Record Display for the EPA National Library Catalog


Main Title Trophic equilibrium of Lake Washington /
Author Edmondson, W. T.
CORP Author Washington Univ., Seattle. Dept. of Zoology.;Corvallis Environmental Research Lab., Oreg.
Publisher Corvallis Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency ;
Year Published 1977
Report Number EPA-600/3-77-087; EPA-R-802082
Stock Number PB-273 106
OCLC Number 03525765
Subjects Eutrophication--Washington (State)--Washington, Lake ; Chemical equilibrium ; Washington (State)--Lake Washington
Additional Subjects Limnology ; Plankton blooms ; Lake Washington ; Sewage ; Nutrients ; Concentration(Composition) ; Phosphorus ; Transparence ; Nitrogen ; Chlorophylls ; Chemical equilibrium ; Balancing ; Abundance ; Trends ; Winter ; Zooplankton ; Washington(State) ; Trophic level ; Daphnia ; Epilimnion
Internet Access
Description Access URL
Library Call Number Additional Info Location Last
EJBD ARCHIVE EPA 600-3-77-087 Headquarters Library/Washington,DC 01/11/2011
EJBD  EPA 600-3-77-087 Headquarters Library/Washington,DC 05/23/2014
ELBD  EPA 600-3-77-087 AWBERC Library/Cincinnati,OH 01/29/2019
ESAD  EPA 600-3-77-087 Region 10 Library/Seattle,WA 06/10/2005
ESBD  EPA-600-3-77-087 CPHEA/PESD Library/Corvallis,OR 09/05/2017
NTIS  PB-273 106 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation viii, 36 pages : illustrations, tables ; 28 cm
Sewage effluent was diverted progressively from Lake Washington during 1963-1968, and the chemical conditions changed in close relation to the amount of sewage entering. The total phosphorus content of the lake decreased rapidly to 1971 after which year it varied around a value of about 50,000 kg (= 17 micro/l) with a slight decreasing trend. The lake has retained about 56% of the phosphorus that entered during 1971-1975. Winter means of nitrate and the annual mean total content of Kjeldahl nitrogen has decreased at a slow rate during the entire period. Phytoplankton as measured by chlorophyll in the epilimnion during summer dropped to a low value in close proportion to phosphorus during diversion, but has decreased faster than phosphorus during 1971-1976. A large increase in transparency occurred in 1976. A major change is taking place in the character of the zooplankton of Lake Washington in that Daphnia became very abundant in 1976. This event is probably not directly related to recovery from eutrophication, so the lake is entering a new phase.
Includes bibliographical references (pages 15-18).