Bull Trout Restoration Efforts 1992 - 2010

Bull Trout restoration efforts at Crater Lake began in 1992, and as of 2013 fisheries biologists have;

• increased the bull trout population from as few as 200 individuals to as many as 6000 individuals,
• eradicated brook trout from Sun Creek inside Crater Lake National Park and Sun Pass State Forrest (Oregon),
• and, installed three fish passage barriers to keep brook trout from returning to Sun Creek.

Refer to this page to see a description of restoration projects for 2010-2013.

The threats to Bull Trout survival include:

• Habitat degradation and lack of connectivity in stream networks
• Competition and hybridization with introduced brook trout (S. fontinalis)

 

Map of Bull Trout restoration efforts on Sun Creek from 1992 - 2010.

NPS

Project Area: Sun Creek

• 72-km2 watershed in southern Oregon Cascades
• Ownership and land use: Crater Lake National Park, Sun Pass State Forest (Oregon), private cattle ranches
• Historically connected with Wood River Fish Community
• Only extant bull trout population within Crater Lake National Park and one of only two populations remaining in the Wood River Valley
• Bull trout historically occupied entire stream downstream of headwater falls
• Nonnative trout stocked throughout the stream as early as 1912
• Bull trout distribution severely truncated in sympatry with Brook Trout and Brown Trout
  

• Objectives:

• Eradicate nonnatives and monitor Bull Trout response
  

• Methods:

• Artificial barriers installed to exclude nonnatives.
• Electrofishing removal, multiple piscicide treatments, total effort in field > 2000 person days.

• Results:

• No Brook Trout in upper watershed since 2005.
• Bull trout have expanded distribution and increased in abundance following removal of nonnatives.