Separating
the Nass River Sockeye
populations using DNA
High Tech comes to the North Coast
The need to distinguish endangered populations
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In the summer of 99, some local fishers (commercial and sport) were quick to point out that ‘there were lots of Coho around’ and thus the severe restrictions implemented by DFO were seen as a ‘conspiracy’ to get rid of fishers. Well yes, the coastal populations were strong; it was the upper Skeena River ones that were endangered The need and capability for distinguishing one “stock” from another has only come into public policy in the last decade. What ever the history and rationale the information on the smaller runs of commercial fish has just not been collected with the same zeal as “escapement” to the main tributaries like the Babine on the Skeena and the Meziadin on the Nass. (What kind of salmon??) |
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The recent publication in a Canadian scientific journal on attempts
to find a fast accurate means of distinguishing Nass River sockeye salmon thus
is indicative of what will soon be commonplace for the North Coast.—Here is the Abstract
and here is the ref: Application of microsatellite DNA variation to
estimation of stock composition and escapement of Nass River sockeye salmon
(Oncorhynchus nerka)Terry D. Beacham and Chris C. Wood- Pages 297-310
Canadian Journal Fisheries and Aquatic Sciences Volume 56, Number 2, February
1999;
here is older discussion why microsatellite DNA used—quick
and easy to do thus effective tool.
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While the Meziadin Lake run is about three quarters of the total there is much variety among the lesser runs—the present work distinguishes seven other populations roughly dividing between the lower river “sea run” and the upper river “lake” sockeye. (See the above DFO watershed map for the approximate locations of these populations) The figure also gives some indications of the how different (far apart) each population is. |
Nothing is
ever simple
Unfortunately the closer we humans look, the more complex the world appears—thus the Zolzop Creek area has 2 quite distinct populations – probably marking two different periods on colonization. (Perhaps at different stages or periods of last ice age).
DFO Habitat maps and complexity
I like these maps and unfortunately can’t provide a direct link—you have to go in the front door and work yourself thru.
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Here is map showing contours and distance between Meziadin and Bonney Lakes Here is sample of reports on site: Gazetteer Name: Watershed code: SISS/RAB code: Lake Seq. No.: 2 |
Looks
pretty Straight forward until
When one gets down to the ground all those easy generalizations evaporate—look at the complexity of the watersheds in the Kwinageese / Bonney Lake area!!
How can one expect to find only 7 unique populations?
Tools—
Here are some links from DFO habitat reports site – these kinds of tables have high value as the grey literature becomes more accessible to a wider public--- This is for the Kwinageese--
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ONE OF MAJOR SK PRODUCERS IN NASS SYSTEM. |
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PH, DISSOLVED OXYGEN, DISSOLVED SOLIDS. |
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And here is the weakness of this kind of database – this is for a lower Nass River—
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HEAVY SPORT FISHING PRESSURE FROM BRIDGE TO MOUTH.
CLOSURES ENACTED BUT LOCAL RESIDENTS IGRNORED THEM. MANY SPAWNING CH AND CO
WERE TAKEN. |
We don’t have enough information to evaluate this report—what year was it? How serious?
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