09-08-2014, 05:34 PM
[quote doggonefishin][quote riverdog] And of course the nutrient rich flow of early releases where long gone. [/quote]
That is a factor that cannot be underestimated in discussing the early giants of Lees Ferry.[/quote]
The invertibrates below the dam are the same invertabrates that were there in the 70's.
what early release nutrients were causing those fish to grow that isn't there today?
It's population size. The more fish per mile you have, the smaller average size you have. It's simply math. It's not genes, it's not food, it's not nutrients. It's population size. Plain and simple. Reduce the population size, and average size fish will go up.
This isn't some new theory. This is documented.
http://www.azgfd.gov/w_c/research_managi...erry.shtml
[quote Arizona Game and Fish]Shortly after completion of the dam, the Arizona Game and Fish Department stocked rainbow trout...
...The trout began to flourish in the Lees Ferry reach from 1970-1985 when catches of rainbow trout above 10-pounds were not uncommon, and angler pressure was relatively low. In 1991, however, the Bureau of Reclamation implemented the Record of Decision flow regime, which consisted of higher minimum and more stable flows and allowed for increased trout reproduction and survival. Under these conditions, a huge population of trout developed causing individual fish growth rates to decline. Quite simply, there was a large number of fish competing for limited space and food items, resulting in a fishery where trout less than 14-in were dominant.[/quote]
population size. That's it.
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That is a factor that cannot be underestimated in discussing the early giants of Lees Ferry.[/quote]
The invertibrates below the dam are the same invertabrates that were there in the 70's.
what early release nutrients were causing those fish to grow that isn't there today?
It's population size. The more fish per mile you have, the smaller average size you have. It's simply math. It's not genes, it's not food, it's not nutrients. It's population size. Plain and simple. Reduce the population size, and average size fish will go up.
This isn't some new theory. This is documented.
http://www.azgfd.gov/w_c/research_managi...erry.shtml
[quote Arizona Game and Fish]Shortly after completion of the dam, the Arizona Game and Fish Department stocked rainbow trout...
...The trout began to flourish in the Lees Ferry reach from 1970-1985 when catches of rainbow trout above 10-pounds were not uncommon, and angler pressure was relatively low. In 1991, however, the Bureau of Reclamation implemented the Record of Decision flow regime, which consisted of higher minimum and more stable flows and allowed for increased trout reproduction and survival. Under these conditions, a huge population of trout developed causing individual fish growth rates to decline. Quite simply, there was a large number of fish competing for limited space and food items, resulting in a fishery where trout less than 14-in were dominant.[/quote]
population size. That's it.
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