12707 – Limnological Studies of Crater Lake

Investigator’s Annual Reports (IAR’s) for Crater Lake National Park

Limnological Studies of Crater Lake


Report Number: 12707

Permit Number: CRLA1991AADP

Current Status: Checked in

Date Received: Jan 01, 1998

Principal Investigator: Gary Larson, Cooperative Parks Study Unit, College of Forestry, Oregon State University, Corvallis, OR

Additional investigator(s): Dr. David McIntire, Mark Buktenica

Park-assigned Study Id. #: CRLA1991AADP

Permit Expiration Date: Jan 01, 1998

Permit Start Date: Jan 01, 1998

Study Starting Date: Jan 01, 1982

Study Ending Date: Jan 01, 1992

Study Status: Completed

Activity Type: Other

Subject/Discipline: Other

Objectives: Develope a reliable data base for use in the future.;Develope an understanding of the physical, chemical and biological features of the lake.;Establish a long-term monitoring program.;If changes in lake condition are detected, develop studies to identify the cause(s) and if anthropogenic, recommend mitigation actions.

Findings and Status: Secchi disk readings were in the mid-30 m range in June, but decreased to the low 20 m range in August and September. Picoplankton (cyanobacteria) may play an important role in primary production in the lake. (Daphnia) were in low abundance relative to their densities in the late 1980’s. Kokanee salmon were abundant again this year.

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: 133000

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

<< previousnext >>