Ecological Archives A025-041-A2

Sigrid D. P. Smith, Peter B. McIntyre, Benjamin S. Halpern, Roger M. Cooke, Adrienne L. Marino, Gregory L. Boyer, Andy Buchsbaum, G. A. Burton Jr., Linda M. Campbell, Jan J. H. Ciborowski, Patrick J. Doran,11 Dana M. Infante,12 Lucinda B. Johnson, Jennifer G. Read, Joan B. Rose, Edward S. Rutherford, Alan D. Steinman, and J. David Allan. 2015. Rating impacts in a multi-stressor world: a quantitative assessment of 50 stressors affecting the Great Lakes. Ecological Applications 25:717728. http://dx.doi.org/10.1890/14-0366.1

Appendix B. Additional tables and figures for survey of Great Lakes experts, including additional data displays of respondents, new stressors, and components of ecosystem impact.

Table B1. Additional stressors which respondents suggested were not included in Great Lakes survey (Part IIB responses). We summarized 58 individual responses from 246 people reaching Part II, of which 196 respondents completed Part IIA as instructed. One response is sometimes classified in more than one topic below, since some responses had multiple ideas mentioned.

Response topic

No.

(n = 58)

Hydrology or water level regulation new stressor (sometimes with management comment)

14

Disease-related new stressor (e.g., fish/bird pathogens, SSOs, septic tanks)

10

Other new stressors:

  • Lack of native fish community (2 responses)
  • Land use in and around tributaries, loss of riparian habitat and connectivity with floodplains, loss of large woody debris
  • Acidification
  • Ships biofouling
  • Changing intensity, timing, and tracks of storms
  • Agricultural tile drainage
  • Declines in density of submerged aquatic vegetation in rivermouths
  • Wind turbines

9 (1 each unless noted)

Variations of included stressors, such as broadening stressors (e.g., lumping all bioaccumulating toxics as one stressor)

28

Management concern (e.g., funding shortfall)

6

Interactions among stressors

3

Feedback about survey instrument

4

 

Table B2. Distribution and attrition statistics for the survey of Great Lakes experts.

Stage of invitation/survey

No. of people

Responses (%)

Total original invitation attempts

787

 

Known undeliverable emails*

- 114**

 

Total invitations sent (approximate)

721**

 

 

 

 

Out of office auto-replies

- 13

 

Declined survey (removal requests)

- 24

 

Opened link to survey

306

100

Reached page 2 (survey instructions)

296

97

Reached Part II instructions

276

90

Reached Part IIA

246

80

Reached Part III

237

77

Reached Part IV instructions

170

56

Filled out at least some of Part IV

141

46

Clicked end twice (for Qualtrics "finish")

140

46

*We were able to measure bounced emails and auto-replies by sending one mailing from Microsoft Outlook, but we were unable to measure the number of messages not read by recipients, such as from spam filters.

**For 48 of the bounced emails (11 to NGO and 37 to literature experts), we found a new address and resent it, but these people had less time to complete the survey, and we do not know whether the new invitations were received due to only using Qualtrics for resending.

 

Table B3. Stated duration of experience/expertise of respondents for each lake and zone in the survey of Great Lakes experts. Shown are the number of respondents selecting the given answer from multiple choice questions in Part I of the survey. Respondents chose answers for each lake and zone separately, and they were able to choose responses for "no specialization" as well (data not shown).

A.  By lake

Lake

1 (no experience)

2 (1–2 yr)

3 (3–5 yr)

4 (6–10 yr)

5 (>10 yr)

Superior

51

26

40

27

54

Michigan

50

20

30

35

67

Huron

53

19

30

35

55

Erie

39

26

28

35

67

Ontario

63

26

22

26

53

B.  By zone

Zone

1 (no experience)

2 (1–2 yr)

3 (3–5 yr)

4 (6–10 yr)

5 (>10 yr)

Wetland-rivermouth

36

29

32

37

66

Littoral, hard substrate

45

19

24

34

56

Littoral, soft substrate

36

15

32

33

61

Sublittoral, hard substrate

58

18

24

23

43

Sublittoral, soft substrate

48

15

28

22

53

Offshore

58

9

27

21

65

Tributaries and/or whole watershed

21

16

30

36

107

 

Table B4. Weights (shown as proportions) for the importance of 5 components of ecosystem impact (mean ± 1 SD) from scenario comparisons in the survey of experts in the Laurentian Great Lakes. Results are shown for respondents by self-declared primary work activity and for all respondents combined."Other" activities included all other responses, such as restoration, advocacy, and teaching. See Methods and Appendix A for details

Primary work activity

n

Spatial extent

Frequency

Ecological scope

Magnitude

Recovery time

Research

78

0.21 ± 0.11

0.14 ± 0.10

0.22 ± 0.12

0.20 ± 0.11

0.24 ± 0.10

Natural resource management

24

0.21 ± 0.11

0.14 ± 0.10

0.22 ± 0.12

0.20 ± 0.11

0.24 ± 0.11

Other

21

0.20 ± 0.11

0.17 ± 0.11

0.21 ± 0.12

0.20 ± 0.11

0.22 ± 0.11

All respondents

123

0.21 ± 0.11

0.13 ± 0.10

0.22 ± 0.12

0.21 ± 0.11

0.23 ± 0.10

 

FigB1

Fig. B1. Respondent demographics for the Great Lakes expert survey, for both respondents who started the survey (left panels) and officially finished it (i.e., selected button to formally record responses; right panels). Shown are year of birth to indicate age (A–B, n = 259 starters, 135 finishers) and proportion of respondents who were female for those who identified themselves as male or female (C–D, n = 264 starters, 136 finishers).


 

FigB2

Fig. B2. Categories of stressors for which respondents had experience/expertise from the Great Lakes expert survey, for both respondents who started the survey (left panel; n = 271) and officially finished it (i.e., selected button to formally record responses; right panel; n = 140). Respondents could select as many categories as they desired. Abbreviations: CC = climate change, TX = toxic chemicals, NP = nonpoint source pollutants, AQ = aquatic habitat alterations, CD = coastal development, IN = invasive and nuisance species, FI = fisheries, WD = water withdrawals and diversions.


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