UPDATED : 2018 DNR Preliminary Survey Results

Hi again Paul –

Joelle informed me that she was able to meet you on Friday, and that her and Matt were able to share the draft spring summary (attached) of our netting and electrofishing results on Oxbow Lake……I’ll try to answer some questions you might be thinking of after having reviewed that summary and comparing it with the email I sent you below, which was my initial gut feeling from having participated in the surveys themselves…….

After running the adult walleye population estimate, the numbers of adult fish did come out a little lower than I anticipated (2.9/acre). This was the result of our electrofishing survey, and specifically the fact that we recaptured a fairly high % of the larger adult fish we had handled during netting, while recapturing a smaller % of the smaller adult fish we had handled during netting. This results in a lower estimate of the “large” adult fish and a higher estimate of the relatively “small” adult fish to be present in the Oxbow Lake adult walleye population. This is a good example of why we do our population estimate surveys the way we do (netting and electrofishing); using different gears (e.g. netting, electrofishing, and angling) might give you a slightly different picture/sample of the fishery due to the potential biases and selectivities associated with each survey type (for example: our fyke netting, along with the time we do it and the locations we set the nets – best spawning areas, typically better samples the larger, adult female fish in the population; while electrofishing the entire shoreline of the lake may give you a better representation of the entire adult male population in the lake).

Higher numbers of young, adult fish is a common characteristic we observe in our good, naturally-reproducing walleye fisheries that experience a fair amount of annual recreational and tribal walleye harvest. This seems to match what some experienced anglers of Oxbow Lake have mentioned to Matt, and it’s what our netting-electrofishing results showed for the most part. Matt’s work through the angler creel survey will give us another sample to add to the walleye/fish community pictures we have, and putting all the survey results together will give us a very good overall view of how the fishery is functioning.

The 2.9/acre adult walleye population estimate, although a little lower than past surveys on Oxbow Lake, is still a solid number of adult fish when compared with our better walleye fisheries. Our best walleye fisheries can fluctuate quite a bit from year to year given differences in year class strength from one year to the next. That being said, there are a lot of 10-11 inch fish coming up in the Oxbow fishery, and keep in mind there are more than what’s depicted in the walleye graphic in the report since a lot of that size fish aren’t mature yet (e.g. immature/juvenile females) and therefore aren’t included in our estimates on the number of “adult” fish present. As a result, as those juvenile fish continue to grow and mature, it could very well drive up the number of “adult” fish present next spring to over 4 or even 5/acre. The most important thing in sustaining a good walleye fishery is good natural reproduction, and Oxbow Lake appears to be continuing to do well in that department.

Anyways, hope this helps put things in a little better perspective, and may address any concerns folks might have.

Have a good rest of the summer!

Lawrence

View the WI DNR Draft Spring Summary Report