TPWD 1955 F-5-R-2 #139: Creel Census of Lake Nasworthy

--- Page 1 --- STATE Texas PROJECT NO, Fe5eR=2, Job Bee PERIOD June 22, 1952 - May 1, 1955 Job Completion Report by Lawrence S. Campbell TITLE wks gl des reel Census of Lake Nasworthy. oO OBJECTIVES To estimate the total catch by species and to obtain data regarding the growth From October 1953 through February 1954 an actual count of all creels was at~- tempted, Because of the difficulty involved in contacting each fisherman and because yveful. investigation revealed that a complete count was not being recorded in spite of iiligence by workers; it was concluded that an estimate eould be obtained that would be ° “ficiently reliable for practical purposes by making periodic counts of ail persons o, The total number of persons fishing from the lake shore was usually determined +ing from an automobile, and persons fishing from boats were counted by a boat crew ng the entire length of the lake at the same time the shore count was being taken. nts were taken each morning and two counts were taken each afternoon. These ken one hour apart and the average number of fishermen on the lake from morn= added to the average number of fishermen for the afternoon to produce the number of fishermen for the day. The sum of the averages described was the total number of fishermen because actual creels indicated that vir~ ermen spent more than half a day fishing on the lake without returning to ity of San Angelo, or to their homes. The time that counts were taken was the total number of hours of daylight for the various seasons of the year ‘ sely described as mid-worning and mid-afternoon, Night counts were made ng the latter three months of work, and the number of night fishermen were added to daily total. The average number of fishermen, hours fished, and their average creel e é month to produce total. Creel days were selected at random. Creel census stations were each day's fishing rs fished, method v Pi at Pour sites on the lake during creel days, and sample A. Method of Determining Time of Morning Counts. Number of Hours Sunrise to Noon minus 30 min. «= a. Time for First Count 2 plus 30 min. = b. Time for 2nd Count --- Page 2 --- 2 B, Method of Determining Time of Afternoon Counts. Number of Hours Noon to Sunset minus 30 min. = a. Time for First Count 2 plus 30 min. = b. Time for 2nd Count Cc, Method of Determining Daily Totals (a. plus b.) (a. plus b.) plus plus tot. night count = Total Fishermen for Day 2 2 Total Fishermen X 1. Avg. catch from sample creels = Total catch Total Fishermen X 2. Avg. hours fished from sample creels = Total hours fished D, Method of Determining Monthly Totals (Avg. of Seven Day Sample) X (Number of Days in Month) = Monthly Total E, Annual Totals are the product of all Monthly Totals FINDING Lake Nasworthy is located approximately 6.5 miles southwest of the city of San Angelo in Tom Green County, Texas. The reservoir has about 1,300 surface acres and a volume of about 14,040 acre feet at emergency spillway. The dam creating the lake is located approximately one-fourth mile below the confluence of the South and Middle Concho CPsiec Increasing water demands resulting from rapid growth of the city have resulted n extreme fluctuation of this lake, and during much of the census period the lake was re~ ed in volume to an extent that prevented many persons from attempting to fish. During , dune, and July of 1954 the tremendous increase in the number of fishermen using the e is attributed not only to the vacation season, but also to the fact that many out-of~- n ishing parties came to Lake Nasworthy who had originally intended camping at San Angelo Reservoir. These campers moved to the smaller lake because of adverse weather con- 4 ons and/or because of it's more accessible, convenvenient, and pleasant camping lities, Although virtually all persons contacted were very willing to be interviewed, | attempted to co-operate in every way with personnel doing this work, difficulty was sountered in obtaining accurate information on many aspects of the catch. The size of fish released, the species or type of fish the person was attempting to catch, and the re DG D n of time actually fished were especially difficult to determine in many instances. =re are other unaccounted-for factors influencing the included data; such as the skill, termination, and knowledge of the lake by fishermen. The data on night fishing is in« ufficient, and many persons maintain trotlines in the lake throughout the year. It was iPPieult to know when these lines were actually being used and when they were simply -cupying desirable space in the lake. > RS Res Dt a W fas A 2 Co hb Fh ©) oO During the census period of twelve months, 116 days were actually spent taking creels on the lake. This includes both the five month period when an actual count was attempted and the following seven months when the described method of estimate was adapted. For that reason the percentage of the total time when creels were actually taken, 31.78 ‘cent, may be misleading. The following tables are intended to present most of the data obtained in such manner as to reveal the more important aspects of the fishing effort and the resulting catch by sportsmen. --- Page 3 --- Table 1 The data contained in this chart are the monthly and annual total estimates. ae number of persons who fished, the total effort expended, and the results in fish per man hour for the year are included. As shown, about six thousand fishermen had an average catch of slightly over one fish each during the twelve month period, and an average person fished about three and one-half hours to catch that fish. Because of inexperience by the personnel doing this work and because the method of estimation used during the first five month's work was found to be inadequate in estimating the number of persons fishing at night, the total estimates are known to be too conservative for the entire census period. However, the catch per unit effort is believed to be reasonably reliable for the year; and since night fishing was not a major factor, except in the summer months, it is hoped that the total number of fishermen and their total catch is not too far below the actual USAZE o Table 2 The number and numerical percent for each of the various species caught each month is presented here. Because it was necessary to accept the statement of sportsmen concerning the identity of virtually all fish released, all sunfishes and warmouth bass are grouped under a single heading. As shown in the chart, sunfishes and white crappie made up over 60% of the total catch, and carp were third in numbers. These latter fish appear to be select with a group of local fishermen who make little attempt to fish for other species. Table 3 The relative size of the various species of fish in the catch is shown. The icluded estimates are based on fish that were actually measured in taking creel re= vaults during the various months of the year. The number of individuals making up this sample exceeds twenty percent of the total estimated catch in all species except sun-= fishes, white crappie and carp. Although sunfishes averaged over 4. inches in length; a significant percent of the fish measured were in the three inch category, and less than sever percent were large enough to be regarded as desirable pan fish. One of the diffi- culties in obtaining data on the sunfish catch was in measuring these fish before they were released. About twenty percent of the white crappie taken were toc small to be "Keepers" and in spite of the high percentage of these fish taken from the lake, few els were deemed "good catches" by the sportsmen making the catch. Largemouth bass were less numerous than most species taken, but the average size of these fish was sreater than other species except carp and channel catfish. This data permits a general comparison of the catch by species, showing the numerical percentage of each species as compared to it's percentage of the total weight the catch. It is believed probable that this comparison of species by weight more accurately represents the extent to which each species of the catch was utilized as food, and may be more expressive in accounting for the amount of pleasure each species afforded the public. Carp contributed 36 percent of the total weight of the catch and white bass contributed 13 percent of that total. However catches of these species were ially desired and utilized as food by only a few individuals who actually sought these ish, and probably most of the pleasure derived from catches of carp, and to a lesser extent white bass, was confined to the sporting aspects of the catch. Largemouth bass 14 channel catfish were about 35 percent of the total weight of the catch and were the species most desired by sportsmen. ei or --- Page 4 --- Table 5 The monthly and the total catch per unit effort for each species is shown in ais data. Apparently sunfishes may be caught with relatively little effort during al- most any month; however, fishing results for white crappie and largemouth bass appear to nave declined during the summer and early fall months. The best months for largemouth bass were October, November and January; for white bass October, November, December and J a Ss agai for white crappie November, December and April; and for southern channel catfish an and January. Carp were taken in abundance from April through November. Insufficient vidence was obtained to permit generalities for other species included in the catch. a u Table 6 As shown in this table still fishing was the most popular and the most reliable of all methods employed in taking all species of fish except white bass. The highest yields per unit effort were obtained by fly fishing for sunfishes; however, the skill, determination, and other unaccounted-for aptitudes of the fishermen involved is believed to be superior to that of the average fisherman. Trolling for white bass was relatively successful; however, this method of fishing did not appear to be popular during the cen-~ sus period; and the above named aptitudes may well have been contributing factors in the results obtained with this method. Trotline fishing yielded the smallest number of fish per unit effort; however, the actual numbers of fish taken by this method was greater than those for casting and trolling. The relatively low fish per unit effort for trotlines is regarded as resulting from a lack of dilligence in baiting and maintaining lines, as well as possitle ineffectiveness of that method. After several months experience at this work it wa arbitrarily concluded that trotline data should be based on eight man hours fishing for each trotline set for a party setting more than one line, and at sixteen man hours fisming where only one line was employed. fable 7 Miznows and worms were the most successful baits used; however, a greater total uumber of largemouth bass and white bass were taken on lures than on natural baits. Dough bait captured more carp. A greater variety of baits were successful in capturing channel catfish than any other species. Although no factual records were obtained during days when the census was conducted a number of these fish were reported to have been taken by casting and trolling. Q Table 3 Mais data presents the total and monthly fishing effort comparing successful ing effort to unsuccessful effort. Since as discussed under Table 5, the winter appear to produce a higher yield per unit effort than summer months; the high per- centage of persons "skunked" in December and February may be a result of fishermen quit- tisg because of adverse weather conditions rather than a lack of the quality of the fish- ing. According to the evidence obtained, approximately one out of every four fishing attempts by an average fisherman resulted in a complete failure to catch fish. SUMMARY 1. From October 1953 through February 1954 1, an actual count of all creels was attempted and found to be virtually impossible. For the remaining seven months of the year, March 1954 through September 1954, a method of estimate was employed to obtain the required data and is believed to be more reliable and efficient than the data obtained when an attempt was made to contact all fishermen. --- Page 5 --- LO. Des Because of inexperience in doing this type work, insufficient evidence was obtained for accurately estimating night fishing, and many aptitudes of in- dividual fishermen, such as their skill, determination, and familarity with the lake are not adequately illustrated. No attempt is made to account for the influence of weather and accessibility on the fisherman effort or the fishing results. About six thousand fishermen had an average catch of slightly over one fish each during the twelve month period, and an average person fished about three and one-half hours to catch that fish. Sunfishes and white crappie made up over 60% of the total catch numerically and carp were third in numbers. Carp are select with a group of fishermen who make little attempt to catch other species. Less than seven percent of the sunfish catch was large enough to be regarded as desirable pan fish, and there were few desirable catches of white crappie. Largemouth bass, channel catfish, and carp had the largest average sizes. Largemouth bass and channel catfish were thirty-five percent of the estimated total weight of the catch, and it is believed this figure more accurately illustrates the pleasure that these species afforded the public. The best months for largemouth bass were October, November and January; for white bass, October, November and December; for white crappie, November, December and April; and for channel catfish, July and January. Carp were taken in a greater abundance from April through November. Still fishing was the most popular and the most reliable of all methods. Fly fishing for sunfishes had the highest yield per unit effort, and trol- ling for white bass was relatively successful. Trotlings yielded the smallest number of fish per unit effort; however, the actual number of fish taken by this method was greater than those for casting and trolling. Minnows and worms were the most successful baits used. A greater number of largemouth bass and white bass were taken on lures than on natural baits. A greater variety of baits were successful in taking channel catfish than any other species. According to the data obtained from the census, approximately one out of every four fishing attempts by an average fisherman resulted in a complete failure to catch fish. --- Page 6 --- Table 1. Monthly Creel Census Data for Lake Nasworthy From October 1953 through September 1954 Oct. Number of Fishermen 58 Hours Fished hol Number of Fish Caught 129 Fish/ man hour » 322 Nov. 62 228 137 580 Dec. 8h aot 110 316 Jan. 184 606 62 O99 Feb. 71 256 gu 2367 Mar. 280 1,090 301 .276 Apr. 620 2,300 1, 330 2578 May 1 D a 7231 ,924 481 250 Jun.» 1,121 14h 1,494 333 Jul. 1,243 Aug. 821 3,829 1,648 765 .200 557 2341 Sept. 82 2,585 251 » 900 Total 5,857 23,648 6,711 » 20h nnn Table 2. Sunfish White crappie Largemouth bass White bass Channel catfish Flathead catfish Freshwater drum Yellow bullheads Carp River carpsuckers Number of Each Species of Fish Caught Per Month From Lake Nasworthy Oct 23 22 7 22 29 - Nov. LT 7 2 28 Dec. ) 90 Jan. 3 38 b Feb. 19 6 i, 14 Mar. 118 61 19 21 43 Apr. ALS 669 12 8 28 May Jun. 397 601 384 312 20h = gh 118 113 115458 0 0 93 105 6) 0 170 211 ) 0 Jul. Aug. 131 84 98 160 98 38 61 0 211 101 @) © 62 12 0 fe) 104 162 ) 0 Sept. 149 22 12 23 19 +2 Total 1,995 1,976 491 OL 630 2 289 9 891 af Percent 29.730 29.450 7.320 5.960 9.300 O10 4.310 140 13.290 460 Totals 129 137 1L1O 301 1,330 1,481 1494 251 6,711 100.00 --- Page 7 --- Table 3. Size of Fish Caught From Lake Nasworthy During Year October 1953 through September 1954 Species Sunfish White crappie Largemouth bass White bass Channel catfish Size of Fish = Total Length in Inches Avg. Length 3. 4, 5. 66 T° 8. No, 38 128 28 16 13 iF 434 % 16.89 56.39 12.34 705 5513 1.76 100.00 (Based_on a Sample of 227 individuals of four species) Size of Fish - Total Length in Inches Avg. Length h, 5. 6. ve 8. a 20 2 ih, No. 24 31 130 9 30 28 14 4 2 6.59 %, 8.83 11.39 47.80 3.31 11.03 10.29 5.15 1.47 .75 100.00 (Based on a Sample of 272 individuals) Size of Fish - Total length in Inches Avg. Length ll. 12. 13. 1h. 15. 16. No. 14 48 38 26 11 11 12.95 % 9.46 32.45 25.68 17.51 Toh5 TAS 100.00 (Based on a of 148 individuals Size of Fish - Total Length in Inches Avg. Length 7. 10. ll. 12. 135 Lee No. 12 31 18 46 18 5 11.14 % 9.23 23.84 13.85 35.38 13.85 3.85 100.00 (Based on a Sample of 130 individuals) Size of Fish - Total Length in Inches Avg. Length 10, il. 12. 156 Ql. 22. 23 No. 8 14 21 13 1 2 2 12.98 % 13.12 22.91 34.43 21.31 1.64 3027 4 ©=—. 3-27 100.00 (Based _on a_ of 61 individuals) Sample (Continued ) --- Page 8 --- Table 3. (Continued) Carp Freshwater drum —__ en Size of Fish - Total length in Inches ll. 612. 13. 15. 18. 20. No. 23 ‘hl 54 18 12 11 % 16.55 7.91 38.84 13.00 8.64 TO (Based on a Sample of 139 individuals) Size of Fish - Total Length in Inches 6. Ts 8, 9. 10. 4. No. 6 9 21 4 6 4 % 11.54 17.30 40.39 7.69 11.5% 7.69 (Based on a Sample of 52 individuals) Avg. Length 22. 10 14.71 7.19 100.00 Avg. Length 18. 22. 1 1 8.85 1.93 1.93 100,00 --- Page 9 --- Table 4. Estimated Weight and Numerical Data for Sportsmen Catch From Lake Nasworthy from October 1953 through September 1954. Pop. Est. Tot. Avg. Weight Est. Tot. Numerical Percent of Species Sample No. Caught (ounces ) Weight Percentage Tot. Weight (lbs. ) Sunfish 227 1,995 1.66 207 29.73 5,84 White crappie 272 1,976 2.01 198 29.45 5.59 Largemouth bass 148 OL 23.50 721 7.32 20.35 White bass 130 4O1 20.50 486 5.96 13.72 Southern channel catfish 61 630 12.85 530 9.30 14.98 Carp 139 891 23.00 1,280 13.290 36.16 Freshwater drum 52 289 6.55 113 4.31 3.34 1,029 aul 3,542 100.00 100.00 Table 5. Fishing Results Per Unit Effort by Species From Lake Nasworthy from Oct. 1953 through Sept. 1954. , Fish/ Species Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Total man hr. No. 23 17 5 3 19 118 4448 397 601 131 8h. 149 1,995 1.0129 Sunfish Fish/man Hr. .32 .92 .69 .39 1.02 1.55 1.07 .58 .26 .38 .28 1.78 No. 22 74 90 38 46 61 669 384 312 98 160 22 1,976 .2805 White crappie Fish/man Hr. .61 1.09 1.2 39 @©6©.685—ss«w 18 1.00 .16 .25 11 ~ «16 .026 No. 7 2 6) h i 19 12 20h 94 98 38 12 hol, 2348 Largemouth bass Fish/man Hr. .39 1.6 O 2.0 25 )=— 08S 13—St—t«i«S 2B «2Hs—“‘(iztCd«d 265 No. 22 28 9 9 4 21 8 118 113 61 @) 5 hOl .677 White bass Fish/man Hr. .81 1.16 .86 .64 .93 .2h .15 .69 .93 .89 6) 42 --- Page 10 --- Table 5. (Continued) mm F ish/ Species Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Total man hr. No. 29 7 fe) 1 14 43 28 115 58 211 101 23 630 .1925 Southern channel catfish Fish/man Hr. .17 = .35 Oo .83 .57 .30 .06 .19 15 40 .16 68 No. 7 7 3 5 1 37. 165 #170 211 104 162 19 891 275 Carp Fish/man Hrs Ls4 ofl 64 22 #39 36 .81 1.10 .27 24 1.144 09 Table 6. Fishing Results By Method From Lake Nasworthy from Oct. 1953 through Sept. 1954. encores teenie nineteenth erent eee nt EAA LS, Species Still Fishing Trotlining Casting Fly Fishing Trolling number 1,342 605 Sunfish percentage 68.93 31.07 Hrs. fished 1,497.70 a9. Fish/man Hr. .8960 1.55 number 1, 386 143 207 16 White crappie percentage 70.10 8.16 11.82 92 Hrs. fished 5,114 960 518 180 Fish/man Hr. Til 148 2399 .89 number 164 16 131 81 86 Largemouth bass percentage 34. 30 3.35 27.40 16.95 18.00 Hrs. fished 364 208 580 328 602 Fish/man Hr. 45 .O77 223 025 215 --- Page 11 --- Table 6. (Continued) nT ee Still Fishin Trotlining Casting Fly Fishing Trolling number 79 4.3 211 White bass percentage 23.73 12.91 63.36 Hrs. fished 189 266 61 Fish/man Hr. 42 -79 <¥o number 182 41 Channel catfish percentage 30.69 69.31 Hrs. fished 728 2,357 Fish/man Hr. 25 17 number a Flathead catfish percentage 100 Hrs. fished 4.2 Fish/man Hr. -230 number 869 Carp percentage 100 Hrs. fished 2,040 Fish/man Hr. 43 number 13 River carp suckers percentage 100 Hrs. fished 7.8 Fish/man Hr. 1.66 --- Page 12 --- Table 7. Species Sunfish White crappie Largemouth bass White bass Southern channel catfish Flathead catfish Carp River carp suckers Freshwater Drum Total Catch From Lake Nasworthy Oct. 1953 through Sept. 1954 by Type of Bait Used minnows No. 250 % 12.85 No. 1,053 % 60.10 No. 180 % 37.65 No. 64 % 19.22 No. 2le % Cope) No. % No. 16 % .85 No. % No. cray- dough blood — cut worms shad fish bait _bait shrimp bait bait 977 83 50.17 4.27 663 38.98 15 4,50 8 103 19 54 ) 13 104 80 1.35 17.36 3.20 9.11 @) 2.19 17.54 13.50 1 100 853 98.15 13 100.0 48 6h 17.26 23.02 “stink — flies | lures 605 32 31.07 1.64 16 .92 81 217 16.95 45.40 42 a1 12.91 63.36 fe) @) @) fe) --- Page 13 --- Table 8, Comparison of Successful and Unsuccessful Fishing Effort. Lake Nasworthy, October 1953 through September 1954. a Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Total Hrs. fished 326 150 133 529 117 878 1890 4914 3153 2625 Vuoh 1674 17,793 Successful Fishermen percent 81.3 65.8 44.8 87.3 45.3 80.6 82.17 82.9 70.3 68.6 85.0 64.8 75.25 Hrs. fished 715 78 1643 77 139 212 410 1010 1331 1204 ehh 911 5,855 Unsuccessful Fishermen percent 18.7 37.5 55.22 12.7 54.3 19.5 17.8 17.0 29.7 31.5 15.0 25.2 24.75