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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Review of Management Practices for Controlling the Water Quality Impacts of Potential Pollutants in Irrigated Agriculture Stormwater Runoff and Tailwater Discharges
G. Fred Lee,Anne Jones-Lee +1 more
TL;DR: The Central Valley Regional Water Quality Control Board irrigated agriculture waiver water quality monitoring program will likely show that irrigated agricultural stormwater runoff and tail water/subsurface drain water discharges cause violations of existing and soon to be developed water quality objectives (standards).
Journal ArticleDOI
The impacts of changing nutrient load and climate on a deep, eutrophic, monomictic lake
TL;DR: In this paper, the authors quantified internal and external nutrient loads at Rostherne Mere, U.K., a deep, monomictic eutrophic lake (average annual total phosphorus >100μg/L) with a long, stable period of stratification (c. 8.5 months).
Journal ArticleDOI
Primary productivity in receiving reservoirs: links to influent streams
TL;DR: Gradients within reservoirs in chlorophyll a, depth of photic zone, and primary productivity indicated an influence of the major tributary on reservoir conditions in several of the reservoirs.
Journal ArticleDOI
Plankton diversity and limnological characterization in two shallow tropical urban reservoirs of Pernambuco State, Brazil
TL;DR: Plankton diversity was higher in Apipucos reservoir, especially to phytoplankton, showing that eutrophication and pollution can favor plankton diversity in tropical urban shallow reservoirs.
Journal ArticleDOI
Time scales of external loading and spatial heterogeneity in nutrients-chlorophyll a response: Implication on eutrophication control in a large shallow lake
Tao Xu,Tao Yang,Manling Xiong +2 more
TL;DR: In this article, the authors used generalized additive models (GAMs) to detect the response of chlorophyll a (Chl-a), in-lake nutrient concentrations, and external phosphorus loading in four ecological zones of Lake Okeechobee.
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.