scispace - formally typeset
Search or ask a question
Journal ArticleDOI

A trophic state index for lakes1

01 Mar 1977-Limnology and Oceanography (Wiley-Blackwell)-Vol. 22, Iss: 2, pp 361-369
TL;DR: 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 is

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI
13 Feb 2015-Science
TL;DR: An updated and extended analysis of the planetary boundary (PB) framework and identifies levels of anthropogenic perturbations below which the risk of destabilization of the Earth system (ES) is likely to remain low—a “safe operating space” for global societal development.
Abstract: The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth system. Here, we revise and update the planetary boundary framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth system into a new state should they be substantially and persistently transgressed.

7,169 citations

Journal ArticleDOI
TL;DR: This review examines how eutrophication influences the biomass and species composition of algae in both freshwater and costal marine systems and suggests that efforts to manage nutrient inputs to the seas will result in significant improvements in coastal zone water quality.
Abstract: Humans now strongly influence almost every major aquatic ecosystem, and their activities have dramatically altered the fluxes of growth-limiting nutrients from the landscape to receiving waters. Unfortunately, these nutrient inputs have had profound negative effects upon the quality of surface waters worldwide. This review examines how eutrophication influences the biomass and species composition of algae in both freshwater and costal marine systems. An overview of recent advances in algae-related eutrophication research is presented. In freshwater systems, a summary is presented for lakes and reservoirs; streams and rivers; and wetlands. A brief summary is also presented for estuarine and coastal marine ecosystems. Eutrophication causes predictable increases in the biomass of algae in lakes and reservoirs; streams and rivers; wetlands; and coastal marine ecosystems. As in lakes, the response of suspended algae in large rivers to changes in nutrient loading may be hysteretic in some cases. The inhibitory effects of high concentrations of inorganic suspended solids on algal growth, which can be very evident in many reservoirs receiving high inputs of suspended soils, also potentially may occur in turbid rivers. Consistent and predictable eutrophication-caused increases in cyanobacterial dominance of phytoplankton have been reported worldwide for natural lakes, and similar trends are reported here both for phytoplankton in turbid reservoirs, and for suspended algae in a large river. A remarkable unity is evident in the global response of algal biomass to nitrogen and phosphorus availability in lakes and reservoirs; wetlands; streams and rivers; and coastal marine waters. The species composition of algal communities inhabiting the water column appears to respond similarly to nutrient loading, whether in lakes, reservoirs, or rivers. As is true of freshwater ecosystems, the recent literature suggests that coastal marine ecosystems will respond positively to nutrient loading control efforts. Our understanding of freshwater eutrophication and its effects on algal-related water quality is strong and is advancing rapidly. However, our understanding of the effects of eutrophication on estuarine and coastal marine ecosystems is much more limited, and this gap represents an important future research need. Although coastal systems can be hydrologically complex, the biomass of marine phytoplankton nonetheless appears to respond sensitively and predictably to changes in the external supplies of nitrogen and phosphorus. These responses suggest that efforts to manage nutrient inputs to the seas will result in significant improvements in coastal zone water quality. Additional new efforts should be made to develop models that quantitatively link ecosystem-level responses to nutrient loading in both freshwater and marine systems.

1,816 citations


Cites background from "A trophic state index for lakes1"

  • ...…been made to apply the OECD's critical load concept to Norwegian marine waters (Hessen et al. 1992), and Janicki (2001) has developed a chlorophyll a-based trophic state index for Florida (USA) estuaries that parallels the highly successful trophic state index created by Carlson (1977) for lakes....

    [...]

Journal ArticleDOI
TL;DR: In this article, a simple linear regression between log10 transformed mercury (Hg) concentration and stable nitrogen isotope values (δ15N), hereafter called trophic magnification slope (TMS), was used to represent the overall degree of Hg biomagnification.
Abstract: The slope of the simple linear regression between log10 transformed mercury (Hg) concentration and stable nitrogen isotope values (δ15N), hereafter called trophic magnification slope (TMS), from several trophic levels in a food web can represent the overall degree of Hg biomagnification. We compiled data from 69 studies that determined total Hg (THg) or methyl Hg (MeHg) TMS values in 205 aquatic food webs worldwide. Hg TMS values were compared against physicochemical and biological factors hypothesized to affect Hg biomagnification in aquatic systems. Food webs ranged across 1.7 ± 0.7 (mean ± SD) and 1.8 ± 0.8 trophic levels (calculated using δ15N from baseline to top predator) for THg and MeHg, respectively. The average trophic level (based on δ15N) of the upper-trophic-level organisms in the food web was 3.7 ± 0.8 and 3.8 ± 0.8 for THg and MeHg food webs, respectively. For MeHg, the mean TMS value was 0.24 ± 0.08 but varied from 0.08 to 0.53 and was, on average, 1.5 times higher than that for THg with a...

634 citations

Journal ArticleDOI
TL;DR: This special issue was stimulated by a symposium that culminated in the publication of the first special issue of Limnology and Oceanography on nutrients and eutrophication, edited by G. Likens (Likens 1972a).
Abstract: Initial understanding of the links between nutrients and aquatic productivity originated in Europe in the early 1900s, and our knowledge base has expanded greatly during the past 40 yr. This explosion of eutrophication-related research has made it unequivocally clear that a comprehensive strategy to prevent excessive amounts of nitrogen and phosphorus from entering our waterways is needed to protect our lakes, rivers, and coasts from water quality deterioration. However, despite these very significant advances, cultural eutrophication remains one of the foremost problems for protecting our valuable surface water resources. The papers in this special issue provide a valuable cross section and synthesis of our current understanding of both freshwater and marine eutrophication science. They also serve to identify gaps in our knowledge and will help to guide future research. Knowledge of the links between nutrients and aquatic productivity began with the pioneering work of Weber (1907) on German peat bogs and with Johnstone’s (1908) studies of the North Sea. A crystallization of freshwater eutrophication concepts took place soon thereafter in Northern Europe, where the first trophic classification systems for surface waters were developed. These early classification systems were based on the intensity of aquatic organic matter production, as well as nutrient supply conditions and ecosystemlevel consequences of increased production (e.g., hypolimnetic oxygen depletion; Rodhe 1969). There was a lot of uncertainty in the subsequent 50 yr about the physical, chemical, and ecological details of the eutrophication process, and hot debates raged about the relative roles of different mineral nutrients as constraints on, or regulators of, primary productivity, especially the macronutrients nitrogen (N), phosphorus (P), and carbon (C). Work on the eutrophication process accelerated in the 1960s and 1970s. Particularly important was the landmark 1971 American Society of Limnology and Oceanography (ASLO) eutrophication symposium that culminated in the publication of the first special issue of Limnology and Oceanography (L&O) on nutrients and eutrophication, edited by G. E. Likens (Likens 1972a). This special issue was similarly stimulated by a symposium that the three of us 1

632 citations


Cites background from "A trophic state index for lakes1"

  • ...Building on the trophic state classification systems for lakes (Carlson 1977; OECD 1982), Dodds (2006) developed a new trophic state classification system for rivers and streams....

    [...]

Journal ArticleDOI
TL;DR: The proposed trophic boundaries for streams generally include a broader range of values in the mesotrophic range than conventional criteria for lakes, reflecting the greater variance in streams.

621 citations

References
More filters
Journal ArticleDOI
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.
Abstract: 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 chlorophyll concentration from a single measurement of phosphorus concentration at spring overturn. This equation is not significantly different from a previously published phosphorus-chlorophyll relationship derived for a number of Japanese lakes.

1,135 citations


"A trophic state index for lakes1" refers background in this paper

  • ...Sewage diversion began in 1963, and by 1968, 99% of the sewage had been diverted from the lake (Edmondson 1970)....

    [...]

Journal ArticleDOI
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.
Abstract: A theoretical equation for the photosynthesis-light relation is developed which includes the effects of inhibition in intense light. Assuming 1) that phytoplankton adapts to seasonal light changes and 2) that nutrient deficiency affects the carbon:chlorophyll ratio of natural phytoplankton populations, equations arc derived which determine photosynthesis per unit chlorophyll and the carbon: chlorophyll ratio as functions of incident radiation and nutrient concentration. These equations appear to describe the main trends in the open North Sea and in a sea loch on the west of Scotland. The photosynthesis-chlorophyll relation also describes the main trends of observations in the Sargasso. For a very shallow turbid area, the agreement was not so good.

705 citations

Journal Article

554 citations


"A trophic state index for lakes1" refers background in this paper

  • ...Sakamoto (1966) and Dillon and Rigler (1974) have shown a relationship between vernal phosphorus concentration and algal biomass, measured as chlorophyll a conccntration....

    [...]

Journal ArticleDOI

299 citations


"A trophic state index for lakes1" refers background in this paper

  • ...(3) I, is about 10% of I0 (Hutchinson 1957; Tyler 1968) and can be considered to be a constant....

    [...]

Journal ArticleDOI
14 Aug 1970-Science
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.
Abstract: After diversion of sewage effluent from Lake Washington, winter concentrations of phosphate and nitrate decreased at different rates. From 1963 to 1969, phosphate decreased to 28 percent of the 1963 concentration, but nitrate remained at more than 80 percent of the 1963 value. Free carbon dioxide and alkalinity remained relatively high. The amount of phytoplanktonic chlorophyll in the summer was very closely related to the mean winter concentration of phosphate, but not to that of nitrate or carbon dioxide.

275 citations


"A trophic state index for lakes1" refers background in this paper

  • ...The greatest value reported by Hutchinson (1957) is 41.6 m in Lake Masyuko, Japan....

    [...]

  • ...(3) I, is about 10% of I0 (Hutchinson 1957; Tyler 1968) and can be considered to be a constant....

    [...]