Abstract Title

Session S-05E: Managing Floodplain Rehabilitation Success to Inform Decision Making: A Case Study from Hansen Creek, Skagit County

Keywords

Habitat

Start Date

1-5-2014 10:30 AM

End Date

1-5-2014 12:00 PM

Description

Shortly after the construction of the Hansen Creek floodplain restoration project in 2010-2011, we conducted a pilot study of the initial use of the site by juvenile salmonids and the early development of invertebrate communities. We found that juvenile Coho salmon collected from the restored floodplain during periodic inundation events had higher instantaneous rations (a measure of feeding intensity) than Coho collected during regular monthly sampling in the creek channels. The floodplain site also had consistently higher insect abundances. Applying the data and lessons learned from the pilot study, we undertook a more comprehensive 13-month study of Hansen creek and its restored floodplain in 2012 and 2013. We conducted snorkel surveys and electrofishing in pools and riffles in both diked and newly restored habitats within the project site and at a reference area. Diets of juvenile Coho and Steelhead and Cutthroat trout were collected, as well as invertebrates from neuston net samples and fallout traps. In this talk we discuss salmonid distribution seasonally and by reach, compare salmonid diets (prey quantity and quality) among different creek reaches and floodplain habitat, and evaluate the relationship between salmonid diets and invertebrate results.

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May 1st, 10:30 AM May 1st, 12:00 PM

Salmonid early response to restored freshwater floodplain

Room 613-614

Shortly after the construction of the Hansen Creek floodplain restoration project in 2010-2011, we conducted a pilot study of the initial use of the site by juvenile salmonids and the early development of invertebrate communities. We found that juvenile Coho salmon collected from the restored floodplain during periodic inundation events had higher instantaneous rations (a measure of feeding intensity) than Coho collected during regular monthly sampling in the creek channels. The floodplain site also had consistently higher insect abundances. Applying the data and lessons learned from the pilot study, we undertook a more comprehensive 13-month study of Hansen creek and its restored floodplain in 2012 and 2013. We conducted snorkel surveys and electrofishing in pools and riffles in both diked and newly restored habitats within the project site and at a reference area. Diets of juvenile Coho and Steelhead and Cutthroat trout were collected, as well as invertebrates from neuston net samples and fallout traps. In this talk we discuss salmonid distribution seasonally and by reach, compare salmonid diets (prey quantity and quality) among different creek reaches and floodplain habitat, and evaluate the relationship between salmonid diets and invertebrate results.