INVESTIGATIONS IN FISH CONTROL

71. Field Tests of Isobornyl Thiocyanoacetate (Thanite) for 

Live Collection of Fishes

United States Department of the Interior 

Fish and Wildlife Service
Investigations in Fish Control, published by the Fish and Wildlife Service, include reports on the 

results of work at the Service's Fish Control Laboratories at La Crosse, Wis., and Warm Springs, 

Ga., and reports of other studies related to that work. Though each report is regarded as a separate 

publication, several may be issued under a single cover, for economy. [See Investigations in Fish 

Control 47-50 (in one cover) for list of issues published prior to 1970.]

35. Toxicology of Thiodan in Several Fish and Aquatic Invertebrates, by Richard A. 

Schoettger. 1970. 31 pp.

(Reports 36 through 38 are in one cover.)

36. A Method for Rating Chemicals for Potency Against Fish and Other Organisms, by Leif L. 

Marking. 1970. 8 pp.

37. Comparative Toxicity of 29 Nitrosalicylanilides and Related Compounds to Eight Species of 

Fish, by Leif L. Marking and Wayne A. Willford. 1970. 11 pp.

38. Toxicity of 33NCS (3'-chloro-3-nitrosalicylanilide) to Freshwater Fish and Sea Lampreys, by 

Leif L. Marking, Everett L. King, Charles R. Walker, and John H. Howell. 1970. 16 pp.

(Reports 39 and 40 are in one cover.)

39. Effects of Antimycin A on Tissue Respiration of Rainbow Trout and Channel Catfish, by 

Richard A. Schoettger and Gerald E. Svendsen. 1970. 10 pp.

40. A Resume on Field Applications of Antimycin A to Control Fish, by Robert E. Lennon and 

Bernard L. Berger. 1970. 19 pp.

(Reports 41 through 43 are in one cover.)

41. Identification of MS-222 Residues in Selected Fish Tissues by Thin Layer Chromatography, by 

John L. Alien, Charles W. Luhning, and Paul D. Harman. 1970. 7 pp.

42. Dynamics of MS-222 in the Blood and Brain of Freshwater Fishes During Anesthesia, by 

Joseph B. Hunn. 1970. 8 pp.

43. Effect of MS-222 on Electrolyte and Water Content in the Brain of Rainbow Trout, by Wayne A. 

Willford. 1970. 7pp.

44. A Review of Literature on TFM (3-trifluormethyl-4-nitrophenol) as a Lamprey Larvicide, by 

Rosalie A. Schnick. 1972. 31 pp.

(Reports 45 and 46 are in one cover.)

45. Residues of MS-222 in Northern Pike, Muskellunge, and Walleye, by John L. Alien, Charles W. 

Luhning, and Paul D. Harman. 1972. 8 pp.

46. Methods of Estimating the Half-Life of Biological Activity of Toxic Chemicals in Water, by Leif 

L. Marking. 1972. 9 pp.

(Reports 47 through 50 are in one cover.)

47. Preparation and Properties of Quinaldine Sulfate, an Improved Fish Anesthetic, by John L. 

Alien and Joe B. Sills. 1973. 7 pp.

48. Toxicity of Quinaldine Sulfate to Fish, by Leif L. Marking and Verdel K. Dawson. 1973. 8 

pp.

49. The Efficacy of Quinaldine Sulfate as an Anesthetic for Freshwater Fish, by Philip A. 

Gilderhus, Bernard L. Berger, Joe B. Sills, and Paul D. Harman, 1973. 9 pp.

50. Residue of Quinaldine in Ten Species of Fish Following Anesthesia with Quinaldine Sulfate, 

by Joe B. Sills, John L. Alien, Paul D. Harman, and Charles W. Luhning. 1973. 9 pp.

(Reports 51 and 52 are in one cover.)

51. Methods for Simultaneous Determination and Identification of MS-222 and Metabolites in 

Fish Tissues, by Charles W. Luhning. 1973. 10 pp.

52. Residues of MS-222, Benzocaine, and Their Metabolites in Striped Bass Following Anesthesia, 

by Charles W. Luhning. 1973. 11 pp.

Use of trade names does not imply U.S. Government endorsement of commercial products.
INVESTIGATIONS IN FISH CONTROL

71. Field Tests of Isobornyl Thiocyanoacetate (Thanite) for 

Live Collection of Fishes

By Ralph M. Burress 

Philip A. Gilderhus 

Kenneth B. Gumming

United States Department of the Interior 

Fish and Wildlife Service

Washington, B.C. 1976
Contents

Page

ABSTRACT ................................................................ 1

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

MATERIALS AND METHODS ............................................. 2

RESULTS .................................................................. 2

McGraw Pond, Dundee, Illinois ........................................... 2

Barnes Pond, Merrillville, Georgia......................................... 5

Watkins Pond, Morganville, Alabama ..................................... 7

Scott Ponds A and B, Montgomery, Alabama ............................. 7

Reeves Pond, Greenville, Georgia.......................................... 8

Ebert Pond, West Salem, Wisconsin ....................................... 9

West Sunken Camp Lake, Ashland, Wisconsin............................. 10

DISCUSSION .............................................................. 11

ACKNOWLEDGMENTS.................................................... 12

LITERATURE CITED...................................................... 12
FIELD TESTS OF ISOBORNYL THIOCYANOACETATE (THANITE)

FOR LIVE COLLECTION OF FISHES

by

Ralph M. Burress

Southeastern Fish Control Laboratory, P.O. Box 9 

Warm Springs, Georgia 31830

Philip A. Gilderhus and Kenneth B. Gumming

Fish Control Laboratories, P.O. Box 862

La Crosse, Wisconsin 54601

Abstract

Eight ponds containing a total of 28 species of fish were treated with isobornyl 

thiocyanoacetate (Thanite) to test its efficacy for the live collection offish. Twenty-six species 

were collected alive after 1- to 4-#1/1 applications of Thanite. Most scalefishes except carp 

(Cyprinus carpio) were relatively easy to collect, and catfishes (Ictaluridae) were generally the 

most resistant to effects of the chemical. With the exception of northern pike (Esox lucius), most 

fish recovered quickly after being placed in fresh water. Most fish collected within 1.5 h after 

treatment survived, but survival rates decreased with time of exposure. The concentrations 

effective for collection of live fish did not routinely eliminate all fish; small numbers of at least 

eight species offish survived treatments of 1.5 H 1/1 or more. The high percentages offish (of 

most species) collected alive demonstrated that Thanite is effective for the intended purpose.

Introduction

The development of a safe, efficacious, and relatively inexpensive chemical that would permit the live 

collection of desirable fishes from a body of water 

would be of distinct benefit to fishery management 

programs. The availability of a chemical that 

facilitated live collection would make it possible to 

harvest predator fish at comparatively low cost. 

Sport fishing could benefit in yet another way: 

desirable fishes that are otherwise lost when ponds 

and lakes are renovated or when flood waters dry up 

could be salvaged for stocking in public fishing areas.

Various investigators have tested many compounds to determine their advantages and 

limitations as collecting aids: cresol (Embody 1940; 

Wilkins 1955; Rowland 1969); sodium sulfite (Westman and Hunter 1956); sodium sulfite catalyzed with 

cobalt chloride (Vanderhorst and Lewis 1969); 

sodium cyanide (Lewis and Tarrant 1960; Tatum 

1969); fresh walnut hull extracts (Westfall et al. 1961); 

LSD-25 (Loeb 1962); derivatives of d-lysergic acid

(Loeb et al. 1965); rotenone (Tate et al. 1965); rotenone 

followed by immediate immersion of treated fish in a 

solution of methylene blue (Bouck and Ball 1965); 

Aqualin (Louder and McCoy 1965); eight anesthetics, 

including Anileridine, Tribromoethanol, Ethinamaie, and RO 40403 (Blanchard 1966); and isobornyl 

thiocyanoacetate, or Thanite (Lewis 1968; Buckner 

and Perkins 1975; Burress and Bass 1975). Factors 

that must be considered in evaluating the potential 

usefulness of such compounds include efficacy, cost, 

availability, effects on target and nontarget 

organisms, rate of degradation, and hazards to users. 

Thanite (82% isobornyl thiocyanoacetate and 18% 

other active terpenes) is an insecticide with low 

mammalian toxicity (Hercules Powder Company 

1962). It has been widely used for some 30 years to 

control common household pests and external human 

parasites. Lewis (1968), who was the first to use 

Thanite for the live collection of fishes, reported 

excellent results in collecting largemouth bass 

(Micropterus salmoides) from two ponds in southern 

Illinois. In 1968, Buckner and Perkins (1975) began
using Thanite in the management of ponds in 

southwestern Georgia. They collected and moved 

2,000 to 4,000 largemouth bass annually and made 

live collections of at least 14 other species of fish. 

Burress and Bass (1975) collected largemouth bass 

and 12 other species alive from two ponds in Florida 

and reported that Thanite was relatively safe and 

inexpensive.

The field trials reported here were conducted 

primarily to document the efficacy of Thanite as an 

aid in the live collection of fish and to facilitate the 

process of registering the compound with the U.S. 

Environmental Protection Agency (EPA) for that 

use. These efficacy tests were conducted in four 

states, in eight ponds with different physical, 

chemical, and biological characteristics (Table 1).

Materials and Methods

The general methods and procedures described by 

Burress and Bass (1975) were used in mixing and 

applying Thanite solutions; collecting, holding, and 

measuring (total length) live fish; collecting and 

counting fish killed by the Thanite treatment; and 

later treating the waters with a fish toxicant. The 

formulation used in six of the eight ponds consisted of 

Thanite, kerosene, and the emulsifier Atlox 1045A 

mixed in a ratio of 70:20:10 parts by volume. The other 

formulations used consisted of an 80:20 mixture of 

Thanite and Atlox 1045A in EbertPond, and an 80:20 

mixture of Thanite and Atlox 3408F in West Sunken 

Camp Lake. Additional information on minor 

variations in methodology, descriptions of the ponds, 

and environmental or other factors that influenced 

test results is included with the results to facilitate 

discernment of possible cause and effect 

relationships. The species of fish present in the 

various ponds are listed in Table 2. During the 

treatment and collection periods, we also tried to 

observe the effects of Thanite on macroscopic 

nontarget organisms.

Results

Fish that were exposed to effective concentrations 

of Thanite tended to surface in distress and swim 

about in a disoriented manner. About 20% of them 

reacted by jumping or briefly skittering across the 

pond surface. As sedation deepened, many fish 

moved toward shore. Some sought cover while others 

floated listlessly at the surface or settled to the 

bottom. In general, small fish were affected first and 

died sooner than large ones. Occasionally, a large 

fish in noticeably poor physical condition surfaced 

before healthy young fish were sedated. Low 

temperatures slowed responses and delayed the onset

of mortality, enabling pickup crews to cover larger 

areas more effectively. Fish that were collected in 

early stages of sedation recovered quickly after being 

placed in fresh water, but recovery times and 

mortality rates increased as exposures lengthened. 

Additional observations in each of the eight ponds 

are detailed in the following sections.

McGraw Pond, Dundee, Illinois

This pond, on property of the Max McGraw Wildlife Foundation, was the only pond not of conventional construction. It was C-shaped, contained three 

islands, and had been dug with bulldozers. The 

bottom was covered with deposits of soft muck 

overlying a substrate of coarse gravel that contained 

a mixture of rocks 15 to 20 cm in diameter. Parrot 

feather (Myriophyllum sp.) was distributed along 

most of the shoreline to a depth of 1.2 m. Before 

treatment, the water level was lowered about 35 cm to 

prevent overflow of the treated water. At this lowered 

level, the pond had a surface area of 2.83 ha. We 

treated a 0.61-ha section at the deeper end, which was 

blocked off with a net (1.3-cm mesh, stretched 

measure).

We made three applications in a period of 2 h to 

observe the response of six species of fish (Table 2) 

to increasing concentrations of Thanite. The 

cumulative concentrations produced by successive 

applications were 0.8, 1.2, and 1.6/A 1/1. Differences 

between the methods followed in this test and those 

described by Burress and Bass (1975) included the use 

of a pump to apply Thanite to the pond surface; a 

search of the pond bottom by divers for both living 

and dead fish on the second day after treatment; 

retention of captured fish in live cages in an adjacent 

pond for 24 h to evaluate their survival; and the use of 

antimycin to eradicate the fish remaining in the 

pond. Four boats operated by two-man crews were 

used to collect fish as they surfaced during the 3.5 h 

after the first application. The average area covered 

by each crew was 0.15 ha.

The first application of Thanite (0.8/A 1/1) was too 

light to be effective, but the second (0.4/u, 1/1 applied 

below the surface in deep water) quickly facilitated 

collection of numerous sunfish and intermediatesized bass. A third application (0.4 ju, 1/1, at the 

surface) was needed, however, before adult sunfish 

and large bass were affected. Many sunfish were 

captured along the block net, and numerous small 

white crappies were gilled in it. Wind-induced 

currents carried Thanite beyond the net, and distressed crappies were seen 6 m beyond the treated 

area. No fish were killed in the untreated area, 

however, suggesting that Thanite can safely be used 

to collect fish from selected areas of larger bodies of 

water.
Table 1. Physical and chemical characteristics of ponds treated with Thanite.

Pond, and month 

and year of 

treatment

McGraw Pond

(10/72)

Barnes Pond

(1/74)

( Watkins Pond

(1/74)

Scott Pond A

(2/74)

Scott Pond B

(2/74)

Reeves Pond

(2/74)

Ebert Pond

(10/74)

West Sunken

Camp Lake (6/75)

Surface 

area

(ha)

0.61

0.47

0.32

0.30

1.30

0.49

0.81

1.21

- Depth (m)

Average

1.52

1.07

0.98

0.67

1.24

1.58

1.25

2.52

Maximum

2.13

1.82

1.82

1.59

2.58

3.04

2.75

4.87

Volume

9,251

5,033

3,121

2,072

16,302

7,907

10,135

30,837

Temperature (°C)

Surface

16.0

13.9

15.0

13.5

13.5

8.5

15.0

20.0

Bottom

13.9

10.0

13.0

13.0

12.7

8.5

12.0

16.5

Secchi disk 

transparency

(cm)

53.3

10.2

10.2

15.2

30.4

3.8

67.0

256.5

pH a

surfa

8.2

7.0

8.0

9.3

9.3

6.9

7.5

6.4

1 Not measured.
Table 2. Species of fish present in ponds treated with Thanite, 1972-75a.

McGraw Barnes Watkins Scott Scott Reeves Ebert West Sunken" 

Species Pond Pond Pond Pond A Pond B Pond Pond Camp Lake

Centrarchidae

Largemouth bass XXXXXXS S 

(Micropterus salmoides)

Bluegill XXXXXXXS 

(Lepomis macrochirus)

Redear sunfish XX X 

(Lepomis microlophus)

Pumpkinseed S 

(Lepomis gibbosus)

Green sunfish X X 

(Lepomis cyanellus)

Rock bass S 

(Ambloplites rupestris)

White crappie X 

(Pomoxis annularis)

Black crappie S 

(Pomoxis nigromaculatus)

Warmouth X 

(Lepomis gulosus)

Dollar sunfish X 

(Lepomis marginatus)

Ictaluridae

Channel catfish XX X S 

(Ictalurus punctatus)

Brown bullhead X S X 

(Ictalurus nebulosus)

Yellow bullhead X 

(Ictalurus natalis)

Black bullhead X 

(Ictalurus melas)

Cyprinidae

Golden shiner XXX X 

(Notemigonus crysoleucas)

Carp X 

(Cyprinus carpio)

Percidae

Walleye S 

(Stizostedion vitreum vitreum)

Yellow perch X X 

(Perca flavescens)

Esocidae

Northern pike S 

(Esox lucius)
Table 2. Species offish present in ponds treated with Thanite, 1972-75 a. (Continued)

Species

McGraw Barnes Watkins Scott Scott Reeves Ebert West Sunken** 

Pond Pond Pond Pond A Pond B Pond Pond Camp Lake

Chain pickerel 

(Esox niger)

Redfin pickerel 

(Esox americanus americanus)

Catostomidae

White sucker

(Catostomus commersoni)

Redhorse 

(Moxostoma spj

Lake chubsucker 

(Erimyzon sucetta)

Clupeidae

Gizzard shad 

(Dorosoma cepedianum)

Poecilliidae

Mosquitofish

(Gambusia affinis)

Salmonidae

Chinook salmon 

(Oncorhynchus tshawytscha)

S= stocked within 2 to 6 weeks before treatment; X= long-term residents of the waters treated.

Two bullheads of undetermined species and one longnose sucker (Catostomus catostomus) stocked in West Sunken Lake 

are not included in the test or tables. The bullheads were found dead after treatment; the longnose sucker was not 

recovered.

The primary objective of the pickup crews was to 

collect every largemouth bass that could be captured; 

they collected 89% of the total population (Table 3). 

Forty-four of 50 largemouth bass and 2 of 3 white 

crappies considered to be large enough for table use 

(more than 20 cm long) were collected alive. Of the 

total of 62 bass collected, 60 survived for 24 h.

The Thanite treatment killed all uncollected 

centrarchids, yellow perch, and some carp up to about 

30 cm long. (No attempt was made to collect sedated 

or dead carp.) A 5-ji g/1 antimycin treatment applied 

3 days later killed the remaining carp, but no other 

fish were found.

Barnes Pond, Merrillville, Georgia

Thirteen species of fish were found in this highly 

fertile pond. The bottom was soft mud, and wading 

cows had roiled the water. Aquatic macrophytes were 

virtually absent, but the pond surface was covered by

a distinct bloom of blue-green algae. The first Thanite 

application of 1 /x 1/1 was used to facilitate collection 

of the more susceptible scalefishes. Two additional 

1-//1/1 treatments were made within 3 h in an effort to 

collect brown bullheads, yellow bullheads, and 

channel catfish. Intermittent showers and Winds 

occurred during the treatment but the pond did not 

overflow. Three pickup crews, each covering about 

0.16 ha, collected fish for 4.5 h.

The combination of excessive turbidity (Secchi disk 

transparency about 10 cm), intermittent rain, and 

wind greatly hampered visibility and markedly 

reduced success in capturing fish (Table 4). The 

following percentages of bass and sunfish longer 

than 12.7 cm were collected: largemouth bass, 56; 

bluegill, 62; redear sunfish, 52; and warmouth, 43. 

Nearly all were collected after the first treatment 

(1 /j. 1/1). Percentage mortalities of the fish within 3 h 

after collection were as follows: bass, 0; bluegill, 4; 

redear sunfish, 2; and warmouth, 6. We captured two
Table 3. Numbers and percentages offisha collected alive or recovered dead in a 0.61-ha section ofMcGraw 

Pond after a 1.6-fj.l/l treatment with Thaniteb on 16 October 1972.

Fish

Species

Largemouth bass

White crappie

Bluegill

Green sunfish

Yellow perch

Total

Length

range (cm)

7-60

7-40

3-20

3-20

10-20

captured

Number

62

540

275

46

3

926

alive

Percent

89

68

75

82

100

72

Number recovered

dead

8

260

91

10

0

369

Carp were killed by Thanite and antimycin treatments, but were not collected.

Three applications of Thanite (0.8, 0.4, and 0.4 p 1/1) were made during a period of 2 h.

Table 4. Numbers and percentages of fish collected alive or recovered dead in Barnes Pond after a 3.0-ftl/l

treatment with Thanitea on 7 January 1974.

Species

Largemouth bass

Bluegill

Redear sunfish

Warmouth

Dollar sunfish

Chain pickerel

Redfin pickerel

Lake chubsucker

Golden shiner

Mosquitofish

Channel catfish

Brown bullhead

Yellow bullhead

Total

Length 

range (cm)

7-40

3-20

3-20

3-20

3-12

15-20

10-30

20-30

5-15

3- 5

40-60

10-25

10-20

Fish 

captured

Number

5

810

480

2,139

10

0

2

111

640

205

0

7

2

4,411

alive

Percent

50

28

56

33

23

0

100

68

15

29

0

3

100

28

 JN um ber recovered

dead

5

2,053

374

4,398

34

6

0

53

3,659

512

3

225

0

11,323

Three 1-//1/1 applications of Thanite made during a period of 3 h killed the entire fish population.
redfin pickerel, the only ones present, but six small 

chain pickerel were not collected alive. Dollar 

sunfish, lake chubsucker, golden shiner, and mosquitofish also were collected alive after the first 

application. Additional golden shiners, lake chubsuckers, and some small bullheads (both yellow and 

brown) were collected after the second treatment 

(ljul/1) was applied. The third treatment (ljul/1) 

brought up additional golden shiners and brown 

bullheads, but no live channel catfish were observed. 

However, the Thanite treatment killed the entire fish 

population, as shown by the negative results of a 

2-jul/l treatment of rotenone several days later.

Watkins Pond, 

Morganville, Alabama

Five species of fish were present in this pond, and 

we stocked brown bullheads before the test. The pond 

was highly turbid and lacked aquatic plants. Again, 

we applied 1 /A 1/1 at the beginning of the study and a 

2-jul/l treatment 2.5 h later, in an effort to collect the 

catfish. Rain and gusty winds struck before the 

second treatment was applied. Fish were collected by 

two pickup crews (0.16 ha per crew) over a period of 

4.5 h.

Although difficulties with turbidity, wind, and rain 

were much the same as those encountered during the 

treatment of Barnes Pond, substantially higher 

percentages of the scalefishes longer than 20 cm 

were collected (Table 5). The improvement in success 

was largely due to the smaller total number offish in 

the pond. Of the "catchable" sized fish, 82% of the 

bass, 89% of the bluegills, 100% of the redear sunfish, 

and 64% of the channel catfish were captured alive. 

Nearly all of the scalefishes and about 3% of the 

brown bullheads were captured after the initial

treatment with 1 ju, 1/1 of Thanite. About an equal 

number of bullheads were collected alive after the 

2-jul/l treatment and an additional 27.6% were killed 

by the Thanite. Later treatment with 2/xl/l of 

rotenone killed no additional scalefish, but killed the 

remaining 135 brown bullheads.

Scott Ponds A and B, 

Montgomery, Alabama

The water level in Scott Pond had been lowered by 

about 1.2 m several months before our trial. The 

reduction in water level created two isolated ponds 

identified here as Pond A and Pond B. Both had mud 

bottoms and lacked aquatic vegetation. Pond/A 

contained only largemouth bass, bluegills, and 

golden shiners; Pond B contained these species and a 

few gizzard shad. A 1-yul/l Thanite treatment was 

applied in Pond A at noon, and a similar treatment 

was added 2 h later to aid in the collection of large 

golden shiners. Three crews (0.10 ha per crew) 

collected fish for about 3.5 h. A single 1-jul/l treatment was applied in Pond B and four cretvs (0.33 ha 

per crew) collected fish for about 2.5 h.

Excellent results were achieved in Scott Pond A, 

where 99.6% of the total fish population was collected 

alive (Table 6). The weather was almost ideal clear, 

calm, and relatively cool. Furthermore, each pickup 

crew had to cover an area of only 0.10 ha, the total 

fish population was low, and the response of the fish 

was optimal for live collection; many of them swam 

slowly at the surface or quietly nosed up to the bank 

as sedation deepened. Most fish were collected alive 

after the first treatment (lyul/1), but a few of the 

largest bluegills and golden shiners were captured 

after the second 1-jul/l application. Mortality of the 

fish in the holding tank was negligible during the 6 h

Table 5. Numbers and percentages offish collected alive or recorded dead in Watkins Pond aftera3.0-fJi.l/l

treatment with Thanitea on 28 January 1974.

Species

Largemouth bass

Bluegill

Redear sunfish

Green sunfish

Channel catfish

Brown bullhead

Total

Length

range (cm)

30-40

3-20

3-20

7-15

20-50

12-20

Fish 

captured alive

Number

9

449

63

3

9

12

545

Percent

82

21

100

100

64

6

22

Number recovered

dead

2

1,701

0

0

lb

56b

1,760

L Two applications of Thanite (1.0 and 2.0/il/l) were made during a period of 3 h.

' Number of dead fish does not include 4 channel catfish and 135 brown bullheads killed with rotenone after treatment with 

Thanite.
Table 6. Numbers and percentages of fish collected alive or recovered dead in Scott Pond A after a 2-/J.I/1

treatment with Thanitea on 4 February 1974.

Species

Largemouth bass 

Bluegill 

Golden shiner 

Total

range (cm)

40-50 

3-20 

5-15

Fish 

captured alive

Number Percent

1 100 

969 100 

44 92 

1,014 >99

dead

0 

0

0

a Two l-jij/l applications of Thanite were made during a period of 2 h. 

Number of dead fish does not include four golden shiners that were killed by rotenone after treatment with Thanite.

after collection. No dead fish were found in the pond 

after the Thanite application, and a 2-^1/1 rotenone 

treatment several days later killed only four adult 

golden shiners.

The reaction of fish to the 1-ju.l/l treatment in Scott 

Pond B appeared to be nearly optimal, but a 

combination of unfavorable circumstances resulted 

in live collection of only 43% of the total fish 

population (Table 7). The numerous shoal areas 

hampered free movement of the boats, each pickup 

crew had to cover about 0.33 ha, and collection efforts 

had to be terminated prematurely because of 

darkness. We captured 44% of the catchable sized 

bass. Six of nine bass not collected alive were large 

fish, not adequately sedated by the 1-fil/l dose. Of the 

bluegills longer than 20 cm, 43% were collected alive 

and the rest were killed by the treatment. Fewer than 

1% of the golden shiners were collected alive; those 

that were left apparently were not harmed, as none 

were found dead until after the rotenone treatment. 

The entire population of gizzard shad (30 fish) was 

collected alive, and all survived a 2-h confinement in 

a heavily loaded recovery tank. Recovery of other

fishes in the holding tank was excellent and mortalities were negligible during the 2 h after collection. 

Later application of a 2-/xl/l treatment of rotenone 

killed the following percentages of each species 

originally present: largemouth bass, 37.5; bluegills, 

0.5; and golden shiners, 90.9.

Reeves Pond, Greenville, Georgia

We treated this pond primarily to determine what 

effect extreme turbidity might have on the efficacy of 

Thanite. Silt washed into the pond by heavy rains 

had reduced Secchi disk transparency to less than 

4 cm. A trickle of water flowed through the pond 

throughout the field trial. The pond contained no 

aquatic plants. The first treatment was limited to a 

1-fj.l/l concentration, and 2.5 h later a 3-yul/l treatment was applied to facilitate the collection of catfish. 

Three crews (0.16 ha per crew) collected fish for 4 h. 

Conditions for collecting fish were less than ideal; 

extreme turbidity and glare greatly hampered 

visibility.

Table 7. Numbers and percentages of fish collected alive or recorded dead in Scott Pond B after a 1-fj.l/l

treatment with Thanite on 4 February 1974.

Species

Largemouth bass

Bluegill

Golden shiner

Gizzard shad

Total

Length

range (cm)

30-50

3-20

5-15

10-45

Fish

captured alive

Number Percent

7 44

2,814 43

3 <1

30 100

2,854 43

,

dead

3a

3,748Oa

0

3,751

Number of dead fish does not include 6 largemouth bass, 30 bluegills, and 327 golden shiners that were killed by rotenone 

after treatment with Thanite.
The live collection of fish longer than 20 cm was 

regarded as successful despite the turbidity; 69% of 

the bass, 100% of the bluegills, and 50% of the redear 

sunfish were captured after the application of the 

1-//.1/1 treatment (Table 8). A few small brown 

bullheads (100-125 mm) also were taken. The addition of a 3-fil/l treatment 3 h after the first resulted in 

collection of a 1.8-kg channel catfish, but no other 

fish were observed. Mortality of fish during a 3-h 

period in the recovery tank was negligible. The 

Thanite treatment killed all fish in the pond except 

seven brown bullheads, which were killed when 2 ^u 1/1 

of rotenone was applied later. These fish apparently 

survived in a small flow of spring water at the 

extreme upper end of the pond. On the day after 

treatment, a hatch of small mayflies was observed, 

but many died before they could leave the water.

Ebert Pond, West Salem, Wisconsin

Ebert Pond was chosen to evaluate the activity of 

Thanite in hard, fertile water against northern 

strains of fish. Dense, marginal stands of sago 

pondweed (Potamogeton pectinatus) occurred in 

shallow water, which included about 25% of the total 

pond area. Moderate amounts of duckweed (Lemna 

minor) and unidentified filamentous algae were 

interspersed throughout the vegetated area. The pond 

initially contained a population of black bullheads 

and bluegills; in addition, 100 chinook salmon, 15 

channel catfish, and 109 largemouth bass were 

stocked 6 weeks before treatment. The pond was 

treated once with an 80:20 mixture of Thanite and 

Atlox 1045A surfactant to give a concentration of 

1.5 fj. 1/1 of Thanite. The chemical was applied to the 

deeper open water with a pump and weighted hose

and to the weedy perimeter with backpack pumps.

Although the application required only a half hour, 

chinook salmon, bluegills, and largemouth bass were 

surfacing by the time the application was completed. 

Bullheads and channel catfish were not seen until 

5 h later and none were captured. Salmon and 

centrarchids were easily captured with dip nets. We 

did not attempt to capture all of the bluegills because 

of the large number present, but collected 90 kg (35% 

of the total weight), of which 51 kg were placed in 

fresh water for recovery. This amount severely 

overloaded the two 378-liter recovery tanks and 

caused significant stress. Data on collection, 

recovery, and mortality of fish are given in Table 9. 

The failure of some fish to recover was probably due 

to oxygen deficiency in the tanks caused by 

overloading. The high percentage of stocked fish not 

accounted for indicated that many of them died 

between stocking and the time of treatment.

After the fish had recovered their equilibrium in the 

recovery tanks, representative samples of salmon, 

bluegills, and bass were loaded in an aerated tank 

and hauled 16 km to the laboratory. This trip 

required 25 min. Survival of these fish 5 days later 

was 100% for 6 salmon and 11 bass and 69% for 584 

bluegills. The trial in Ebert Pond demonstrated the 

need for adequate recovery tanks to handle unexpectedly large numbers of fish.

The time required for the 1.5-jul/l concentration of 

Thanite to degrade was determined by conducting onsite toxicity tests with caged bluegill fingerlings. On 

the 10th day after the treatment, 10 fingerling 

bluegills were placed in a live cage in the pond; 7 died 

by day 12. A second lot of 10 bluegills was placed in 

the pond on day 12 and a third lot on day 13. Two fish 

of the second lot, but none of the third, died by day 16. 

Thus, the Thanite had degraded to a nontoxic level by 

the 13th day after application.

Table 8. Numbers and percentages offish collected alive or recovered dead from Reeves Pond after a 4-pl/l

treatment with Thanitea on 12 February 1974.

Fish.

Species

Largemouth bass

Bluegill

Redear sunfish

Channel catfish

Brown bullhead

Total

Length

range (cm)

10-50

3-20

3-20

40-50

10-20

captured

Number

39

137

208

1

5

390

alive

Percent

83

1

47

50

6

4

dead

8

10,087

237

1

67b

10,400

Two applications of Thanite (1.0 and 3.0fji 1/1) were made during a period of 3 h.

Number of dead fish does not include seven brown bullheads that were killed by rotenone after treatment with Thanite.
10

Table 9. Sizes and numbers offish collected alive and recovered dead in Ebert Pond after a 1.5-^1/1 treatment 

with Thanite on 30 October 1974, and survival offish transported to a laboratory raceway after recovery.

Length (cm) of fish 

captured alive Number of fish in treated pond

Fish hauled to laboratory 

raceway after recovery

Species

Chinook salmon

Bluegill

Largemouth bass

Channel catfish

Black bullhead

Average

20.2

10.1

16.5

Not

Not

Range

18.0-23.0

7.0-14.0

13.5-21.0

measured

measured

Stocked

100

Oa

109

15O a

Collected

alive

12

4,914

19

0

0

Recovered

dead

2

13,925

23

2

25

Unaccounted

for

86,b

67

13

-b .

Number

6

584

11

0

0

Survival

after 5

days (%)

100

69

100

Existing population in pond. 

Not known.

The pond was treated with rotenone (3.1 /* 1/1 of 5% 

formulation) 1 year after the Thanite treatment. This 

treatment was delayed to accommodate studies on 

recovery of invertebrate populations. The toxicant 

killed 363 kg of bullheads 5 to 36 cm long and 1.8 kg 

of bluegills 3 to 12 cm long, indicating that the 

1.5-jul/l Thanite treatment killed less than 1% of the 

bullheads, but about 99% of the bluegills.

West Sunken Camp Lake, 

Ashland, Wisconsin

We treated this small lake to assess the efficacy of 

Thanite for collecting northern species offish in very 

soft, acid water. The water was much clearer than 

other waters studied (Table 1); the bottom was devoid 

of vegetation. The lake was connected to East Sunken 

Camp Lake by a narrow neck of shallow water, which

was closed with a plastic barrier before treatment to 

prevent circulation of water. Large numbers of golden 

shiners (7-12 cm long), yellow perch (8-16 cm), and 

white suckers (14-20 cm) were resident in the lake. 

The lake was stocked with the following species, of 

various sizes (Table 10), by the Wisconsin Department of Natural Resources about 2 weeks before the 

trial: redhorse, northern pike, bullhead, rock bass, 

pumpkinseed, bluegill, largemouth bass, black crappie, and walleye. Fish collected during the trial were 

placed in live cages in the untreated section to assess 

their survival for 24 h after collection.

A single 1.5-jul/l Thanite treatment was applied, 

but the chemical formulation and the application 

procedure were somewhat different from those 

previously used. The Thanite stock solution consisted 

of an 80:20 mixture by volume of Thanite and Atlox 

3408F, a surfactant used to replace the Atlox 1045A 

previously employed in making stock solutions. The

Table 10. Numbers, sizes, and percentages of stocked fish collected alive and recovered dead in West Sunken 

Camp Lake after a 1.5-fil/l treatment with Thanite on 10 June 1975.

Species

Redhorse

Northern pike

Rock bass

Pumpkinseed

Bluegill

Largemouth bass

Black crappie

Walleye

Length 

range 

(cm)

22-24

22-100

14-26

10-15

10-22

12-40

13-30

16-71

Number 

stocked

4

15

54

63

120

49

13

17

Captured alive

Number

2

9

31

49

89 '

46

7

13

Percent3

50

64

72

83

81

95

54

81

Weight (kg)

0.1

3.8

3.5

3.5

6.7

8.8

0.7

11.8

Recovered dead"

Number

2

5

.12

10

21

2

6

3

Weight (kg)

1.2

3.6

1.9

0.5

1.1

0.5

1.4

0.5

Percent of the total number recovered, both living and dead. 

Preceding application of antimycin.
11

stock solution was diluted about 5:1 with water, and 

was divided into three 115-liter portions. The first was 

applied in a crisscross pattern at a depth of about 30 

to 60 cm; the second was applied to the deeper part of 

the lake with a weighted hose which distributed the. 

material at depths of 3.0 to 3.7 m; and the third was 

divided between deep and shallow water. The 

distribution unit consisted of a small boat, a small 

outboard engine, a submersible pump with control 

valve in the chemical container, and a weighted hose 

that hung over the stern of the boat. Fish were 

collected by three or four men wading in shallow 

water and by two two-man crews in boats in the 

deeper water. The fish were placed in tubs of fresh 

water and delivered to the recovery cages within 20 

min after capture. Fish were placed in four cages, 

according to the time elapsed after completion of the 

treatment. The time periods were the first, second, 

and third half-hours, and from 1.5 to 3.0 h posttreatment. Major effort was devoted to capturing 

game fish, but large numbers of other fishes were also 

taken. Weather (clear and calm) and water conditions 

were ideal for capturing fish.

Application of the Thanite required 1 h, and the 

first yellow perch were captured within 10 min after 

completion of the treatment. Shortly thereafter, 

sunfishes and walleyes were netted, but the more 

resistant golden shiners, white suckers, and northern 

pike showed no signs of sedation for nearly 1.5 h. 

Captures increased with time after treatment; more 

than twice as many fish were collected during the 

second 1.5-h period of netting as in the first 1.5 h. All 

game fishes taken alive were collected within 3 h 

after treatment. All of 408 fish (except 1 bluegill)

collected in the first 1.5 h survived. After that, 

survival appeared to decrease with increasing length 

of exposure. Survival rates of most game species were 

excellent, ranging from 76% for walleyes to 93% for 

largemouth bass (Table 11). Northern pike were an 

exception in that none of nine survived, even though 

they were collected alive.

Sunfishes, largemouth bass, and walleyes were 

especially susceptible to capture; the percentages 

collected ranged from 74 to 94 (Table 10). The range of 

sensitivity between individuals appeared to be wider 

in certain other species such as rock bass and black 

crappie (collection rates near 50%); some were quickly 

affected and easily netted, whereas others were not 

seen until they were found dead in shallow water the 

day after treatment. Some white suckers and golden 

shiners were still alive in the lake 21 h after 

treatment, and a number of suckers were seen 

thrashing about at the surface. However, there was 

no sign of live fish 24 h after treatment. Except for 

about a 90% mortality of 1-cm frog tadpoles in the 

shallow water near the barrier, no mortality of 

nontarget organisms was noted.

The lake was treated with a 7.5# g/1 application of 

antimycin about 4 weeks later. Fish killed by the 

antimycin included 221 golden shiners, 15 white 

suckers, 1 bluegill, and 11 yellow perch.

Discussion

Application of 1.0- to 1.6-/*1/1 treatments of Thanite 

proved to be efficacious for collecting many sizes of 

several species of sport fish under a wide variety of

Table 11. Fish captured alive at selected time intervals after treatment of West Sunken Camp Lake with

Thanite, and percentage survival 24 h after capture.

Time after treatment (h)

0-0.5

Species

Golden shiner

White sucker

Redhorse

Northern pike

Rock bass

Pumpkinseed

Bluegill

Largemouth bass

Black crappie

Yellow perch

Walleye

Number

collected

0

0

1

0

4

11

5

2

2

35

3

Survival

(%)

100

100

100

80

100

100

100

100

0.5-1.0

Number

collected

0

0

0

0

4

6

13

9

1

91

6

Survival

(%)

100

100

100

100

100

100

100

1.0-1.5

Number

collected

5

6

1

1

7

8

25

13

3

45

1

Survival

(%)

100

100

100

0

100

100

100

100

100

100

100

1.5-3.0

Number

collected

293

113

0

8

16

24

46

22

1

188

3

Survival

(%)

61

83

0

81

71

80

86

0

47

0

Total

survival

(%)

61

89

100

0

90

86

88

93

85

72

76
12

conditions. Bluegills, white crappies, dollar sunfish, 

and yellow perch were the most sensitive to Thanite. 

Redear sunfish, warmouths, green sunfish, 

largemouth bass, gizzard shad, lake chubsuckers, 

and walleyes were somewhat less sensitive. Golden 

shiners, mosquitofish, carp, chain pickerel, and 

redfin pickerel were moderately resistant, and catfishes were the most resistant. Channel catfish were 

less resistant than brown or yellow bullheads; yellow 

bullheads were the most resistant species tested.

Northern pike were observed in only one test, but 

their reaction was unique. Of 15 fish stocked in West 

Sunken Camp Lake, only 9 were captured alive and 

none survived for 24 h after being transferred to 

fresh water. Apparently the fish absorbed a lethal 

dose of chemical before they became sufficiently 

sedated to be vulnerable to netting.

One recommendation regarding the use of Thanite 

should be added to the general guidelines suggested 

by Burress and Bass (1975). If, for example, 

largemouth bass of widely varying sizes are collected, 

the application of a 1-/X.1/1 treatement followed by a 

second application of 0.5/A 1/1 could apparently be 

expected to give good results. In our trials, the first 

treatment was strong enough to produce good 

sedation and still permit rapid recovery of small fish; 

the later boost in concentration usually affected the 

more resistant large fish within a short time. If only 

large fish are sought, a single application of 1.5 to 

2.0/A 1/1 should suffice.

Channel catfish can be collected alive with high 

concentrations of Thanite. However, additional 

research will be required to determine the concentrations needed under different environmental conditions. Bullheads appear to be so resistant to 

Thanite that their live collection is not economically 

feasible.

We believe that Thanite has many advantages as 

an aid in the live collection of fish. It is safe and 

convenient to handle and apply. Concentrations of 

2 /JL 1/1 or less are required to effect prompt response of 

numerous species of fish, and degradation of the 

compound to nontoxic levels occurred within about 2 

weeks in Ebert Pond (the only water in which such 

test was conducted). Variations in pH, temperature, 

hardness, conductivity, and turbidity appeared to 

have little effect on efficacy. However, treatment at 

low temperatures tended to reduce mortality. Survival of fish (other than northern pike) that were 

collected and placed in fresh, well aerated water 

within 2 h after treatment was excellent. Although 

Thanite was clearly effective for collecting several 

species of fish, its efficacy for collecting largemouth 

bass was especially noteworthy: even though 

weather and water conditions were adverse in four of 

eight tests, we collected more than 83% of a total of 226 

bass (7-60 cm long) alive.

Acknowledgments

We thank the McLaughlin Gormly King Company 

of Minneapolis, Minnesota, for supplying the 

Thanite; ICI America Incorporated, Wilmington, 

Delaware, for providing the Atlox 1045A and 3408F; 

the Max McGraw Wildlife Foundation and pond 

owners Barnes, Ebert, Reeves, Scott, and Watkins for 

permission to use their ponds for experimental 

purposes; and G. V. Burger (Max McGraw Wildlife 

Foundation), W. W. Thomaston, and R. M. Gennings 

(Georgia Department of Natural Resources), S. L. 

Spencer (Alabama Department of Conservation and 

Natural Resources), and members of the Wisconsin 

Department of Natural Resources for their assistance 

in conducting the field work.

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Burress, R. M., and D. G. Bass. 1975. Thanite (isobornyl

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Embody, D. R. 1940. A method of estimating the number

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fish-collecting aids, with some toxicities for the isomers

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Lewis, W. M., and R. M. Tarrant, Jr. 1960. Sodium

cyanide in fish management and culture. Prog. FishCult. 22(4): 177-180. 

Loeb, H. A. 1962. Effect of lysergic acid diethylamide

(LSD-25) on the surfacing behavior of laboratory

carp. N.Y. Fish Game J. 9(2): 127-132. 

Loeb, H. A., H. H. Gettner, and H. A. Abramson. 1965. Effect of 48 derivatives of d-lysergic acid on

the surfacing behavior of laboratory fish. N. Y. Fish

Game J. 12(2): 79-98.
13

Louder, D. E., and E. G. McCoy. 1965. Preliminary Westfall, B. A., R. L. Russell, and T. K.

investigations of the use of aqualin for collecting Auyong. 1961. Depressant agent from walnut hulls.

fishes. Proc. Annu. Conf. Southeast. Assoc. Game Fish Science 134(3490): 1617.

Comm. 16(1962): 240-242. Westman, J. R., and J. V. Hunter. 1956. Preliminary

Tate, B., T. Moen, and B. I. Severson. 1965. The use of observations on the lowering of dissolved oxygen by

rotenone for recovery of live fish. Prog. Fish-Cult. sodium sulfite and its effects on certain fishes, with

27(3): 158-160. particular reference to problems in fish management.

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sodium cyanide in stream surveys. Proc. Annu. Conf. , Wilkins, L. P. 1955. Observations on the field use of cresol

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(Reports 53 through 55 are in one cover.)

53. Toxicity of Mixtures of Quinaldine Sulf ate and MS-222 to Fish, by Verdel K. Dawson and Leif 

L. Marking. 1973. 11 pp.

54. The Efficacy of Quinaldine Sulfate:MS-222 Mixture's for the Anesthetization of Freshwater 

Fish, by Philip A. Gilderhus, Beranrd L. Berger, Joe B. Sills, and Paul D. Harman. 1973. 9 

pp.

55. Residues of Quinaldine and MS-222 in Fish Following Anesthesia with Mixtures of Quinaldine 

Sulfate:MS-222, by Joe B. Sills, John L. Alien, Paul D. Harman, and Charles W. 

Luhning. 1973. 12 pp.

(Reports 56 through 59 are in one cover.)

56. Toxicity of the Lampricide 3-trifluoromethyl-4-nitrophenol (TFM) to 10 Species of Algae, by A. 

A. Maki, L. D. Geissel, and H. E. Johnson. 1975. 17 pp.

57. Acute Toxicities of 3-trifluoromethyl-4-nitrophenol (TFM) and 2',5-dichloro-4'-nitrosalicylanilide (Bayer 73) to Larvae of the Midge Chironomus tentans, by J. A. Kawatski, M. M. 

Ledvina, and C. R. Hansen, 1975. 7 pp.

58. Acute Toxicity of the Lampricide 3-trifluoromethyl-4-nitrophenol (TFM) to Nymphs of 

Mayflies (Hexagenia sp.), by C. R. Fremling. 1975. 8 pp.

59. Toxicity and Residue Dynamics of the Lampricide 3-trifluoromethyl-4-nitrophenol (TFM) in 

Aquatic Invertebrates, by H. O. Sanders and D. F. Walsh. 1975. 9 pp.

(Reports 60 through 62 are in one cover.)

60. Toxicity of the Lampricide 3-Trifluoromethyl-4-nitrophenol (TFM) to Nontarget Fish in Static 

Tests, by L. L. Marking and L. E. Olson. 1975. 27 pp.

61. Toxicity of the Lampricide 3-Trifluoromethyl-4-nitrophenol (TFM) to Nontarget Fish in FlowThrough Tests, by L. L. Marking. T. D. Bills, and J. H. Chandler. 1975. 9 pp.

62. Toxicity of the Lampricide 3-Trifluoromethyl-4-nitrophenol (TFM) to Selected Aquatic 

Invertebrates and Frog Larvae, by J. H. Chandler and L. L. Marking. 1975. 7 pp.

(Reports 63 through 66 are in one cover.)

63. Laboratory Efficacy of 3-Trifluoromethyl-4-nitrophenol (TFM) as a Lampricide, by V. K. 

Dawson, K. B. Gumming, and P. A. Gilderhus. 1975. 7 pp.

64. Effects of 3-Trifluoromethyl-4-nitrophenol (TFM) on Developmental Stages of the Sea 

Lamprey, by G. W. Piavis and J. H. Howell. 1975. 4 pp.

65. Accumulation and Loss of Residues of 3-Trifluoromethyl-4-nitrophenol (TFM) in Fish Muscle 

Tissue: Laboratory Studies, by J. B. Sills and J. L. Alien. 1975. 5 pp.

66. Residues of 3-Trifluoromethyl-4-nitrophenol (TFM) in a Stream Ecosystem after Treatment for 

Control of Sea Lampreys, by P. A. Gilderhus, J. B. Sills, and J. L. Alien. 1975. 5 pp.

67. Method for Assessment of Toxicity or Efficacy of Mixtures of Chemicals, by L. L. Marking and 

V. K. Dawson. 1975. 7pp.

68. Development and Evaluation of On-site Toxicity Test Procedures for Fishery Investigations, 

by R. M. Burress. 1975. 8 pp.

(Reports 69 and 70 are in one cover).

69. Toxicity of 3-trifluoromethyl-4-nitrophenol (TFM), 2',5-dichloro-4'-nitrosalicylanilide (Bayer 

73), and a 98.2 Mixture to Fingerlings of Seven Fish Species and to Eggs and Fry of Coho 

Salmon, by T. D. Bills and L. L. Marking. 1976. 9 pp.

70. The Freshwater Mussel (Anodonta sp.) as an Indicator of Environmental Levels of 3- 

trifluoromethyl-4-nitrophenol (TFM), by A. W. Maki and H. E. Johnson. 1976. 5 pp.

Fish Control Laboratories

Fish and Wildlife Service

U.S. Department of the Interior

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Interior has responsibility for most of our nationally owned public lands 

and natural resources. This includes fostering the wisest use of our land 

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environmental and cultural values of our national parks and historical 

places, and providing for the enjoyment of life through outdoor 

recreation. The Department assesses our energy and mineral resources 

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our people. The Department also has a major responsibility for American 

Indian reservation communities and for people who live in island 

territories under U.S. administration.

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