Journal ArticleDOI
A trophic state index for lakes1
TLDR
A numerical trophic state index for lakes has been developed that incorporates most lakes in a scale of 0 to 100, which represents a doubling in algal biomass as well as various measures of biomass or production.Abstract:
A numerical trophic state index for lakes has been developed that incorporates most lakes in a scale of 0 to 100. Each major division ( 10, 20, 30, etc. ) represents a doubling in algal biomass. The index number can bc calculated from any of several parameters, including Secchi disk transparency, chlorophyll, and total phosphorus. My purpose here is to present a new approach to the trophic classification of lakes. This new approach was developed because of frustration in communicating to the public both the current nature or status of lakes and their future condition after restoration when the traditional trophic classification system is used. The system presented hcrc, termed a trophic state index (TSI), involves new methods both of defining trophic status and of determining that status in lakes. All trophic classification is based on the division of the trophic continuum, howcvcr this is defined, into a series of classes termed trophic states. Traditional systems divide the continuum into three classes: oligotrophic, mesotrophic, and cutrophic. There is often no clear delineation of these divisions. Determinations of trophic state are made from examination of several diverse criteria, such as shape of the oxygen curve, species composition of the bottom fauna or of the phytoplankton, conccntrations of nutrients, and various measures of biomass or production. Although each changes from oligotrophy to eutrophy, the changes do not occur at sharply defined places, nor do they all occur at the same place or at the same rate. Some lakes may be considered oligotrophic by one criterion and eutrophic by another; this problem isread more
Citations
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Journal ArticleDOI
Features of the limnological behavior of Salto Grande's reservoir (Argentina-Uruguay)
TL;DR: The results indicate that the phytoplankton of the reservoir is limited by the inorganic turbidity, except at the end of the arms, and is mainly determined by water renewal in the center of the reservoirs aand by the washing effect due to rainfall on the lateral arms.
Journal ArticleDOI
The distribution of phytoplankton along trophic gradients and its mediation by available light in the pelagic zone of large eutrophic lakes
TL;DR: In this article, the authors describe the pattern and principal factors affecting the phytoplankton biomass-nutrient relationship in the pelagic zone of large lakes and show that the response to available light of these key species play a central role in modulating the biomass/nutrient relationships.
Journal ArticleDOI
Zooplankton Community Metrics as Indicators of Eutrophication in Urban Lakes
Sara Lodi,Ludgero Cardoso Galli Vieira,Luiz Felipe Machado Velho,Claudia Costa Bonecker,Priscilla Carvalho,Luis Mauricio Bini +5 more
TL;DR: The main implication of the results is that arguments against the use of simple community-level metrics as indicators of eutrophication cannot be generalized and the need of complete sample analyses to estimate reliable ecological indicators of i.e., identification and counting is suggested.
Journal ArticleDOI
Phytoplankton functional groups in a high spatial heterogeneity subtropical reservoir in China
TL;DR: This is the first application of the assemblage index to a water supply reservoir for the Middle Route Project (MRP) for South-to-North Water Transfer (SNWT) in China and suggests P-limitation of phytoplanlcton growth.
Journal ArticleDOI
Phosphorus supply pathways and mechanisms in shallow lakes with different regime.
TL;DR: In this article, 12 sampling sites from 4 basins of two lakes were studied seasonally from October 2017 to July 2018 in Wuhan City, China, to better understand the pathways and mechanisms of phosphorus (P) supply under different regimes.
References
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Journal ArticleDOI
The phosphorus‐chlorophyll relationship in lakes1,2
P. J. Dillon,F. H. Rigler +1 more
TL;DR: In this article, data for summer chlorophyll and spring total phosphorus concentration were collected from 19 lakes in southern Ontario and combined with data reported in the literature for other North American lakes to produce a regression line that can be used to predict the average summer CHP from a single measurement of phosphorus concentration at spring overturn.
Journal ArticleDOI
Environmental control of photosynthesis in the sea
TL;DR: In this article, a theoretical equation for the photosynthesis-light relation is developed which includes the effects of inhibition in intense light, assuming that phytoplankton adapts to seasonal light changes and that nutrient deficiency affects the carbon:chlorophyll ratio of natural phyto-ankton populations.
Journal Article
Primary production by phytoplankton community in some Japanese lakes and its dependence on lake depth
Journal ArticleDOI
Phosphorus, Nitrogen, and Algae in Lake Washington after Diversion of Sewage
TL;DR: After diversion of sewage effluent from Lake Washington, winter concentrations of phosphate and nitrate decreased at different rates, but nitrate remained at more than 80 percent of the 1963 value and free carbon dioxide and alkalinity remained relatively high.