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
Response of Lake Norrviken to reduced nutrient loading: With 3 figures and 1 table in the text
Journal ArticleDOI
Regional distribution of Secchi disk transparency in waters of the United States
Dana L. Bigham Stephens,Robert E. Carlson,Christine A. Horsburgh,Mark V. Hoyer,Roger W. Bachmann,Daniel E. Canfield +5 more
TL;DR: In this paper, the authors collected individual Secchi disk measurements from across the United States to understand regional distribution in water transparency, with lower water transparencies occurring in nutrient-rich regions and higher watertransparencies appearing in nutrientpoor regions.
Journal ArticleDOI
Methane emission from aquatic ecosystems of Mexico City
Karla Martinez-Cruz,Karla Martinez-Cruz,Rodrigo Gonzalez-Valencia,Armando Sepulveda-Jauregui,Fernando Plascencia-Hernández,Yadira Belmonte-Izquierdo,Frederic Thalasso +6 more
TL;DR: In this paper, water quality indicators were positively correlated with CH4 emission, therefore a decrease in untreated wastewater discharge may result in a significant reduction of the greenhouse gas footprint of Mexico City, after a transitional period during which the organic content of the sediment would be degraded.
Journal ArticleDOI
Impact of urbanization on the quality of water in a natural reservoir: a case study with the Deepor Beel in Guwahati city, India.
TL;DR: The Deepor Beel is a natural, freshwater wetland in the south-west corner of Guwahati, India as mentioned in this paper, which is a Ramsar site since 2002.
Journal ArticleDOI
Antibiotic resistance and plasmid profiling of Vibrio spp. in tropical waters of Peninsular Malaysia.
TL;DR: Vibrio species isolated from four different sampling stations in the west coast of Peninsular Malaysia were screened for their antimicrobial resistance and plasmid profiles and multidrug-resistant Vibrio spp.
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.