Biologist Report July 30, 2021
Greetings, Lake Vilbig Residents!
This letter is to discuss our July 2021 management efforts. I came out twice in July, on the 7th and 29th.
On the 7th water, temp was 86 F. It is summer at this point, but we have been fortunate with below-average temperatures and above-average rainfall. Alkalinity was 120, which is right around where it should be. Fish Bowl and volleyball court both had more chara than I would normally like to see. So I went ahead and sprayed those two areas with cutrine plus to minimize the chara growth. The main focus is to keep it off the volleyball court and minimized it in the shallow southwest corner of Fish Bowl. Visibility was 24 inches, about what it was in June. But a little clearer than it has been the past couple of months. This is normal. The normal life cycle of plankton is to die off a little as water temperatures heat up in the summer. Water is very fertile. This is a good thing as it helps to shade out deeper water, helping to manage excess vegetation growth.
Things were a bit different on the 27th. The Water temp was 88 F, so it is rising. I won’t be surprised if it reaches the low 90s before summer is over. We have been fortunate with our below-average temperatures. Until late July, when we started eclipsing 100 F. Alkalinity was 130. Visibility was 33 inches. pH was still high. 8.2. Chara treatment in early July seems to have done the trick. It looks a lot better. Really everything has been a lot better this year. I really cannot find any bushy pondweed anywhere, so really, we are just in a maintenance phase of lake management as far as vegetation management goes. We need to keep an eye on water quality, especially as water temperatures continue to rise. The main thing to look for is fish behavior. They can get stressed out in summer. There is an inverse relationship between water temp and dissolved oxygen levels. As the water gets hotter, there is less dissolved oxygen in the water. The benefit of Lake Vilbig is its’ size. We generally don’t have to worry about dissolved oxygen levels on larger bodies of water. Also, it is important to be extra gentle with fish caught during this time of year. Please treat them with kindness so they will survive.
Thanks, Vilbig Residents!
Chad Fikes Fisheries biologist
