Friday, August 22, 2008

Steelhead migration information

For folks wondering about migration rates and movement of steelhead we thought we would put together some info from previous studies.
And as expected when dealing with fish there was quite a range of movement. Some fish really go for it and travel fast....some fish just do the slow and steady.

These reports below mostly deal with steelhead movement in the approach waters and the Skeena mainstem. There are further studies on the MOE website for steelhead movement rates once within their home tributaries.
From M. Lough's study in 1981, a steelhead was travelling at a rate of 72 kilometres per day before being caught in a native gillnet. While an upper Skeena tributary fish travelled at only 5 km per day rate.
It seems the average rate of movement is 10km per day in the lower river with a slow increase as they progress higher up the system.
A good resource for Skeena fisheries information in general is this site from the Min. of Environment that catalogues studies and papers from the past and present.

Skeena steelhead migration facts from study SK-32 by M. Lough
Lough, M.J. 1981. Commercial interceptions of steelhead trout in the Skeena River - radio telemetry studies of stock identification and rates of migration.
-steelhead may take only one to two days to travel from Tyee to the tagging sites 75 km upstream: M.Lough
-The 1 or 2 day delay between the commercial and test fisheries plus the 1 or 2 day delay between the test fishery and tagging sites combine to indicate that steelhead which were radio tagged actually moved through the commercial fishery 2 to 4 days earlier.
-the mean rates of migration for individual fish ranged from 2.1 km/day to 27 km/day the mean rates of all fish to pass these scanners was 8.6 km/day
-no significant difference between the rates of fish destined for the Bulkley/Morice and the upper Skeena
-Rates of migration were also calculated for fish that travelled beyond the scanning stations and for fish that were captured in sport and native fisheries. The rates of travel for these 18 fish were slightly higher (10.1 km/day).
The fastest steelhead travelled 144 km at a mean rate of 72 km/day before being caught in a native gillnet.
-Another fish travelled 306km at a mean rate of 21.9 km/day before being caught on the Morice River by a sport angler.
-One steelhead was found in Kluayaz Lake (Kluatantan River), 444 km from the tagging site; travelling at a mean rate of 5.1 km/day. All these figures represent minimum rates of travel because any of these fish could have arrived at their destination before they were captured.
-evidence seems to indicate that most of the Bulkley/Morice steelhead move past Hazelton about two weeks before the upper Skeena run moves into the Skeena above Hazelton.

Skeena steelhead movement from study SK-62: C. Spence 1988
-seine caught steelhead in Skeena approach waters
-The average rate of travel from points of tagging to the river was approximately 8 km/day.
-It was estimated that steelhead took 12 days to migrate through the entire commercial fishing area.
-Travel through the river mouth where the highest gillnet catches of steelhead occur, took 2 – 3 days.
-Rates of movement in the Skeena mainstem averaged 10.4 km/day for the area downstream of the Zymoetz River, and 20.2 km/day between the Zymoetz River and Bulkley River.
-Individual fish travelled as quickly as 32.0 km/day in the upper Skeena River beyond its confluence with the Bulkley.

Skeena steelhead migration study: SK-69 Beere, M.C., 1991. Steelhead migration behaviour and timing as evaluated from radio tagging at the Skeena River Test Fishery, 1989
-study tagged steelhead caught at the Tyee test Fishery by gillnet
-boat caught 113 steelhead of which 55 (48.7%) were dead when landed
-49 stld radio tagged, 9 stld anchor tagged
-7 radio tagged stld were located by a stationary radio receiver 98km upstream of the tagging site
-these 7 stld had an average migration rate of 7.0km per day ( less than the seine caught stld at 10.4km per day)
All information courtesy and copyright of BC Min. of Environment

No comments: