Historically, the marshes surrounding Upper Klamath Lake were some of the most important nursery and rearing habitats for several sucker species. The Native Americans in the area utilized the abundant sucker fisheries as an important source of protein in the spring, when other sources of food had become depleted. However, with the onset of agriculture and ranching in the basin, the lake suffered from large scale wetland conversion/loss. This practice has degraded water quality and reduced the available habitat for larval and juvenile suckers. Combined with overfishing, this led to diminished populations and the 1988 federal endangered listing of the Lost River sucker (Deltistes luxatus) and shortnose sucker (Chasmistes brevirostris). The Williamson River Delta restoration project was designed to address both water quality and habitat availability to directly benefit sucker populations.

 

Following the initial restoration, a monitoring program was implemented to document any changes in sucker populations.  From 2000-2011 various sampling methods were used to investigate the sucker populations. From 2000-2005 populations were studied in pilot restoration areas. A long-term monitoring program was established in 2006 to study effects of the large scale project. The specific objectives of this program were to:

1. Determine the distribution, abundance, and habitat use of endangered larval suckers at the Williamson River Delta, with a focus on the Tulana and Goose Bay portions of the delta
2. Determine if other species (native and non-native) are using the restored wetlands
3. Describe and characterize fish condition (age, size, growth, gut fullness) of larval suckers
4. Determine how restoration at the delta changes the distribution and patterns of habitat use by larval suckers along Upper Klamath Lake (UKL) shorelines and in South Marsh
5. Build collaborative relationships with scientists and managers across the Upper Klamath Basin to share information and better understand sucker life history dynamics.

 

For data acquisition, pop-nets were used to collect the fish samples for later analysis. When sucker monitoring was completed in 2011, the results were promising. Larval suckers certainly inhabited the restored wetlands and were exhibiting greater body lengths and fuller guts in the vegetated areas.  Currently, approximately 2,500 acres of emergent wetland habitat have been made available for larval and juvenile sucker rearing, with an additional 3,000 acres of open water habitat.