TPWD 1953 F-7-R-1 #5: Experimental Control of Undesirable Fish Species: Job Completion Report for Segment 1

STATE Texas PROJECT N06 FmTwal Job Eel W PERIOD June 15‘9 1953mMay Big l95h Job Completion Report for Segment l ”by Leo Du Lewis and Walter W; Dalqnest TITLE Experimental Control of undesirable Fish Speciesu OBJECTIVES To develop methods for the selective control of undesirable fish specieso TECHNIQUES Original plans called for laboratory and field experimentation in the above subjecto In generala the following outline was followed as closely as possible; though we'were hampered in some reapects by lack of equipmento Ao Laboratory experimentationo 10 Representative fish species of Region Bel will be subjected to different concentrations of fish toxicants to determine toxicity limits of each species to each toxicanto 20 These experiments will be conducted for each different water quality type in Region Bml and at varied temperatureso 3” Reactions of each species to electrical shock? treated baits? small scale models of nets and traps? etcoj will be determined in laboratory vatso Ba Field experimentationa lo The practical application of the information obtained by laboratory experimentation will be determined by further expenmentation in the fielda 2° Accurate measurements will be made on ponds and small lakes in Region Bul which contain excessive populations of ondersirable fisho Chemim cal methods will be attempted as a means of control by utilizing informw ation obtained in the laboratory as a basiso 3a Efforts will be made to concentrate different-Species of undesirable fishes into a suitable harvest area by treated baits, driving or ""herdinrlg't devises; habitat alterations, etc.o so Experimental nets and traps will be rigged and set to simplify and increase rough fish removalo HISTORY OF PROJECT PRIOR TO FEDERAL AID The possibility of selective control of rough fish species was presented by a fortuitous event during routine fisheries work in January, l953 A fish pOpula- tion check was made of the Lamar Fain Lake near Wichita Falls, Texasu Gill nets rangm ing from l2 to 3 inches in mesh size, were set across the lake and since it was not possible to check the lake with a minnow seine, a small cove on the north east shore was rotenonedO to check Oon the forage fish pepulation, The water temperature at this time was llO C (51 80 F) During the night a strong southwest wind, blow— ing directly down the long axis of the cove, d.eveloped and continued for A8 hours. Apparently the wind blew the rotenone out of the cove and wave action dispersed it over the entire lake in a uniform concentration, The next morning the gill nets and the northeastern shore of the lake were heavily laden with dead gizzard shad. The nets ,when'checked, contained living, healthy, black bass, channel catfish, European carp and white crappie but no live gizzard shad Most of the stomachs of the larger black bass and catfish contained shad One eight pound catfish contained 22 shad, averaging A inches in length The lake was drained and seined two weeks after the treatment and it was noted that no fish other than shad had been affected by the rotenone. All shad were dead Consideration of the size of the pond and the amount of rotenone used revealed that the shad had been killed with less than 02 pound of the toxicant per acre foot of water° Following the accidental shad kill in the Lamar Fain Lake an attempt was made to duplicate the evento The 6E acre Jerry Vinson Lake, also near Wichita Falls, was treated with 03 pounds of rotenone per acre foot of watero Again the water temperature was llO C. Gizzard shad began to die in large numbers twelve hours later and continued to die for the next ten days. Two weeks later the lake was checked with gill nets but no living shad were foundo The possi.bility that the gizsard shad, at least, could as selectivel.y poisoned, was thus suggested, andl laboratory experiments followed A iish transport vat, complete with circulator, was borrowed from the Dundee Fish Hatchery and used, in these exper. iments, with 100 gallons of watero Test animals included gar, gis~ card shad, black bullhead catfish, channel catfish, white bass, sunfish and drumn Concentrations of rotenone used ranged from the equivalent of ,2 pounds per acre foot of water through gradual increases to one pound per acre footo Effects on the test animals were recorded for 36 hours, _Water temperature varied from 9,50 C to llO C, Briefly summarised, the results were: (1) At ,2 pounds per acre foot ( 0? ppm) to 4 pounds per acre foot ( lh ppm) gizzard shad were all killed but other Species of fish appeared to be unaffected (2) At 5 lbs, per acre ft ( 18 ppm) all shad were killed, most white bass were moribund after 36 hours, and some drum appeared to be in distress, Other species appeared to be unaffected (3) At ( lbs,/acre fto, all fish except one large sunfish and gar were dead within 36 hours, (A) At 1.0 lbswfacre fto, all fish but gar were dead within 36 hours, v-vr 1!.) 1.9.3310 These results were encouraging, as were the results of some other samll field experimentso However, possibilities of error existed in virtually all aspects of these experiments that required accurate measurementso In the laboratory experiments, reliable apparatus was not available while we had no accurate methods of measuring the experimental ponds and samll lakes used in our field worko It was obvious that much experimental work was needed before the action of the tow- icants used in different water types and at different temperature could be under— stoodo Further work was postponed until funds and equipment could be obtainedo Opportunity to continue this research became_available through funds prom vided by the Dingell-Johnson Acto WORK COMPLETED DURING THIS PROJECT PERIOD Laboratory Work and Experiments Pregress on this aspect has been seriously hampered by lack of essential laboratory apparatus, Only recently have the necessary agitators and electrical air pumps for laboratory and transport vats been obtaineda Transport vats suitn able for our work have been improvised from 30 and 55 gallon oil drumso Some large battery jars were obtained from the Rockport marine Laboratory, but adequate lab« oratory vats are not yet on hand. It is expected, however, that suitable apparatus will be available for the next projectperiodo Field Experiments It was planned, originally, to conduct laboratory experiments before each field experiment, using water and fishes from the pond or lake concernedo Howe ever, as explained above, these ideal conditions were not realized because the essential laboratory apparatus and accurate lake measuring devices were lacking until recent weeks, Nevertheless, advantage was taken of several opportunities to carry on field experiments where landowners so requested and furnished measurements of the waters concernedo Only two of these experiments are here discussed in detailo By early June 1953, Lake Wichita near Wichita Falls, has been reduced by drought to approximately 1 ,A25 acrewfeet from its capacity of 13,96A acre feet, The lake was heavily overpopulated with severa.l species of rough fishes, among which the giszard shad and drum dominatedo As a result of low water level and large rough fish population, a situation critical to the survival of the game species was brought about, When treatment was Obegun, the surface acre measured #75 acres and water temperature was 22 5 0C (72 50 F) Retenone at a concentratio n of approxi— mately 35 pounds to the acrewfoot of water was distributeda Almost immediately after treatment, large numbers of shed and drum began to die, Both Species were observed on the surface in a moribund condition but only drum were being washed ashore in large numbers, Apparently most of the shad were Sinking after deatho During the night the shed, which had sunk during the day, floated to shoreo The next day there was a striking stratification of dead fish, with drum forming a broad bank highest on the beaches and shad forming another broad bank beneath the drum and forming thick windows in the shallows, The thousands of drum ranged from three to twenty inches in length but were underweight and obviously in poor -u—- mic conditiona The shady on the other hand; were fat and apparently in excellent Jhealtho They ranged from eight to sixteen inches in length; apparently all hmature fisho Several days were required to clean up the dead fisho For the first twodays they were hauled to a rendering plant; in dump trucks and pickup trunk9 where they were weighed and renderedo After the second day they were hauled to abanw doned ' gravel pits and covered over with bulldozerso Observations were made dur~ ing the pickwup period as to the Species killed and their sizeso The total weight of fish killed, based on number of trucks employed and average load per truck? is estimated at 3605 tons (733000 lbs)o The treatment was effective almost entirely on drum.and shado Not more than one per cent of the fish killed consisted of all other species combinedn The river carpsucker made up most of this one per cento A few small mouth buffaloy white bass and channel catfish were also killedo Crappie9 small shad and minnows were strikingly absento Indeed; seining during the pickingmup period of the dead fish showed minnows to be abundant and apparently in the best of healtho Ten days later; the high turbidity and muddy color of the lake had abatn ed and the'water appeared rich blue° Word had spread that the lake had been poisoned and few fishermen tried their lucko, The lingering odor of decayed fish kept others awayo Polesandmline fishermen reported nothing but gars being caughto Trotline fishermen? however, reported better than average catcheso Checkmseining at this.time showed most species in their usual proportions but drum and shad were very scarceo The presence of any drum and shad was surprisingo It is possible that these fish were unusually healthly individuals that had survived the rotenoneo it is perhaps more likely that they had been in certain shallow parts of the lake we were unable to treat with rotenoneo9 or they may have entered the lake after the treatment from irrigation ditcheso A local fisherman aptly described the treatw ment as a "Spring tonic for a sick lakeo" The Lake Wichita experiment was by far the most spectacular from the stands point of quality of water treated and of rough fishes killedo Another interesting experiment? involving the use of slightly larger concentrations of rotenoney was carried out with the Louis Sykes Lake“g located at the southern city limits of Wichita Fallsa The lake has a surface area of 35 acres and was treated with 05 pounds of rotenone per acrewfoot ofwatero The temperature at the time of treatmenty April 263 l95h9 was 230 C (739h0 F)o The treatment was 'rapidly effective and within three hours after the distribution of the rotenoney large numbers of shad and drum were observed dead and dying on the surface of the lakeo A few carpy smallmouth buffalo and river carpsuckers were noted in a moribund conm ditiona The lake was checked twentwaive hours after treatmento Apparently all the fish susceptible to rotenone in the concentration used gamidied by this timeo An accurate count of the various species of dead and partially decayed fish was not possible but it was obvious that the dead animals consisted almost entirely of rough fishes with a very few game fisheso Shad and drum.were by far the most num— erous while carpsuckers‘9 EurOpean carp and smallmouth buffalo were less abundanto Several black bullhead catfish; channel catfish; crappie and sunfish were noted? especially in the shallow; upper end of the lake where a heavier concentration or rotenone was accidentally appliedo Workman in charge of the cleanup work estimated that more shad and drum were killed than any other species combined; but that by weight; carp and sucker made up the bulk of the killo WI pu- m: ’o-n The following day the lake was checked with gill nets and seines. All those species detected before treatment were also found after the treatmento Howe every shad were very rare {only one was taken) and drum were scarceo Carp9 carpsuckers and buffalo were present in obviously reduced numberso These two experiments are considered validy in large part because quite accurate measures of water volume and surface area were availableo Several additionw sly less dependableg experiments were completed in which we were forced to estimate surface area and water volume by crude methodso A brief summary of the pertinent findings follows: (i) In three instances when rotenone equivalent of 03 lb/ acremftn was appliedy only giszard shad were killeda (2) In Januaryy 195% a concentration of 05 lb/ acremfto was applied to tBe Gordon Cummins Lake in the Texas Panhandleo Water temperature was 2 Co and it was necessary to break a thin layer of ice to distribute the rotenonea The treatment was ineffectivea (3) In this same lake? when the water temperature was 5° Co; o5 lb/acremfta killed approximately equal numbers of giseard shad and EurOpean Carp as well as a small number of bullhead catfish? small sunfish and one crappieo (A) In most instances when a aS/lb acremft. was applied to water with temperatures greater than 210 Coy white bass; dram9 carp; young black bass9 crappie and sunfish as well as gizsard shad were killedo PREPARATIONS FOB FETURE WORK Consent of a number of landowners has been secured for future field emser:"Lmentsé9 and the water quality and fish populations of some of these ponds and lakes has been determinedo Equipment and apparatus for laboratory work is now largely on hando Field ewperiments are hampered by lack of adequate measuring devices (plane tabley ail...:idaéhsv9 etc.)y essential to the computation of water volumea Such equipment now has been orderedo Pertinent literature has been reviewed in search of information on the toxicity of various chemicals to fishy9 natural history and food habits of rough fish SpSTiES3 fish harvesting methods? and other subjects that might have some appliw cations to selective control of undesirable fish species. Correspondence has been initiated with other fisheries biologists and individuals working with various aspects of rough fish control methodso SUMMARY. The possibility of selective removal of gissard shad by chemical methods was revealed in l953 when accidental application of about 62 pounds of rotenone per acremfoot of water killed all the giasard shad in a small lakeo Rough checks in the field and laboratory validated these first findings? but funds and apparatus were lacking for carrying the work further at that time. In the past project period? further research has been carried ono Much of the needed materials and apparatus is now on hand or ordereda Several field experimentsy including one that involved a moderately large lakefl have been successful. It has been found that rough fishes can be killed with rotenone concentrations up to a o5/lb acrewftay without endangering game fishes to any great extenta under certain conditions. Gizzard shad can'be killed with rotenone concenm trations as low as .3 lb/acre ft. Water temperature seems to be an. important factor. At 20 0.? treatment with .5 lb/acremft. was not effective but the same concentration was highly effective on. rough fishes Oat a temperature of 5°C. This same concentration at temperatures greater than 210 C killed game species as well as rough fishes. Preparations for further experiments are under way.