Historical Birge - Juday Lake Survey - major ions 1900 - 1943

Data collected by Birge, Juday, and collaborators, mostly in north-central Wisconsin,
from 1900 through 1943; generally one sampling event per lake during the summer,  but on
some lakes, especially around Trout Lake Station, several sampling events for several
successive years. This data set contains both surface data (depth of zero) and multi-depth
data. Note that not all variables were measured on all lakes. Documentation: Johnson, M.D.
(1984) Documentation and quality assurance of the computer files of historical water
chemistry data from the Wisconsin Northern Highland Lake District (the Birge and Juday
data).Wisconsin DNR Technical Report. Note: Values of -99999 in water quality data indicate
trace amount of parameter was present. Number of sites: 663 (generally one sampling point
per lake; occasionally, several sampling points per lake on multibasin, large lakes). Note:
This data set was updated in 2013 to include multi-depth and additional surface data for a
large subset of lakes. These additions expanded the number of sites from 605 to 663, and
expanded the date range from 1925-1942 to 1900-1943 . Furthermore, 14 lakes in Minnesota
were added to the data set contributing additional surface and multi-depth data.  Another
dataset was added in 2013 collected by Wisconsin limnologists Chauncey Juday and Edward
Birge, this data set contains variables that are still commonly used in research. For
example, temperature, dissolved carbon dioxide, color, pH, secchi disk, plankton, and
silica. However, the data set also includes variables that are not commonly used, for
example, crude protein, non-amino nitrogen, ether extract, and total organic and inorganic
material. These data are characteristic of water chemistry analysis from the time in which
they were compiled (5/31/1915 - 8/29/1938). The data set features data from 586 different
lakes, primarily lakes in the Northern Highland Lakes District of Wisconsin. However, there
is also data from lakes in southeastern and southcentral Wisconsin. Furthermore, there is a
minimal amount of data  from lakes in Minnesota, Ohio,New York, Alaska, the Philippines, and
the United Kingdom. Documentation:Birge, E.A., and Juday, C. 1922. The inland lakes of
Wisconsin. The Plankton I. Its quantity and chemical composition. Bulletin, Wis. Geol. and
Nat. Hist. Survey No. 64: (Scientific series 13), ix-222.