Nebraska Zebra Mussel Case Studies

ALLISON ZACH, COORDINATOR

ZorinskyCarter

4 Positive Waterbodies2 Suspect Waterbodies

Offutt AFB Lake (Bellevue)113 acre lakeZM found in 2006Closed outlet tubes taking water to the MO riverBanned motorized boats from being usedTreated with copper sulfate in 2008 and 2009 New infestation found in 2014Research has been done annually since 2014 to monitor the populationIntroduction of 60,000 redear sunfish

July 30, 2014Found juveniles covering rocks

JUNE 6, 2014

September 26, 2014Found far less zebra mussels than in July and August. They had grown to adult size.

Offutt AFB lake zebra mussel densitiesCollection Date Average Density Water Temperature

5/29/2015 56 626/1/2015 192 63

6/26/2015 121 727/1/2015 22 77

7/17/2015 96 848/7/2015 2 86

1,500 µl/sub sample

Unmanned Aerial Vehicle Sampling

•Filters gallons of waters through a filter

•Successfully sampled veligers in 2015

•Revisions would be needed to increase detection using this method

•Easy to use at multiple waterbodies due to removal tube and filter

Future plansCover rip rap in the lake to reduce available habitat

Lake Zorinsky (Omaha)

• 2009 beer can found by boy scout

• USACE drew down 255 acre lake 17 feet in winter 2010

• Refilled in 2011 & reopened in 2012

Outlet

• Public report in May 2016-found one on a fishing line

• Took water samples the next day

• Veliger was identified by NISP on 5/25

• On 6/22 MT lab confirmed veligers (3 life stages observed)

• USACE and NGPC technicians surveyed for adult mussels

• eDNA confirmed week before July 4th

• Was then considered a suspect waterbody

3 separate plankton tows on 5/24

These 3 Life Stages Observed (>100/280 ml)

Confirmed veligers found from sample collected here

NGPC Technician searched for adult ZM in these areas 6/25

•Suspect waterbody signage was posted

•No plans to draw down the lake

•Will be considered suspect until an adult is confirmed

•Conducted boater surveys to determine travel patterns of lake users

AIS Watercraft Inspections & Outreachwill have 8 Techs this year

• Tablet Surveys

• Real time results

• Study travel patterns to target inspections and outreach areas

Watercraft Owner Behaviors90%

26%

45%

77%

39%

92%

21%

46%

95%

42%

82%

44%

95% 96%

Drained Water Flushed Motor Rinsed with Water Visually Inspected Removed Vegetation

2012 2013 2014

AIS Program funded by motorboat fee

◦Resident motorboat registration fee ($5) every 3 years◦Non-resident motorboat AIS sticker ($15) annually

NGPC AIS Program

Lewis & Clark Lake31,400 surface acres

90 miles of shore line

Max depth 45 feet

Lewis & Clark Lake

November 2014-Single Adult found on Midway boat ramp dock

August 18, 2015-Adult zebra mussels were found on 2 boats at a SD boat repair shop

August 19-SD did snorkeling in marinas

The mussels were of multiple sizes, indicating that zebra mussels are reproducing in Lewis and Clark Lake

Lewis & Clark Lake

What is Being done at Lewis & Clark LakeTransportation zone in SD

2 full time techs with decon units

Study with divers of ZM population

Certifying boat shops and marinas to decon watercrafts

Nebraska survey of slip renters

Nebraska technician

Municipal water and irrigators put in touch with other state contacts

MO River Zebra MusselsAdult zebra mussels found at MO River boat launches in 2016

The entire length of MO River in Nebraska is considered infested with zebra mussels

Watercrafts in the MO River NEED: to Clean, Drain & Dry for at least 5 days prior to relaunch

2016 Zebra Mussel Finds on MO River boat launches

Fort Calhoun

North Omaha

NE City

Omaha Public Power District FacilitiesFACILITY DATE NUMBERS OBSERVED

Fort Calhoun 3/14/2016 2

Fort Calhoun 4/20/2016 4

Fort Calhoun 9/6/2017 10,000

North Omaha 2/8/2017 20

NE City 5/18/2017 6

NE City 6/6/2017 500

NE City 8/23/2017 10,000

NE City 10/4/2017 6,200,000

Nebraska City Station

10/4/2017~ 6 million Observed

OPPD’s Pathway ForwardThe immediate action following the large numbers observed at NCS was to create a Work Request to power wash and remove the mussels on the intake screen mesh was created.

A project to perform an assessment of treatment options has been implemented. This project includes all three of our generation facilities along the Missouri River (NOS, NCS, FCS).

While waiting for a permanent solution to be implemented, manually cleaning is being used on selected equipment to insure plant operability without de-rates.

Learn More at: Neinvasives.com

Allison Zach Email: Azach3@unl.edu

Website: Neinvasives.com