Report Number: 12726
Permit Number: CRLA1992ADOY
Current Status: Checked in
Date Received: Jan 01, 1998
Reporting Year:
1992
?????Address:
Oregon State University, Cooperative Park
Studies Unit, Corvallis, OR 97331
????Additional investigator(s):
Gary Larson
Park-assigned Study Id. #
CRLA1992ADOY
Permit Expiration Date:
Jan 01, 1998
Permit Start Date:
Jan 01, 1998
Study Starting Date:
Jan 01, 1992
Study Ending Date:
Jan 01, 1992
Study Status:
Completed
Activity Type:
Other
Subject/Discipline:
Other
Objectives:
Prepare and submit final report of 10-year
congressionally mandated study of Crater Lake. Report is to contain results and
conclusions of studies conducted at Crater Lake between 1991 and 1992.
Findings and Status:
Secchi disk readings were in the mid-30 m
range in June, but decreased to the low-20m range in August and September.
Picoplankton (cyanobacteria) may play an important role in the primary
production in the lake. Kokanee salmon were abundant again this year, but in
poor condition. Nitrate concentrations in Spring 42 were at levels similiar to
those reported in previoius years. Analyses of the data collected between 1982
and 1992 indicated that Crater Lake is a complex and dynamic system. Deep-lake
mixing appears to be important to lake productivity. Cyclic patterns in primary
production, chlorophyll, phyoplankton, zooplankton and kokanee salmon were
observed. The clarity of the lake is high, and this appears to be associated
with vertical partitioning of the water column by phytoplankton and zooplankton
species to a depth of 200 m. The level of the lake dropped by about 3 m during
the period from 1984 to 1992. No apparent long-term declines in lake clarity
were observed.
For this study, were one or
more specimens collected and removed from the park but not destroyed during
analyses?
No
Funding provided this
reporting year by NPS:
40000
Funding provided this
reporting year by other sources:
0
Full name of college or
university:
n/a
Annual funding provided by
NPS to university or college this reporting year: 0
