Doc mentioned "Ricker Curve"....had not heard of it........maybe others in same boat....so here it is....:


Ricker curve

Ricker curve
named for William Ricker, a Canadian fisheries biologist, this is a mathematical model of fish population dynamics. A graph of mature progeny and spawners is used to determine average maximum catches for a fishery. One line on the graph is the line of natural replacement where spawners are replaced by an equal number of progeny. The natural equilibrium point is where spawners equal progeny without fishing. Past this point crowding is a factor depressing the numbers of fish through egg loss on spawning beds. A curved line shows the maximum sustainable catch (see Ricker (1975) for details)
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"Worse day sport fishing, still better than the best day working"

"I thought growing older, would take longer"