A good read, plenty informative
THESE ARE SIENCTIFIC FACTS: Keep vs Catch and release of big fish. I hope you take the time to read this and maybe stop judging one way or the other. : Division of Wildlife studies have shown consistently that most female Lake Erie walleye reach sexual maturity at age four; most of the males are ripe at two or three years old. Of course, a few fish always vary from the norm; age at maturity can be affected by things like food availability and growth rate. In a few certain years the females have all been mature by age three.
A widely acknowledged principle in fishery science is that while long-lived fish species may produce more eggs as they get older and larger, the percentage of those eggs that are viable (capable of being fertilized and incubating into normal fry) drops off significantly. That's why hatcheries tend to rotate broodstock on a regular basis, replacing older females with youger ones.
The word "fecundity" refers to the numbers of eggs produced. The word "fertility" refers to the number of actual offspring produced. After reaching sexual maturity, Lake Erie walleye are likely to be at peak fertility for around three to five years. Their peak fecundity may occur later.
This should help rest your concerns regarding keeping those big 30+ inch females caught during the spring.
To help add to your understanding of sexual maturity, here is some additional information to add to Fred's comments on sexual maturity in Lake Erie walleye as compared to walleye elsewhere and farther north of here. This information has been provided in the past as well here on the discussion board.
"Regarding older walleye vs. younger walleye----the older, larger 'hog size walleye' may produce more eggs than younger fish. However, it's a well known fisheries science fact that as females grow older and bigger, the 'viability' of those eggs (ability to become fertilized, incubated and hatched) decreases significantly. The younger females, ages 4-7 and lengths of 18-24 inches (these are averages, and can vary), will produce the most 'viable' eggs.
In comparison, walleyes in far northern Ontario lakes are known to reach sexual maturity at age 7, and may only be 13-14 inches at that time, compared to age 4 and 17-18+ inches in Lake Erie. Northern Ontario walleyes exhibiting the highest 'viability' of eggs range from 13-22 inches---with walleye over 22 inches significantly less viable than the younger, shorter females.
Why is this? In Lake Erie, due to our warmer waters and abundant food supply, our walleyes grow fast and die young. Colder waters and less abundance of food result in northern Ontario walleyes growing slow and dying old.
Regulations a few years ago for specific regions in Northern Ontario for walleye allowed a bag limit of 4. All 4 must be 16 inches and under, or 3 can be under 16 inches, with one being over 22 inches (this provides a big trophy walleye to be taken by outfitter/guide clientele). This protects their most viable spawners and helps improve recruitment when a walleye stock is low. Mixed emotions were raised among anglers when first imposed, yet the realization for a better fishery in the near future has now been accepted. This may be a great management program for cold, northern Ontario lakes where food abundance is low, grow rates are slow, and both angling pressure and native Indian netting has impacts on the fishery. However, you must remember that these northern cold water lakes are NOT comparable to the size and productivity we experience on Lake Erie. "
Just thought you might like some additional info regarding walleye age/size/sexual maturity from a different region and management perspective.
To take this one step farther, and to answer what I believe will be the next question in this thread, here is some information provided by John Hageman on 'Prime size for breeding walleye from 11-08-05. This will help identify age vs. size for Lake Erie walleye.
"According to the ODNR, Div of Wildlife report cited earlier, in 2001 walleyes caught averaged the following lengths lakewide: 1+year old walleyes caught=10 1/2" 2+year old walleyes caught=14 1/4" 3+year old walleyes caught=17 1/4" 4+year old walleyes caught=18 7/8" 5+year old walleyes caught=20 1/4" 6+year old walleyes caught=21 1/4" 7+year old walleyes caught=22 3/4" 8+year old walleyes caught=24 1/4" 9+year old walleyes caught=26 1/4" 10+year old walleyes caught=27 1/2" Now to clarify a couple of things. The "+" refers to the fact that it was beyond the anniversary of its hatching date, which in the main lake is in late April/early May. Most harvest occurs during the summer, so a 1+ fish would be approximately 13 months old in May, 14 months old in June, etc.-but nearly 2 years old during ice fishing season, so you can't really pinpoint an exact size unless you only measure fish caught in a certain month. Also, growth rates vary with available food supply. In years where there is a big year class of walleyes competing for a finite amount of forage (bait fish), growth may be slower than in years where the walleye population is smaller and/or bait production is higher. Another big point is that the females grow larger and quicker than males, and this chart only reflects the average of the female/male growth rates. The three to seven year old walleyes don't look like they grow too fast, but it's because the average is muted by the slower growing males measured in the samples taken.There were not distinctions made at the time of sampling between males and females due to it being summer and there is not an easy way of telling them apart without cutting open the fisherman's catch."
Hope this helps to answer your questions.
Dave Kelch, District Sea Grant Extension Specialist, Ohio Sea Grant College Program Ohio State University Extension
