Abstract Title

Session S-04C: Importance of Puget Sound Lowland Streams

Proposed Abstract Title

Effects of barriers on the distribution of sculpins (Cottus spp.) in Puget Sound lowland streams

Presenter/Author Information

Daniel LantzFollow

Keywords

Freshwater

Location

Room 6C

Start Date

1-5-2014 5:00 PM

End Date

1-5-2014 6:30 PM

Description

Barriers to fish passage can prevent the migration of native fish which can have severe implications to their distribution and indirectly affect other components of the ecosystem. This has been recognized by managers in the past and barriers such as antiquated culverts, weirs and dams have been evaluated for passage of salmonids and other game fish, but not for benthic, non-game native fishes. In the Puget Sound lowlands, native sculpins (Cottus spp.) are an ecologically important component of stream ecosystems and one of the most species diverse and numerous families of resident fish. We examined the distribution and relative densities of sculpins above and below man-made barriers (primarily a series of log or metal weirs) in 14 eastern Puget Sound lowland streams using backpack electrofishing equipment. All sculpin captured were identified to species, enumerated, and the total length (mm) measured. Preliminary results indicate there was a precipitous decline in the abundance of coastrange sculpin (C. aleuticus) and prickly sculpin (C. asper) upstream of the barrier. Both species typically inhabit lower stream reaches and their ability to disperse to upper stream reaches appears to be restricted by barriers in this study. Also, the few coastrange sculpin and prickly sculpin that were captured above barriers were, on average, larger than sculpins downstream of the barrier. In four streams, other sculpin species (shorthead sculpin [C. confusus], torrent sculpin [C. rhotheus], and/or riffle sculpin [C. gulosus]) were common in upper reaches but were rare below the barrier. These findings suggest that barriers not only segregate sculpin species, but also select for larger individuals that can overcome the physical and hydrological effects of the barrier. Our study did not intend to determine specific passage requirements for sculpins, and thus further studies are needed to quantify what is a barrier. However, future management decisions in designing stream restoration projects should consider fish passage of native, non-game species.

This document is currently not available here.

Share

COinS
 
May 1st, 5:00 PM May 1st, 6:30 PM

Effects of barriers on the distribution of sculpins (Cottus spp.) in Puget Sound lowland streams

Room 6C

Barriers to fish passage can prevent the migration of native fish which can have severe implications to their distribution and indirectly affect other components of the ecosystem. This has been recognized by managers in the past and barriers such as antiquated culverts, weirs and dams have been evaluated for passage of salmonids and other game fish, but not for benthic, non-game native fishes. In the Puget Sound lowlands, native sculpins (Cottus spp.) are an ecologically important component of stream ecosystems and one of the most species diverse and numerous families of resident fish. We examined the distribution and relative densities of sculpins above and below man-made barriers (primarily a series of log or metal weirs) in 14 eastern Puget Sound lowland streams using backpack electrofishing equipment. All sculpin captured were identified to species, enumerated, and the total length (mm) measured. Preliminary results indicate there was a precipitous decline in the abundance of coastrange sculpin (C. aleuticus) and prickly sculpin (C. asper) upstream of the barrier. Both species typically inhabit lower stream reaches and their ability to disperse to upper stream reaches appears to be restricted by barriers in this study. Also, the few coastrange sculpin and prickly sculpin that were captured above barriers were, on average, larger than sculpins downstream of the barrier. In four streams, other sculpin species (shorthead sculpin [C. confusus], torrent sculpin [C. rhotheus], and/or riffle sculpin [C. gulosus]) were common in upper reaches but were rare below the barrier. These findings suggest that barriers not only segregate sculpin species, but also select for larger individuals that can overcome the physical and hydrological effects of the barrier. Our study did not intend to determine specific passage requirements for sculpins, and thus further studies are needed to quantify what is a barrier. However, future management decisions in designing stream restoration projects should consider fish passage of native, non-game species.