Application and Modification of an Auger Trap to Quantify Emigrating Fishes in Lake Ontario Tributaries

Abstract

Assessments of natural reproduction, rates of survival, and patterns of migration by Pacific salmon Oncorhynchus spp. in Great Lakes tributaries require quantification of emigrating smolts. Auger smolt traps were modified and tested during annual downstream migrations of juvenile chinook salmon Oncorhynchus tshawytscha, coho salmon O. kisutch, and steelhead O. mykiss in three eastern Lake Ontario tributaries. The traps were scaled to fit small‐ to medium‐sized streams (third or fourth order) that had fluctuating flows and high debris outputs. During periods of reduced discharge, up to 85% of the streamflow was sampled by one trap. The fraction of migrating smolts captured (efficiency) was determined with wild and hatchery‐released fish. Site choice played a major role in determination of trapping efficiencies, which ranged from 1.3 to 17% for wild salmonids. The highest efficiencies were found for wild chinook salmon smolts (11–17%) in a tributary of the Salmon River, New York. No salmonids appeared to be injured by the trapping mechanism on any of the streams sampled from 1988 to 1991. The traps also proved effective at capturing brown bullheads Ameiurus nebulosus and golden shiners Notemigonus crysoleucas that were migrating to Lake Ontario from ponds and beaver impoundments in the drainage.

Kootenai River Fisheries Investigations : Rainbow Trout Recruitment : Period Covered: 1997.

“…We used a rotary-screw trap (Thedinga et al 1994, Kennen et al 1994) to capture juvenile rainbow trout outmigrating from the Deep Creek drainage to the Kootenai River. The trap was located on Deep Creek near Moravia ( Figure 2).…”

“…In addition, saggital otoliths were used to estimate the ages of outmigrants captured in October. A mark-recapture technique was employed to estimate trap efficiency for juvenile rainbow trout (Seelbach et al 1985, Kennen et al 1994, Thedinga et al 1994, Roper 1995. Juvenile rainbow trout were fin-clipped and released approximately 400 m above the trap to ensure mixing with the unmarked population.…”

Emigration of Natural and Hatchery Naco x (Chinook salmon; Oncorhynchus tshawytscha) and Heeyey (Steelhead; Oncorhynchus mykiss) Smolts from the Imnaha River, Oregon from 5 October 2006 to 21 June 2007, Annual Report 2007.

“…Solutions Inc., Corvallis, Oregon, was used to capture migrating salmonids (Figure 3). Similar traps have been used to capture migrating juvenile salmonid species in New York and Alaska (Kennen et al 1994;Thedinga et al 1994). The screw trap used in the spring and fall consists of a 2.1 m diameter-trapping cone supported by a metal A-frame and two six-meter pontoons that provided flotation.…”

Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2003-2004 Annual Report.

“…We used a rotary-screw trap to capture juvenile trout out-migrating from Boundary Creek from March 16 to August 23, 1999(Thedinga et al 1994Kennen et al 1994). The trap was located in the SW ¼ of Section 11, Township 65 N., Range 2 W, just downstream of the United States Geological Survey (USGS) gauging station.…”