Report Number: 12843
Reporting Year: 1999
Permit Number: CRLA1999014
Date Received: Jan 01, 1999
Principal Investigator:
Mark Buktenica,
National Park Service,
Crater Lake, Oregon 97604
Additional investigator(s):
Brain
Mahoney, Dr Gary Larson, Scott Girdner
Park-assigned Study Id. #
CRLA1999014
Permit Expiration Date:
Jan 01, 1999
Permit Start Date:
Jan 01, 1999
Study Starting Date:
Jan 01, 1992
Study Ending Date:
Jan 01, 2001
Study Status:
Completed
Activity Type:
Other
Subject/Discipline:
Fish / Ichthyology
Objectives:
Restore native bull trout to
historic numbers and distribution in Sun Creek, within the park, remove
non-native brook trout, and prevent re-invasion of non-native species in the
future.
Findings and Status:
Bull trout are the only native
fish in Crater Lake National Park. In 1989, biologists discovered that bull
trout had been drastically reduced, and restricted to a small section of one
creek in the park because of the introduction of non-native brook trout. The
bull trout's survival in the park was jeopardized due to competition and
hybridization with the introduced brook trout. To ensure their survival, a bull
trout restoration plan was written and reviewed by a panel of national experts
in October 1991. The long-term goals of the plan were to: 1) restore the remnant
population of bull trout to historic numbers and distribution in Sun Creek; 2)
eradicate brook trout, and 3) prevent re-invasion of non-native fish.
Restoration fieldwork began in 1992. Barriers were constructed to prevent
re-invasion of non-native fish. Biologists used a combination of techniques to
remove brook trout, including electroshocking, snorkel diving, trap nets, and
the fish toxin Antimycin. Because of these efforts, bull trout populations
increased from approximately 200 individuals in 1992 to 600 in 1999, and they
have reclaimed approximately 7 miles of the creek.
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: 0
Funding provided this
reporting year by other sources:
60000
Full name of college or
university:
n/a
Annual funding provided by
NPS to university or college this reporting year: 0
