As I mentioned I would earlier, here is the link from the workshop on straying in pacific salmon.
http://www.nwfsc.noaa.gov/publications/scipubs/techmemos/tm30/tm30.html#tocOne of the most fascinating pieces is the one titled "HOMING, STRAYING, AND COLONIZATION". Here is a piece of it:
"In addition to differences in straying among rivers, straying can also differ from year to year. Interannual variability may be associated with catastrophic events such as the eruption of Mount St. Helens (Leider 1989). Less dramatic environmental changes such as variation in flow and temperature may also contribute to temporal variability in straying, but definitive studies do not seem to have been conducted on these subjects. There is some evidence that temporal variation in straying is associated with population size (Quinn and Fresh 1984). In years when many fish returned to the Cowlitz River hatchery, homing was better than in years when fewer fish returned. This suggests that the dynamics of small populations may be different from those of larger populations. This is an important issue and it needs to be evaluated with other data sets. There is also interannual variation in straying from a site, perhaps related to water quality, rearing conditions, or the number of returning salmon. The tendency of hatchery-produced salmon to enter their hatchery, as opposed to spawning in the river, can also vary greatly from year to year (Nicholas and Downey 1983).
Age at return also contributes to variability in straying. Older chinook salmon tend to stray more than younger fish (Quinn and Fresh 1984, Quinn et al. 1991, Unwin and Quinn 1993, Pascual et al. 1995). The difference in the rate of straying by chinook jacks and by 4- or 5-year-old fish may be an order of magnitude (Quinn and Fresh 1984). Age-specific straying rates have also been observed for coho salmon (Labelle 1992), but not for Atlantic salmon (Potter and Russell 1994). Perhaps, the longer a fish is out to sea, the more it forgets the olfactory cues it needs to return to its natal locality. The turnover of sensory epithelial cells associated with odor recognition (Nevitt et al. 1994), changes in the odors of river water, or some unknown evolutionary mechanism may be responsible for this age effect. Hatchery practices can also influence the age structure of the spawning population, which may in turn influence straying."
To the extent that pink salmon have been found to crowd out the other salmons species when they are very abundant, I wouldn't consider the low return this year a bad thing. However, if it is a signal that ocean conditions are bad for all salmon, that might mean bad coho, chum and chinook returns in the next two years. I personally won't mind if I don't have so many pinks getting in the way this year (in the Chedder) - 2 years ago it was really difficult to find chinook and coho when the river was choked with pinks. Only when a good rain washed out all the zombie pinks did the coho fishing really take off.
As for the majority of the run already passing - look at what happened with the Bristol Bay sockeye this year. The run seemed to be early and then tapered off quickly. Only after many of the tenders and processors left did the main part of the run show up - very late and very abundant.
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Topic: Lower Pinks (Read 14325 times)