• TABLE OF CONTENTS
HIDE
 Front Cover
 Abstract
 Acknowledgement
 Table of Contents
 List of Tables
 List of Figures
 Introduction
 Survey design and response
 Socioeconomic profile of respo...
 Trip activities and expenditur...
 Hydrilla perceptions, levels experienced,...
 Willingness to pay for hydrilla...
 Aggregate fishing effort and the...
 Summary and conclusions
 Reference
 Telephone survey form
 Mail survey form














Group Title: Economics report - University of Florida Agricultural Experiment Station ; 118
Title: An economic analysis of sport fishing and the effects of hydrilla management in Lake County, Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027492/00001
 Material Information
Title: An economic analysis of sport fishing and the effects of hydrilla management in Lake County, Florida
Series Title: Economics report
Physical Description: vi, 47, (13) p. : i8ll. ; 28 cm.
Language: English
Creator: Milon, J. Walter
Welsh, Rick
University of Florida -- Food and Resource Economics Dept
Publisher: Food and Resource Economics Dept., Agricultural Experiment Station, Institute of Food and Agricultural Sciences. University of Florida
Place of Publication: Gainesville (Fla)
Publication Date: 1989
 Subjects
Subject: Fishing -- Economic aspects -- Florida -- Lake County   ( lcsh )
Hydrilla -- Control -- Florida -- Lake County   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 47).
Statement of Responsibility: J. Walter Milon, Rick Welsh.
General Note: "July 1989."
 Record Information
Bibliographic ID: UF00027492
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 001478337
oclc - 20974882
notis - AGZ0267

Table of Contents
    Front Cover
        Front Cover
    Abstract
        Page i
    Acknowledgement
        Page ii
    Table of Contents
        Page iii
    List of Tables
        Page iv
        Page v
    List of Figures
        Page vi
    Introduction
        Page 1
    Survey design and response
        Page 2
        Page 3
        Page 4
        Page 5
    Socioeconomic profile of respondents
        Page 6
        Page 7
        Page 8
        Page 9
    Trip activities and expenditures
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
    Hydrilla perceptions, levels experienced, and rankings of management plans
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
    Willingness to pay for hydrilla controls
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
    Aggregate fishing effort and the total economic value of sport fishing and hydrilla controls
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
    Summary and conclusions
        Page 44
        Page 45
        Page 46
    Reference
        Page 47
    Telephone survey form
        Page 48
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
    Mail survey form
        Page 9
        Page 10
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
Full Text


Ecov. IM S-
SJu


1989


Economics Repof :ti-:
*' : .. ".,:
.." ."


An Economic Analysis of Sport Fishin and

the Effects of Hydrilla Management n
Lake County, Florida


- "*.. i.


I Hi .. i III I l. l tiII i jiiiiiII .i.ii0 IiH." tI1 iiiiii r ..iiiiiiiii. .iiitii.,II.aIiiiiiiiit I iII .11 1.1 .i.t 1



,-04


Central Science
Library


L. '


JAN 11 1990

University of Florida


Food and Resource Economiesm Department
:Agricultural *iEperiment Station
Institute of Fod and Agricultural Sciences
University of Florida, Gainesville, 32611
S, A


Ii


y ",," : .. -"

,', .
r:" 4

1. :. ..



J. Waor Muon
Rik Welsh
:::1 "
:l "-^ *. .. '
*' = i '


II ''


w w r










ABSTRACT


The results of a telephone and mail survey to identify sport anglers'

preferences and economic values for aquatic plant control in Lakes Harris

and Griffin in Lake County, Florida are reported. The survey was designed

to evaluate the effects of different information about the effects of

hydrilla management on anglers' preferences and willingness to pay for

control. The survey results indicate that anglers prefer to have some

hydrilla growing in the Lakes but only a small minority would like

uncontrolled growth. Total annual willingness to pay for hydrilla controls

was estimated to range from $50 thousand to $176 thousand depending on the

level of control. The largest portion of the benefits from hydrilla

controls accrued to anglers from Lake County but nonresidents also received

significant benefits. In addition, anglers using the Lakes generated total

expenditures over $1.75 million in Lake County with the largest portion

attributable to resident anglers. Complete details of the survey design

and questionnaire are provided.





Key words: economic benefits, aquatic plant control, sport fishing

values, Lakes Harris and Griffin, hydrilla









ACKNOWLEDGFMENTS


This research project was funded under a grant from the Lake County

Water Management Authority. Thanks to Will Davis for his cooperation and

assistance during the project. Thanks also to Bill Johnson and Louis

Prevatt of the Florida Game and Fresh Water Fish Commission (Eustis) for

their advice on survey design and in providing information from the

Commission's creel census for this project. Valuable technical assistance

was also provided by Chuck Cichra and Doug Colle, Center for Aquatic

Plants, University of Florida. Special thanks to Lavon Mikell for her help

in final preparation of the manuscript. All errors and opinions expressed

in this publication are those of the authors.













TABLE OF CONTENTS


Pae


ABSTRACT . . . . . . . i

ACKNOWLEDGEMENTS . . . . . . ii

LIST OF TABLES . . . . . . iv

LIST OF FIGURES . . . . . . .

1. INTRODUCTION. . . . ... .. . 1

2. SURVEY DESIGN AND RESPONSE. ..... . . .. 2

3. SOCIOECONOMIC PROFILE OF RESPONDENTS . . . 6

4. TRIP ACTIVITIES AND EXPENDITURES . . .. 10

5. HYDRILLA PERCEPTIONS, LEVELS EXPERIENCED, AND RANKINGS
OF MANAGEMENT PLANS. . . . . .. 15

5.1. Perceptions of Hydrilla Problems. . .. .... 15
5.2. Previous Hydrilla Levels Experienced. . .. .... 21
5.3. Rankings of Alternative Hydrilla Management Plans .. 25

6. WILLINGNESS TO PAY FOR HYDRILLA CONTROLS. . . ... 30

7. AGGREGATE FISHING EFFORT AND THE TOTAL ECONOMIC VALUE
OF SPORT FISHING AND HYDRILLA CONTROLS .. ..... 37

7.1. Aggregate Fishing Effort and Sample Adjustments ... 37
7.2. Total Expenditures Associated with Sport Fishing
at Lakes Harris and Griffin ........ .. 39
7.3. Total Willingness to Pay for Hydrilla Controls on
Lakes Harris and Griffin. . . .. . 42

8. SUMMARY AND CONCLUSIONS . . . . ... 44

REFERENCES . . . . . . 47

APPENDIX A . . . . . . . 48

APPENDIX B . . . . . . 57










LIST OF TABLES


Table Page


1 Number of anglers intercepted at Lakes Harris and Griffin
by month and residence zone . . . . 4

2 Summary of contacts with anglers by phone and mail. . 5

3 Respondents completing surveys by residence zone. . 5

4 Socioeconomic profile of respondents completing both phone
and mail surveys by residence zone. . . . 7

5 Socioeconomic profile of respondents completing the phone
survey only by residence zone . . . . 8

6 Fishing ability, fishing mode, and horsepower ratings as
reported by mail survey respondents, by residence zone . 9

7 Distribution of all respondents' fishing trips to selected
lakes in Lake County by residence zone during previous
four months . . . . ... 10

8 Purpose and length of fishing trips by residence zone for
all respondents . . . . ... . .12

9 Fishing preference, club membership, fishing experience and
license type by residence zone for all respondents. .... 13

10 Average per family, per trip expenditures for all respondents
for trips to Lakes Harris and Griffin by residence zone . 14

11 Percentage of correct, incorrect, and don't know responses
to questions concerning hydrilla characteristics by residence
zone for those completing the phone survey only . ... 16

12 Percentage of correct, incorrect, and don't know responses
to questions concerning hydrilla characteristics by residence
zone for those completing both the mail and phone surveys 17

13 Respondents' opinions on hydrilla conditions by residence
zone. . . . . . . .... .19

14 Hydrilla levels experienced and levels that would prevent
fishing by residence zone . . . . ... 23

15 Highest level of hydrilla infestation encountered on
Lakes Harris or Griffin by residence zone . ..... .. 24











16 Preference rankings of hydrilla management plans. ... .. 28

17 Preference rankings of hydrilla management plans by
residence zone. . . . . .. ... 29

18 Willingness to pay for hydrilla control on Lakes Harris and
Griffin using alternative payment mechanisms and information
forms for all respondents . . . . 33

19 Willingness to pay for hydrilla control on Lakes Harris and
Griffin using alternative payment mechanisms and information
forms, by residence zone. .. ... . . . 35

20 Average willingness to pay for hydrilla controls on Lakes
Harris and Griffin for all forms, by residence zone . 36

21 Reasons given for refusal to pay for any management plan
presented by residence zone . . . .. 36

22 Estimated total fishing effort (man-hours) at Lakes Harris
and Griffin from creel surveys . . . . 38

23 Quarterly and annual expenditures by sport anglers at
Lakes Harris and Griffin in 1987-88 by residence zone .... 41

24 Estimated total annual willingness to pay for hydrilla
controls on Lakes Harris and Griffin by residence zone. ... 43









LIST OF FIGURES


Figure Page

1 Alternative levels of hydrilla infestation. . . ... 22

2 Basic form presentation of hydrilla management plans. ... 26

3 Enchanced form presentation of hydrilla management plans. 27

4 Independent format for willingness to pay for alternative
levels of hydrilla control. . . . ... 31

5 Additive format for willingness to pay for alternative
levels of hydrilla control. . . . ... ... 32









AN ECONOMIC ANALYSIS OF THE EFFECTS OF HYDRILIA ON
SPORT FISHING IN LAKE COUNTY, FLORIDA


J. Walter Milon and Rick Welsh*


1. INTRODUCTION

Hydrilla (Hydrilla verticillata) is a nonnative aquatic plant that has

become a serious problem in many lakes and rivers throughout Florida and

the Southeastern United States. Under suitable conditions, the plant grows

rapidly and can form dense mats on the surface that can crowd out native

aquatic plants, impede or prevent boat traffic, and may change fish and

other wildlife populations.

Since the early 1980's, Lakes Harris and Griffin in Lake County,

Florida have had infestations of hydrilla that required expensive control

measures to be undertaken by local agencies. These measures were taken in

order to maintain recreational uses, to maintain shoreline access, and to

protect the natural environment of the Lakes. Unfortunately, relatively

little is known about the economic value of recreational uses of the Lakes

and, in particular, sport fishing. Both Lakes Harris and Griffin are

nationally acclaimed sport fisheries and the site of several major bass

fishing tournaments each year.

To provide information about the economic impact of sport fishing on

the Lake County economy and the effects of hydrilla, the Lake County Water

Authority authorized a research project on sport fishing on Lakes Harris

and Griffin. This report summarizes the findings of that project.


J. Walter Milon is a professor and Rick Welsh is a former graduate
research assistant in the Food and Resource Economics Department,
University of Florida.











2

Specifically, the objectives of the project were to:

a) quantify the level of sport fishing activity on Lakes Harris and
Griffin;

b) estimate the economic impact of sport fishing on the Lake County
economy:

c) determine sport anglers' preferences for alternative levels of
hydrilla control; and,

d) estimate the economic value of alternative levels of hydrilla
controls to sport anglers using Lakes Harris and Griffin.

This report provides information about usage rates, socioeconomic

characteristics of sport anglers, users' preferences for hydrilla controls,

economic expenditures, and the value of hydrilla controls identified in

this project. The report describes the methodology and results of a mail

and telephone survey of anglers using Lakes Harris and Griffin during the

period November, 1987 through June, 1988. This analysis considers only the

economic benefits of hydrilla controls in Lake County and does not provide

a comparison with control costs. In addition, this report does not

consider the effects of hydrilla controls on other recreational groups such

as water skiers and pleasure boaters who may also benefit.


2. SURVEY DESIGN AND RESPONSE


In order to obtain a sample of anglers using Lakes Harris and Griffin,

a cooperative agreement was arranged with the Florida Game and Freshwater

Fish Commission to obtain name and address information from anglers

contacted as a part of the Commission's on-going creel survey on the Lakes.

Creel design, procedures and creel sections are described elsewhere and

will not be repeated here. During the period November 1, 1987 through June

30, 1988, creel clerks requested name, phone number and address information









3

from anglers who indicated they would be willing to participate in a survey

concerning their fishing trips to lakes in Lake County. Ten anglers per

survey day were selected randomly from five areas of Lakes Harris and

Griffin. This procedure was followed to ensure that all possible entry

points and fishing areas were represented in the sample. Anglers who had

been asked to participate in the survey once were not asked again.

This on-site sampling procedure resulted in a total of 1264 angler

contacts on Harris and Griffin of which 779 were Lake County residents, 342

were residents of other counties in Florida, and 143 were residents of

other states. Table 1 presents the month by month distribution of the

anglers contacted, as well as the distribution by residence zone. Table 1

shows that anglers from Lake County are the principal users of the Lakes.

The table also shows that anglers from areas outside Lake County and from

outside Florida comprise a larger share of the user population during the

January through April period. However, the low percentage of Lake County

residents reported in the table for May and June are misleading. These low

percentages occur because the creel clerks avoided repeat contacts during

May and June with anglers already surveyed. Since repeat contacts were

more likely to occur with local anglers, the share of local anglers

actually using the Lakes during these months was most likely much higher.

From the list of names, addresses and phone numbers obtained by the

creel clerks, phone calls were made by an interviewer from the University

of Florida during the period January through July. The calls were made

twice a week, during the evening, with the intention of reaching ten

anglers per phone session. Of the 1264 anglers on the creel survey list,

803 were called and 528 were actually contacted. Of the 528 anglers










4

Table 1. Number of anglers intercepted at Lakes Harris
month and residence zone


and Griffin by


Residence Zones
Inside Outside
Month Lake Co. Florida Florida Total


November 94 28 17 139
(67.6)* (20.1)* (12.2)*
December 106 19 12 137
(77.4) (13.9) (8.8)
January 146 41 12 199
(73.4) (20.6) (16.0)
February 137 28 31 196
(69.9) (14.3) (15.8)
March 125 51 28 204
(61.3) (25.0) (13.7)
April 104 71 18 193
(53.9) (36.8) (9.3)
May 46 51 9 106
(43.4) (48.1) (8.5)
June 21 53 16 90
(23.3) (58.9) (17.8)
TOTAL 779 342 143 1,264
(62.0) (27.0) (11.0)
*Numbers in parentheses indicate the percentage of the monthly total.
Percentages may not sum to 100% due to rounding.

contacted, 399 (75.6 per cent) successfully completed a phone survey. The

phone survey (see Appendix A) contained questions on the number of fishing

trips each angler made to fishing lakes in Lake County, the expenditures by

anglers during trips to Lakes Harris and Griffin, the socioeconomic profile

of the anglers, and questions to determine the anglers' knowledge of the

effects of hydrilla. The phone survey respondents were also asked if they

would complete a follow-up mail survey; of the 399 phone interviewed, only

three refused. Table 2 summarizes the phone survey contacts.

The mail survey (see Appendix B), asked anglers their opinions about

the severity of the hydrilla problem in Florida lakes, previous experiences










5

Table 2. Summary of contacts with anglers by phone and mail
Percent of
Number of anglers total reached

Anglers called 803

Anglers reached 528 100.0%

Anglers completing
phone survey 399 75.6%

Anglers completing phone
and mail surveys 288 54.5%
aTotal number of angler residences called.
bTotal number of anglers actually contacted by phone.

with hydrilla, their rankings of four separate management plans for

hydrilla on Lakes Harris and Griffin, and their willingness to pay for

hydrilla control based on the four management plans presented. After the

survey was mailed, follow-up phone calls were made to anglers who failed to

respond within three weeks. This procedure resulted in 288 completed mail

survey returns or 72.2 per cent of the total number of phone respondents

(Table 3). Table 3 shows that the highest response rate for the mail

survey was by Lake County anglers and the lowest was by respondents from

outside Florida.

Table 3. Number of respondents completing surveys by residence zone
Residence Zones
Inside Outside
Lake Co. Florida Florida Total

Phone survey 202 132 65 399

Phone and mail
survey 151 94 43 288

Percentage of phone
respondents who
completed both phone
and mail surveys 74.8% 71.2% 66.2% 72.2%










6

3. SOCIOECONOMIC PROFILE OF RESPONDENTS



For the purpose of evaluating the results of the survey, respondents

were separated into two groups: those respondents completing the phone

survey only, and those respondents completing both the phone and mail

surveys. Table 4 presents socioeconomic data for respondents completing

both surveys, while Table 5 presents data for respondents completing only

the phone survey. The descriptive statistics for respondents completing

both the phone and mail surveys are discussed first, and then compared to

the socioeconomic data of the respondents who did not complete the mail

survey.

Table 4 shows that the average age of survey respondents was

relatively high. The mean age was 57 years for Lake County residents, 50

years for Florida residents, and 54 years for out of state residents. In

addition, the overwhelming majority were males. Also, a high school degree

was the highest level of education reached by more than 50 per cent of all

respondents within each zone. The majority of Lake County residents were

retirees with lower incomes than their counterparts from the rest of the

state and outside Florida. Nearly 61 per cent of respondents from Lake

County indicated that they were retired, while 61.7 per cent of Florida

residents and 65.1 per cent of out-of-state residents were employed. In

addition, 53.1 per cent of Lake County respondents earned less than $25,000

per year compared to 38.2 per cent of Florida residents and 35.7 per cent

of non-Florida residents.

The socioeconomic profile of the phone survey only respondents was

somewhat different than those completing both surveys. Overall, the phone










7

Table 4. Socioeconomic profile of respondents completing both phone and
mail surveys by residence zone
Residence Zones
Inside Outside
Lake Co. Florida Florida

Number of respondents 151 94 43
Mean age 57 50 54


. % - - -

Sex
Female 6.7 6.3 2.4
Male 93.3 93.7 97.6


Education
Grades 1-8 7.3 2.1 14.0
Grades 9-12 9.3 13.9 9.3
High School Graduate 54.0 52.1 53.5
Some College 2.0 1.1 0.0
Community College 13.3 12.8 7.0
College 12.0 11.7 11.6
Graduate Degree 2.0 3.2 4.7
Ph.D. 0.0 0.0 0.0


Employment
Employed 37.7 61.7 65.1
Retired 60.9 36.2 34.9
Not Employed 1.3 2.1 0.0


Household Income/Yr.
Under $15,000 18.6 13.5 11.9
$15,000-$25,000 34.5 24.7 23.8
$25,000-$45,000 30.3 32.6 26.2
Over $45,000 16.6 29.2 38.1



only respondents were somewhat younger, less educated, were more likely to

be employed, and tended to earn lower or middle incomes than those

completing both phone and mail surveys. For example, the mean age of

Florida and out-of-state residents were lower, 47 and 44 respectively; a

greater percentage of all resident groups did not finish high school.











8

Also, Lake County residents earning under $15,000 annual income was 31.8

per cent for phone only respondents as compared to 18.6 per cent for phone

and mail respondents; Florida residents' incomes were slightly lower also;

and, for non-Florida residents, more respondents earned less than $25,000

per year, and less earned more than $45,000 per year. These results for

the phone survey only respondents suggest that the mail survey may have

elicited responses from a less representative sample of anglers than the

telephone survey.

Table 5. Socioeconomic profile of respondents completing phone survey
only, by residence zone
Residence Zones
Inside Outside
Lake Co. Florida Florida


Number of respondents 51 38 22
Mean age 57 47 44

- - % - - -

Sex
Female 12.0 12.5 0.0
Male 88.0 87.5 100.0

Education
Grades 1-8 20.0 15.6 16.0
Grades 9-12 12.0 21.9 20.0
High School Graduate 56.0 37.5 32.0
Some College 2.0 3.1 0.0
Community College 0.0 12.5 12.0
College 4.0 9.4 20.0
Graduate Degree 0.0 0.0 0.0
Ph.D. 0.0 0.0 0.0

Employment
Employed 44.0 71.9 68.0
Retired 56.0 25.0 20.0
Not Employed 0.0 3.1 12.0

Household Income/yr.
Under $15,000 31.8 20.7 14.3
$15,000-$25,000 29.5 20.7 14.3
$25,000-$45,000 31.8 41.4 42.9
Over $45,000 6.8 17.2 28.6









9

Information was also collected with the mail survey on anglers' rating

of their fishing ability, fishing mode, and horsepower ratings of their

boat engines. The results are presented in Table 6 for the different

residence zones. The majority of each resident group rated themselves as

intermediate in their skill as anglers. Respondents from Lake County and

Florida residents were more likely to rate themselves as advanced

intermediate or expert anglers while nonresidents were more likely to rate

themselves as advanced novices. The vast majority of anglers in all

residence groups usually fished from a boat. Finally, the horsepower

ratings of the boat engines were fairly evenly distributed across the size

categories. No resident group appears to prefer one size engine

substantially over another. However, a slightly higher percentage of all

resident groups use an engine of over 100 hp.

Table 6. Fishing ability, fishing mode and horsepower ratings as reported
by mail survey respondents, by residence zone
Residence Zone
Inside Outside
Lake County Florida Florida
% ---- --- % --- --- % ---
Ability

Expert 7.4 4.3 5.1
Advanced Intermediate 31.5 26.1 7.7
Intermediate 49.7 60.9 56.4
Advanced Novice 6.0 4.3 28.2
Novice 5.4 4.3 2.6

Fishing Mode

Boat 94.0 94.8 94.9
Shore 6.0 5.2 5.1

Horsepower

0-25 21.1 20.7 18.9
20-50 27.4 28.3 24.3
51-100 22.4 17.4 21.6
100 + 28.8 33.7 35.1










10

4. TRIP ACTIVITIES AND EXPENDITURES


During the phone interview respondents were asked to report the number

of fishing trips they made to Lakes Harris, Griffin, Yale, Eustis, Dora,

Beauclair, and Apopka during the previous four months. Table 7 gives the

results for all respondents completing the phone survey. Since all the

anglers in the study were initially contacted on Lakes Harris and Griffin,

these lakes dominate the distribution of trips. Lake County residents

preferred Lake Harris to Griffin by a small margin as did Florida residents

outside Lake County. Non-Florida residents made substantially more trips

to Lake Griffin than Harris, 61.1 per cent of trips made by non-Florida

residents were to Griffin and 23.7 per cent to Harris. Lake Eustis was the

third most popular lake among the anglers interviewed for all three

residence zones and Lake Dora the fourth. Lake Apopka was the least

popular for all resident groups.

Table 7. Distribution of all respondents' fishing trips to selected lakes
in Lake County by residence zone during previous four months
Residence Zones
Inside Outside
Lake Lake Co. Florida Florida



Harris 3600 47.0 978 43.2 246 23.7
Griffin 3108 41.0 829 36.6 634 61.1
Yale 32 0.4 62 2.7 8 0.007
Eustis 535 7.0 217 9.6 97 9.3
Dora 251 3.0 151 6.7 50 4.8
Beauclair 84 1.0 25 1.1 3 0.003
Apopka 16 .0.002 1 0.0004 0 0.0
Total trips 7626 100.00 2263 100.00 1038 100.00









11

Information on the characteristics of the anglers' fishing trips was

also collected during the phone interview. Table 8 reports the purpose and

length of fishing trips made by all respondents, as well as the fishing

mode, whether the angler was participating in a tournament, and the average

number of people fishing with the respondent. As expected, out of state

respondents indicated a much longer average length for their fishing trips

to Lakes Harris and Griffin than either Florida residents or Lake County

residents, 8.63 days compared to 1.6 and 1.03 days, respectively. Average

hours fished per day were much closer, with non-Florida residents averaging

5.91 hours per day while Florida residents averaged 5.85 and Lake County

respondents averaging 4.24. Out-of-state anglers also combined fishing

trips with other purposes more often than either Lake County residents or

Florida residents: 99.5 per cent of Lake County residents and 100 per cent

of Florida residents indicated that fishing was the primary purpose of the

last trip they made to either Lake Harris or Griffin. In contrast, only

76.9 per cent of non-Florida residents indicated that their primary reason

for making the trip was to fish in Harris or Griffin. Almost all

respondents reported that they fished on Harris or Griffin from a boat.

Finally, 20.5 per cent of Florida residents reported they participated in a

fishing tournament during their last trip to either Harris or Griffin, as

compared to only 10.8 per cent of non-Florida residents and 3.5 per cent of

Lake County residents. Non-Florida residents also were more likely to have

fished with other people and members of their family in their fishing part

than respondents in the other residence groups.













Table 8. Purpose and length
respondents.


12

of fishing trip by residence zone for all


Residence Zones
Inside Outside
Lake Co. Florida Florida

Average length of fishing
trip (days) 1.03 1.60 8.63

Average hours fished per day 4.24 5.85 5.91


. % - -
Fishing was primary purpose
Yes 99.5 100.0 76.9
No 0.5 0.0 23.1

Fishing
Boat 88.6 91.7 95.4
Shore 11.4 8.3 4.6


Tournament fishing
Yes 3.5 20.5 10.8
No 96.5 79.5 89.2

Average number of people
fishing with the
respondent 0.86 1.01 1.4

Average number of family
members fishing with the
respondent 0.39 0.52 0.54



Information about the personal traits of anglers was collected and is

reported in Table 9. Lake County residents averaged 14.7 years fishing

inside Lake County as compared to 11.9 and 6.2 for Florida residents and

non-Florida residents, respectively. The greatest difference between

groups occurred in the type of fish the anglers targeted. The majority of

Lake County residents, 63.2 per cent, reported that panfish was the primary

target; Florida residents were almost equally split between panfish and

bass as the primary target while 58.5 per cent of out-of-state residents










13

were bass fishermen. In addition, when asked if the primary target

indicated was the usual target species, the overwhelming majority of all

resident groups said yes. The vast majority of Lake County resident

anglers were not members of a fishing club but 29.5 per cent of Florida

resident anglers and 29.2 per cent for non-Floridians were fishing club

members. As expected most non-Floridians held non-resident fishing

licenses, and Florida and Lake County residents held resident licenses.

Nearly 21 percent of Lake County resident respondents had no fishing

license because the State of Florida does not require licenses for anglers

over 65 years of age.

Table 9. Fishing preference, club membership, fishing experience and
license type by residence zone for all respondents
Residence Zones
Inside Outside
Lake Co. Florida Florida

Average years fishing
experience in Lake Co. 14.7 11.92 6.23

- - - % - - -

Primary species targeted
Bass 36.8 48.5 58.5
Panfish* 63.2 51.5 41.5

Usual target species
Yes 83.1 84.8 90.8
No 16.9 15.2 9.2

Fishing club member
Yes 9.0 29.5 29.2
No 91.0 70.5 70.8

License type
Resident 67.2 81.1 26.2
Non-resident 11.4 9.8 69.2
No license due
to age 20.9 9.1 1.5
No license 0.5 0.0 3.1
Panfish include speckled perch, bream, and catfish.










14

In addition to anglers' fishing trip activities and traits,

information on expenditures for trips to Lakes Griffin and Harris for a

variety of goods and services was collected during the phone survey. These

data are presented in Table 10. As expected, out-of-state visitors spent

more than Lake County and Florida residents on lodging and travel costs.

Table 10. Average per family, per trip expenditures for all respondents for
trips to Lakes Harris and Griffin, by residence zone
Residence Zones
Inside Outside
Lake Co. Florida Florida


Travel cost* $0.79 $ 7.92 $ 9.16

Bait, tackle, boat fuel,
food, and ice 13.26 20.61 16.31

Launch fees 1.73 0.61 0.46

Lodging (per day) 0.20 5.33 32.34

Boat/Motor rental 0.0 0.15 0.68

Fishing guide, 0.0 5.30 0.0

Other expenses 0.0 4.33 0.46
Total expenditures $15.98 $44.25 $59.41
Travel cost is the reported miles driven to Lakes Harris or Griffin
multiplied by two, divided by the reported miles per gallon, and the
quantity multiplied by $1.00.


The largest expenditures for out-of-state visitors were for travel

expenses, lodgings, and bait, tackle, boat fuel, food, and ice. The lowest

travel cost reported was for Lake County residents, $0.79 per family, since

the average distance travelled to the Lakes was 5.81 miles. Lake County

and Florida residents generally incurred expenses for travel costs and

bait, boat fuel, tackle, food, and ice. Little or no money was spent by

these resident groups on boat or motor rentals, fishing guide services, or

launch fees. Launch fees usually range from one to two dollars only and









15

tend to be included in lodging fees for fish camps and trailer parks; this

explains the small amount reported and why Florida and non-Florida

respondents paid less than Lake County residents. Respondents from outside

Lake County tended to stay longer than one day, and therefore their launch

fees were included as part of their lodging expenses. "Other" expenses

primarily entailed entrance fees for fishing tournaments. Overall, per

trip total expenditures by non-Florida and outside Lake County respondents,

while significantly higher than for Lake County residents, were relatively

similar because so many non-Florida respondents established temporary

residences in the Lake County area.



5. HYDRILLA PERCEPTIONS, LEVELS EXPERIENCED, AND

RANKINGS OF MANAGEMENT PLANS



5.1. Perceptions of Hydrilla Problems

As part of the phone survey, respondents were asked a set of questions

to determine their understanding of the effects of hydrilla on freshwater

lakes. Tables 11 and 12 present the questions and responses (categorized

as correct, incorrect, or a "don't know" if the respondent had no answer).

Table 11 includes respondents only completing the phone survey, while Table

12 includes those respondents completing both the phone and mail surveys.

The correct answer is given in parentheses after each question.

Since the mail survey was concerned primarily with management

alternatives for hydrilla, it is useful to compare the answers of the phone

survey only respondents with those completing both surveys. Those

respondents completing both surveys had a much higher percentage of correct











Table 11. Percentage of correct, incorrect, and don't know responses to questions concerning
hydrilla characteristics by residence zone for those completing the phone survey only
Phone Survey Only

---------------------------------- Residence Zone ---------------------------------
Inside
Inside Outside
Lake County Florida Florida
Don't Don't Don't
Questions Correct Incorrect know Correct Incorrect know Correct Incorrect know
Is hvdrilla a ---------- % ---------- ---------- % ---------- ---------- % -----------


native Florida
plant? (No)
Can hydrilla grow
in water deeper
than 5 feet? (Yes)
Does the amount of
hydrilla in a lake
affect the number
or size of the fish
in the lake? (Yes)
Do small amounts of
hydrilla improve
sport fishing in
a lake? (Yes)
Would the number
and size of large-
mouth bass caught
increase if hydrilla
covered more than
half of a lake? (No)
Can hydrilla be
completely cleaned
out from a lake
with one or two
treatments of
chemical weed
killer? (No)


28 36



4 36


12 24


20 12






40 16


12 40 58 14 28 52 8 40


12 40 58 14 28


52 8 40









Table 12. Percentage of correct, incorrect, and don't know responses to questions concerning hydrilla
characteristics by residence zone for those completing both mail and phone surveys

Mail and Phone Survey Completed
-------------------------------------- Residence Zone ------------------------------
Inside
Inside Outside
Lake County Florida Florida
Don't Don't Don't
Questions Correct Incorrect know Correct Incorrect know Correct Incorrect know
Is hydrilla a ---------- % ----------- ----------- % ----------- ---------- % -----------
native Florida
plant? (No) 47 19 34 54 13 33 37 19 44
Can hydrilla grow
in water deeper
than 5 feet? (Yes) 71 11 18 78 10 13 63 14 23
Does the amount of
hydrilla in a lake
affect the number
or size of the fish
in the lake? (Yes) 77 7 17 82 12 6 70 14 16
Do small amounts of
hydrilla improve
sport fishing in
a lake? (Yes) 76 21 3 79 15 6 80 9 11
Would the number
and size of large-
mouth bass caught
increase if hydrilla
covered more than
half of a lake? (No) 60 21 19 51 29 20 63 21 16
Can hydrilla be
completely cleaned
out from a lake
with one or two
treatments of
chemical weed
killer? (No) 66 10 24 68 11 21 51 19 30











18

answers. The mail and phone survey respondents were more

knowledgeable than the phone only respondents on every question, and for

every residence zone, except one. These results might explain why some

respondents refused to mail back the surveys even after being reminded.

They may not have understood the hydrilla problem and could not respond to

the management alternatives.

Many respondents in both survey groups did not know that hydrilla is

not a native Florida plant. However, relatively high percentages in each

survey group and residence zone knew that hydrilla can grow in water deeper

than five feet. In addition many respondents knew that the amount of

hydrilla in a lake affects the number and size of fish and that small

amounts of hydrilla improve sport fishing in a lake. The majority of phone

and mail survey respondents were aware that hydrilla coverage of greater

than 50 per cent of a lake does not increase the number and size of

largemouth bass caught but many phone survey only respondents were

incorrect or did not have a response to this question. Finally, most

respondents knew that hydrilla could not be completely cleaned out with one

or two treatments of chemical weed killer.

Mail survey respondents were asked to express their opinions on four

statements about hydrilla conditions in Florida and the effect on their

sportfishing. The statements are given in Table 13 and the possible

responses were: A-strongly agree, B-agree, C-no opinion, D-disagree, and

E-strongly disagree. The percentage of respondents in each response group

are reported in Table 13 by residence zone. Also reported is the entropy

statistic which measures the degree of agreement between respondents. A

value close to 1 indicates relatively little consensus.










Table 13. Respondents' opinions' on hydrilla conditions by residence zone (continued)
Residence Zone

Outside
Florida
Statement A B C D E Entropy


Aquatic weeds such
as hydrilla are a
serious problem in
Florida lakes


I like to fish on
lakes with lots
of hydrilla


I like to fish on
lakes with no
hydrilla at all


Aquatic weed
control is a
necessary part
of fish management
for Florida lakes


15.4 43.6 12.8 28.2 0.0




0.0 25.6 10.3 41.0 23.1


10.3 25.6


15.4 38.5 10.3


25.6 64.1 2.6 5.1 2.6


1The opinion responses for each statement are A-strongly agree, B-agree, C-No opinion, D-disagree, E-Strong disagree.
2The entropy statistic is a measure of the degree of consensus among respondents. A value near zero indicates
almost complete consensus and a value near one indicates no consensus.










Table 13. Respondents' opinions1 on hydrilla conditions by residence zone
Residence Zone

Inside

Lake County Florida
Statement A B C D E Entropy2 A B C D E Entropy


Aquatic weeds such
as hydrilla are a
serious problem in
Florida lakes


I like to fish on
lakes with lots
of hydrilla


I like to fish on
lakes with no
hydrilla at all


Aquatic weed
control is a
necessary part
of fish management
for Florida lakes


30.5 45.0 7.9 14.6 2.0


25.0 41.7


4.7 18.7 5.3 45.3 26.0




13.8 25.7 9.9 38.8 11.8


5.2 26.0 2.1


8.4 21.1 12.6 44.2 13.7


10.5 21.1 14.7 43.2


10.5


33.8 57.0 2.0 4.0 3.3 .63 35.4 51.0 6.3 6.3 1.0 .66


33.8 57.0 2.0 4.0 3.3 .63


35.4 51.0 6.3 6.3 1.0 .66









21

Seventy-five per cent of Lake County respondents agreed or strongly

agreed that aquatic weeds are a serious problem in Florida lakes, while

only 66.7 per cent of Florida residents, and 59.0 per cent of non-Florida

respondents agreed or strongly agreed with the statement. The majority of

respondents in all groups disagreed that they did not like to fish on lakes

with lots of hydrilla but less than a majority of all groups agreed that

they like to fish on lakes with no hydrilla at all. The relatively high

entropy statistic for these responses suggests that there is a considerable

diversity of opinion about the desirable level of hydrilla in a fishing

lake. Finally, Table 13 shows that a large majority of all respondents to

the mail survey either agreed or strongly agreed with the statement:

"Aquatic weed control is a necessary part of fish management for Florida

lakes". This reflects a higher degree of consensus among respondents for

this statement than for any other.



5.2. Previous Hydrilla Levels Experienced

Mail survey respondents were asked to indicate what level of hydrilla

they had experienced on any lake in Florida, which level would force them

to visit another lake, and which level of infestation they had experienced

on Lakes Harris or Griffin. These responses were given using the four

levels of hydrilla infestation described in Figure 1. These levels were

intended to be representative of hydrilla conditions that have occurred in

lakes throughout Florida and were not designed to describe conditions

exclusively at Lakes Harris and Griffin.

Table 14 presents respondents previous levels of hydrilla experienced

at any Florida lake and the level that would cause them to fish at another






22
Figure 1. Alternative levels of hydrilla infestation.

HYDRILLA




HYDRTLLA LEVEL 1
Pasrintion
Bydras prh nt mly in a frw rmall. iholtd at rmche in to of
the iake. Oth.e autic lants Ulik gras. war baonets, ad lilUs
iOOt. fanmtrictij on boat travel at ay tim.
Covers 1 of Lake

---------------------------------------------------------------------------------------
HYDRILLA



HYDRILLA LEVEL 2

Descriotion
Nydrills, cover many shallow reas of the take and am ne boat ramon.
Hydrilla is InJ with other aquatic plants in theb aWr. oats with IMj
suinem can have foulinir nablem in ma with hdrilla.

Covers 10-20X of Lake

----------------------------------------------------------------------------------------
HYDRLLA



HYDRILLA LEVEL 3

Description
Sydrilla oem all Srhflowr ara of the lake and all ar nea boat raoms.
Very few other sauatic plants ae present in ua eovew d by hydriUa. Bo1tL
with stanl enrine can only travel on hals from boat rnpam and n deep
after areas of the lake.

Covers 35-50X of Lake

----------------------------------------------------------------------------
WYDRIUA



Y HYDRILLA LEVEL 4



HydrillsU Cover the atire lake acept for deepest bhles. J ohf SL.autiE
aakt anr present. Only boats with air atain can tkrv on the lake but
even these can hae fouling problem.
Covers 0-80X of Lake









Table 14. Hydrilla levels experienced at any lake and levels that would prevent fishing by residence zone
Residence Zone

Inside Lake County Inside Florida Outside Florida
Levels that Levels that Levels that
Levels would prevent Levels would prevent Levels would prevent
Experienced fishing Experienced fishing Experienced fishing
----------- ----------- ----------- % ---------- ----------- ----------


Level 1

Level 2

Level 3

Level 4


12.6

55.6

19.9

11.3


I have never seen
hydrilla at any of
these levels on
any lake


0.1


0.1

6.0

54.3

33.8




NA


6.6

34.0

37.2

22.3




0.0


2.1

4.3

39.4

43.6




NA


25.6

44.2

18.6

9.3




2.3


2.3

11.6

51.2

30.2




NA


None of these
levels would
cause me to go
to a different
lake


lake 5.2 NA 10.6 NA 4.7


5.2 NA 10.6


NA 4.7











24

lake. The majority of respondents in all residence groups indicated that

the highest level they had experienced was either level 2 or 3. Florida

residents from outside Lake County generally had the most experience with

high levels of hydrilla. Most respondents indicated they would not be

inhibited from fishing on a lake with hydrilla until it reached level 3.

But, Florida residents were generally more willing to tolerate higher

levels of hydrilla. Only a very few respondents from all resident groups

indicated that they had never experienced any of these levels at Florida

lakes. Also, only a small percentage of each group indicated that none of

these levels would prevent them from fishing.

Table 15 presents information about the levels of hydrilla infestation

encountered by respondents at Lakes Harris and Griffin. Levels 1 and 2

were cited most often as the highest levels of hydrilla encountered by all

resident groups. And, the level of consensus was somewhat higher for Lakes

Harris and Griffin than for other lakes in Florida. Only a small

percentage of respondents indicated they had experienced Level 4

infestation on Lakes Harris and Griffin.

Table 15. Highest level of hydrilla infestation encountered on Lakes Harris
or Griffin by residence zone
Residence Zone

Inside Lake County Inside Florida Outside Florida
------- % -------- ----- ------% ..... % ------

Level 1 19.5 23.7 35.7

Level 2 63.1 62.4 45.2

Level 3 17.4 14.0 11.9

Level 4 0.0 0.0 7.1









25

5.3. Rankings of Alternative Hydrilla Management Plans

To determine anglers' preferences for different levels of hydrilla

control, respondents were asked to rank four alternative plans for controls

on Lakes Harris and Griffin. The plans range from almost complete control

(Plan A) to no controls (Plan D) and are shown in Figures 2 and 3. The

difference in the two figures is the type of information presented to

respondents. Each respondent received only one of the two management

information forms. The basic form (Figure 2) presents information only

about the effects of the management plans on hydrilla. The enhanced form

(Figure 3) presents information about both hydrilla and the fish

populations in the Lakes that might occur with the different plans. In

general, the enhanced form shows that harvestable sport fish populations

would increase with some hydrilla in the Lakes but the effect would be the

same under Plans B, C, and D. These possible responses of the fish

populations to alternative hydrilla levels were based on data collected by

the Eustis office of the Florida Game and Fresh Water Fish Commission and

on conversations with Dr. Chuck Cichra and Douglas Colle in the Center for

Aquatic Plants, University of Florida, Gainesville.

Tables 16 and 17 present the respondents' rankings of the management

plans using the two information forms. Table 16 presents the aggregate

ranking for all resident groups and Table 17 shows the rankings for

different residence zone groups. In general, Table 16 shows that plans A

and B were the two most preferred plans, but the type of information

presented to respondents did influence their ranking of the alternatives.

With the basic form, Plan B was selected over Plan A as the most or 2nd

most preferred by a relative narrow margin. However, with the enhanced







Basic form.presentation of hydrilla management plans.


RYDRILUA


HYDRILLA MANAGEMENT PLAN A


NBdrEUl would be emtroll*d so tJt ely few m iall. oed tches are
pment ino ame of the Lak with watr dethls than 5 feet. drill
is t rkmoL rM .


Coern 1X of Lake


------ -DRA
HYDRILlA


HYDRILLA MANAGEMENT PLAN B


Covers 10-20X of Lake


Hydrilla anagement would alow bydrilla to moar v an.s of the akes
lmh than t fot deep. Hydrill would be mixed with other Meustic olante in
tbhe shallow uare. MsR hydrill would he rrowiu n bhot ram ,areu.


HYDRILIA


HYDRILLA MANAGEMENT PLAN C


Bydrilla would cover jll JW or the Lakel hrI thn 8 feet deen. Control
would ahly be med to maintain trails from boat r p ape to dee-Xr *re of th
liaM. HydrWi would be owint in boat ramp aras and would be er dense
outside the bout trails. Vy few other Mustic plants would be powin in
area with hydrila.


Coers 35% of Lake
(TroBs)


KYDRULA


HYDRILLA MANAGEMENT LAN D


No control on drill growth w d b d. r would ee d. d Woud r al&.all
of the Lakes l than I ft deep. om Mtrails from boat rma to deeper
water would be keLt oen by boats with l enr ne cutting thbou5h the
hydrill. HydrUll would be v dene in all e and few other aquaic
plant, would be rowing.


Cover 40X of Lakes
(No Trolls)


Figure 2.






FIGURE 3: Enchanced form presentation of hydrilla management plans.


HYDRILLA SPORTFISH


AH other
BSPECS 4X
SPECS 4X


Covers 12 of Lakes


HYDRILLA MANAGEMENT PLAN A


nydr*il would be e->bnild t" Mm ly sa iS
-.,, oholted a tey m a imret ID ma of the
al with water deaths In than feet. Ng
tlll bt i rn w .earL The amber of oortfish
iD tM Lakes would be the m as. the historical
gam e lso-n in the flma01tBoShet.


8.000 fish per re


All other
ponfish
673





Cvers 15-20X of Lakes 9500 fish per ocre


HYDRILLA MANAGEMENT PLAN B


Hydrila manage t would allow ydrills to over
- 3X marn rr of the Lakes lie than 5 ft dep.
Hydrbl would be mixed with other acuatic plants in
- OX those shallow areas. hydriU would be growing
i boat remno a.M. The aumkr of sportfish in the
Lakes would be emater than the historical aerares
and tbhe ix of different kinds of fish woud ch
t tht boo te te fliuren the let. The
wee rilse of him way also 1aaint


COi' 35X of Lakes
cralls)


All other
87X BASS 3X
SPECS 10x


8.500 fish per ar


HYDRILLA MANAGEMENT PLAN C
PDscrition
HBrdrill would wwr aL.Amm dof the Lakem bt tha
Sftt deeo. Controls would gg be used to
m naintin. itr i tro boat amp. to deerMr ae .o
the ILk. HydridU would be mrwin in bot ranm
LM and would be ver dense outside the bott
tuilt. Ve few other muatic plants would be
rowin ti im a with hydrill. The number of
inorfih in the Laks would be mater th. n the
hitorical averam and the mix of different kinds of
fbh would chann to that bow n tlhe fcur on the
MI. The ervm i m of ba my abo Iae A .


Covers 4 of Lakes
(No TroiS)


9,500 fish per acre


HYDRILLA MANAGEMENT PLAN D



No op= Lan khdrMI Sowthb would be sed.
drla would veor aup rM of the Les les thm&
Lt deep. Sem tCll from boe t ram to deepr
wter would be kLnt monn by botS with I.
alDam cuttiaU through the hydrill. ydrill would
sb very dmee in all me and few etr quatic
plants would be growing. Tbnhe Umr L sportfish in
the rLke would be ma thmn the historical
m uEa r ad the ami of different kinds of ish
would .chan to that shown i the f i ur on the
lft. The verTae msi of bai may ao nlabeS


---------------------------------r- ----- - - - - -


- --- ---- ---- ---- ---- -------- -- -- --- -- -- --- -- -- -- --- -- -- --- -- -- --


-------------------, ----- ---------- ---------------------------r--------------r----













Table 16. Preference rankings of


Planned control
level and rank


Plan A
Most preferred
2nd most preferred
3rd most preferred
Least preferred


Plan B
Most preferred
2nd most preferred
3rd most preferred
Least preferred


Plan C
Most preferred
2nd most preferred
3rd most preferred
Least preferred


Plan D
Most preferred
2nd most preferred
3rd most preferred
Least preferred


28

hydrilla management plans
Information on plan effects
Hydrilla Hydrilla levels
level only and fish populations
--- % --- --- % ---

42.1 29.1
29.2 34.6
13.3 22.6
14.7 14.3


49.7
46.5
3.5
1.4



8.3
20.8
69.9
0.7



0.0
3.5
13.3
80.4


62.0
35.3
2.3
0.0



9.0
28.6
62.4
0.0



0.0
1.5
12.8
83.5


form, a clear majority ranked Plan B as the most preferred alternative.

Plans C and D were highly preferred by only a small percentage of the total

respondents.

Table 17 shows that Lake County and Florida residents generally

preferred Plan B level controls and that their rankings were influenced by

the type of information presented to them. Out-of-state respondents were

influenced the most by the type of information presented. With the basic

form, out-of-state respondents were the most likely of all groups to prefer

Plan A controls but with the enhanced form they were the most likely to









Table 17. Preference rankings of hydrilla management plans by residence zone.
Residence Zone
Inside Outside
Lake Co. Florida Florida
Planned control Hydrilla Hydrilla Hydrilla Hydrilla Hydrilla Hydrilla
level and rank levels and fish levels and fish levels and fish
only levels only levels only levels


Plan A
Most preferred 42.3 28.4 33.3 29.2 59.1 31.6
2nd most preferred 31.2 38.8 28.9 25.0 22.7 44.4
3rd most preferred 14.3 1.5 18.2 29.2 0.0 16.7
Least preferred 11.7 0.0 0.0 16.7 18.2 11.2

Plan B
Most preferred 50.0 62.7 55.6 58.4 36.4 68.5
2nd most preferred 46.8 35.8 42.2 37.5 54.5 27.8
3rd most preferred 2.6 1.5 2.3 4.2 9.1 0.0
Least preferred 1.3 0.0 0.0 0.0 4.5 0.0

Plan C
Most preferred 7.7 9.0 11.1 12.5 4.5 0.0
2nd most preferred 19.5 23.9 26.7 35.4 13.6 27.8
3rd most preferred 72.7 67.2 63.6 52.1 72.7 72.2
Least preferred 0.0 0.0 0.0 0.0 4.3 0.0

Plan D
Most preferred 0.0 0.0 0.0 0.0 0.0 0.0
2nd most preferred 2.6 1.5 2.2 2.1 9.1 0.0
3rd most preferred 10.4 11.9 15.9 14.6 18.2 11.2
Least preferred 84.4 86.6 81.8 83.4 72.7 88.9











30

prefer Plan B controls. These results suggest that out-of-state

respondents probably have the least amount of experience with hydrilla as

compared to other respondent groups so new information has a greater impact

on them than more experienced groups. When hydrilla levels and fish

populations are linked, then every respondent group ranks plan B over A as

the most preferred plan.



6. WILLINGNESS TO PAY FOR HYDRILLA CONTROLS



In addition to the rankings of the alternative management plans,

respondents were also asked to give their willingness-to-pay for these

plans. This was done in the form of a special stamp for a fishing license

to fish on Lakes Harris and Griffin. To determine whether the procedure

used to elicit willingness-to-pay for different levels of control had any

influence on the aggregate results, two different formats were used for the

payment question. The first, shown in Figure 4, is an independent format

in which the willingness-to-pay for successive levels of control does not

depend on the prior level of payment. The second format shown in Figure 5

is additive so that the payment for any level of control depends on the

prior level. Each respondent received only one of the two payment formats.

This was done to test two possible effects: (1) whether linking fish

populations with hydrilla levels affects willingness to pay for the

management plans and, (2) whether willingness to pay for the management

plans differs if the questions are presented independently versus an

additive format.







Figure 4. Independent format for willingness to pay for alternative levels
of hydrilla control.


Controlling hydrilla on Lakes Harris and Griffin is a costly operation that
is paid from tax revenues collected by local and state agencies. Suppose
these tax revenues were not available for hydrilla management and some
other way to pay these costs was needed. One possible solution would be to
issue a special hydrilla management stamp for the Lakes. This stamp would
be purchased with your regular fishing license and would be required to
fish on these Lakes. All proceeds would be used to control hvdrilla.
Please answer the following questions about this stamp. These questions
will help public agencies understand how valuable hydrilla management is to
you. Your answers will not be used to increase license fees. Please
answer even if you are not required to buy a fishing license.

#8 Consider for a moment your current and possible future use of Lakes
Harris and Griffin. If there was no money available for hydrilla
control, the only management plan that would be possible is PLAN "D"
as described on the opposite page. If you could pay for a special
hydrilla management stamp that would provide money to finance
management PLAN "C", what is the most you would be willing to pay
annually to support PLAN C? Please circle an amount.

$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25

$30 $35 $40 $45 $50 $55 $60 $65 $70 $75 $80


#9 Suppose that as an alternative to PLAN "C", you could pay for a
special hydrilla management stamp that would provide money to finance
management PLAN "B". This means that PLAN B would be used instead of
PLAN D. What is the most you would be willing to pay annually to
support PLAN B? Please circle an amount.

$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25

$30 $35 $40 $45 $50 $55 $60 $65 $70 $75 $80


#10 Finally, suppose that as an alternative to either PLAN C or PLAN B,
you could pay for a special hydrilla management stamp that would
provide money to finance management PLAN "A. This means that PLA A
would be used instead of PLAN D. What is the most you would be
willing to pay annually to support PLAN A? Please circle an amount.

$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25


$60 $65 $70 $75 $80


$30 $35 $40


$45 $50 $55









Figure 5. Additive format for willingness to pay for alternative levels
of hydrilla control.

Controlling hydrilla on Lakes Harris and Griffin is a costly operation that
is paid from tax revenues collected by local and state agencies. Suppose
these tax revenues were not available for hydrilla management and some
other way to pay these costs was needed. One possible solution would be to
issue a special hydrilla management staN& for the Lakes. This stamp would
be purchased with your regular fishing license and would be required to
fish on these Lakes. All proceeds would be used to control hydrilla.
Please answer the following questions about this stamp. These questions
will help public agencies understand how valuable hydrilla management is to
you. Your answers will not be used to increase license fees. Please
answer even if you are not required to buy a fishing license.

#8 Consider for a moment your current and possible future use of Lakes
Harris and Griffin. If there was no money available for hydrilla
control, the only management plan that would be possible is PLAN "D"
as described on the opposite page. If you could pay for a special
hydrilla management stamp that would provide money to finance
management PLAN "C", what is the most you would be willing to pay
annually to support PLAN C? Please circle an amount.

$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25

$30 $35 $40 $45 $50 $55 $60 $65 $70 $75 $80



#9 Suppose instead that you could pay for a special hydrilla management
stamp that would provide money to finance management PLAN "B". In
addition to the amount you circled above in #8 what is the most you
would be willing to pay annually to support PLAN B? Please circle an
amount.
$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25

$30 $35 $40 $45 $50 $55 $60 $65 $70 $75 $80


#10 Finally, suppose you could pay for a special hydrilla management stamp
that would provide money to finance management PLAN "A". In addition
to the amounts you circled above in #8 and #9, what is the most you
would be willing to pay annually to support PLAN A? Please circle an
amount.
$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25


$60 $65 $70 $75 $80


$30 $35 $40


$45 $50 $55









33

Table 18 presents the average willingness to pay for all respondents

for the alternative management plans using the different payment formats.

In general, respondents who received the enhanced information form

indicated a slightly higher willingness to pay for all management plans but

the difference was not statistically significant for any of the plans.

However, the payment formats do result in statistically different average

payments for Plan B with both information forms and for Plan C with the

enhanced information form. Generally the additive format results in higher

willingness to pay for Plans B and A but lower willingness to pay for Plan

C. This may be due to the fact that respondents using the additive format

considered their responses to all levels before responding with an initial

payment for Plan C.

Table 18. Willingness to pay for hydrilla control on Lakes Harris and
Griffin using alternative payment mechanisms and information
forms, for all respondents.
Management Plans Means of Means of
and Type of Willingness to Pay Payment Forms
Information Forms Independent Additive Equal?


PLAN C
- Hydrilla Only** $ 8.63 (11.17)* $ 5.42 (6.94) No
- Hydrilla and Fish** 9.06 (11.75) 6.21 (7.94) Yes

PLAN B
- Hydrilla Only** 11.50 (13.99) 13.25 (15.42) Yes
- Hydrilla and Fish** 12.19 (16.27) 13.94 (13.83) Yes

PLAN A
- Hydrilla Only** 10.31 (14.78) 25.28 (24.13) No
- Hydrilla and Fish** 11.82 (16.38) 24.03 (16.96) No


*Number in parentheses is the standard deviation.

**For each management plan the pairs of means by type of information
provided are not statistically different at the .05 level.










34

Table 19 shows that the effects of the alternative payment formats on

willingness to pay varied considerably across residence groups. Lake

County and Florida residents generally gave similar responses for Plans C

and B under the two payment formats but their average payment for Plan A

was considerably higher with the additive format. With the independent

format, Plan B had a higher average willingness to pay than the alternative

plans, but with the additive format Plan A clearly had the highest average

payment. Out-of-state respondents had significantly higher responses for

all plans with the additive format.

The willingness to pay for hydrilla control averaged across all forms

for each residence group is reported in Table 20. The responses by Lake

County and other Florida residents were generally very similar for all

levels of control. Non-Florida anglers had the lowest average willingness

to pay for all three control levels. In general, the results indicate that

respondents clearly understand the need for hydrilla controls and they were

willing to state that these controls were economically valuable to them.

The fact that different residence zone groups had different values for

hydrilla controls is a reflection of the diversity of anglers using the

Lakes and the different factors that influence their interest in future use

of the Lakes.

Not all respondents, however, were willing to pay for hydrilla

controls. Those respondents who would not were asked for their reason for

refusing any plan provided and their responses are presented in Table 21.

Overall, the percentage of respondents who refused to indicate any

willingness to pay was relatively small with the Lake County resident group

having the highest fraction at 6.9 per cent. The reason most often given









Table 19. Willingness to pay for hydrilla control on
and information forms, by residence zone.


Lakes Harris and Griffin using alternative payment mechanisms


Willingness to Pay
Independent Additive
Management Plans - - - - Residence Zone - - - - -
and type of Inside Inside Outside Inside Inside Outside
Information Forms Lake Co. Florida Florida Lake Co. Florida Florida


PLAN C
- Hydrilla Only** $ 7.68 (9.88)* $11.69 (14.06) $4.25 (4.00) $ 4.32 (5.24) $ 6.35 (8.99) $ 7.00 (6.98)
- Hydrilla and Fish** 10.45 (12.24) 8.32 (11.73) 2.20 (4.38) 6.90 (6.92) 4.23 (4.78) 7.67 (12.45)

PLAN B
- Hydrilla Only** 11.79 (15.29) 12.64 (13.42) 6.25 (4.43) 11.26 (14.28) 13.25 (17.69) 17.64 (14.56)
- Hydrilla and Fish** 14.92 (19.16) 9.36 (11.84) 5.60 (4.39) 13.80 (11.90) 14.37 (16.04) 13.60 (15.00)

PLAN A
- Hydrilla Only** 10.89 (16.38) 10.20 (13.85) 7.25 (5.73) 21.48 (16.38) 26.10 (35.13) 32.50 (28.84)
- Hydrilla and Fish** 14.82 (18.06) 8.80 (14.07) 4.20 (8.84) 25.10 (22.01) 21.78 (20.12) 25.13 (30.70)

*Number in parentheses is the standard deviation.


**For each plan, the pairs of means by
the .05 level.


type of information provided to respondent are not statistically different at











36

Table 20. Average willingness to pay for hydrilla control on Lakes Harris
and Griffin for all forms, by residence zone
Residence Zones
Hydrilla Management Inside Outside
Plan Lake Co. Florida Florida

Plan C $7.54 (9.39)* $7.81 (10.82) $6.10 (9.08)

Plan B $18.11 (22.17) $17.51 (21.49) $13.56 (13.46)

Plan A $27.67 (33.86) $24.72 (31.78) $19.13 (19.12)

Number in parentheses is the standard deviation.

by all residence groups for refusing to pay for any management plan was:

"I object to any proposal that might increase the cost of fishing." Non-

Lake County resident respondents were more likely than Lake County

residents to indicate that they would rather fish at another lake than pay

to control hydrilla on Lakes Harris and Griffin: 31.3 per cent of Florida

residents chose this answer and 28.6 per cent of non-Florida residents, as

compared to only 5.0 per cent of Lake County residents.

Table 21. Reasons given for refusal to pay for any management plan
presented, by residence zone
Residence Zone
Inside Outside
Reasons Lake County Florida Florida
-- % -- -- -- -- % --

% of total respondents who indicated
no willingness to pay 6.9 5.5 2.4

My most preferred plan is plan D
and I don't want to pay for
unnecessary hydrilla control 10.0 6.3 0.0

I would rather fish at another
lake then pay to control hydrilla
on Lakes Harris or Griffin 5.0 31.3 28.6

I object to any proposal that might
increase the cost of fishing 75.0 56.3 71.4

I did not understand the question 10.0 6.3 0.0









37

7. AGGREGATE FISHING EFFORT AND THE TOTAL ECONOMIC VALUE OF

SPORT FISHING AND HYDRILLA CONTROLS


This section provides a discussion of the procedures used to

extrapolate the results from the survey to the population of anglers using

Lakes Harris and Griffin. The first part describes the data and

assumptions used to estimate total use of the Lakes based on Florida Game

and Fresh Water Fish Commission (FGFWFC) creel surveys. The next two parts

describe how these use estimates are combined with survey results to

estimate economic impacts.



7.1 Aggregate Fishing Effort and Adjustments

As discussed in Section 2, this survey was conducted as part of the

on-going FGFWFC creel survey on Lakes Harris and Griffin. Based on the

creel survey, quarterly and annual estimates of total fishing effort on the

Lakes are prepared using a computerized program maintained by North

Carolina State University. These estimates are the only available source

of data on total sport fishing use of the Lakes. Quarterly and annual

effort data for the study period are reported for the two Lakes in Table

22. The data show that Lake Harris receives more fishing effort than Lake

Griffin at all times of the year. However, these data are estimates of

man-hours expended in the fishery only and do not provide information about

the number of fishing trips during each period or the number of anglers

using the Lakes.

To provide estimates of the number of fishing trips, data from the

survey conducted for this study were used with the total effort data.

First, the total effort data for each quarter were decomposed into effort











38

Table 22. Estimated total fishing effort (man-hours) at Lakes Harris and
Griffin from creel surveys
Lakes
Quarter Harris Griffin


July-September, 1987 31,220 21,230
October-December, 1987 44,968 27,430
January-March, 1988 163,147 102,008
April-June, 1988 61,390 33,648
Total Effort (Man-hours) 300,725 184,648
Source: Data provided by Florida Game and Fresh Water Fish Commission,
Eustis, FL.

by each of the three residence zone groups (Lake County, inside Florida and

out of state) based on the distribution identified during the survey (e.g.

Table 1). Since there was some concern, however, that these data might not

have reflected the true distribution of use (especially during the latter

months of the survey), assumptions were made about the actual residence

zone distribution. The resulting quarterly distribution of total effort is

as follows:

Lake Co. Florida Out-of-state
July September 85% 10% 5%
October December 72% 18% 10%
January March 65% 20% 15%
April June 72% 18% 10%

These percentages were then multiplied by the quarterly total effort

estimates for both Lakes and the product was divided by the average number

of hours per fishing day by respondents in each residence group (Table 8)

to estimate the total number of trips to each Lake by residence group.

These estimates are used with expenditure data to estimate total fishing

related expenditures.

The estimated total number of trips was also used to estimate the

total number of anglers using the Lakes. This was done by dividing the











total number of trips by each residence group by the number of trips to the

Lakes by a representative respondent in each group. For this calculation,

the mode of the distribution was used because the average (mean) was skewed

by a relatively small number of anglers who had a very high number of trips

to the Lakes. In this type of situation, the mode gives a more

representative estimate than the average. The estimated (one day) trips

per angler per year used to calculate the number of anglers from each

residence zone using the Lakes are: Lake County 23 trips; inside Florida

residents 8 trips; and out of state 6 trips. This results in estimates

of the number of anglers by residence group of 3,496 in Lake County, 1,907

anglers from other counties in Florida, and 1,672 anglers from out-of-

state. For comparison purposes, the number of fishing licenses sold to

residents in Lake County in 1987-88 were 16,987 and non-resident license

sales were 12,475. The estimated number of anglers using Lakes Harris and

Griffin are a large fraction of the total license holders but they are not

the majority of anglers in Lake County. These results suggest that while

Lakes Harris and Griffin are popular sport fishing sites, anglers in this
area have many other fishing sites to choose from.


7.2. Total Expenditures Associated with Sport Fishing on Lakes Harris
and Griffin

Using the estimated total number of fishing trips, the total

expenditures by sport anglers using Lakes Harris and Griffin in 1987-88

were estimated. Expenditures per angler trip by residence group were based

on the reported average family expenditures (Table 10). These average

family expenditures were divided by the average number of family members in

a fishing party (Table 8) to account for shared trip expenses between

family members.











40

Results of the calculations are presented in Table 23 for each Lake

and each quarter during 1987-88. The estimates show that Lake County

residents account for approximately 50 per cent of the economic activity

associated with both Lakes. In addition, Florida residents from outside

Lake County account for a larger share of the total expenditures than

anglers from out-of-state. This is due to the data in Section 7.1 that

Florida residents from outside Lake County account for a larger share of

total effort than out-of-state anglers.

The January to March quarter clearly generates the most use and

economic activity. More expenditures are incurred for sport fishing on the

Lakes during this one quarter alone than for the other three quarters

combined. This is due to the greater levels of effort by all residence

groups during this quarter and to the larger share of nonresident anglers

with higher daily expenditures than Lake County anglers. This is not

surprising since the winter and early spring months are active periods for

both bass and panfish, and these months are a peak period for tourism in

Central Florida.

The total expenditures for sport fishing of $1,755,673 is one measure

of the economic activity associated with Lakes Harris and Griffin. An

additional measure can be estimated based on the expenditures by non-

Florida residents. These expenditures are a flow of money into the Florida

and Lake County economy that might not occur if the Lakes could not be used

by recreational fisherman. The flow of money creates a "multiplier effect"

on the economy that increases employment and income in the area. The

multiplier effect only applies to non-resident expenditures since fishing

related expenditures by residents would probably occur anyway.









41

Table 23. Quarterly and annual expenditures by sport anglers at Lakes
Harris and Griffin in 1987-88, by residence zone
Residence Zones
Inside Outside
Lake and Quarter Lake Co. Florida Florida Total

Lake Harris
July-September $ 72,657 $15,661 $ 10,224 $ 98,542
October-December 88,654 40,608 29,398 158,660
January-March 290,364 163,773 160,030 614,167
April-June 121,026 55,455 40,162 216.643

Annual $572,701 $275,497 $239,814 $1,088,012


Lake Griffin
July-September $ 49,416 $ 10,654 $ 6,944 $ 67,014
October-December 54,073 24,773 17,940 96,786
January-March 181,551 102,380 100,038 383,969
April-June 66,988 30,682 22,222 119.892

Annual $352,028 $168,489 $147,144 $667,661

TOTAL $924,729 $443,986 $386,958 $1,755,673



To properly estimate the multiplier effect of non-resident fishing

expenditures for an area like Lake County, it is necessary to have

estimates of expenditure multipliers for the area. Such a task is beyond

the scope of this study. However, in previous research Milon, Mulkey and

Ellerbrock (1982) estimated an expenditure multiplier for sport fishing in

Florida of 2.63. This means that for each $1 of expenditures by non-

resident anglers an additional $1.63 of expenditures are created in

Florida. This figure is an upper bound for an area as small as Lake County

since some initial expenditures may occur outside the County and not all of

the additional spending effects will occur within the County. Applying

this multiplier to the estimated non-resident annual expenditures of

$386,958 gives an estimate of $1,017,700 attributable to the direct and










42

induced effects of these expenditures. Combined with the resident

expenditures of $1,368,715, the total economic activity associated with

Lakes Harris and Griffin is estimated to be $2,386,415.



7.3. Total Willingness to Pay for Hydrilla Controls on Lakes Harris
and Griffin

The survey results reported in Section 6 clearly demonstrate that

sport anglers have preferences for different levels of hydrilla control and

these controls are economically valuable. The individual measures of

willingness to pay for hydrilla controls are one indicator of these

economic values. To extrapolate these individual measures from the survey

to the population of anglers affected by hydrilla controls, it is necessary

to define the group of anglers who benefit from a control program. For

this analysis it is assumed that the number of anglers using Lakes Harris

and Griffin, as estimated in Section 7.1., is the relevant user population.

This definition implies th t only anglers who use the Lakes would be

willing to pay for hydrilla controls and that other anglers in Lake County

(whether resident or not) who fish on other lakes would not be willing to

pay for controls on Lakes Harris and Griffin. Alternatively, the

population could be defined as all fishing license holders in Lake County

since some anglers may be concerned about hydrilla in Lakes Harris and

Griffin even though they do not currently fish on these Lakes. However,

since this survey targeted only current users of Lakes Harris and Griffin,

the survey results cannot be extrapolated to other anglers.

Table 24 presents estimates of the total user group willingness to pay

for hydrilla controls on Lakes Harris and Griffin based on the estimated

number of anglers and the average willingness to pay for different levels









43

of hydrilla controls for all respondents (Table 20). The figures show that

the Lake County resident group has the highest economic value for hydrilla

controls; this is consistent with the earlier results which show this group

also accounts for the most fishing effort and economic expenditures. It

should be noted, however, that the willingness to pay by the Lake County

resident group is approximately 50 per cent of the total for the three

levels. This indicates that non-residents have a significant interest in

and place a high value on hydrilla controls in the Lakes.

Table 24. Estimated total annual willingness-to-pay for hydrilla controls
on Lakes Harris and Griffin by residence zone
Residence Zones
Hydrilla Management Inside Outside
Plan Lake Co. Florida Florida Total

Plan C $26,360 $14,890 $10,196 $51,446

Plan B $63,313 $33,383 $22,666 $119,362

Plan A $96,735 $47,129 $31,976 $175,840

Based on average responses with no adjustment for bidding or information
form. The estimated total number of anglers from each residence zone Lakes
Harris and Griffin in 1987-88 is: Lake County 3,496, Inside Florida-
1,907, and Outside Florida 1,672.

Finally, the total willingness to pay estimates show a positive

progression as the level of control increases. This suggests a clear

pattern of angler preferences for higher levels of control. However, this

result occurs because the estimates are based on the average willingness to

pay estimates as presented in Table 20. Different estimates of the total

would result if the individual willingness to pay were based on the means

from the different survey forms described in Section 6 (see Table 19). In

particular, if the total estimates were based on results from the

independent survey form only, the total willingness to pay for Levels B and

/










44

A would be approximately the same. Therefore, the reader should be careful

to consider the differences in anglers' preferences for hydrilla controls

discussed in Section 5 and should recognize that estimates of the total

economic value of hydrilla controls depend on the specific type of question

used to elicit anglers' willingness to pay for these controls.



SUMMARY AND CONCLUSIONS

The purpose of this study was to measure the economic activity

associated with sport fishing on Lakes Harris and Griffin in Lake County,

Florida and to identify anglers' preferences and value for hydrilla

control. The study used a combined telephone and mail survey based on

initial contacts with anglers during the on-going creel census on the

lakes. The results show that Lakes Harris and Griffin are popular fishing

sites that attract large numbers of Lake County resident anglers, residents

from other Florida counties, and anglers from other states. The Lakes are

an important economic entity accounting for approximately $1.7 million in

direct economic expenditures and $2.3 million in total economic activity.

The survey results also showed that a large majority of resident and

non-resident anglers want management controls on hydrilla growth in the

Lakes, but they have differing preferences for specific levels of control.

Most anglers would prefer to have some level of hydrilla but not to such an

extent that it covers large areas and impedes normal boat travel. In

addition, these controls are economically valuable to anglers as reflected

by their willingness to pay for different levels of controls. A specific

estimate of the value of hydrilla controls, however, depends on the type of

survey question used to elicit respondents' willingness to pay and









45

alternative assumptions about the relevant group of anglers affected by

hydrilla controls on Lakes Harris and Griffin.

It is difficult to compare the results of this study because very few

other studies of sport fishing and hydrilla for Florida (or other states)

lakes have been conducted. Two lakes that have been studied are Orange and

Lochloosa Lakes in North-Central Florida. Colle et al. (1987) estimated

total annual expenditures associated with sport fishing on Orange Lake to

be approximately $1 million in 1978-79. Expenditures decreased by 90 per

cent in 1977 due to almost total coverage of the Lake by hydrilla. This

estimate was based only on changes in fishing effort on the Lake since

expenditure data were not collected but were derived from prior work by

Babcock (1975) on Lake Jackson in Leon County, Florida. Aside from actual

changes in effort, no data on angler preferences or the economic value for

hydrilla control were collected in the study.

Milon, Yingling and Reynolds (1986) used interview and mail survey

data to estimate total expenditures associated with sport fishing on Orange

and Lochloosa Lakes to be $5.6 million in 1985. Total economic activity

was estimated to be $10.8 million. The range of anglers' average

willingness to pay for levels of aquatic weed control comparable to those

used in the present study was $8.92 to $16.11; these averages are very

similar to the averages reported for this study (Section 6.). Total annual

willingness to pay for plant controls comparable to levels B and A

discussed earlier in this report (Section 5) were $386,000 and $480,000,

respectively.

The differences between the results for Orange and Lochloosa Lakes and

those reported in this study of Lakes Harris and Griffin can be attributed











46

to the larger number of anglers using Orange and Lochloosa and the higher

average expenditures by non-resident anglers. Lakes Orange and Lochloosa

had more than six times the number of anglers in 1985 than Lakes Harris and

Griffin in 1987-88. In addition, non-residents using Orange and Lochloosa

Lakes spent nearly twice as much per day as non-residents using Lakes

Harris and Griffin. This is because many non-resident anglers using Lakes

Harris and Griffin can be described as "snow-birds" who establish temporary

residence with relatives or in relatively inexpensive housing. By

contrast, non-resident anglers using Orange and Lochloosa were more likely

to stay in the area for only a few days and to spend money for motel/hotel

lodging and fishing guide services.

Despite the differences in fishing effort and economic activity

measures, the respondents in the two surveys provided quite similar

information about their preferences for hydrilla control. In general,

hydrilla is neither all good or all bad. Most respondents believe some

amount of hydrilla is desirable but high levels of infestation are

preferred by only a very small minority. In addition, sport anglers

recognize that hydrilla management is costly and they expressed a

significant willingness to pay for controls. The consistency between the

results from this survey and the earlier survey of anglers using Orange and

Lochloosa Lakes is an encouraging indication that sport anglers in Florida

understand the hydrilla management problem and the economic benefits of

management can be measured. This information can be used to establish

hydrilla controls that are consistent with the public's interest in

economically justifiable resource management programs.












REFERENCES



Babcock, S. C. 1975. Lake Talquin and Jackson investigations. Florida
Game and Fresh Water Fish Commission, Federal Aid in Fish Restoration,
F-31-R-1, Annual Progress Report, Tallahassee.

Colle, D. E., et al. 1987. Influence of hydrilla on harvestable sport-fish
populations, angler use, and angler expenditures at Orange Lake,
Florida. North American Journal of Fisheries Management 7:410-417.

Milon, J. W., W. D. Mulkey, and M. J. Ellerbrock. 1982. Regional impact
analysis and recreation multipliers. Review of Regional Studies
12:11-21.

Milon, J. W., J. Yingling, and J. E. Reynolds. 1986. An economic analysis
of the benefits of aquatic weed control in North-Central Florida.
Economics Report 113, Food and Resource Economics Department,
University of Florida, Gainesville.







































APPENDIX A: Telephone Survey Form









4'








Hello,


May I speak with (If they respond with, "Who may I say is
calling?", state your name and that you are calling as part of a research project for the
University of Florida.)

(If he or she is not home, then find out when he/she will be there. When you do
contact the desired party, say.)

My name is, and I am calling you as part of a research
project for the University of Florida. I got your name from a survey of fishermen conducted
by the Florida Game and Fresh Water Fish Commission at Lake in
Do you remember being contacted during that survey?

We are conducting a follow-up survey to ask fishermen's opinions on fishery management
for improving fishing in Lake County, to find out about the fishermen using lakes in Lake
County, and to obtain information on economic activity associated with fishing in Lake
County.

If you don't mind, I would like to ask you some questions about your fishing trips and
expenses incurred over the last four months. All information is confidential and please ask
me to repeat if you don't understand the questions.

May we begin?

Thanks!

SURVEY NUMBER
1-4
LAKE (HARRIS 1, GRIFFIN 2)
5

Is the address I have here (read the address) your permanent home address? (If
residence is outside Florida but temporary home in Lake County area, then record temporary
address). [Write in full name and address below.]


(Verify Name)



(Street and Name/P.O.Box)



City State


ZIP CODE
6-10

If respondent was contacted at Lake Harris begin with (I)a. If at Lake Griffin begin
with (I)b.









2

(1) a. How many times have you fished at Lake Harris in the last four months?

[Go to (lb)]
11-12

b. How many times have you fished at Lake Griffin in the past four months?

(Go to (1)a].
13-14



(2) Did you fish at other lakes in Lake County? [1 if yes; 2 if no]

15

[If the answer is no, prompt them by asking: Does this mean you did not fish at Lake
Yale?.... If still no, then move on]

--If so, then which ones, and how many times have you visited each in the last four
months?

Lake Yale
16-17



Lake Eustis
18-19


[Go to #3]

Lake Dora
20-21



Lake Beauclair
22-23



Lake Apopka
24-25










(3) Now try to recall your last trip to Lake (Harris or Griffin). In what month did this
trip take place? (1 January, 2 February, 3 March, 4 April, 5 May, 6 June, 7 July, 8
August, 9 September, 10 October, 11 November, 12 December)
[Go to #4]

26-27


(4) Was this a one-day trip?


(1) Yes [Go to #5b)

(2) No [Go to #5]



(5) a. How many days were you fishing on this trip?


b. Was fishing the primary purpose of this trip?
(1) Yes
(2) No

c. Were you fishing from shore or from a boat?
(1) Shore
(2) Boat


d. Were you participating in a fishing tournament?
(1) Yes
(2) No



(6) How many hours were you actually fishing on the lake
on this trip?


28





29-30



31




32


33



34-35


(7) Did you
(1)
(2)


drive your own car?
Yes (Go to #8]
No [Go to #9]


(8) How many miles per gallon does your car get?


a. (1)
(2)
(3)
(4)
(5)


0-10
10-15
15-20
20-25
25-30


36


(6) 30-35
(7) 35-40
(8) 40-45
(9) 34-50
(10) 50-55


37











b. Could you estimate how many miles you drove from your
residence to the Lake? (Use temporary residence if they
are living in Lake County area.)
[Go to #10]


(9) Since you did not drive:

(1) Do you live on the lake?

(2) Did you rent a car?

(3) Did you go with someone else?
[Go to #10]


(10) a. How many people were fishing with you on this trip?
(Enter 0 if fishing alone.)

b. Were any of these people members of your family?
(If YES, write in 0; if NO, enter 0.)


38-40


41


42


43


(11) Could you estimate the amount of money you and your family spent on your last trip to
Lake (Harris or Griffin) for bait, ice, food, drinks, tackle, and fuel for the boat? (If
they have trouble estimating, then read the categories below.)


(1) 0 to $10
(2) $10 to $20
(3) $20 to $30
(4) $30 to $40


(5) $40 to $60
(6) $60 to $80
(7) $80 to $100
(8) $100 to $150
(9) more than $150
[Go to #12]


(12) Did you have any of the following expenses?
rounded to the nearest dollar.)

Fishing guide

Boat/motor rental


44


(If yes, ask how much for each item


45-47

48-50


Launch fees or slip rental


Lodging


[Go to #13]


Other


51-53

54-56

57-59










(13) On this trip, what kind of fish were you trying to catch? (Let him/her answer;
don't read the choices.)

(1) Bass (Largemouth or striped)


(2) Speckled Perch (Crappie), Bream, Catfish


60


(14) Do you usually fish for this type of fish when you go to Lake (Harris or Griffin)?

(1) Yes

(2) No 61


To be sure we have fairly represented all fishermen in this study, I need to ask you a
few questions about yourself.


(15) First, how old were you on your last birthday?


62-63


(16) What is the highest grade of school you completed? (Allow respondent to answer.)

No Degree 1-12
High School 12
Community College 14
College 16
Graduate Degree 18
Doctorate 20
64-65


(17) How many years have you been fishing in Lake County?


66-67


(18) Which of the following best describes your current
employment status?


(1) Employed
(2) Retired
(3) Not employed


68












(19) Is your total household income over or under $25,000?
(If UNDER) Is it over or under $15,0007
(If OVER) Is it over or under $45,000?


I under 15,000
2 15,000 25,000
3 25,000 45,000
4 over 45,000


(20) Are you a member of a fishing club?


(1) Yes
(2) No


(21) Do you have a resident or nonresident fishing license?


(1) Resident
(2) Nonresident
(3) No license due to age
(4) No license


71


(22) a) Do you know what hydrilla is?


(1) Yes
(2) No


72


b) (If Response is "NO" read: "Hydrilla is a long, stringy aquatic plant that grows in
dense clumps in fresh water lakes in Central Florida.")

Have you ever come across hydrilla on your fishing trips in Central Florida?


Yes
No
Don't know


73


(23) I need to ask you a few short questions about your perceptions of hydrilla. You only
need to answer "YES" or "NO" to each question or just tell me you "DON'T KNOW".

(a) First, do you think hydrilla is a native Florida aquatic plant?
(1) Yes
(2) No
(3) Don't know
74


69


70










(b) Do you think hydrilla can grow in water more than 5 feet deep?
(1) Yes
(2) No
(3) Don't know
75

(c) Do you think that the amount of hydrilla in a lake has an effect on the number or
size of fish in the lake?
(1) Yes
(2) No
(3) Don't know
76

(d) Do you think that small amounts of hydrilla will improve sport fishing in a lake?
(1) Yes
(2) No
(3) Don't know
77

(e) Do you think that hydrilla coverage of more than 50% of a lake will increase the
number and size of largemouth bass caught?
(1) Yes
(2) No
(3) Don't know
78

(f) Do you think that hydrilla can be completely cleaned out from a lake with I or 2
treatments of chemical weed killer?
(1) Yes
(2) No
(3) Don't know
79

(24) a. I have only one last question. To complete our research, we would like to mail you
a short questionnaire on your opinions about hydrilla control in Lake County. Some
of these questions are too detailed to ask over the phone but they would only take
you a few minutes to complete at home. We would include a postage paid envelope
to return the questionnaire, so it would not cost you anything to mail it back to
us.

Would you be willing to complete this questionnaire? (CIRCLE THEIR RESPONSE)

(1) Yes (Go to b.)
(2) No (Go to c.)











b. If I mail the survey within the next 10 days, can I mail it to the address I checked
with you earlier? (If NO, then write in address for mailing.)


Name


Street # and Name/P.O.Box


City


State


Zip Code


c. Thank you for taking the time to answer our questions. Your answers will help to
provide a lot of useful information for fishery management in Lake County. (If YES
to 24 a., also say: When you receive the questionnaire in the mail, please complete
it and send it back as soon as possible.]

Have a good evening!


(WRITE IN: MALE 0, FEMALE 1)


Survey mailed


80


FORM 0


Follow-up.


Survey returned

































APPENDIX B: Mail Survey Form









PAGE 1


1e Please circle the umber on the following scale that you feel best
describes your fishing ability.


1
ICE
IGPICE


3
XITRMDIATB


5
IMDIT


*2 Do you usually fish from a boat or from shore?

I FROM A BOAT

2 FROM SHORE


If you fish from a boat, please write in the horsepower rating
of the boat engine you use for fishing: HP


03 Please indicate to what extent you agree or disagree
following statements. Please circle your answers.


STRONGLY
AGREE


0o
WEm


Aquatic weeds such as
hydrilla are a serious
problem in Florida lakes.


I like to fish on lakes
that have lots of hydrilla


I like to fish on lakes
that don't have any
hydrilla at all .


Aquatic weed control is
a necessary part of fish
management for Florida
lakes .


. 1


. 4


4


. 2


4. ...


. . 5


PLEASE TVRN TO PAGE 2


with the


STRONGLY
DISAGREE DISAGREE


AGREE







PAGE 2


04 Please look at the f lures and text on the oRosite guee (PAGE 3) t1
shows 4 Ievels of hvdrilla infestation in a freshwater lake. Plea
read the description for each level so that you understand how th
level of hydrilla affect the lake. Please circle the answer bel
that corresponds to the highest level of hydrilll infestation oMb h
exterienced on nv lake in Florida.

LEVEL 1

LEVEL 2

LEVEL 3

LEVEL 4

I HAVE NEVER SEEN HYDRILLA AT ANY OF THESE LEVELS ON ANY LAKE


#5 Suppose these 4 levels described possible conditions on a lake yc
aight use for fishing. Which level would cause you to stop fishing a
this lake and instead go to some other lake?

LEVEL 1

LEVEL 2

LEVEL 3

LEVEL 4

NONE OF THESE LEVELS WOULD CAUSE ME TO GO TO A DIFFERENT LAKE


*6 Suppose that these 4 levels of hydrilla infestation described actus
conditions on Lakes Harris and Griffin. Please circle the answer
below that corresponds to the highest lavel of bydrilla infestatior
you have xaierienced on either Lakes Harris or Griffin.


LEVEL 1


LEVEL 2


LEVEL 3


LEVEL &


PLEASE TURN TO PAGE 4




PAGE 3


MDRILLA


BYDRILLA LIMVL 2


ais only a- toM h ah is o
j ju s j h b 46 k aim esa bees vow a s rdoo
Cu*0n IN of Lake










WIYDRLLA
jYDR]LLA LIEL 2


J!"MA arm MOCZ Ahlefo- M the lob Md MD
Uydr~a I N b VHMaLow sm ofk Ph. hki Om all T s'Mt 4l raihmh
SMAK c is .bffiaw caomh in Moss mt baLs.

wini m10m20X of Lle










H UA
H"YDRMLLA LEVIL 3


ft Irw evo ms of aw A s sold an are" amp best rU ILMDO
With ML11vftmnftcantl 7 vl boati Lwk- siod "b







ibmr -Y hav Iin LJI
Cavs 30-30X of Lake

~~~~~--~~~~~----~~----~-- -- - - -- - - -- - - -
W ft.ILA



L7A NVDRrLLA LZVT-L 4



dak an PM j-" Wi rr rth bsn M1d= oee, IMVW 40 She W but

covars 60-sa o Lamu




PACE 4


Once hydrillsa has startd grw#n Ln lakes like Ji .ris a. d Criffin it iL almost Lorrfa re
to ramletlv ell rinte. Therefore local and state raSneles responsible for jajk
mn- rem must choose a BjaD to amtrolT IEfrdlliT n Lrakes garrs d Grfflf. E or
possible -arm-eeo lans and their ffets an the lakes are described an the figures and
Z=t co the oonosite nam (page 5). The descriptions are based a the bet aafllabl
scientific informtiM1n about bthebe makes. Please read the duecrlptifn carefully and
answer the following questlons.


*7 Suppose Mu could ricamind your most preferred and last referred hydrills
maunalmr nt plans to local and state agencies. Please consider the management Rag
ati2onL on the opoaDDitLe Then write tn the lettr for Bach S an in the ApASUc
beovy to indicate ror ranking of these plans from the ot srafarred to the &A.ul
preferred.

MOST PREFERRED (PLASE BE SURE TO
2ND MOST PREFERRED I WITE-IN A LL1TER
3RD MOST PREFERRED FOR ACHR ANK)
LEAST PREFERRED

Controlling bydrillsa o Lakes azrrls and Griffin is a cstly oaaratlon that is pid frlo
ta. revues collected by local and state gmcels. Ajppose these m ae rmenues were not
awlable for hydrilla mnagMnent and some ocher Swa to pay tbese costs was needed. One
possible solution would be to issue a special Abdrfilla mna t stam for the Iakes.
This stawp would be purchased witb your regular fishnlg license and would be required to
fish on these Lakes. Al nroceeds would be used to control bydrilll Please answer the
following questions about this stamp. These questions will help public agencies
understand bow valuable hydrilla management is L o. rour anwers will a be used to
increase 11cease fees. Please answer even if you are ot reured to buy a fishing
license.

48 Consider for a moment your current and possible future use of Lakes Harris and
Griffin. If there vas no aone available for hydrilla control, the nly management
plan that would be possible is PIA *D as described on the opposite page. If yoa
could pay for a special hydrilla management stanr that would provide money to
finance management FLAN C', what is the BaI you would be killing to pay annually
to support PLAN C? Please circle an amount.

$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25
$30 $35 $40 $45 $50 $55 $60 $65 $70 $75 $80

w9 Suppose that as an alternative to PIAN *C, eou could nay for a special bydrilla
management stanm that would provide money to finance management ILAN *.*. This
eans that ZI .J would be used instead of I'AL D. What is the BRst you would be
willing to pay annually to support LFN B? Please circle an amount.

$0 $1 $3 $5 $7 $10 $12 $15 $17 $20 $25
$30 $35 $40 $45 $50 $55 $60 $65 $70 $75 $80

#10 Znall., suppose that s an alternative to either PLAN C or PUIN -, would av
Sa= a special bydrilla manaement m that would provide money to finance
management PlAN "A'. This means that Na A would be used inftea of 6LAI What
is the Wost you would be willing to pay annually to support PLAN A? Please circle
an amount.

$0 $1 $3 $5 $7 $10 $12 $15 $17 ; $20 $25
$30 $35 $40 $45 $50 $55 $60 $65 $70 $75 $80


PLEASE TURN TO PAGE 6




PAGE 5


WfDRLLA


MYDRTLLA MANArg*MINT PLAN A

Iyala mweald h te t m17 m am mly
s ms e of S. Lame wil k dSoh m a B f Byrill'
h hetam es


COms Is of Lake

H-yDR-A- -- --------- -
IffDRLLA


RYDRTLLA MANAGEMENT PLAN B


2A


Uydr*lU sumagt mweld aBow krydrila to wr i. n r m toh Lake
ii thM...hllt dep. ydriU4 wa mld b mzad wfth oth samuutic alnt, in
the sallow urse. IaL hfdLa muld be aSrw' in. bohat a.mm use


Cower 10-20X of Lake


fDRL.LA


HrYDRILA MANAGEMENT PLAN C


Iydria woud svr olJM of thi Lake im thma I feet d A Controls
w ud 2b b Nmed to ~intan tmils ftm beot rap* to t der samu of tht
UU. Byd-ria wouldd b oaew in boat am a re. md moud be ir- dt
tmmide the b ait ls. Very Ir ether aauta aMlants wmuld be Iprowwi a
aom with bydriWa.


CoverM 35S of Lake
Crrls.)


IYDRILLA MANAGEMENT PLAN D


e hydrI grth wmed be med. rdruga wuld wvr gaL.aCl
rLtiS e bwtha M f dmt du e. bar ls. faenm ht mmm to d0per
wter wmed hI kwt An Iby he wirth am e. riJ cuni ta shro the
l*WliUr. Wydrill uld be 1 dlam a.ll 'rea.. d fto etLer equU&
lantu weld be prowls.


C.rm 40X of Lake
(No Trela)









PACE 6


ell If you indicated in Questions *8, 9 and 10 that you would not .a for
yW hydrill management plan, which of the following statements bgS
explains your answer? [Please skip this question if you AdW circle a
$ mount Athar than t. 00I in either *8, 9 or 10.)

1 My most preferred plan is plan D and I don't want to pay for
unnecssary hydrilla control.

2 I would rather fish at another lake than pay to control hydrilla
on Laks Harris and Griffin.

3 I object to any proposal that might increase the cost of fishing.

4 I did not understand the questions.





Think you for takig the tie to complete this survey. Tour answers will
be very helpful In developing hydrilla mmasament programs la Lake County
and throughout Florida. Don't forget to put your copleted survey in the
enclosed prepald mavelope and drop it in the mall as soon s possible.
Thank youl



*----------------........................................................

Please take one more minute to help us evaluate this survey. Overall, how
would you describe this survey:

1 Easy to answer

2 Somevhat hard to ansver

3 Very hard to ansver

Please write-in the numbers of any questions that you thought were
confusing or hard to answer accurately.


Question os




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs