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
More filters
Journal ArticleDOI
Interannual variability in trophic status of shallow lakes on the Boreal Plain: Is there a climate signal?
TL;DR: This article explored relations between climate and trophic status of shallow lakes (lake area > 5 ha, mean depth < 32 m) located on the subhumid western Boreal Plain of Canada.
Journal ArticleDOI
Influence of land use on trophic state indexes in northeast Brazilian river basins
Olandia Ferreira Lopes,Olandia Ferreira Lopes,Felizardo Adenilson Rocha,Lucas Farias de Sousa,Daniela Mariano Lopes da Silva,Andrique Figueiredo Amorim,Ronaldo Lima Gomes,André Luiz Sampaio da Silva Junior,Raildo Mota de Jesus,Raildo Mota de Jesus +9 more
TL;DR: The results showed that, among three basins analyzed, Cachoeira River basin presented the worst values for trophic state index (TSI) due to the high level of anthropization, while best results were found in Una basin, which verified that land use exerted a significant influence on the water quality of bodies of water evaluated.
Journal ArticleDOI
Phytoplankton in the ecological status assessment of European lakes – advantages and constraints
TL;DR: A review of the current phytoplankton-based methods for assessing the ecological status of European lakes is presented in this article, with particular attention paid to the ways of solving problems arising from the need to reflect the complex and dynamic plankton algal communities on a numerical scale in order to gain reliable information about the state of the ecosystem.
Journal ArticleDOI
Impact of Water Level Fluctuation on Water Quality and Trophic State of Lake Nasser and its Khors, Egypt.
TL;DR: In this article, the effect of water level fluctuation on the water quality of Lake Nasser and its morophometry configuration was investigated. And the results of water quality index (WQI) calculations during this study showed that the drop in Lake water levels led to a decline in water quality, while during low water level either phosphorus (P or nitrogen (N) could be limiting phytoplankton growth.
References
More filters
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.