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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Direct and indirect effects of zooplankton grazing on phytoplankton in a hypereutrophic lake
TL;DR: Daphnia may reduce the relative abundance of blue-green algae and total phytoplankton biomass by grazing directly on the large, colonial algae such as Microcystis and through heavy grazing pressure producing a set of abiotic factors favoring edible, non-blue-green forms which are more efficiently consumed.
Journal ArticleDOI
Relationships between light availability, chlorophyll a, and tripton in a large, shallow subtropical lake
TL;DR: The relationship between planktonic chlorophyll a and mean light availability in the mixed layer was examined for Lake Okeechobee, a shallow eutrophic lake in south-central Florida.
Journal ArticleDOI
The microbiome and antibiotic resistance in integrated fishfarm water: Implications of environmental public health.
TL;DR: The presence of intersecting health risk factors in aquaculture facilities is demonstrated and can lay the foundation for addressing these risks in Aquaculture management in rural China, with potential applicability in other developing regions dependent on aquacculture.
Journal ArticleDOI
Trophic assessment in Chinese coastal systems - Review of methods and application to the Changjiang (Yangtze) Estuary and Jiaozhou Bay
Yongjin Xiao,João G. Ferreira,Suzanne B. Bricker,João Osvaldo Rodrigues Nunes,Mingyuan Zhu,XL Zhang +5 more
TL;DR: In this article, the authors compared traditional Chinese assessment methods and compared with other currently-used methods, such as the Oslo-Paris Convention for the Protection of the North Sea (OSPAR) Comprehensive Procedure and Assessment of Estuarine Trophic Status (ASSETS).
Journal ArticleDOI
Influence of fish density and relative productivity on growth of Kokanee in ten oligotrophic lakes and reservoirs in Idaho
Bruce E. Rieman,Deborah L. Myers +1 more
TL;DR: A significant interaction was found that indicated the general response of growth to density was more pronounced in waters of lower productivity, and density dependence may be more obvious in populations fluctuating at low density or in unproductive waters than in populations at higher densities.
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.