Hey, gang.
Thought I'd update my report with what little fishing news I have, along with news of the recent DNR fall trawl results taken on the Bay a couple of weeks ago. This sampling is preliminary as of right now and won't be fully determined or understood until early next year. But it gives us a fairly good idea at the results of this past springs natural walleye spawning success. I want to thank my good friend at the DNR for sharing with me and now you, these trawl results.
Firstly, I got out last Sunday (10-01-06) on the Saginaw River. We did some fan casting along the shoreline from Smith Park in Essexville to the mouth of the river. We caught a variety of species, including one 3 pound walleye (picture below). Bass was the main specie we caught, in sizes that would surprise even the most avid bassmaster. The DNR launch at the mouth was full of boats trailers, and people further out in the Bay than I fishing for perch. Talking to a few coming in, the perch success was minimal on that day.
I expect the walleye river run to be a tad early this year. There is already news of a good flux of Gizzard shad in the river systems and the water temps are 5 to 7 degrees cooler right now, than the same times in years past. All this to me spells a good fall season on the rivers. Now for the trawl results and some fallow up questions I had for my DNR bud. Enjoy.
Hey, Dan.
I've been wondering when you'd ask. Yes, we finished the trawling's last week. It's hard to answer your question this year, however, because there was such a range of sizes and growth rates among the juvenile walleye, that it was very difficult to recognize what was an age-0 (YOY) walleye and what was a yearling and older. Normally we could just visually separate the
YOY and get a count and then see what the catch rate was and compare to other years. This time, we'll have to wait until we age the fish so we can be sure we know what year class each fish is from.
However, based on our best guess at what a YOY was, it looks like maybe (and this still has to be confirmed) that the natural year class produced this year was comparable to 1998 level. You will recall that the 1998 year class was our old record before this string of strong year classes came along beginning in 2003. So to say that this year class is maybe like 1998, isn't too bad. Previously we would have characterized that as a strong year class. Now, however, (with recent years to compare to) a year class of the 1998 proportion might only be characterized as "moderate" in size. Again, however, once we get to aging these fish (over the next few months) we will be able to put some specific numbers to this and our assessment may change up or down.
A more modest year class of walleye this year, however, is neither unexpected nor necessarily a bad thing. Remember that its rare to have a strong year class follow another strong year class in sequence in a walleye population. We've had three in a row so far on Saginaw Bay so its not surprising that this one is more modest (relatively speaking).
Also we observed that our overall prey base in the bay this year is some of the lowest we've measured in many years. I feel pretty sure this is a result of the much increased predation pressure from the growing abundance of walleyes. You'll remember that increasing predation rates was one of our recovery goals so this too isn't necessarily a bad thing. The growth rates of walleye were anticipated to come down as abundance increases and that's exactly what's happening. In the long run, year classes as strong as 2003 - 2005 may not be fully sustainable, and a series of more intermediate or modest year classes is probably more desirable. By depending on natural reproduction (as opposed to stocking), we are allowing the system to regulate it's self to the right balance. At least that's our goal.
I still think the decision to not stock this past year was the right decision. The decision to stock or not for the coming year won't be made until about February. In our survey nets, we caught a lot of older and adult walleye as expected (mostly from the 2003 - 2005 year classes). Of course we have similar information from our survey regarding perch and other species too and we'll be better able to summarize all that in a few months. Remember this is all very preliminary, based on initial impressions. Check back around January or February for the complete picture.
"Question"
What is the DNR classifying/calling prey?
Would your trawl nets get near the bottom where the Gobies live during these trawls?
Would the small mesh nets capture the smaller prey?
Dan.
In general we index 'prey' as the soft rayed fishes that include: Alewife (usually Young of the Year (YOY) in the bay which there has been few of since 2004), smelt, gizzard shad (again YOY), spottail shiners, trout-perch, and round goby.
There are others that might be included but these are the main ones we index. Yes gobies are very vulnerable to the trawls (trawls do best on bottom-oriented species, and less well on suspended species). Gobies were down this year, YOY Alewives remain scarce, gizzard shad YOY were up some, spottails were up some. Emerald shiners (not normally part of this index) were also down.
This doesn't tell the whole story since we know that walleye will also eat spiny rayed prey too. We'll be assembling a more full and representative picture of the prey base in the coming months. It appears that the main prey index will be down but no one is necessarily saying there isn't enough forage or anything like that. We'll need to look at the whole picture. Also, remember that until now, there was a mismatch with too much prey and not enough predators in the bay (kind of the opposite of the main basin). One of our goals was to bring this more in balance. We'll be looking to the walleye growth rate to help us decide where that balance is. Again, this information is all preliminary and we'll have the full analysis later this winter. Be safe, Fish smart, Tight lines. Capt. Dan.
