scholarly journals Prediction of hypoxia in eutrophic polymictic lakes

2021 ◽  
Author(s):  
A. Cortés ◽  
A. L. Forrest ◽  
S. Sadro ◽  
A. J. Stang ◽  
M. Swann ◽  
...  
Keyword(s):  
Polymictic Lakes

Abundance Patterns and Community Attributes of Fishes Relative to Environmental Gradients

1987 ◽  
Vol 44 (S2) ◽  
pp. s198-s215 ◽  
Author(s):  
T. R. Marshall ◽  
P. A. Ryan
Keyword(s):  
Food Webs ◽  
Environmental Gradients ◽  
Species Abundance ◽  
Lake Area ◽  
Secchi Disk Transparency ◽  
Abundance Patterns ◽  
Morphoedaphic Index ◽  
Environmental Unpredictability ◽  
Polymictic Lakes ◽  
Canadian Boreal Forest

Seventy-five lakes of the Canadian boreal forest were examined for patterns of fish species abundance and community structure in relation to gradients of four environmental variables: (1) lake area, (2) mean depth, (3) Secchi disk transparency, and (4) morphoedaphic index (MEI). Mean depth appeared to exert the greatest control on the relative abundance of the species considered. The remaining variables influenced abundance in unique ways, although, as with mean depth, this influence was mainly a consequence of changes in thermal and nutrient regimes. An examination of lower trophic components indicated that these regimes appear to structure food webs, with distinctly different patterns in food webs occurring in dimictic and polymictic lakes. Major shifts in aquatic biota occur in the transition region between lake types. Lakes with these characteristics are at a lower successional state due to environmental unpredictability, as demonstrated by an increasing importance of r- over K-strategists.

scholarly journals Overgrowing of two polymictic lakes in Central-Western Poland

2010 ◽  
Vol 10 (3-4) ◽  
pp. 147-156 ◽  
Author(s):  
Agnieszka Ławniczak
Keyword(s):  
Water Level ◽  
Plant Cover ◽  
Emergent Vegetation ◽  
Eutrophic Lakes ◽  
Aerial Photos ◽  
Littoral Zones ◽  
Polymictic Lakes ◽  
Major Factors ◽  
Level Reduction ◽  
Intensive Growth

Overgrowing of two polymictic lakes in Central-Western PolandThis study examined the overgrowth in two eutrophic lakes during the period 1961-2008. In addition, for comparative studies, analyses of plant community structures in these lakes were performed to assess the effects of human pressure, such as water level reduction and increase of nutrient availability on changes in the range of the littoral zone surface. To achieve these aims aerial photos, ortophotmaps, GPS measurements were used to evaluate changes in plant cover in two lakes: Niepruszewskie and Tomickie. Considerable differences between the studied lakes located in an agricultural catchment were observed. Lake Niepruszewskie was characterised by a threefold higher rate of overgrowing, measured per hectare, in comparison with Lake Tomickie. Moreover, in comparison with lake areas, rates of overgrowing were substantialy higher in Lake Tomickie than Lake Niepruszewskie, which is almost seven times bigger. The littoral zones of both lakes are dominated by emergent vegetation. Compared to the data from 1961, the zone of Lake Niepruszewskie increased almost threefold. The biggest changes in overgrowing were observed after reduction of water level (>2002) which was 1.30 ha yr-1. During almost 50 years, emergent vegetation in Lake Tomickie increased more than fivefold. The most intensive growth was observed in years from 1961 to 1986, which amounted to 0.73 ha yr-1. Probably, water level reductions in Lake Niepruszewskie and high eutrophication in Lake Tomickie were recognised as major factors causing intensive overgrowing in the studied lakes.

scholarly journals The water clarity of Polish lakes with charophyte vegetation in the years 1953-1968

2018 ◽  
Vol 49 (1) ◽  
pp. 15-28
Author(s):  
Andrzej Hutorowicz
Keyword(s):  
Trophic State ◽  
Morphological Characteristics ◽  
Water Clarity ◽  
Trophic State Index ◽  
Small Contribution ◽  
Ecological Memory ◽  
Management Project ◽  
State Index ◽  
Polymictic Lakes ◽  
Made In

Abstract A total of 313 lakes with charophyte vegetation were identified based on the data presented in 1111 manuscripts under the shared title of “Assumptions for the fisheries management project in Lake (lake name)”, based on the results of an environmental inventory carried out by the Inland Fisheries Institute in 1953-1968. The lakes’ morphological characteristics were described, hydrophyte species that most frequently accompanied charophytes were identified, differences in summer water transparency were analyzed in 281 lakes with charophyte vegetation and the results were compared with the observations made in 657 other lakes, and the potential trophic state of lakes with charophyte vegetation was determined using Carlson’s trophic state index (1996). More than half (54%) of 171 dimictic lakes with charophyte vegetation were classified as mesotrophic and 31% as oligotrophic, whereas 50% of 110 polymictic lakes were classified as eutrophic, and 40% as mesotrophic. The frequency of taxa that contribute to the eutrophication (degradation) of water bodies, including Ceratophyllum spp. Myriophyllum spp. and Elodea canadensis, increased with a decrease in the percentage of charophytes in communities of submerged hydrophytes. Regardless of the proportion of charophytes in submerged hydrophyte communities, water in the lakes colonized by charophytes was more transparent than in the 659 lakes without charophytes. Water in many polymictic and dimictic lakes with charophyte vegetation, including lakes with a small contribution of charophytes, was more transparent than in lakes without charophytes, which suggests that charophytes are sensitive indicators of water quality and are components of ecological memory in aquatic ecosystems.

Nutrient economics and trophic status of Lakes Sorell and Crescent, Tasmania

1976 ◽  
Vol 27 (1) ◽  
pp. 151
Author(s):  
DMH Cheng ◽  
PA Tyler
Keyword(s):  
Trophic Status ◽  
Nutrient Inputs ◽  
Short Term ◽  
Management Plans ◽  
Increase Productivity ◽  
Flow Through ◽  
Polymictic Lakes ◽  
Enriched Cultures

Effects of various nutrients on short-term photosynthetic carbon uptake and longer-term yield of algae were assayed for two similar, connected lakes (Lake Sorell flowing into Lake Crescent) with contrasting plankton populations. Phosphorus (P) and phosphorus plus nitrogen (P+N) were the only nutrients to stimulate 14C uptake, and more for Lake Crescent than for Lake Sorell, over 3-h incubations, and P+N was only marginally more effective than P alone. Added SiO2 was inhibitory in short-term but not in long-term incubations. During 3-day incubations, P, N and P+N increased 14C uptake for Lake Sorell but usually not for Lake Crescent. Micronutrients and chelators also accelerated 14C incorporation for Lake Sorell but not for Lake Crescent. No nutrient tested singly increased the ultimate yield of algae, but P+N, Na2CO3 and SiO2 added incrementally produced marked, incremental increases in yield, and more so in Lake Sorell than in Lake Crescent. Addition of micronutrients had no further stimulatory effect. Removal of tripton from lake samples seriously impaired yields, even in P+N-enriched cultures. Incremental replacement of tripton produced incremental restoration of yields. Volume for volume, Lake Crescent water contained more tripton and a more organic tripton than Lake Sorell water. Weight for weight, Lake Crescent tripton stimulated faster growth than Lake Sorell tripton but ultimate yields were the same. Micronutrients and chelators together could substitute for native tripton, the role of which seems to be the maintenance of micronutrients in solution in the oxidizing milieu of the polymictic lakes. The greater productivity and greater phytoplankton biomass of Lake Crescent rests on its greater tripton load, derived from greater scouring of sediments, its flow through from Lake Sorell and an abundant fringing marshland. It is likely that the distinctive floras of the two lakes are adapted to the different nutrient conditions, so that flow-through inocula of Lake Sorell algae cannot become established in Lake Crescent. As Lakes Sorell and Crescent are already mesotrophic and eutrophic respectively, and since additions of P and P+N considerably increase productivity and yield, management plans for this recreational area should seek to limit nutrient inputs.

scholarly journals Assessment of selected physicochemical properties of restorated water of the Mogileriskie Lake

2018 ◽  
Vol 44 ◽  
pp. 00011
Author(s):  
Krzysztof Beiieć ◽  
Bożena Szejniuk ◽  
Magdalena Michalska
Keyword(s):  
Ammonium Nitrogen ◽  
Biogenic Elements ◽  
Water Quality Improvement ◽  
Artificial Aeration ◽  
Sampling Points ◽  
Invasive Method ◽  
Polymictic Lakes ◽  
Economic Use ◽  
Water Eutrophication ◽  
Reclamation Process

Excessive supply of nutrients contributes to gradual eutrophication of water. This process can happen fast, especially in shallow lakes which are more prone to degradation. This also causes deterioration of settlement conditions of many organisms and limits economic use of water. Eutrophication can lead to gradual shallowing and shrinking of water reservoirs and subsequently disappearance of lakes. Therefore, appropriate diagnosis and reduction of the amount of pollutantsflowing into lakes are crucial for the water quality improvement and prevention from further degradation. The Mogileńskie Lake, like many other town lakes was supplied with sewage. As a consequence, the reservoir stopped being an attractive urban element, and became an object cumbersomeaud dangerous to the residents health. For this reason the lake has been subjected to many protection and reclamation processes.The water samples were taken 10 times from 3 sampling points between September 2014 and June 2015. The contents of total phosphorus, phosphorates, total nitrogen, nitrates, nitrites, and ammonium nitrogen was measured in the tested water. The results obtained from the water analyzed for biogenic elements, and their compounds indicate low effectiveness of the carried out reclamation. According to many authors, the choice of artificial aeration as a reclamation process for the Mogileńskie Lake was a mistake.This cleaning method does not provide the expected results when used for shallow and polymictic lakes, especially in combination with an invasive method of dredging and the controversial deposing of the extracted residues in the direct proximity of the lake.

Daphnia control of the spring clear-water phase in six polymictic lakes of varying productivity and size

2008 ◽  
Vol 30 (2) ◽  
pp. 186-190 ◽  
Author(s):  
Iris Dröscher ◽  
Kerri Finlay ◽  
Alain Patoine ◽  
Peter R. Leavitt
Keyword(s):  
Water Phase ◽  
Clear Water ◽  
Clear Water Phase ◽  
Polymictic Lakes

Contrasting responses of dimictic and polymictic lakes to environmental change: a spatial and temporal study

2009 ◽  
Vol 72 (1) ◽  
pp. 97-115 ◽  
Author(s):  
Zofia Ecaterina Taranu ◽  
Dörte Köster ◽  
Roland I. Hall ◽  
Theo Charette ◽  
Francine Forrest ◽  
...  
Keyword(s):  
Environmental Change ◽  
Temporal Study ◽  
Polymictic Lakes
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