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
Water clarity modeling in Lake Tahoe: Linking suspended matter characteristics to Secchi depth
Theodore J. Swift,Theodore J. Swift,Joaquim Pérez-Losada,Joaquim Pérez-Losada,S. Geoffrey Schladow,John E. Reuter,Alan D. Jassby,Charles R. Goldman +7 more
TL;DR: An additive semi-analytic model of water clarity for the forward problem of calculating apparent optical properties (AOPs) of diffuse attenuation and Secchi depth from the inherent optical properties due to suspended matter in oligotrophic waters is presented in this paper.
Book ChapterDOI
Sources, concentrations and characteristics of organic matter in softwater lakes and streams of the Swedish forest region
TL;DR: In this paper, water samples from 18 Swedish forest lakes covering a wide range of dystrophy were studied in order to quantify and characterize the organic matter in the water with respect to origin (allochthonous or auto-chonous), physical state (particulate or dissolved) and phosphorus content.
Book ChapterDOI
Use of algae in environmental assessments
R. Jan Stevenson,John P. Smol +1 more
TL;DR: Algae have been used to assess environmental conditions in aquatic habitats throughout the world as mentioned in this paper, based on the environmental sensitivities and tolerances of individual taxa and species composition of assemblages (e.g., diatom frustules and chrysophyte scales).
Journal ArticleDOI
Dissolved oxygen model for regional lake analysis
Heinz G. Stefan,Xing Fang +1 more
TL;DR: A deterministic, one-dimensional, unsteady dissolved oxygen (D.O.) model has been formulated to simulate summer D.O. conditions (stratification) in a wide raange of lakes of the north central United States and to study potential impacts of global climate change.
Journal ArticleDOI
Challenges for mapping cyanotoxin patterns from remote sensing of cyanobacteria
Richard P. Stumpf,Timothy W. Davis,Timothy T. Wynne,Jennifer L. Graham,Keith A. Loftin,Thomas H. Johengen,Duane C. Gossiaux,Danna Palladino,Ashley M. Burtner +8 more
TL;DR: A dual-model strategy can provide an approach to address the challenges of using satellite imagery to quantify the spatial patterns of cyanobacterial toxins, provided cyanotoxin variability is addressed.
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.