Fishing with Rod Discussion Forum
Fishing in British Columbia => General Discussion => Topic started by: salmonrook on November 03, 2017, 06:25:24 PM
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Was on the Vedder today, boy was it cold , only saw 4 people.
I saw some spawned out chum in the side channels and they had tags on them .
They had 2 round orange tags just below the dorsal fin and one with 2 round green tags just below or at the bottom of the dorsal fin.
I assume they are for tracking the fish and their patterns and location .
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So let me answer my own question
They are Petersen Disc tags applied at a location downriver and apparently counted or recovered upriver to track migration patterns and spawning habits. Would like to know the original tagging location but that is probably classified info from DFO.
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https://www.facebook.com/fishingwithrod/photos/a.10154359608502712.1073741831.78768862711/10155168364482712/?type=3&theater
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I'm curious how they control for high water events that would wash the carcasses downstream and confound any data re. spawning location. Although I suppose that's less of an issue for off channel habitat that is less susceptible to water fluctuations.
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I'm curious how they control for high water events that would wash the carcasses downstream and confound any data re. spawning location. Although I suppose that's less of an issue for off channel habitat that is less susceptible to water fluctuations.
I talked to the people as they were tagging and the tags are used to estimate the total return of chums for the year by going to spawning beds and counting the ratio between tagged and untagged fish. Those high water events would wash away an equal ratio of tagged vs. untagged fish so the data would not be impacted too significantly.
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I'm curious how they control for high water events that would wash the carcasses downstream and confound any data re. spawning location. Although I suppose that's less of an issue for off channel habitat that is less susceptible to water fluctuations.
I talked to the people as they were tagging and the tags are used to estimate the total return of chums for the year by going to spawning beds and counting the ratio between tagged and untagged fish. Those high water events would wash away an equal ratio of tagged vs. untagged fish so the data would not be impacted too significantly.
certainly are a large number of uncontrollable variables involved in estimating the number of salmon that leave as young and re-enter as adults. Goes some way to explaining why there can be a large difference between the estimated return and the actual return.