Clear Lake CLP Harvested Areas To Date
- CLPO, Inc.
- Jun 4, 2020
- 7 min read
Updated: Aug 21, 2020
August 21, 2020 - Report by Bruce Hall
Continued good news on oxygen levels in the lake! They continue to inch up or hold steady,esp. in deeper water. This, plus the lack of new lakewide algae blooms and only localized blue-green algae means that the fuel (nutrient load) in the lake is lower now, and algae are not dying off and pulling down the oxygen levels (biological oxygen demand). By removing CLP early in the summer, and with clearer water from less run-off this spring, we allowed more native aquatic vegetation to grow. Of course, that also allowed some areas of EWM to kick in. We removed the bulk of that, but some exists in shallow water, even in among the cattails, that we will never be able to remove. We may yet see that clearer water and less CLP may allow for more EWM in the future, but for this year we are seeing more eelgrass, sago pond weed, native elodea - all native aquatic vegetation pioneers that add oxygen to the lake given enough sunlight penetration to the lake bottom.
Fish on the sonar fish finders shows a much more normal fish distribution at different depth levels and fish using more bottom structure in water less than 12' deep. Lake temps. are staying in the 70's due to cooler nights, more precipitation and loss of heating sunlight hours during the day. Fish populations appear higher than other years at this time. The odds of a late season fish kill due to high temps. and low oxygen is now pretty low! We appear steady at 8 lakewide algae blooms and hoping the algae bloom cycle has gone bust for this year, but that might be hopeful thinking. Last year we saw algae blooms into October, which ended up bringing oxygen levels down below normal before ice up and ultimately caused a major winter fish kill on Little Mud and probably a minor one in late winter on Clear Lake.
August 12, 2020 - Report by Bruc
e Hall - Clear Lake AIS 2020 - EWM STRIKES BACK!
We're very close to the end of AIS removal on Clear Lake for this 2020 open water season. We have removed 87 loads of AIS, nuisance weeds from boating access areas and floating algae from Clear Lake and 1 load from Little Mud Lake. We are now over 300,000 lbs removed from Clear Lake. We have seen a resurgence in late growth Eurasian Water Milfoil (EWM) this year. Likely due to the much clearer water we enjoyed in May and June. It just is another lesson on AIS for us; a heavy year of Curly-leaf pondweed (CLP) does not necessarily mean no EWM growth after the CLP disappears.
We will be taking the harvester out of Clear Lake on Saturday, August 15 at 9:30am at the north access and doing the final hydraulics greasing for the year. Then we will dry dock for the required 7 days and finish on Little Mud in the afternoon of Saturday, August 22 after our end of summer CLPO Board meeting.
Attached is the expanded map of EWM infestation on both lakes as of August 12. We may get one more trailer load out of CLear and 2 loads or so out of Little Mud on August 22. The green areas are EWM as of August 12. The red overlay is areas where EWM has been removed in the amount of 25-30,000 lbs. There are some areas; i.e. the camp ground marina inside the docks, one small area on the east side just south of the point, and also inside the dock area at DeJulianne's that are just too shallow (1' or less) for the harvester to access and remove. We suggest some discussion at the next Board meeting on shallow water chemical treatment for these areas in late July or early August of 2021. There are also some single EWM plants in various areas around the lake.
June 24, 2020 - Report by Bruce Hall
Below is the final CLP removal map for Clear Lake and initial removal on Little Mud Lake for 2020. Green dots being the initial May 3 assessment of CLP on Clear Lake., solid green line is the latest expansion of the CLP in the lake and the red areas are removal areas we have emphasized in 2020.
June 20, 2020 - Report by Bruce Hall
The CLP on Clear Lake is dying off now quickly from shallow to deep water. The last green algae bloom which still continues has been a bad one and has piled floating algae on the top of dying CLP, while infusing the water column with green algae also. I think our sechi disk value is now probably down to 4' or less, a huge drop from the clear water we have enjoyed so far in the spring.
With this heavy, lakewide algae bloom, we are starting to see a summer pattern on fish and oxygen levels in the lake.
On June 20 we had the following water column profile:
Surface temp: 72 F.
1' deep - temp: 72 F., oxygen level 5.6 ppm, 65% oxygen saturation
3' deep - temp: 72 F., oxygen level 5.8 ppm, 67% oxygen saturation
6' deep - temp: 72 F., oxygen level 6.0 ppm, 68% oxygen saturation
10' deep - temp: 70 F., oxygen level 5.0 ppm, 57% oxygen saturation
12' deep - temp: 69 F., oxygen level 4.75 ppm, 53% oxygen saturation
15' deep - temp: 69 F.., oxygen level 4.4 ppm, 49% oxygen saturation
Lake bottom (17.5') - temp: 68 F., oxygen level 2.1 ppm, 21.5% saturated
Fish are starting to leave the lake bottom due to low oxygen and use shallow water weed structure or suspend from 6-10' deep.
The north main tributary to Clear Lake is running at 1.52' depth prior to recent rain, 66 deg. F., 0.12 ppm oxygen level, 1.5% oxygen saturation and 2.5 ppm soluble phosphorus. Blue green algae present in surface areas. The south main tributary is primarily dry (not running) at this point. The Clearwater River is less than 1' deep at the egress point from Clear Lake. Water levels are very low despite limited, recent rains.
June 12, 2020 - Report by Bruce Hall
As of today we have removed 70 trailer loads (somewhere between 200,000 to 210,000 lbs.) from Clear Lake. Some of the shallow water CLP is starting to set seed and some deeper water CLP is still coming to the surface, as deep as 15.' Surface water temps. are now in the low 70 deg. F. range. We have noted some large pike, large bullhead and panfish dead on the lake. Not large numbers, but enough to notice. DNR Fisheries is telling us this is likely due to spawning stress on some of the larger, mainly female fish. The Clear Lake water column remains very clear and we have not had a full, lake wide algae bloom on the lake to date!
On the attached CLP removal maps, remember that the red areas are those where we have removed CLP at least once. It does grow back if not removed 2-4 times during the growing season, so the lake does not appear like we just "cleared it out" from the red zone removal areas. Also, I added the green solid line to show the expansion of CLP now in deeper lake zones where it is now coming to the surface. Our current primary goal is to maintain previously opened boating channels and open more access channels to the main lake area from more individual boat docks and groups of boats.
We have volunteer operators Saturday AM, and next week Mon., Tues., and Wednesday. Hoping more will fill in to request some volunteer hours. The Eco-Harvester now has 85.5 hours on it, and was greased, maintained and fueled up for the weekend today.
June 2, 2020 - Report by Bruce Hall
We are now working on the south end this week where the CLP has bloomed a bit later than the northern half of the lake. We are also letting the vegetation come back a bit on the PF/WSC property on the north side while we dump loads on the Meeker County Park fallow field near the south park landing. We have had some additional Ag use removal of the north stacked pile. We hope this keeps up!
We have removed 52 trailer loads of CLP thus far; over 140,000 lbs. We are finding that where we harvest for several runs a few days apart, the CLP is not recovering to refill these multiple harvest areas. We find we always need to go over the same area at least twice in order to keep that area navigable. We also continue to avoid pan fish bedding areas, now mainly sunfish, as crappies and bass are now mainly off their nests on Clear Lake.
The rain today was much needed, and being this late in spring, should not result in too much Ag field run off. Rick and I noted some green algae starting to bloom today on the surface and some starting to turn blue-green on the west side. Not an official lake bloom, but might grow into one if winds are calm for a day or two. To date only 2 algae blooms, mostly filamentous chara in late April/early May. Last year by this time, we had already had 6 lakewide green algae blooms and our waters remain much clearer than past years at this time. Of course, clearer water grows CLP.
May 27, 2020 - Report by Bruce Hall
43 Trailer loads at 2,000 to 3,500 lbs. each = 100,000 - 125,000 lbs. removed to date.
Approximately 7-8 trailer loads used for agricultural applications from above.
To date all storage has been on the PF/WSC property on the north side of the lake accessed off of 375th street. We now also have storage area from Meeker County Parks along the south side of the lake.
Harvested area in red is superimposed on May 3 delineation of Curly-Leaf Pondweed growth areas on Clear Lake. It appears we will have to harvest at least twice to be most effective in each area.
CLP is now in bloom in north end, shallow growth areas and will start seeding by June 15.
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