Preliminary Sockeye Escapement Results
DISCLAIMER: ALL DATA IS PRELIMINARY, NUMBERS MAY CHANGE
|
Sproat | March 28, 2024 | April 8, 2024 | 0 |
Stamp River (Great Central) | April 8, 2024 | April 8, 2024 | 0 |
Somass Total | | | 0 |
The adult escapement numbers shown above will be at least 3 days behind the current date.
Fish passing through both fishways are recorded 24 hours a day (i.e., tunnels are lit up at night) using a video monitoring system. Trained and experienced observers review a subsample of the video from both sites in order to generate estimates of escapement to each system. The sub-sampling routine consists of the observers reviewing a portion of the minutes of each hour of video footage and these counts are expanded to estimate hourly counts. During times of high fish passage the observers may only review 5, 10, 15, 20, or 30 minutes of each hour in order to keep up to date on counts. During periods of slow migration the observers may review all 60 minutes of each hour. See the link below for an assessment of the accuracy of the sub-sampling routine.
Link to assessment of sub-sampling routine: Overview of Video Subsampling Analysis
Please note that only adult escapement numbers are shown above (i.e., jacks not included). Biological samples are collected 2-3 times/week from fish at both counting sites to estimate the age and sex composition of escapement. The age results from biosampling are applied to total escapement numbers in order to estimate daily adult and jack escapement numbers.
Link to in-season escapement bulletins: In-Season Escapement Bulletins
Test Fishery:
A test fishery is utilized in-season to estimate abundance of sockeye in the Alberni Canal, to collect biological specimens for assessment (age and stock composition and parasite load) and to provide observations of fish behavior and condition. The test fishery uses a combination of hydro-acoustic soundings and seine sets to determine the abundance of sockeye in Alberni Inlet. The boat follows a systematic route sounding throughout the canal by zigzagging in transects from one side to another. Choice of set location is dependent on either identifiable sockeye schools or typical holding areas. For both the area "inside" 10-mile point and for the area "outside" 10-mile point, an average catch per set is determined. These numbers are then expanded to total abundance for each area given scalars to account for the quality of sets/fishing conditions and also a scalar approximating the number of similar sets that are required to fish the entire area. There is considerable judgment and
subjectivity involved in the determination of the abundance estimate; however over the years this information has been an important component of the in-season re-forecast method.
Link to in-season test boat updates: Link to Test Fishery Data