THE ART AND SCIENCE OF FINDING ZEBRA MUSSELS: A DISCUSSION OF IN-LAKE EARLY

Transcription

1 THE ART AND SCIENCE OF FINDING ZEBRA MUSSELS: A DISCUSSION OF IN-LAKE EARLY DETECTION SEARCH METHODS IN MINNESOTA KYLIE CATTOOR, KEEGAN LUND, ALLISON GAMBLE MINNESOTA DEPARTMENT OF NATURAL RESOURCES 2016 UPPER MIDWEST INVASIVE SPECIES CONFERENCE OCTOBER 19 TH, 2016 LACROSSE, WISCONSIN

2 ZEBRA MUSSEL LIFE CYCLE

3 NEW INFESTATIONS INTO A WATERBODY Potential vectors of spread: adults, juveniles, and veligers at variable times of the year human pathways: watercraft, docks & lifts - residual water limited risk connected waters Detection challenges: water clarity (turbidity, water flow, algae) substrate (algae coating, muck, silt) shade (under rocks, low light, small crevices) veliger tiny animals, large waterbodies- potentially localized at low densities

4 REPORTING NEW INFESTATIONS IN MN 1. Receive report photo or voucher specimen general location, date 2. Field inspection confirm presence lake wide assessment 3. Designate waterbody 4. Potential rapid response

5 REPORTING NEW INFESTATIONS IN MN 1. Receive report photo or voucher specimen general location, date 2. Field inspection confirm presence lake wide assessment 3. Designate waterbody 4. Potential rapid response

6 REPORTING NEW INFESTATIONS IN MN 1. Receive report photo or voucher specimen general location, date 2. Field inspection confirm presence lake wide assessment 3. Designate waterbody 4. Potential rapid response

7 EARLY DETECTION MONITORING Methods Settlement plates (passive) - potentially reproducing - covers large spatial range - citizen involvement - cost effective & easy data collection Photos provided by Minnehaha Creek Watershed District

8 EARLY DETECTION MONITORING Methods Settlement plates (passive) - potentially reproducing - covers large spatial range - citizen involvement - cost effective & easy data collection Veliger tows (active) - requires high veliger density - time consuming on large scale - specialized equipment - confounding results Photos provided by Minnehaha Creek Watershed District Photo provided by MAISRC

9 EARLY DETECTION MONITORING Methods In-lake searches - wade v. snorkel v. SCUBA - quadrat v. transect v. random FOCUS AT THE ACCESS! MCWD early detection monitoring program

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11 CASE STUDY 1: LAKE INDEPENDENCE, HENNEPIN CO. Designated infested: September 2014 Reported by: water resource manager Discovered: public boat launch (juveniles + adults attached to rock) Field inspection ~2,000/m 2 adults on access ramp + underneath dock Blue Water Science, 3RP, DNR in-lake searches + veliger tows for 29 hours Rapid response efforts barrier containment pesticide control (EarthTec QZ & Muriate of Potash) in fall 2015: 49 adults outside treatment (12 hour search) summer/fall 2016: 3 adults, 2 juveniles (13 hour search)

12 CASE STUDY 2: LAKE STELLA, MEEKER CO. Designated infested: July 2015 Reported by: lake property owner Discovered: (?) attached to native, 2 additional reported Field inspections in-lake searches (wade + snorkel) for 15 hours 5 DNR staff, no zebra mussels found More searches fall 2015: 21 hours (snorkel + SCUBA) 4 DNR staff, 3 confirmed zebra mussels fall dock removal, no zebra mussels reported

13 CASE STUDY 3: WHITE BEAR LAKE, RAMSEY/WASHINGTON CO. Designated infested: September 2014 Reported by: recreational smorkler Discovered: 3 juveniles attached to small rocks Field inspection in-lake searches for 30 hours, 13 juveniles found Blue Water Science, RCWD, WBLCD staff, WBL volunteers, DNR Zebra mussel population monitoring study developed

14 ZEBRA MUSSEL POPULATION MONITORING Methods 4 50 meter belt transects veliger tows (July & August) intensive grid (100 x 100 meter) settlement plates & dock/lift checks

15 Log 10 zebra mussel density (# per 10 m 2 ) (Year 1) 2016 (Year 2) T1 T2 T3 T4 Monitoring Station

16 Log 10 veliger density (# per m 3 ) (Early) 2015 (Late) 2016 (Early) 2016 (Late) 2, Monitoring Station

17 SAMPLING GRID 100 X 100 M QUADRATS 200 RANDOM QUADRATS (2%) ZM Sampling Grid (Rand 200) Zebra Mussel Count " 0 " 1-5 " 6-10 " " " 50+ ZM Sampling Grid (100 x 100m) Zebra Mussel Count " 0 " 1 " 2 " 3 " 4 " 5

18 WHAT CAN WE LEARN Truly an art and science! what is your purpose? - early detection v. confirmation what are your resources? - time and money Early detection monitoring is KEY! Photo provided by MAISRC Regardless low densities are tough to find Photo provided by MCWD

19 WHAT CAN WE LEARN Just confirming? random in-lake searches snorkel/wading/scuba verify infestation extent Photo provided by MAISRC Photo provided by MCWD

20 WHAT CAN WE LEARN Early detection efforts limited resources - settlement plates + regular access searches (get wet) search the access (monthly, weekly, daily) lakewide surveys (monthly) - wade/snorkel/scuba - suitable habitat optimal times of year (biologically & environmentally) Photo provided by MAISRC Photo provided by MCWD

21 CONTINUING EFFORTS IN MN Watercraft Inspector Program- MN DNR boat access searches Early detection monitoring protocol developed by DNR & MAISRC Continued partnerships U of Minnesota- Extension detectors MAISRC Other ED programs, e.g. MCWD monitoring program

22 QUESTIONS