Baishali Bakshi, Adam Doll, Andy Holdsworth

Operations Services Division

Ecological and Water Resources Division

Minnesota Department of Natural Resources

January 24, 2017

Outline of Talk Watercraft Inspection Program (WIP)

Data Description

Analysis Questions

Methods

Results

Maps

Insights

Watercraft Inspection ProgramEstablished: 1992

Goal: Prevent the spread of aquatic

invasive species (AIS) within Minnesota

• boater education

• watercraft inspections

• watercraft decontaminations

Total state spending on AIS in FY2015:

$10.5 million.

The WIP program: Over 40% of this

amount i.e. > $4 million.

Watercraft Inspection Process

Program Growth

New ‘tier’ system

Inspection Authority

delegated to LGUs

Data Description Answers to survey questions asked to boaters

Years: 2013, 2014, 2015

Data changes over three years

Large datasets: Example: 2014 data

Rows / col = 230,426 / 75

Entry / Exit = 124,958 / 83,925

Waterbodies = 281

Survey DesignEntry Exit

Analysis Questions

What are the violation rates at the

Through years

Boat level?

Lake level?

Where are inspectors finding the most zebra mussels?

How common are ‘repeat offenders’?

Risk Factors for AIS Violation Drain Plug (DP) in

Boat has been out of water for less than 24 hours

Boat has been in water for more than 24 hours

Didn’t see Inspector in a month or more

Launching again soon

Plants and Zebra Mussels (ZM) found: specify hand removal or decon needed

ZM stuck on vegetation found

Lake infested

Need further decontamination

Refused decontamination

1st Question/Risk Factor: Drain PlugDrain Plug Question-Entry Drain Plug Question-Exit

204,191

138,858

5,480 133,378

8,999195,192

Methods Code risk factors using R

Aggregate risk factors for entry and exit for each year

Present aggregated risk factors using charts at boat and

lake level

Prepare maps using

Analysis Results for ZM at lake level

Infested Waters shapefile

Spreadsheet on inspected lakes

Repeat offenders: Individual level analysis

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

2013 2014 2015

Drain Plug and ZM Violations in Minnesota

DP_Entry

DP_Exit

ZM_Entry

ZM_Exit

Drain Plug Violations for 2015Entry Exit

Boat Type

Drain

Plug is

Out

Drain

Plug is

In Total

Violation

% -

natural

wht

Violation

% -

imposed

wht

Canoe 4,799 84 4,883 2 1

Dock/Lift 505 6 511 1 1

Duckboat 774 49 823 6 6

Fishing Boat 119,120 5,329 124,449 4 2

Personal Watercraft 9,870 716 10,586 7 4

Pontoon 14,783 379 15,162 2 1

Runabout or Ski-Boat

with no Ballasts 38,709 2,185 40,894 5 3

Sailboat 1,676 67 1743 4 4

Wakeboard Boat with

Ballasts 4,956 184 5,140 4 3

Total 195,192 8,999 204,191 4 3

Boat Type

Drain

Plug is

Out

Drain

Plug

is In Total

Violation

% -

natural

wht

Violation

%-

imposed

wht

Canoe 3,339 20 3,359 1 0

Dock/Lift 491 2 493 0 0

Duckboat 857 21 878 2 2

Fishing Boat 90,849 4,074 94,923 4 2

Personal Watercraft 5,868 227 6,095 4 3

Pontoon 8,331 145 8,476 2 1

Runabout or Ski-Boat

with no Ballasts 20,090 920 21,010 4 2

Sailboat 1,282 9 1,291 1 1

Wakeboard Boat with

Ballasts 2,271 62 2,333 3 2

Total 133,378 5,480 138,858 2 2

Size class Weight

0-2000 1

2001-5000 0.8

5001-10000 0.7

10001-20000 0.6

20001-50000 0.5

More than 50000 0.4

ZM and Plant Violations: Exiting Boats

Most boats have more

violations for plants than

ZM

Fishing boats have

maximum plants

violations while Ski

boats stand out in ZM

violations

Both plant and ZM

violations are larger for

those boats that do not

have drain plug

violations but this is an

artifact of sampling.

Number of Boats

Boat Type

ZM not

found

ZM

found

ZM

(hand)

ZM

(decon)

Plants

(hand)

Plants

(decon)

Drain Plug

is Out Canoe 261 3 0 2 206 0

Dock/Lift 99 109 24 51 112 18

Duckboat 175 6 0 1 182 0

Fishing Boat 13,542 258 31 31 14,091 87

Personal Watercraft 1,014 46 0 6 1,020 9

Pontoon 1,570 201 43 71 1,559 92

Runabout or Ski Boat

with no Ballasts 3,981 460 44 106 4,158 145

Sailboat 356 8 1 5 262 84

Wakeboard Boat with

Ballasts 664 36 4 4 681 2

Drain Plug

is In Canoe 2 0 0 0 2 0

Dock/Lift 0 0 0 0 0 0

Duckboat 5 0 0 0 6 0

Fishing Boat 705 2 1 0 870 5

Personal Watercraft 55 0 0 0 51 1

Pontoon 21 0 0 0 25 0

Runabout or Ski Boat

with no Ballasts 240 20 0 5 250 6

Sailboat 3 0 0 0 3 0

Wakeboard Boat with

Ballasts 20 2 0 1 22 1

All Risk Factors for 2015 Exiting

Boats

Boat type DP in

In > 24

hrs

Launch

again

soon

Didn't

see

Inspector

Plants

-hand

Plant

s-

decon

ZM-

hand

ZM-

deco

n

ZM

on

veg

Lake

infested

Need

more

decon

Refus

ed

decon

Total

Score

Wtd.

Score

Fishing Boat 4,074 8,873 8,741 11,715 15,017 92 32 31 3 257 1,268 189 50,292 20,117

Runabout or Ski-Boat with no

Ballasts 920 4,623 911 2,324 4,418 151 44 111 4 480 501 157 14,644 8,786

Pontoon 145 3,339 591 1,696 1,655 95 43 71 1 201 331 75 8,243 5,770

Personal Watercraft 227 1,911 301 873 1,084 11 0 6 1 46 147 37 4,644 3,715

Wakeboard Boat with Ballasts 62 530 143 204 704 3 4 5 0 38 80 18 1,791 1,791

Canoe 9 515 28 244 265 84 1 5 0 8 22 2 1,183 1,183

Dock/Lift 20 58 171 493 208 0 0 2 0 3 12 3 970 970

Sailboat 2 213 71 29 112 18 24 51 0 109 13 0 642 642

Duckboat 21 33 95 99 188 0 0 1 0 6 13 1 457 457

Total Violation 5,480 20,095 11,052 17,677 23,651 454 148 283 9 1,148 2,387 482 82,866 43,432

Average Violation 609 2,233 1,228 1,964 2,628 50 16 31 1 128 265 54 9,207 4,826

Size class Weight

0-2000 1

2001-5000 0.8

5001-10000 0.7

10001-20000 0.6

20001-50000 0.5

More than 50000 0.4

All Risk Factors for Exiting Boats-Lake Level

Case # DP In BIW Launch Inspector Found

ZM

found

Plants-

hand

Plants-

decon

ZM-

hand

ZM-

decon

ZM on

veg

Lake

infested

More

decon

Refused

decon Total Boats #

27013311 53 326 68 133 1210 208 1084 60 12 48 0 208 72 30 3512 4224

18003401 77 920 192 247 739 0 737 0 0 0 1 0 3 0 2916 2392

27013303 32 337 42 100 717 223 604 56 6 46 4 223 93 39 2522 1458

27013309 83 120 72 95 834 78 791 18 5 9 0 78 45 16 2244 3331

18031203 75 660 113 114 409 25 387 4 5 7 0 24 25 10 1858 1631

11030501 133 507 99 267 232 44 180 3 11 19 0 44 81 59 1679 1835

10005902 37 36 163 216 576 1 557 2 0 0 0 1 31 6 1626 3571

27013302 39 213 42 102 490 86 428 32 8 17 1 86 45 13 1602 1683

18031201 94 652 90 156 233 53 182 1 7 38 0 53 5 2 1566 1200

10000201 2 15 54 66 672 0 658 3 0 0 0 0 1 0 1471 1696

North

Region

Metro

Region

Metro

Region

North

Region

Metro

Region

North

Region

Metro

Region

Who is a Repeat Offender?

A response of ‘Yes’ to a question about a violation, being

recorded more than once for the same license plate

number.

For example: Plate# X said Yes to the question “Were

ZM found?”, three times.

Repeat Offenders for EntryID Boat type # ZM

Violations

Entering Water

body

Last visited Going to

041jgc Runabout (2) 2 Mississippi NA NA

312gkx Wakeboard

/Runabout

2 Minnetonka Minnetonka Minnewashta

503gjn Pontoon 4 Lower Prior Lower Prior Lower Prior

520rew Pontoon 3 Le Homme Dieu;

Victoria

Cowdry; Le

Homme Dieu

Le Homme

Dieu; Victoria

870jtl Runabout (2) 2 Minnetonka Minnetonka Minnetonka

ybb4897 Runabout (2) 2 Minnetonka NA NA

ybm5927 Dock

Lift/Pontoon

2 Christmas/Minneto

nka

Upper Prior;

Minnetonka

Christmas;

Minnetonka

17

Repeat Offenders for ZM-2015

Repeat offenders: 62Repeat offenders: 7

ZM Violators:

188

Entering

boats:

129,526

Exiting boats:

93,488

ZM violators: 964

Potential Insights

On average: 0.6% ZM violations and 4% DP violations in 2015.

Both types of violations are higher for exiting boats ZM for entry: 0.1%; ZM for exit: 1%

Fishing boats had the most plant violations while runabout boats had the most ZM violations

We found that a very small fraction of boats were repeat offenders for ZM, and these boats were mainly pontoon and/or runabout boats

We’re able to focus on a short list of lakes with a high tendency for ZM violations on exit. This will help prioritize inspection efforts for the most AIS prone lakes.

Recommendation: Recording a metric for AIS, such as #/lbs ZM found—valuable to understanding the distribution of AIS across lakes and boat types. It will also improve the ‘Violation Rate’ metric used in annual report.

Possible Future Steps Maps on risk factors other than ZM

Repeat offenders across categories

What is the relation between time spent on inspection and

violation rates for any risk factor?

Targeted analysis at specific infested lakes

Acknowledgments

Adam Doll

Andy Holdsworth

Ann Pierce

Bart Richardson

Heidi Wolf

Extra Slides

January 24, 2017

State spending on Invasive Species

Questions dividing Boaters in Survey

Things found for Entry Boat in water (<>) 24 hours

100,4722,508

5,377

57,128

48,870 5,070

5044,873

High-riskLow risk

Decontamination: 5%-8%

Decon for Entry Decon for Exit

1302,378

9,086152

707

9,740

Key point: The total number of exiting boats is lower than entering boats but a higher

percentage of exiting boats are decontaminated compared to entering boats.

DP and ZM Violations in Minnesota

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

2013 2014 2015

ZM_Entry

ZM_Exit

DP_Entry

DP_Exit

North-

East

Region

North-

West

Region

January 24, 2017