary embankment. The studies were carried out from the 1950s, when the lake functioned as a natural reservoir, through to the 1980s (the transformation of the lake), to the 2020s. Lake Wytyckie was transformed into a retention reservoir by increasing its size and flooding the areas inhabited mainly by peat bog, meadow and forest vegetation, which contributed to the impoverishment of both species and habitat diversity of the area, while it increased the nutrient richness of the water. This was reflected both in the decline in the value of individual diversity indices as well as in the ecological index numbers. In the first period of the research, the area was dominated by wetlands, not drained, with a large variety of species that preferred good lighting conditions. Additionally, the habitat was characterized by low reaction, temperature and trophic values. In the following period, there was an increase in the depth of the water of the reservoir, characterized by high water visibility values, which contributed to the presence of protected species, as did the low moisture content of the areas within the embankment and a neutral pH. The factors currently influencing the formation of the vegetation structure are the high humidity of the entire embankment area, the increase in pH, and the significant increase in the share of built-up areas in the immediate vicinity.

Assessment of mercury bioaccumulation within the pelagic food web of lakes in the western Great Lakes region

Ecotoxicology ◽  
2011 ◽  
Vol 20 (7) ◽  
pp. 1520-1529 ◽  
Author(s):  
Kristofer R. Rolfhus ◽  
Britt D. Hall ◽  
Bruce A. Monson ◽  
Michael J. Paterson ◽  
Jeffrey D. Jeremiason
Keyword(s):  
Great Lakes ◽  
Food Web ◽  
Great Lakes Region ◽  
Pelagic Food Web ◽  
Western Great Lakes ◽  
Mercury Bioaccumulation

Water movements in lakes during summer stratification; evidence from the distribution of temperature in Windermere

1952 ◽  
Vol 236 (635) ◽  
pp. 355-398 ◽  
Keyword(s):  
Internal Waves ◽  
Mathematical Form ◽  
Historical Survey ◽  
Thermo Electric ◽  
Stratified Lakes ◽  
Natural Lakes ◽  
Complicating Factors ◽  
Internal Seiches ◽  
Theoretical Analyses ◽  
Scottish Lochs

The first part of this paper is taken up with an historical survey of the relatively few observations, some detailed and some less so, of internal seiches (internal standing waves) in lakes. After a description of the thermo-electric thermometer employed, there follow details and illustrations of the evidence, from temperature observations, for such internal waves in the northern basin of Windermere. Two main phases could be distinguished: (i) motion under wind stress leading to quasi-steady states with some or all of the isotherms tilted; (ii) internal seiche motion which developed after the wind had dropped. These observations confirm the findings of Wedderburn and his collaborators on the Scottish Lochs (1907-15). The results from Windermere are presented, not because any such confirmation is necessary, but in order to secure belated recognition of the fact that Wedderburn’s ‘ temperature seiche ’ is not an isolated phenomenon, but is an everyday feature of movement in stratified lakes subject to wind action. As this movement is an important and largely unrecognized factor in lake environment, this paper is addressed mainly to limnologists. In its latter part, results of theoretical analyses of a detailed series of observations are presented in non-mathematical form. The applicability of a theory of oscillations in a basin with three layers of differing density (set out in an appendix by M. S. Longuet-Higgins) is tested by comparing theoretical and observed deflexions of selected isotherms from their equilibrium levels, resulting from internal waves after a gale. This theory also enables horizontal components of velocity and displacement to be calculated for each layer. Complicating factors in natural lakes are enumerated, and the influence of internal waves on lake biology and sedimentation is discussed.

Cross-basin comparison of mercury bioaccumulation in Lake Huron lake trout emphasizes ecological characteristics

2014 ◽  
Vol 34 (2) ◽  
pp. 355-359 ◽  
Author(s):  
Rachel A. Abma ◽  
Gordon Paterson ◽  
Anne McLeod ◽  
G. Doug Haffner
Keyword(s):  
Lake Trout ◽  
Lake Huron ◽  
Ecological Characteristics ◽  
Mercury Bioaccumulation

Uzbekistan’s Aquatic Environment and Water Management as an Area of Interest for Hydrology and Thematic Tourism

2021 ◽  
Vol 12 (3) ◽  
pp. 642
Author(s):  
Jacek RÓŻKOWSKI ◽  
Mariusz RZĘTAŁA
Keyword(s):  
Water Management ◽  
Agricultural Land ◽  
Groundwater Resources ◽  
Global Scale ◽  
Aral Sea ◽  
Irrigated Agriculture ◽  
Human Consumption ◽  
Irrigation Systems ◽  
Natural Lakes ◽  
Area Of Interest

The functioning of Uzbekistan’s economy is closely linked to the water resources of its huge cross-border rivers: the Amu Darya and the Syr Darya, as well as to the groundwater present within their basins. Both natural lakes and artificial reservoirs (e.g. the Aydar-Arnasay system of lakes, the Kayrakkum Reservoir, the Chardarya Reservoir) are present there, which retain significant amounts of water, and large canals with lengths of up to several hundred kilometres which involve complex hydraulic structures are used for irrigation purposes. All these are components of a water management system which needs optimisation; as much as 80% of agricultural land is irrigated, with 70% of the water being lost due to inefficient irrigation systems. The consequence of this allocation of river flows and the overuse of water in irrigation systems has been the disappearance of the Aral Sea (1960 year – 68,900 km2, 2017 year – 8,600 km2) and the inflow of water into the Sarygamysh Lake as well as the reduction of Uzbekistan’s groundwater resources by about 40%. The intensive development of irrigated agriculture is associated with changes in surface and groundwater quality caused, inter alia, by the increased use of chemicals in agriculture and the discharge of collector-drainage waters into river systems as well as their reuse. The extent of environmental degradation in some areas (especially in the Aral Sea region) is unique on a global scale. The origins of Uzbekistan’s other hydrological tourist attractions are related to attempts to ensure the availability of water for both human consumption and industrial use under conditions of water scarcity in the country’s arid and semi-arid climates. Not just the spectacular watercourses and water bodies present there (e.g. rivers, lakes, canals), but also small water retention facilities and minor infrastructure elements (e.g. wells, springs and retention basins, canals, ditches and flow control structures) are of potential tourist importance.

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