A SURVEY OF THE PRETTY LAKE FISH COMMUNITY, LARGEMOUTH BASS AND WALLEYE POPULATIONS AND FISH HARVEST LaGrange County 2010 Larry A. Koza Assistant Fisheries Biologist Fisheries Section Indiana Department of Natural Resources Division of Fish and Wildlife I.G.C.-South, Room W273 402 W. Washington Street Indianapolis, IN 46204 2011
TABLE OF CONTENTS Page LIST OF TABLES... i LIST OF FIGURES... ii ABSTRACT... iii INTRODUCTION... 1 METHODS... 2 RESULTS... 4 DISCUSSION... 11 RECOMMENDATIONS... 15 LITERATURE CITED... 15 APPENDIX 1 - General survey data pages... 29
LIST OF TABLES Table Page 1. Sampling effort, species composition and relative abundance of fish collected during 1964, 1973, 1979, 1983, 1996 and 2010 fisheries surveys of Pretty Lake...16 2. Pretty Lake walleye stockings 1990 through 2009...17 3. Catch by select size ranges for bluegills and largemouth bass collected during 1964, 1973, 1979, 1983, 1996 and 2010 fisheries surveys of Pretty Lake...18 4. Average number of largemouth bass per acre in medium size natural lakes (100-499 acres) in Indiana prior to and following the imposition of a 14 minimum size limit in comparison to Pretty Lake. Number of lake populations included in the average in ( )..18 5. Length-frequency distribution for walleyes collected during spring trap net and electrofishing sampling at Pretty Lake, 2010...19 6. Fishing pressure, harvest and yield from Pretty Lake, May October, 2010...21 7. Number of legal and sub-legal size largemouth bass and walleyes caught and released at Pretty Lake, 2010...21 8. Monthly fishing pressure and harvest from Pretty Lake, May October, 2010...22 9. Length-frequency distribution for bluegills harvested from Pretty Lake, 2010...23 10. Length-frequency distribution for redear harvested from Pretty Lake, 2010...23 11. Length-frequency distribution for yellow perch harvested from Pretty Lake, 2010...24 12. Length-frequency distribution for black crappies harvested from Pretty Lake, 2010...24 13. Length-frequency distribution for walleyes harvested from Pretty Lake, 2010...25 14. Length-frequency distribution for largemouth bass harvested from Pretty Lake, 2010...25 15. Species, number and weight of additional fish harvested from Pretty Lake, 2010...26 16. Species preference of angling parties interviewed at Pretty Lake, 2010...26 17. County of residence of angling parties interviewed at Pretty Lake, 2010...27 i
LIST OF FIGURES Figure Page 1. Aerial photo of Pretty Lake with sample locations...28 ii
ABSTRACT Four fisheries surveys were conducted at Pretty Lake by Division of Fish and Wildlife fisheries biologists in 2010, a general fish community survey, a largemouth bass population estimate, a walleye population estimate and an angler creel survey. The fish community survey was conducted from June 21 through 24, 2010. A total of 755 fish weighing 185 pounds was collected during the general fish community survey. Nineteen species were represented in the sample. Bluegill dominated the sample by number (55%) followed by redear (17%) and largemouth bass (7%). Redear was the number one species collected by weight (20%), followed by bluegill (18%), largemouth bass (17%) and walleye (15%). The total largemouth bass population estimate for Pretty Lake was 2,410 fish, or 13.1/acre. Of these, 2,135 (89%) were stock size, and their density was 11.6/acre. The estimated number of legal size largemouth bass in Pretty Lake was 94 fish or 0.5/acre. The largest bass collected during the population estimate measured 19.3 in TL. The attempt to estimate a walleye population size for Pretty Lake was unsuccessful due to the small number of marked fish that were collected during the sampling. The creel survey was conducted from May 1 through October 31, 2010. An estimated 6,011 fish weighing 2,141 pounds was harvested during the Pretty Lake creel survey. Eleven species were represented in the harvest. The number one species taken by anglers was bluegill (48%) followed by redear (38%) and yellow perch (6%). Bluegill and redear also dominated the harvest by weight, comprising 43% and 38% of the total respectively. Boat anglers harvested 0.72 fish/h and 11.64 pounds of fish/acre. In addition to the species harvested, anglers caught and released 2,815 largemouth bass and 177 walleyes. Fewer than 1% of the bluegills taken measured less than 6.0 in TL and their average length was 7.4 in TL. Seven and eight-in TL and larger bluegills comprised 84% and 31% of the harvest respectively. Bluegills were harvested at a rate of 0.35 fish/h and 16/acre. On average, medium size natural lakes in Indiana have yielded 0.5 bluegills/h and 23/acre. Walleyes in the harvest averaged 16.5 in TL and 83 fish weighing 128 pounds were taken. The total walleye catch was 260 fish or 0.03 per hour. Approximately 20% of the anglers at Pretty Lake were targeting walleyes. These anglers had a catch rate of 0.46 walleyes per hour. iii
The majority of Pretty Lake anglers were fishing for panfish (45%) while walleye anglers were second and bass anglers were third (16%). Lake residents comprised the largest percentage of anglers at the lake (33%) followed by those from Allen County (20%), DeKalb County (13.5%) and LaGrange County (10.5%). Pretty Lake supports a good sport fish community comprised primarily of bluegills, redear and largemouth bass. Together these species represented 80% of the general fish community survey sample by number and 56% by weight. Bluegill and redear were the dominant species harvested by Pretty Lake anglers, combining to comprise 86% of the total harvest by number and 81% by weight. There is a good aquatic vegetation community present at Pretty Lake comprised of 13 native species. The lake is, however, beginning to have problems with one exotic invasive species, Eurasian watermilfoil, particularly in the area of the inlet on the north end of the lake. Residents should consider a treatment program for the milfoil to inhibit the spread of the plant to other areas of the lake. Recommendations: Walleye stockings of advanced fall fingerlings should continue at Pretty Lake on a bi-annual basis as well as fall electrofishing evaluations. Largemouth bass growth, density and population structure should continue to be evaluated as outlined in DFW Work Plan 300FW1F10D42643. Pretty Lake residents should continue with their efforts to control the Eurasian watermilfoil in the lake. Additional funding should be sought through the LARE program to assist with these efforts. iv
INTRODUCTION Pretty Lake is a 184 natural lake located approximately two miles west of Stroh, Indiana in LaGrange County. It has an average depth of 25 feet and a maximum depth of 82 feet. The inlet to Pretty Lake, which is unnamed, is located on the north shore and originates from drainage. The outlet is located on the east shore and flows east where it merges with the outlet of Mud Lake and flows north to Little Turkey Lake. A state owned public access site with a concrete boat ramp is located on the west shoreline of Pretty Lake off of County Road 890 E. Approximately 95% of the shoreline is developed residentially. Pretty Lake was hydrographically surveyed in 1956. The sport fishery was initially surveyed by fisheries biologists from the Indiana Department of Natural Resources (IDNR) in 1964. Subsequent general fish population surveys were conducted in 1973, 1979, 1983 and 1996. An angler creel survey was also done at the lake in 1983 and 1996 along with a largemouth bass population estimate in 1996. These surveys found that a good sport fish population existed in Pretty Lake (Table 1). Trout were stocked in Pretty Lake beginning in 1964. A trout evaluation survey was conducted in 1980 to evaluate the status of the fishery. A trout tagging project was conducted at Pretty Lake beginning in the fall of 1984, the purpose of which was to determine the contribution of fall stocked trout to the fishery the following year. These fall stocked fish were surplus fish that needed to be moved from the Curtis Creek Trout Rearing Station in order to have enough room to grow the remaining fish to full stocking size. These fish were typically only six to seven inches in length when stocked in the fall. The project results indicated only 11.2% of these fish were harvested through the following fall. Following the project evaluation, it was determined that the fall releases should be discontinued and the fish transferred instead to the Fawn River State Fish Hatchery where they would be over-wintered and stocked in the spring. This practice began in the fall of 1986. Another trout tagging project was conducted at Pretty Lake in 1991. April through December tag returns indicated a 22.4% harvest of spring stocked trout. Based on the results of this survey, and considering the declines in summer trout habitat and trout fishing interest, the trout stocking program at Pretty Lake was terminated. The Pretty Lake Conservation Club initially stocked walleye into Pretty Lake in the mid 1980's. The first IDNR walleye release into Pretty Lake occurred in 1990 (Table 2). Fall 1
sampling by IDNR biologists following the 1990 stocking indicated poor survival of the walleye fingerlings. Walleye were stocked again in 1993 by the IDNR. This time, fall sampling revealed excellent survival. Pretty Lake was then stocked annually through 2007. At that time the first stocking of advanced fall fingerling walleye occurred following the failure of fish stocked that spring, with an additional one in the fall of 2009. Stockings are scheduled to continue on a biannual basis. METHODS The general fish community survey was conducted on June 21 through 24, 2010. Several physical and chemical characteristics of the water were measured in the deepest area of the lake according to the Manual of Fisheries Survey Methods (2001) standard lake survey guidelines. Submersed aquatic vegetation was sampled on August 18, 2010 using methods outlined in the Tier II Aquatic Vegetation Survey Protocol developed by the DFW Lake and River Enhancement Program and used in their aquatic vegetation control grant program. A global positioning system (GPS) device was used to record the location of the limnological data collection site, aquatic vegetation sample sites, and fish collection sites. Fish were collected by pulsed D.C. electrofishing the shoreline at night with two dippers for one hour. One trap net and two experimental-mesh gill nets were fished overnight for three nights. All fish collected were measured to the nearest 0.1 in TL. Length-weight regression equations for Fish Management District 2 were used to estimate the weight of all fish within the sample. Five scale samples per half-inch group were collected from game species for age and growth analysis. Average length-at-age for these species was estimated using the Fraser-Lee method of back calculation and standard intercepts (DeVries and Frie 1996, Carlander 1982). Largemouth bass and walleye were targeted at Pretty Lake in the spring of 2010 in an effort to compute population estimates. Walleye sampling was initiated on March 13 and consisted of trap netting utilizing three Lake Michigan style nets. This type of net is much larger than those usually used for DFW general surveys, has a longer lead and includes wings to help funnel the fish into the net. These nets were fished overnight for nine consecutive nights. Fish were removed from the nets every other morning. Beginning April 28, nighttime pulsed D.C. electrofishing was conducted consisting of four nights of sampling using two dippers. The entire shoreline was covered each night. All largemouth bass and walleyes were collected during these 2
sampling nights, which totaled seven hours of electrofishing over a four week period. The bass and walleyes collected during spring sampling were measured to the nearest 0.1 in TL and marked by removing a fin. Legal and sub-legal size walleyes (legal size is 14 in TL or larger) were differentiated by removing a separate fin for each group in order to determine how many of the sub-legal size fish grew to legal size by the time they were caught during the creel survey. In addition, scale samples and dorsal spines were taken from selected fish to determine age and growth. The walleye trap net catches were pooled and treated as a single sample. The number of bass and walleyes that were re-captured during each electrofishing sample was recorded and a population estimate was made using the Schnabel method. Analysis of largemouth bass abundance concentrated on stock size fish ( 8.0 in TL) which is the main size group used for comparative purposes in scientific literature. In addition, fish smaller than stock size are often times collected in low numbers, making recapture difficult which in turn results in unreliable estimates of abundance. The Pretty Lake angler creel survey was conducted from May 1 through October 31, 2010. The main parameters measured during this survey included fishing pressure, fish harvest and species preference of anglers. Two fishing periods were used for this survey, a morning period and an afternoon period. The morning period began at 7:30 am and ended at 3:00 pm while the afternoon period began at 3:00 pm and ended at 10:30 pm. Angler counts were conducted four times a day and anglers were interviewed as they completed their trip. In addition, any anglers still fishing when the clerk finished his shift were interviewed and noted as partial trips. Information collected from anglers included number of hours fished, number of fish harvested by species and length of fish harvested. The number of largemouth bass and walleye caught and released by anglers was also recorded. Anglers were asked how many of these were legal or sub-legal and this information was used to categorize the data further. Additional information collected included species preference for each angling party, county of residence, angler opinion regarding the quality of the Pretty Lake fishery and how the angler believed the fishing at the lake had changed over time. The data was expanded separately by month, weekend or weekday, and boat and shore fisherman. Holidays were included with the weekend periods. Fish weights were calculated using regional length-weight regression equations. 3
RESULTS The Secchi disk reading at Pretty Lake was 14 ft. Dissolved oxygen concentrations at the time of the general fish community survey were adequate for fish survival down to a depth of 70 ft. A total of 50 sites were randomly sampled during the plant survey, all but two of which fell within the littoral zone in water 15 ft in depth or less. A total of 13 native and 1 exotic invasive species was identified. Aquatic plants were observed at all 48 of the littoral sites sampled. The maximum number of plant species found at one site was six and the mean was two. Chara and spiny naiad dominated the plant community, followed by sago pondweed, eel grass and the one exotic invasive species found, Eurasian watermilfoil. The milfoil was collected at approximately 24% of the sample sites. Seven emergent, floating or floating leaf plants associated with wetlands, including cattails, pickerelweed, spatterdock, spike rush, three-square rush, watershield and white water lily, were also observed. A total of 755 fish weighing 185 pounds was collected during the general fish community survey. Nineteen species were represented in the sample. Bluegill dominated the sample by number (55%), followed by redear (17%) and largemouth bass (7%). Redear was the number one species collected by weight (20%), followed by bluegill (18%), largemouth bass (17%) and walleye (15%). Bluegill ranked first among all species collected by number (55%) and third by weight (18%). They ranged in length from 1.7 (age 1) to 10.1 (age 8) in TL and averaged 4.1 in TL. A total of 416 bluegills weighing 33 pounds was collected. The electrofishing catch rate for bluegills was 205 fish/h. Gill netting yielded only two bluegills/lift and trap nets caught 10/lift. Harvestable size bluegills (6 in TL or larger) comprised 11% of the sample, reaching this size during their fifth year (Table 3). Approximately 5% were 7 in TL or larger. Age-3 through age- 5 bluegills grew at a slightly below average rate for northern Indiana natural lakes while all other ages of fish grew at an average rate. Approximately 8% percent of the bluegills collected in 1996 were harvestable size. In previous years, harvestable size fish comprised 38% of the sample in 1983, 34% in 1979 and 11% in 1973. Bluegills 7 in TL and larger have ranged from 3 to 17% of the sample in the previous surveys. A total of 131 redear weighing 38 pounds was collected during this survey. Redear were second in abundance by number (17%) and first by weight (20%) among all species in the sample. They ranged in length from 3.2 (age 2) to 10.7 (age 8) in TL and averaged 6.8 in TL. 4
Harvestable size redear (6 in TL or larger) comprised 79% of the sample. In addition, approximately 25% were 8 in TL or larger and 6% were 9 in TL or larger. The electrofishing catch rate for redear was 31 fish/h. Trap netting yielded 48 redear/lift while 1/lift was collected during gill netting. All ages of redear grew at an average rate for northern Indiana natural lakes with the exception of age-7 and age-8 fish which grew at an above average rate. Harvestable size redear have ranged from 39% to 98% of the sample in previous surveys but have averaged 79% since 1979. Eight in TL or larger redear have averaged 42% of the sample over that time period and in 1996 21% measured 10 in TL or larger. Redear grew at an average rate in 1979 but increased to above average in 1983 and 1996. Largemouth bass ranked third both numerically (8%) and by weight (17%) among species in the survey as a total of 58 weighing 32 pounds was collected. They ranged in length from 3.9 (age 1) to 15.5 (age 7) in TL and averaged 9.6 in TL. Legal size bass, those 14 in TL or larger, comprised 7% of the bass sample. The electrofishing catch rate for largemouth bass was 43 fish/h. Gill netting yielded three bass/lift while no bass were captured during trap netting. Age-5, age-6 and age-7 bass grew at a slightly below average rate for northern Indiana natural lakes, while all other ages of bass grew at an average rate. In previous Pretty Lake surveys, collections of largemouth bass 14 in TL have been low (6% or less) with the exception of 1996 when 29% were legal size. Bass growth at Pretty Lake has typically been average. However, in 1983 age-3 and older bass exhibited above average growth. A total of 24 walleyes ranging in length from 6.2 (age 1) to 23.2 (age 6) in TL was collected during the general survey. They weighed 28 pounds, which was the fourth highest total weight among all species, and averaged 14.9 in TL. Approximately 75% were legal size fish (14 in TL or larger) while 38% measured 16 in TL or larger and 13% were 20 in TL or larger. In 1996, walleyes up to 20 in TL were collected with 87% of the 30 fish sample comprised of age - 2 and age-3 fish. Fifteen yellow perch were collected comprising 2% of the total sample by number and weight. They ranged in length from 3.1 (age 1) to 11.7 (age 5) in TL and averaged 6.4 in TL. Approximately 20% of the perch in the sample measured 8 in TL or larger, considered harvestable size. The electrofishing catch rate for perch was 11 fish/h. Trap nets captured no perch while 1/lift was caught during gill netting. Perch grew at an average (age 1, 2 and 3) to above average (age 4 and 5) rate for northern Indiana natural lakes. The collection of perch in 5
previous surveys ranged from a high of 92 fish in 1983 to a low of 16 in 1973 while averaging 63 fish. Harvestable size perch at Pretty Lake have historically comprised approximately 40 to 50% of the sample with the exception of 1983 when only 18.5% were harvestable size. Additional sport species collected included 19 rock bass, the largest of which measured 9.6 in TL, three northern pike ranging from 23 to 29 in TL, one black crappie and one channel catfish (19.2 in TL). The total largemouth bass population estimate for Pretty Lake was 2,410 fish, or 13.1/acre. Of these, 2,135 (89%) were stock size and they were present at a density of 11.6 fish/acre. Bass 8 to 12 in TL comprised 75% of the electrofishing sample. Twenty-three of the bass collected (3%) measured 14 in TL or larger which is legal size. Ten of the bass were 16 in TL or larger while five were 18 in TL or larger. The estimated number of 12 to 14 in TL fish in Pretty Lake was 311 (1.7/ac) while the legal size bass estimate was 94 fish or 0.5/acre (Table 4). The estimate of bass 12 in TL or larger was 405 fish (2.2/ac). The largest bass collected during the Pretty Lake population estimate study measured 19.3 in TL. A total of 689 bass, or 29% of the population, was handled during this survey. The estimated largemouth bass population at Pretty Lake in 1996 was 2,870 fish (15.6/ac) of which 2,334 were stock size (12.7/ac). Bass 12 to 14 in TL numbered 729 (4.0/ac) while 14 in TL or larger fish comprised approximately 12% of the population (1.9/ac). The estimate of bass 12 in TL or larger was 1,073 fish (5.8/ac). During spring walleye trap netting, 71 walleyes were collected in 27 lifts (3/lift). They ranged from 12.8 to 29.7 in TL and averaged 18. Legal size walleyes comprised 92% of the sample (Table 5). In addition, 56% of the walleyes were 16 in TL or larger, 49% were 18 in TL or larger and 27% were 20 in TL or larger. Spring electrofishing yielded an additional 103 walleyes in seven hours of sampling (14.7/h). These fish ranged from 5 to 25.8 in TL and averaged 12.2. Approximately 45% were legal size. The percentage of 16, 18, and 20 in TL or larger fish in this sample was 20%, 8% and 7% respectively. The attempt to compute a walleye population estimate for Pretty Lake was unsuccessful due to the small number of marked fish that were collected during the sampling. One explanation for the low number of walleye collected could be starting the trap netting too late in the spring. By the time the nets were set on April 13 the water temperature had already reached 56º F. The late start was due to waiting for the completion of muskie collection for the brood program in order to have the trap nets available for use. Future attempts should focus on beginning netting as soon as possible in the 6
spring so that walleye collection can be completed prior to the start of the muskie brood operation. A total of 373 parties consisting of 649 anglers was interviewed at Pretty Lake during the angler creel survey. Of these, 366 parties (98%) were fishing from a boat. Due to the small number of shore anglers that were interviewed, the estimates for the fish harvest by these anglers were unreliable. Therefore, only the results from boat fisherman will be used in the discussion of the survey results. A total of 6,011 fish weighing 2,141 pounds was harvested during the Pretty Lake creel survey (Table 6). Eleven species were represented in the harvest. The number one species harvested numerically was bluegill (48%) followed by redear (38%) and yellow perch (6%). Bluegill and redear also dominated the harvest by weight, comprising 43% and 38% of the total respectively. Boat anglers harvested 0.72 fish/h and 11.64 pounds of fish/acre. In addition to the species harvested, anglers caught and released 2,815 largemouth bass and 177 walleyes. Legal size fish comprised approximately 10% and 37% of the bass and walleye caught and released respectively (Table 7). A total of 3,960 fish was harvested from Pretty Lake in 1996 (0.42fish/h). The total fishing pressure was 9,494 hours (52 hrs/acre). Bluegills, crappies and yellow perch were the dominant species in the harvest. The highest fish harvest at Pretty Lake occurred in June, with 34%, followed by May (32%) and October (19.5%) (Table 8). The combined harvest for these three months was 5,150 fish which was 86% of the total fish taken. The highest number of fish harvested per hour occurred in May (1.44) followed by October (1.09) and June (1.00). The lowest harvest by total number (143) as well as number per hour (0.19) occurred in September. Total fishing pressure by boat anglers for the Pretty Lake survey was 8,294 hours or 45 hours/acre. June and July dominated in this category as 45% of the fishing pressure (3,686 hours) occurred during these two months. The next highest fishing pressure was exerted during May (1,913 hours), followed by August (1,461 hours). The least amount of fishing pressure for a month occurred during September (744 hours). The average trip length for boat anglers at Pretty Lake was 3.6 hours. Bluegill was the dominant species taken during the creel survey, both by number (48%) and weight (43%). A total of 2,912 bluegills was harvested by Pretty Lake anglers, weighing 921 pounds and ranging in length from 5 to 10 in TL (Table 9). The average length of a 7
harvested bluegill was 7.4 in TL. Only 1% of the bluegills taken measured less than 6.0 in TL, which is considered harvestable size. Bluegills measuring 7 and 8 in TL and larger comprised 84% and 31% of the harvest respectively while 4% were 9 in TL or larger. The harvest rates for bluegills were 0.35 fish/h and 16/acre. On average, medium size natural lakes in Indiana have yielded 0.5 bluegills/h and 23/acre. This is based on the results of creel surveys conducted at 19 medium sized natural lakes in Indiana over the last 30 years. Approximately 12% of the bluegills taken by anglers during that time period were less than 6 in TL while 24% were 8 in TL or larger. The best month for Pretty Lake bluegill harvest was June (35%), followed closely by May (30%) then October (20%). The lowest bluegill harvest occurred in September (1%), followed by July (5%). The estimate for bluegill harvest in 1996 was 2,001 fish, which accounted for 50% of the total creel survey harvest. Approximately 80% measured 6 in TL or larger while 29% were 8 in TL or larger. A total of 2,273 redear weighing 822 pounds was taken by Pretty Lake anglers. Redear ranked second both numerically (38%) and by weight (38%) among species in the harvest. They ranged in length from 5 in TL to 11 in TL and averaged 7.8 in TL (Table 10). All but 17 of the redear harvested were 6 in TL or larger while 45% were 8 in TL or larger and 13% were 9 in TL or larger. Redear harvest was highest in June, when approximately 35% of the fish were taken, followed closely by May with 33%. The fewest redear were taken in August and September, with less than 2% of the harvest occurring during each of these months.. Redear were harvested at a rate of 0.27 fish/h and 12/acre. A total of 110 redear were harvested in 1996 and 56% of these were 8 in TL or larger. Yellow perch contributed 382 fish to the Pretty Lake harvest ranking third by number (6%). They ranged in length from 5 to 10 in TL and averaged 7.4 in TL while weighing 80 pounds (Table 11). Harvestable size perch (8 in TL and larger) comprised 26% of the catch while 2% were 10 in TL or larger fish. June was the dominant month for perch as 52% of them were harvested during this month. July had the lowest harvest at 4%. Yellow perch were harvested at a rate of 0.05 fish/h and 2/acre. Perch was also the third most abundant species taken by anglers in 1996. The 421 fish taken ranged up to 11 in TL and 20% were 8 in TL or larger. The estimate for black crappie harvest at Pretty Lake was 149 fish weighing 62 pounds. The largest crappie measured 11 in TL while the smallest was 7 in TL (Table 12). 8
Approximately 90% of the fish taken were considered harvestable size (8.5 in TL or larger) while 30% were 10 in TL or larger. Crappies were harvested at a rate of 0.02 fish/h and 1/acre. They comprised 26% of the total harvest in 1996 which ranked them second among all species. Over 70% were 8 in TL or larger and 17% were over 10 in TL. Pretty Lake anglers harvested 83 walleyes weighing 128 pounds during this survey, ranking them sixth numerically (1%) and third by weight (6%). Walleyes ranged in length from 14 in TL to 20 in TL and averaged 16.5 in TL (Table 13). Approximately 59% of the fish harvested measured 16 in TL or larger and 23% measured 18 in TL or larger. Age and growth analysis from walleyes collected in the spring of 2010 by DFW biologists indicated age-1 through age-9 fish could have been represented in the harvest, with the exception of age-2 fish which were not present due to the absence of a walleye stocking in 2008. September was the top month for walleye harvest as 32.5% were taken during this month. August and October tied for the second best month for walleyes with 19% of the harvest occurring during each of these months. Walleyes were harvested at a rate of 0.01 fish/h and 0.45/acre. On a weight basis, 0.7 pounds of walleyes/acre were harvested. An additional 177 walleyes were caught and released by Pretty Lake anglers. Of these, 66 were legal size fish (37%) while 111 were sub-legal size. The total walleye catch was 260 fish or 0.03/h. The best month for walleye catch was September (80 fish) followed by July (50 fish) and May (49 fish). Approximately 20% of the anglers at Pretty Lake were targeting walleyes. This group had a catch rate of 0.15 walleyes/h. In other words, it took approximately 6.5 hours of fishing for an angler targeting walleyes to catch one at Pretty Lake. The overall walleye harvest at Pretty Lake in 1996 was 150 fish and 28 were caught and released. They ranged in length from 10.5 to 25 in TL and averaged 16.9 in TL. Approximately 17% of the fish were less than 14 in TL which would be sub-legal size according to the current state wide minimum size limit. However, the size limit was not yet in effect during the 1996 survey. Over 34% of the harvested fish were 18 in TL or larger and 14% were 22 in TL or larger. Harvest consisted primarily of age-2 and age-3 fish but the larger fish probably resulted from the earlier conservation club walleye stockings as well as the 1990 DFW stocking. In 1996 it took anglers targeting walleyes approximately 11 hours to catch one. Eleven percent of anglers interviewed in 1996 were targeting walleyes and an additional 8% were fishing for walleyes in combination with another species, primarily bass. According to DFW criteria, a walleye fishery is considered successful in Indiana if the yield is 1 pound/acre, the harvest is 1 9
fish/acre, or there is a minimum angler preference of 5% with a minimum catch rate of 0.10 walleyes/h for anglers targeting walleyes. Only 25 largemouth bass were harvested at Pretty Lake during the 2010 creel survey. They ranged in length from 14 in TL to 17.5 in TL and averaged 14.9 in TL (Table 14). Bass harvest occurred at a rate of 0.14 fish/acre and 0.01/h. The catch and release of largemouth bass during the survey totaled 2,815 fish or 15 per acre. Combined with bass harvest, this resulted in an overall catch of 2,840 bass at Pretty Lake; a rate of 15 bass/acre or 0.34 bass/h. The average bass catch from seven medium sized Indiana natural lakes since the imposition of a 14 in TL minimum size limit in 1998 was 23 fish/acre and 0.42 fish/h (Table 14). The highest largemouth bass catch occurred in July (797 fish) followed by August (574 fish) and June (522 fish). The fewest number of bass were caught in September (211 bass). Largemouth bass catch/h ranged from a high of 0.49/h in July to a low of 0.25/h in June and averaged 0.34 bass/h. Approximately 16% of Pretty Lake anglers were targeting bass. These anglers caught bass at a rate of 1.17 fish/h. In 1996, 142 bass were harvested and 1.038 were caught and released for a total catch of 1,180 fish. Bass catch was 0.12 fish/h and 6/ac. There were five other species in the harvest for the Pretty Lake in 2010, bullheads, northern pike, pumpkinseed, rock bass and smallmouth bass. Together these species comprised approximately 3% of the total harvest by number and 4% by weight (Table 15). The majority of anglers fishing at Pretty Lake indicted they were fishing for panfish (50%). This category included anyone fishing for any three or more of the following; bluegills, redear, crappies, yellow perch or any miscellaneous sunfish (Table 16). Walleye anglers represented the next highest group (20%) followed by bass anglers (16%). Anglers favored bluegills in 1996 (26%) while 15% were fishing for bass and 11% were pursuing walleyes. Residents from sixteen Indiana counties outside of LaGrange County, as well as the states of Michigan and Ohio, fished at Pretty Lake during this survey (Table 17). The largest portion of Pretty Lake anglers were residents of the lake (33%) while 20% hailed from Allen County, 13.5% were from DeKalb County and 10.5% were from LaGrange County. Anglers were asked to rate the quality of fishing for the species they were seeking that day at Pretty Lake. Approximately 92% responded that they thought fishing for their species was good and only 6% rated it as poor. They were also asked if fishing at Pretty Lake was 10
improving, declining or staying the same. Approximately 82% responded that they thought fishing was improving while only 1% indicated they thought fishing was declining. DISCUSSION Pretty Lake supports a good sport fish community comprised primarily of bluegill, redear and largemouth bass. Together these species represented 80% of the general fish community sample by number and 56% by weight. Bluegill and redear were the dominant species harvested by Pretty Lake anglers, combining to comprise 86% of the total harvest by number and 81% by weight. Yellow perch constituted 6% of the harvest (382 fish). A total of 373 fishing parties fished for 8,294 hours and harvested 6,011 fish weighing 2,141 pounds during the creel survey. Anglers averaged 45 hours of fishing pressure per acre while harvesting 0.72 fish/h. Averages from medium size natural lake creel surveys in Indiana are 50.6 hours of fishing pressure per acre and a harvest rate of 0.69 fish/h. This means that Pretty Lake anglers fished slightly fewer hours per acre than the average and they harvested a similar number of fish/h. Pretty Lake anglers are very satisfied with the fishery as 92% responded that they thought fishing for their species was good and 82% thought fishing was improving at the lake. Bluegill was the dominant species by number in both the general fish community survey (55%) and the creel survey (48%). There were 416 bluegills collected during the general survey and 2,912 harvested during the creel survey. The percentage of 6 and 7 in TL and larger bluegills collected from Pretty Lake in general fish community surveys has varied over the years, experiencing highs in 1979 and 1983. Percentages fell in 1996 before rebounding in 2010 but failed to approach the previous high levels. These percentages are still considered low for natural lakes in Indiana. Overall angler success for bluegills in the creel survey was below average, as number taken per hour and per acre were both approximately 30% below the norm. However, anglers had more success with larger fish as the percentage of 8 in TL and larger bluegills harvested (31%) was approximately 30% above the average. By comparison, at nearby Big Long Lake, which is considered one of the top bluegill lakes in northern Indiana, approximately 62% of the bluegills in the harvest in 2005 were 8 in TL or larger. Total bluegill harvest per hour at Big Long Lake was approximately twice the rate observed at Pretty Lake. 11
Bluegill year classes at Pretty Lake grew at an average to slightly below average rate for northern Indiana natural lakes. Redear were second in abundance (17%) among species collected during the general fish community survey and also ranked second by number (38%) in the creel harvest. The number of redear collected in general surveys has varied somewhat over the years but has topped 100 fish in all but the 1973 survey. The level of harvestable size fish in the samples has averaged 80% since 1979 and good numbers of 8 in TL or larger fish have been collected, including several 10 in TL plus fish in 2010. Redear are very attractive to anglers at Pretty Lake, especially considering 45% of the fish taken by anglers were at least 8 in TL and 13% were 9 in TL or larger. The walleye fishery at Pretty Lake has a good level of interest, as approximately 20% of all anglers indicated that was the species they were seeking during their fishing trip. Although the walleye harvest was below the one fish per acre needed to be considered a successful fishery, the overall catch rate met the minimum criteria for success. Likewise, the walleye yield in pounds failed to meet the criteria for success but the angler preference for walleyes far exceeded the minimum. Thus the walleye stocking program at Pretty Lake is considered a success in establishing and maintaining a walleye fishery. Desirable size walleyes are present in the population as evidenced by the average harvest size of 16.5 in TL with the largest measuring 20 in TL. In addition, walleye trap netting and spring electrofishing yielded individuals up to 29.7 in TL with an average of 14.5 in TL and approximately 15% were 20 in TL or larger. The future of the Pretty Lake walleye fishery looks promising. Largemouth bass are of interest to Pretty Lake anglers as 16% of the parties targeted them. However, bass catch rates were below average at 15 fish/acre compared to the average of 23/acre and 0.34 bass/h compared to 0.42/h on average. Over ten times as many bass were caught and released by Pretty Lake anglers as the number kept. Approximately 10% of the released fish were estimated to be legal size. When comparing the estimate of legal size bass caught during the survey to the population estimate of legal size bass in the lake, each legal size bass was caught approximately four times over the course of the angler creel survey. Pretty Lake had a below average bass population in terms of overall numbers and there was also a shortage of legal size fish in the population. Estimates revealed that the number of legal size bass per acre present in Pretty Lake (0.5/acre) was substantially lower than the medium natural lakes average (3.5/acre). The number of stock size bass at Pretty Lake was estimated at 12/acre, 12
also lower than the natural lakes average of 21/acre. The percentage of stock size bass that were also legal size in Pretty Lake (3.7%) was also substantially below the average for medium size natural lakes in Indiana which is 16.7%. Age and growth data indicated bass grew at an average to below average rate in the lake in 2010 compared to other northern Indiana natural lakes. Historically, bass have grown at an average rate at the lake. The largest difference in growth in 2010 was evident as the bass increased in age. They grew at a rate that would place them at the bottom of the average range at age 1 through age 4. At age 5 they dropped into the below average range and at age 6 fell even further below the average. Typically, slow growth in bass populations is attributed to an overabundance of bass in the lake to the point that the forage base cannot support the population. When this occurs, bass begin to stockpile just below the size limit and they are cropped off by anglers as they slowly reach legal size. Prior to the 1996 survey a 12 inch minimum size limit for bass was in effect in Indiana. This size limit was increased to 14 inches in 1998. If stockpiling was indeed the reason for slow growth, there should have been a noticeable shift in the number of bass in the population that were just short of 14 in TL from 1996 to 2010. When examining the number of 12 to 14 in TL fish estimated for each year, it was discovered that the number of bass in this size range actually dropped in 2010 and as a percentage comprised only 13% of the population compared to 25% in 1996. Further, the number of bass 12 in TL in the Pretty Lake population went from 1,037 (37%) in 1996 to 405 (17%) in 2010. The average length at capture for age-4 bass also declined from 11.6 to 10.2 in TL at the same time, while the average length of age-5 fish went from 13.5 to 11.8 in TL. So despite a decrease in bass density, growth of older bass experienced a decline. Harvest of largemouth bass in 2010 was significantly lower than in 1996, which eliminates increased fishing pressure as a factor in the decline. The first stocking of advanced walleye fingerlings was made at Pretty Lake in 2007. This stocking produced what was considered to be the strongest walleye year class to date at Pretty Lake. A fall fingerling stocking in 2009 also resulted in the establishment of a successful year class. 2010 spring walleye age and growth analysis found fish up to age 11 in the population. Ledet (2010) noted that the average length of age-2 walleyes collected in 2009 fall sampling at Pretty Lake was 14.1 in TL, compared to the average of 15.2 in TL found in previous surveys of the lake, indicating declining growth for walleyes. One of the reasons the stocking strategy for walleyes was changed to an alternate year format for the advanced fingerlings was to reduce the stress on the forage base of Pretty Lake. Still, there may 13
be a link between the expanding walleye population and declines in the growth of both bass and walleye. Further investigation by DFW biologists will be required to research if a link does indeed exist. Declines in largemouth bass density may also be related to the size of the forage base. It is interesting to note that other lakes have experienced declines in bass numbers since the imposition of the size limit, such as Simonton Lake in Elkhart County and Fish Lake in Steuben County. There is a good aquatic vegetation community present at Pretty Lake comprised of 13 native species. The lake is, however, beginning to have problems with one exotic invasive species, Eurasian watermilfoil. The problem has been the worst in the area of the inlet on the north end of the lake. Residents should consider a treatment program for the milfoil to inhibit the spread of the plant to other areas of the lake. No fish diseases or parasites were observed during this survey. Shoreline erosion is minimal. 14
RECOMMENDATIONS Walleye stockings of advanced fall fingerlings should continue at Pretty Lake on a bi-annual basis along with fall electrofishing evaluations. Largemouth bass growth, density and population structure should continue to be evaluated as outlined in DFW Work Plan 300FW1F10D42643. Pretty Lake residents should continue with their efforts to control the Eurasian watermilfoil in the lake. Additional funding should be sought through the LARE program to assist with these efforts. LITERATURE CITED Carlander, KD. 1982. Standard intercepts for calculating length from scale measurements for some centrarchid and percid fishes. Transactions of the American Fisheries Society 111:332-336. DeVries, DR and RV Frie. 1996. Determination of Age and Growth. Pages 483-512 in B. R. Murphy and D. W. Willis, editors. Fisheries techniques, 2nd edition. American Fisheries Society, Bethesda, Maryland. Koza, L. 2006. A Survey of the Big Long Lake Fish Population and Fish Harvest. Indiana Division of Fish and Wildlife. Indianapolis, In. Ledet, N. 2010. Pretty Lake Supplemental Walleye Evaluation. Indiana Division of Fish and Wildlife. Indianapolis, In. Pearson, J. 2003. Indiana natural lakes creel data set. Indiana Division of Fish and Wildlife. Indianapolis, In. Pearson, J. 2003. Indiana natural largemouth bass data set. Indiana Division of Fish and Wildlife. Indianapolis, In. ACKNOWLEDGEMENT The Division of Fish and Wildlife would like to express our appreciation to LeRoy and Wahnee Campbell for allowing us to dock our creel boat on their property during this survey. Submitted by: Larry A. Koza, Assistant Fisheries Biologist Date: 4/28/11 Approved by: Stuart Shipman North Region Fisheries Supervisor Date: 5/13/11 15
Table 1. Sampling effort, species composition and relative abundance of fish collected during 1964, 1973, 1979, 1983, 1996 and 2010 fisheries surveys of Pretty Lake. Species 1964 1973 1979 1983 1996 2010 Black bullhead 4 Black crappie 7 3 8 10 17 1 Bluegill 322 114 152 574 664 416 Bluntnose minnow Common Bowfin 3 1 3 6 1 2 Brook silverside Present Present Brook Stickleback 1 Brown bullhead 7 5 11 28 17 4 Brown trout 1 Channel catfish 1 Golden shiner 4 3 8 4 2 1 Green sunfish 116 38 21 37 9 2 Hybrid sunfish 1 Lake chubsucker 22 38 5 25 1 3 Largemouth bass 110 22 67 158 73 58 Northern pike 45 2 4 4 21 3 Pumpkinseed 13 12 13 19 59 31 Rainbow trout 2 13 Redear 580 28 103 101 184 131 Redfin pickerel 9 1 2 12 3 1 Rock bass 60 15 42 19 70 19 Smallmouth bass 1 Walleye 9 30 24 Warmouth 79 65 43 37 22 26 White sucker 2 Yellow bullhead 49 33 56 40 42 17 Yellow perch 70 16 74 92 64 15 Total 1,513 409 612 1,169 1,280 755 Sampling Effort Electrofishing Effort 8 h AC 2 h AC 1 h AC 1 h DC 1 h DC 1 h DC Gill Net Effort 8 lifts 9 lifts 6 lifts 4 lifts 4 lifts 6 lifts Trap Net Effort 4 lifts 6 lifts 3 lifts 4 lifts 4 lifts 3 lifts 16
Table 2. Pretty Lake walleye stockings, 1990 through 2009. Date Stocked # Stocked Size (inches) 6/90 18,388 1.9 6/93 17,350 2 6/94 19,354 1.6 6/95 20,970 1.9 6/96 19,900 1.7 6/97 19,136 1.7 6/98 18,427 1.5 6/99 20,595 1.8 5/00 18,795 1 5/01 18,675 1.7 5/02 17,900 1.4 5/03 18,641 1.7 5/04 18,400 1.5 6/05 21,781 1.6 6/06 22,948 1.5 6/07 20,810 1.4 10/07 2,280* 8.9 10/09 1,840* 5.9 *Advanced fall fingerlings 17
Table 3. Catch by select size ranges for bluegills and largemouth bass collected during 1964, 1973, 1979, 1983, 1996 and 2010 fisheries surveys of Pretty Lake. Species Length Range (TL) 1964 1973 1979 1983 1996 2010 Bluegill 3.0-5.5 in 244 92 78 290 482 303 6.0-6.5 in 52 9 26 119 22 26 7.0-7.5 in 25 2 15 71 11 9 8.0 in 1 1 10 29 18 11 Largemouth bass 8.0-9.5 in 28 6 13 29 20 27 10.0-11.5 in 15 1 16 49 16 13 12.0-13.5 in 13 27 54 11 3 14.0-17.5 in 3 1 10 11 9 1 18.0 in 3 1 3 1 0 Table 4. Average number of largemouth bass per acre in medium size natural lakes (100-499 acres) in Indiana prior to and following the imposition of a 14" minimum size limit in 1999. Number of lake populations included in the average in (). Size range (inches) Ave. pre-size limit (21) Ave. post-size limit (7) Pretty Lake 1996 Pretty Lake 2010 8.0 in 11.4 20.8 12.7 11.6 12.0 in 3.1 8.8 5.8 2.2 14.0 in 1.7 3.5 1.9 0.5 18
Table 5. Length-frequency distribution for walleyes collected during spring trap net and electrofishing sampling at Pretty Lake, 2010. Total Trap Net Electrofishing Total Length (in.) Catch Percent Catch Percent Catch Percent 5.0 4 3.9 4 2.3 6.0 4 3.9 4 2.3 6.5 1 1.0 1 0.6 7.0 4 3.9 4 2.3 7.5 6 5.8 6 3.4 8.0 6 5.8 7 4.0 8.5 10 9.7 10 5.7 9.0 7 6.8 7 4.0 9.5 3 2.9 3 1.7 10.0 1 1.0 1 0.6 12.5 1 1.4 2 1.9 3 1.7 13.0 2 2.8 2 1.9 4 2.3 13.5 3 4.2 6 5.8 9 5.2 14.0 9 12.7 4 3.9 13 7.5 14.5 5 7.0 8 7.8 13 7.5 15.0 4 5.6 6 5.8 10 5.7 15.5 7 9.9 7 6.8 14 8.0 16.0 1 1.4 6 5.8 7 4.0 16.5 3 2.9 3 1.7 17.0 3 2.9 3 1.7 17.5 4 5.6 1 1.0 5 2.9 18.0 1 1.4 1 0.6 18.5 4 5.6 4 2.3 19.0 5 7.0 1 1.0 6 3.4 19.5 6 8.5 6 3.4 20.0 3 4.2 1 1.0 4 2.3 20.5 1 1.4 2 1.9 3 1.7 21.0 1 1.4 2 1.9 3 1.7 22.5 4 5.6 4 2.3 19
(Continued) 23.0 3 4.2 3 1.7 23.5 1 1.4 1 0.6 24.0 2 2.8 1 1.0 3 1.7 25.0 1 1.4 1 0.6 25.5 2 1.9 1 0.6 26.0 1 1.4 1 0.6 28.0 1 1.4 1 0.6 29.5 1 1.4 1 0.6 Total 71 103 174 20
Table 6. Fishing pressure, harvest and yield from Pretty Lake, April October, 2009. Number Total Weight Species Percent Percent Harvested (lbs.) Bluegill 2,912 48.4 921.23 43.0 Redear 2,273 37.8 821.53 38.4 Yellow perch 382 6.4 79.69 3.7 Black crappie 149 2.5 61.76 2.9 Rock bass 149 2.5 42.30 2.0 Walleye 83 1.4 128.38 6.0 Pumpkinseed 27 0.1 8.64 0.4 Largemouth bass 25 0.1 41.97 2.0 Bullhead 4 0.1 8.19 0.4 Northern pike 4 0.1 22.20 1.0 Smallmouth bass 3 0.1 5.19 0.2 Total 6,011 2,141.08 Total angler hours 8,293.96 Total angler hours per acre 45.08 Total pounds harvested per acre 11.64 Fish harvested per hour 0.72 Table 7. Number of legal and sub-legal size largemouth bass and walleyes caught and released at Pretty Lake, 2010. Species Number Percent (by species) Largemouth bass (sub-legal) 2,540 90.2 Largemouth bass (legal) 275 9.8 Largemouth bass (total) 2,815 Walleye (sub-legal) 111 62.7 Walleye (legal) 66 37.3 Walleye (total) 177 Total 2,992 21
Table 8. Monthly fishing pressure and harvest from Pretty Lake, May October, 2010. Species May June July August September October Total Bluegill 874 1,008 140 282 34 574 2,912 Redear 755 792 123 35 39 529 2,273 Yellow perch 48 200 15 43 27 49 382 Black crappie 90 12 26 16 5 149 Rock bass 96 33 4 11 5 149 Walleye 10 7 7 16 27 16 83 Pumpkinseed 19 4 4 27 Largemouth bass 21 4 25 Bullhead 4 4 Northern pike 4 4 Smallmouth bass 3 3 Total 1,913 2,064 326 392 143 1,173 6,011 Angler hours 1,330.00 2,069.60 1,616.40 1,460.80 744.36 1,072.80 8,293.96 Hours per acre 7.23 11.25 8.78 7.94 4.05 5.83 45.08 Fish per hour 1.44 1.00 0.20 0.27 0.19 1.09 0.72 22
Table 9. Length-frequency distribution for bluegills harvested from Pretty Lake, 2010. Total Length (in.) Number Harvested Percent Total Weight (lbs.) Percent 5.0 20 0.7 1.83 0.2 5.5 8 0.3 0.98 0.1 6.0 77 2.6 12.31 1.3 6.5 353 12.1 72.12 7.8 7.0 738 25.3 189.26 20.5 7.5 824 28.3 261.13 28.3 8.0 572 19.6 220.96 24.0 8.5 211 7.2 98.17 10.7 9.0 73 2.5 40.47 4.4 9.5 32 1.1 20.94 2.3 10.0 4 0.1 3.06 0.3 Total 2,912 921.23 Table 10. Length-frequency distribution for redear harvested from Pretty Lake, 2010. Total Length (in.) Number Harvested Percent Total Weight (lbs.) Percent 5.0 13 0.6 1.20 0.1 5.5 4 0.2 0.49 0.1 6.0 50 2.2 7.99 1.0 6.5 126 5.5 25.59 3.1 7.0 445 19.6 112.92 13.7 7.5 620 27.3 193.56 23.6 8.0 428 18.8 162.20 19.7 8.5 294 12.9 133.67 16.3 9.0 134 5.9 72.34 8.8 9.5 96 4.2 60.96 7.4 10.0 38 1.7 28.15 3.4 10.5 17 0.7 14.58 1.8 11.0 8 0.4 7.89 1.0 Total 2,273 821.53 23
Table 11. Length-frequency distribution for yellow perch harvested from Pretty Lake, 2010. Total Length (in.) Number Harvested Percent Total Weight (lbs.) Percent 5.0 8 2.1 0.45 0.6 5.5 4 1.0 0.30 0.4 6.0 16 4.2 1.61 2.0 6.5 52 13.6 6.78 8.5 7.0 134 35.1 22.17 27.8 7.5 68 17.8 14.05 17.6 8.0 40 10.5 10.17 12.8 8.5 12 3.1 3.71 4.7 9.0 20 5.2 7.43 9.3 9.5 20 5.2 8.85 11.1 10.0 8 2.1 4.17 5.2 Total 382 79.69 Table 12. Length-frequency distribution for black crappies harvested from Pretty Lake, 2010. Total Length (in.) Number Harvested Percent Total Weight (lbs.) Percent 7.0 4 2.7 0.73 1.2 7.5 12 8.1 2.69 4.4 8.0 12 8.1 3.27 5.3 8.5 31 20.8 10.14 16.4 9.0 34 22.8 13.21 21.4 9.5 12 8.1 5.49 8.9 10.0 20 13.4 10.67 17.3 10.5 16 10.7 9.89 16.0 11.0 8 5.4 5.69 9.2 Total 149 61.76 24
Table 13. Length-frequency distribution for walleyes harvested from Pretty Lake, 2010. Total Length (in.) Number Harvested Percent Total Weight (lbs.) Percent 14.0 4 4.8 3.58 2.8 14.5 11 13.3 10.95 8.5 15.0 15 18.1 16.55 12.9 15.5 4 4.8 4.88 3.8 16.0 11 13.3 14.77 11.5 16.5 11 13.3 16.22 12.6 17.5 8 9.6 14.12 11.0 18.5 4 4.8 8.36 6.5 19.5 4 4.8 9.81 7.6 20.0 11 13.3 29.15 22.7 Total 83 128.38 Table 14. Length-frequency distribution for largemouth bass harvested from Pretty Lake, 2010. Total Length (in.) Number Harvested Percent Total Weight (lbs.) Percent 14.0 9 36.0 12.33 29.4 14.5 2 8.0 3.05 7.3 15.0 7 28.0 11.83 28.2 15.5 5 20.0 9.34 22.3 17.5 2 8.0 5.41 12.9 Total 25 41.97 25
Table 15. Species, number and weight of additional fish harvested from Pretty Lake, 2010. Species Number Harvested Total Weight (lbs.) Rock bass 149 42.30 Pumpkinseed 27 8.64 Bullhead 4 8.19 Northern pike 4 22.20 Smallmouth bass 3 5.19 Total 187 86.52 Table 16. Species preference of angling parties interviewed at Pretty Lake, 2010. Species Number of Parties Percent Panfish 188 50.4 Walleye 73 19.6 Bass 61 16.4 Anything 18 4.8 Bluegill 12 3.2 Yellow perch 11 2.9 Black crappie 7 1.9 Northern pike 3 0.8 Total 373 26
Table 17. County of residence of angling parties interviewed at Pretty Lake, 2010. County Number of Parties Percent Lake Resident 121 32.6 Allen 73 19.7 DeKalb 50 13.5 LaGrange 39 10.5 Noble 37 10.0 Elkhart 14 3.8 Adams 7 1.9 Steuben 5 1.3 Wells 5 1.3 Blackford 4 1.1 St. Joseph 4 1.1 Huntington 2 0.5 Kosciusko 2 0.5 Ohio (State) 2 0.5 Whitely 2 0.5 Madison 1 0.3 Michigan (State) 1 0.3 Montgomery 1 0.3 Pulaski 1 0.3 Marion 1 0.3 Total 371 27
Trap Net Gill Net Figure 1. Aerial photo of Pretty Lake with general survey sample locations. 28