Veteran’s Memorial Lake:Fish Community & Blue-Green Algae,

In-Lake Restoration

Bryan SowardsFish Biologist

KDWPT

Veteran’s Lake

13 acres7.3’ ave. depth99 acre feet

FISHERY HISTORY

1987 – Rotenone to reset fishery1990s – Developed Bluegill, Largemouth Bass, Channel Catfish community. Began Rainbow Trout fishery (1997).2000s – Crappie, Common Carp, Gizzard Shad showed back up. Stocked Saugeye as additional predator.

FISHERY OVERVIEW

Good populations of Bluegill, Largemouth Bass, and Saugeye.Largemouth Bass have been strong with 50% or more of the population larger than 12”.Saugeye reached sizes greater than 21” regularly.Rough fish have been a problem but not more than other regional lakes and ponds.

FISHERY OVERVIEW

October 2015 sample indicated no Saugeye or any top predators. There is probably LMB but haven’t sampled for them yet.Forage species, Bluegill, Gizzard Shad, Green Sunfish fairly abundant but not overwhelmingly.Few Common Carp.Channel Catfish were naturally reproducing.

FISHERY OVERVIEW

Catfish & Trout Program: Since 1987

SPECIES # STOCKED 2015 APP. VALUUE

Channel Catfish 26,599 Difficult to determineHatchery & Commercial≈$8,100 ($1.00/lb.)

Rainbow Trout 77,012 fish45,000 lbs.

$175,500 ($3.90/lb.)

APP. TOTAL INVESTMENT $183,600

BLUE-GREEN ALGAE2010 – Blue-Green Algae

External Source: Geese, urban runoff, etc.Internal Source: Internal P loading/cyclingBenthic fish disturbance?

2011 – Last stocking of Rainbow trout***stockings moved to Stone Lake.

Very little fish management has occurred since 2011.

What has this meantto the fishery?

Fish Kills:2011 and August of 2014.Summertime, classic eutrophication-based die offs. Not complete kills but significant.

What has this meantto the fishery?

Catfish & Trout:Popular put-and-take fishery since 1990s.Stockings cease due to HAB…fish kill risk.

Constant complaints that people had trouble catching trout at Stone Lake. They wanted fish back in Veteran’s Lake.

What has this meantto the fishery?

Trout Permit Sales – Barton Co.Year Permit Sales ($$)

2007 $2,212.502008 $2,387.502009 $2,812.50

TOTAL (2007 – 2009) $7,412.502011 $1,437.502012 $825.002013 $1,475.00

TOTAL (2011 – 2013) $3,737.50

BG Algae 2010

RestorationContractor Recommendations:

1. Public Education2. Reduce external P loading –

Stormwater plans, goose removal3. Monitor4. Internal P loading (ALUM)5. Restocking, ecosystem balance

Restoration2015 Veteran’s Lake Geese Deterrent Details:*Scott…

Propane Cannons (negative public opinion)

Screamers***(effective; multi-day use)

Restoration2015 Veteran’s Lake Alum Treatment Details:*Contractor sampled TP in water column & sediment.*Liquid Alum was used.*They used a dose of 10:1 (Al:TP) for both media. Dose was based on active ingredient & not total Alum mass.*Total dose for both media recommended was 5,200 gal. of liquid alum & equates to 2,500 lbs. active ingredient.*They rounded up to 16, 330-gal. totes (5,280 gal.).

Restoration

2015 Veteran’s Lake Alum Treatment Details:

Goal for TP is 60 – 100 µg/L after dosing.

Within this concentration range the contractor recommends ceasing Alum treatments.

Restoration Concerns

The plan did not mention buffering pH which fell from app. 8.5 to 6.8 after treatment. Fell to 6.2 after 2nd treatment.

Plan includes multiple Alum treatments (2 already).

The application rate was fixed (10:1) and not adjusted for sediment mobile P fractions (?).

Application rate ended up being app. 21.8 g/m2; recent publications suggest 100 g/m2 but worldwide mean is app. 31 ± 24 g/m2.

Progress

There has been a definite improvement in water clarity. TP fell from 250 µg/L (9/2014) to 220 µg/L prior to treatment. After treatment the TP has fallen to 70 µg/L (7/2015).Monitoring will continue.Fish management has resumed at the lake. Trout have been restocked. More predators will be stocked and Common Carp will continue to be thinned out.

Progress

TP - May

TP - August

TP goals reached during Summer 2015!

DO

pH

After both treatments there was a marked decrease in pH. The late June pH was nearly 6.2 (concerning)

TurbiditySechi depth is improving. As of August it was nearly 2.1 ft. and dropping.

The picture shows jar test in October, 2015.

Future

Continue to monitor water quality parameters & fish populations.TP & cell counts over time. The past summer was promising! This summer will be critical.

Limit BiomassKeep geese off pond.Common Carp removal.

Future

Common Carp removal:Some studies have shown massive carp removals in lakes with high TP levels to be successful at controlling HAB.-Increases sechi depths-Can decrease water column TP-Moves lake from turbid/algal state to clear/macrophyte state***

Lake Wingra, Wisconsin

2007, turbid/algal state (high densities of Carp)

2012, clear/macrophyte state (low densities of Carp)

Common Carp Exclusion…

ApplicationWhile this project is ongoing there are many cases in which Alum treatments, done with due diligence and planning, can be very effective.

Internal P cycling can account for over 90% of total summer P load.

Water quality goals have been shown to last for 4 – 10 yrs. Or more.

Emphasizes the need for more In-Lake Management such as Alum treatments.

QUESTIONS?