Wahleach Project Water Use Plan Lower Jones Creek ... - BC Hydro

� Staff gauge reading and discharge measurements at the upstream weir.
Discharge was either directly measured with a flow-transect or estimated
from the stage-discharge curve
� Water visibility/clarity was visually estimated.
� Current weather conditions were recorded.
� Water temperature was collected continuously at two locations (Jones Creek
upstream weir and Lorenzetta Creek) with Onset Tid Bit thermistors.
3.4 Fry Trapping
As per previous years, a modified fyke-net and live-box downstream migrant trap was used for
the 2009 enumeration. Trapping is not possible at the furthest downstream extent of Lower
Jones Creek due to inundation of the Fraser River which generally occurs about half way
through the out-migration period. In 2009 the trap was located at the furthest downstream end
of Reach 3 (Figure 2) which is upstream of the Fraser River inundation and provides a reference
point for separating adult escapement counts conducted in the fall. From March 19 to April 24 a
single trap configuration was used in Lower Jones Creek (Appendix 1). Following inundation of
the Lorenzetta trap during the Fraser River freshet, the trap was moved to Lower Jones Creek
to create a dual-trap configuration (Appendix 1) which was used until the completion of trapping
program. Only adult spawners from areas upstream of the trap were considered when
estimating egg-to-fry survival.
The trap consists of a fyke-net (1/8” mesh) with 7 m wing panels funneling to a 1 m 2 opening at
the cod end. Additional panels were added during the course of the study to improve trap
efficiency when possible. The net panels were anchored to the substrate using 5/8 inch rebar
secured via cedar bracing poles. The cod end funneled to an 8 inch diameter PVC pipe
attached by two steel pipe clamps. The 7.4 m PVC pipe discharged directly into a 0.75 x 1.4 x
1.0 m aluminum live-box. A mesh baffle served to reduce turbulence in the box and also
provided the fry with separation from predators that may have also been captured.
The trap operated continuously from March 19 to May 14, 2009, for a trapping effort of 57 days
in total. Traps were fished continually for the entire period with the exception of a few days when
high water levels damaged the traps or clogged the intake. The traps were cleaned of debris
several times daily. Fish were generally counted once in the morning and again at the end of
the day. All efforts were made to keep the traps fishing as efficiently as possible, with slight
adjustments sometimes necessary to ensure that maximum efficiency was maintained.
Lorenzetti Creek was also trapped to increase the overall captures in the system to ensure
adequate numbers for mark and recapture tests in Jones Creek. The trap in Lorenzetti Creek
was similar in design to Lower Jones. It employed the same PVC pipe, though shorter at 4.5 m
in length, with a cod end of 0.5 m 2 . The wings were also smaller, extending only 5m from the
conduit opening. This trap operated from March 23 to April 23 which is when the Fraser River
inundated the area. Mark-recapture experiments were not undertaken on Lorenzetti Creek
since it is not possible to trap the entire outmigration period. We reported on smolt captures
and calculated ATU’s for comparison with Jones Creek. In addition to the downstream trapping,
six days of minnow trapping were completed in Lorenzetti Creek after the downstream migrant
trap was removed.
Fry were transferred from the traps to plastic buckets and moved streamside for processing.
Fry were identified to species and enumerated while ensuring that marked fry were identified
and enumerated separately. Captured fry were stored in covered 20 L buckets until they were
Lower Jones Creek Fish Productivity Monitoring 2008-2009 8