Older fish produce eggs with more lipid energy (larger lipid globules), which in turn gives their larvae a survival advantage when food is scarce.
Older fish have exponentially more eggs per pound of body mass. That means a 40 lb fish carries tens of times more eggs than a 10 lb fish. Killing a single 40 lb fish has the same spawning effect as killing tens of 10 lb fish.
Older fish spawn earlier in the season than smaller fish, which broadens the likelihood of the species total spawning success (some years larvae survival conditions are better early, some years late.....therefore the chances of a good year class are better when spawning is spread out)
Here is another link that has some very pertinent (although not species specific) information on the value of large spawning fish (about 1/2 way thru the article).
http://hmsc.oregonstate.edu/HsO/PDF/...0Fisheries.pdf
Plan for the future, guys. Eat the 28" fish, brag about the big ones you let go, but killing a big one just to "prove" you caught it and build your reputation as a stud fisherman is shortsighted and selfish in this day and age.........even if once upon a time it was the sign of a fisherman worth admiring.
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