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Skeena Tyee Test Fishery
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- In-Season Sockeye Escapement [HTML]
[PDF]
- In-Season
Daily Salmon Indices [HTML]
[PDF]
Historic Escapement
Indices
Problem understanding the indices? Click here
for assistance.
Tyee Test Fishery
Gillnet test fishery operations have been conducted at Tyee
in the lower Skeena River since 1955, in order to evaluate the
magnitude of Skeena River salmon and steelhead trout returns.
This program was developed to provide daily
estimates of sockeye escapements through the commercial fishery. The data
obtained from this operation, combined with estimates of the
commercial catch in Area 4, provides a complete picture of the
sockeye and pink runs as they develop each year. This information
is considered essential for the effective management of all Skeena salmonid species.
The estuary of the Skeena River exhibits the greatest tidal
fluctuations on the Canadian Pacific coast. Tidal differences
of over six meters, common during spring tides, generate tidal
currents of three to four knots in some areas. Debris-carrying
tide rips, unusual current patterns, and sandbars make the setting
of a commercial length gillnet in the Tyee area a very difficult
procedure. The net is allowed to drift within a channel measuring
two to five kilometres long and 0.8 km wide that runs parallel
to the northern shoreline of the river.
The net that was used
until 2002 in the Skeena test fishery is an undyed, fibrous
nylon gillnet of 200 fathoms total length and 20 feet depth,
made up of ten equal length panels of mesh sizes 3.5 inches
to 8 inches. Starting in 2002 a new net has
been used based on the popular 6 strand "Alaska Twist" net used by commercial
gillnetters.
Set times for the Skeena test fishery vary according to two
parameters. The first of these is the tide height, i.e. the
height of a particular tide above Chart Datum. The second factor
is the discharge of the river. Spring freshets generally reach
their peak in the month of June and taper off gradually throughout
the summer.
Sets are made on both high and low water slack during daylight
hours. This usually results in three sets a day, but sometimes
only two can be made. Drifts must be exactly an hour long.
Daily escapement estimates are calculated for sockeye
salmon. Although they are not calculated for the other species
(chinook, coho, chum, pink and steelhead), relative abundance and
timing is determined by comparing the calculated indices for
a given year to those recorded in previous years.
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