INVESTIGATIONS IN FISH CONTROL

72. Toxicity of Rotenone to Fish in Standardized 

Laboratory Tests

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.]

(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. Svendesen. 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. 7 pp.

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.

(Reports 53 through 55 are in one cover.)

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

L. Marking. 1973. 11 pp.

54. The Efficacy of Quinaldine Sulfate:MS-222 Mixtures for the Anesthetization of Freshwater 

Fish, by Philip A. Gilderhus, Bernard 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. 

12pp.

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

72. Toxicity of Rotenone to Fish in Standardized 

Laboratory Tests

By Leif L. Marking 

Terry D. Bills

United States Department of the Interior

Fish and Wildlife Service

Washington, D.C. 1976
Contents

Page

Abstract................................................................... 1

Materials and Methods..................................................... 1

Results .................................................................... 2

Toxicity to various species of fish ........................................ 2

Effects of temperature, water hardness, and pH on toxicity ............... 2

Toxicity of Noxfish to green eggs of rainbow trout........................ 2

Persistence of Noxfish in water .......................................... 6

Detoxification of Noxfish ................................................ 8

Toxicity of different formulations of rotenone............................. 8

Toxicity in flow-through tests ............................................ 8

Discussion................................................................. 10

References ................................................................. 11
Toxicity of Rotenone to Fish in Standardized 

Laboratory Tests

by 

Leif L. Marking and Terry D. Bills

Fish Control Laboratory, P.O. Box 862 

La Crosse, Wisconsin 54601

Abstract

Noxfish®, which contains 5% rotenone, was toxic to a variety of freshwater fish at 

concentrations ranging from 21.5 to 497 y g/1 in 96-h laboratory exposures. Goldfish 

(Carassius auratus) and black bullheads (Ictalurus melas) were the most resistant species, and 

the Atlantic salmon (Salmo salar) was the most sensitive. Toxicity was influenced little by 

temperatures of 7 to 22 C, by water hardnesses of 10 to 300 mg/1, or by pH's of 6.5 to 9.5. In 

exposures of rainbow trout (Salmo gairdneri), newly fertilized eggs were much more resistant 

than fingerlings. Noxfish detoxified in water solutions; the half-life of biological activity was 

22 days at 12 C and 13 days at 17 C. Potassium permanganate was an excellent detoxifier; 

chlorine was less efficient. Noxfish was consistently more toxic in static tests than in flowthrough tests.

Rotenone, a crystalline ketone found in several 

plants of the Leguminosae, has been used as a 

toxicant by fishery managers since the 1930's for 

removing undesired fish populations in lakes (Baker 

and Cordone 1969). Ideal conditions for the reclamation of static waters with rotenone include 

temperatures between 16 and 21 C, alkalinities 

between 150 and 200 mg/1 (ppm), pH's of 8 or less, and 

surface areas of less than 8.1 ha (Spitler 1970). The 

piscicide has been used extensively under a wide 

variety of conditions and is relatively harmless to 

most nontarget organisms (Schnick 1974; Lennon et 

al. 1970). Twenty-nine formulations of rotenone from 

18 companies had been registered for aquatic or 

agricultural use by 1974 by the Environmental 

Protection Agency. Because the registrations are old, 

data supporting the labels must be updated to 

conform to present requirements (Lennon 1967). A 

guide or protocol for evaluating the toxicity of 

candidate fishery chemicals for registration was 

published by Marking (1975).

The present study was designed to determine 

(1) the toxicity of rotenone to fish in standardized 

static and flow-through tests, (2) the toxicity of 

rotenone to newly fertilized trout eggs, (3) the 

residual toxicity of rotenone in water after selected 

periods of aging, (4) the efficiency of two compounds 

used to detoxify rotenone, and (5) the comparative 

toxicities of three rotenone formulations.

Materials and Methods

Three formulations of rotenone (furnished by S. B. 

Penick & Co.) were used in the tests described here: 

Noxfish®, an emulsifiable concentrate containing 5% 

rotenone; Pro-Noxfish®, a synergized emulsifiable 

concentrate containing 2.5% rotenone; and rotenone, 

a powder containing 33% rotenone. Except for tests in 

which the toxicities of the different formulations were 

compared or evaluated, Noxfish was used in all tests, 

and concentrations were based on the total amount of 

Noxfish formulation rather than on the amount of 

rotenone in the formulation. Stock solutions of the 

toxicants were prepared daily, and the portions 

needed to yield the desired concentrations were added 

to test chambers.

Static and flow-through test procedures followed 

those of Lennon and Walker (1964) and The Committee on Methods for Toxicity Tests with Aquatic 

Organisms (1975). In static tests, 10 fish were exposed 

to each concentration in glass jars containing 15 

liters of oxygen-saturated test water prepared from 

deionized water (Marking 1969). Waters of four levels 

of hardness were used (total hardness as mg/1 of 

CaCOa in parentheses): very soft (10), soft (44), hard 

(170), and very hard (300).

In separate tests to assess the effect of pH on 

toxicity, chemical buffers were added to control the 

pH (Marking 1975). Test temperatures were regulated

1
by immersing the test jars in constant temperature 

water baths. In flow-through toxicity tests, 20 fish 

were exposed to each concentration in a system 

similar to that described by Mount and Brungs (1967). 

Modifications included electronic microswitches to 

control cycling, pressure regulators, and an 

automatic pipette (Micromedic®) for injecting the 

toxicants into dilution water. Municipal water used 

for flow-through exposures was carbon filtered and 

had a total hardness of 320 mg/1 and a pH of 7.5. 

Flow rates were maintained at about five chamber 

volumes per 24 h. Temperature was maintained with 

a water bath around the test chambers.

Fish weighing 1 to 1.5 g each were obtained from 

Federal hatcheries and maintained according to 

standardized procedures of the Fish Control 

Laboratory (Hunn et al. 1968). Scientific names for all 

species used are listed in Table 1. Fish were 

acclimated to the test conditions for 4 days before 

they were exposed to the toxicant. Mortalities were 

recorded at 1, 3, and 6 h on the first day of exposure 

and daily thereafter for the remainder of the test. 

Trout eggs were exposed to Noxfish in a manner 

similar to that used for fish, except that the static test 

vessel contained 2.5 liters of test solution. Details of 

methods for exposing eggs were those outlined by 

Olson and Marking (1973).

The methods of Litchfield and Wilcoxon (1949) were 

used in computation of the LCso's (concentrations 

producing 50% mortality) and 95% confidence intervals. Regressions were drawn and inspected for each 

set of data. All data reported fulfilled the chi-square 

test requirement for acceptability.

Deactivation indices for Noxfish were derived in 

soft water at temperatures of 12 and 17 C. Aged 

solutions of the toxicant were bioassayed to determine the biological activity remaining after selected 

time periods. The deactivation index was determined 

by dividing the LC50 of aged solutions by the LC 50 of 

unaged solutions under corresponding test conditions (Marking 1972). The deactivation index was 

plotted against aging time on semilogarithmic 

coordinates to estimate the half-life of biological 

activity. Detoxification procedures with potassium 

permanganate (KMnCh) and chlorine were those 

used by Marking and Bills (1975).

Results

Toxicity to Various 

Species of Fish

Noxfish was toxic to a wide variety of fish at 

concentrations ranging, in 96-h exposures, from 

21.5 |/ g/1 (or parts per billion) for Atlantic salmon to

497 fig/\ for goldfish (Table 1). The 96-h LC 50 was 

less than 100 ^g/1 for bowfins, all six salmonids, 

northern pike, carp, longnose and white suckers, 

smallmouth bass, yellow perch, and walleyes. The 

96-h LC 50 was greater than 100 fig/I for goldfish, 

fathead minnows, black bullheads, channel catfish, 

green sunfish, bluegills, and largemouth bass. 

Goldfish and black bullheads were most resistant 

10 times as resistant as most other species. Generally, 

the resistant species required longer exposures than 

did the sensitive species, before they succumbed. 

None of the goldfish died in 24 h of exposure to high 

concentrations of Noxfish and none of the black 

bullheads in 6 h. On the other hand, most of the 

sensitive species died in 3-h exposures to much lower 

concentrations.

Effects of Temperature,

Water Hardness, and

pH on Toxicity

Noxfish was generally less toxic to rainbow trout, 

channel catfish, and bluegills at the lower than at the 

higher temperatures in 3- and 6-h exposures (Tables 

2, 3, and 4). After 96 h this trend remained but the 

differences in toxicity associated with most 5° 

differences in temperature were insignificant. The 

difference was significant for rainbow trout, 

however, at 7 and 12 C. Trout were consistently more 

sensitive than channel catfish or bluegills.

Water hardness had no effect on toxicity of Noxfish 

(Tables 2, 3, and 4), with one exception; in 96-h 

exposures the LC 50 's for channel catfish were 277 

fig/l in soft water and 328 |/g/l in very soft water 

(Table 3). Water at each hardness contained 

384 mg/1 of sodium bicarbonate to equalize the pH at 

about 8.0, and that quantity of bicarbonate in the soft 

water presumably resulted in slightly decreased 

toxicity to rainbow trout and channel catfish.

The toxicity of Noxfish was not influenced by 

differences in pH within the range of 6.5 to 9.5 (Tables 

2, 3, and 4). Noxfish appeared to be more toxic to 

rainbow trout at pH 9.5 than at lower pH's, but the 

increased sensitivity might have been due to an 

inability of the trout to acclimate fully to the high pH. 

Bluegills responded uniformly at the three different 

pH's in soft water at 12 C; the 96-h LC 50 's ranged 

only from 122 to 138 n g/1.

Toxicity of Noxfish to 

Green Eggs of Rainbow Trout

Newly fertilized eggs of rainbow trout were 47 to 

106 times more resistant than fingerlings to Noxfish; 

the 96-h LC50 ranged from 5.60 mg/1 in very soft 

water to 2.50 mg/1 in very hard water (Table 5).
Table 1. Toxicity of Noxfish® to fish in standardized laboratory tests at 12 C.

Species

Bowfin 

Amia calua

Coho salmon 

Oncorhynchus kisutch

Chinook salmon 

O. tshawytscha

Rainbow trout 

Salmo gairdneri

Atlantic salmon 

S. salar

Brook trout 

Saluelinus fontinalis

Lake trout 

S. namaycush

Northern pike 

Esox lucius

Goldfish 

Carassius auratus

Carp 

Cyprinus carpio

Fathead minnow 

Pimephales promelas

Longnose sucker 

Catostomus catostomus

White sucker 

C. commersoni

Black bullhead 

Ictalurus melas

Channel catfish 

/. punctatus

Green sunfish 

Lepomis cyanellus

Bluegill 

L. macrochirus

Smallmouth bass 

Micropterus dolomieui

Largemouth bass 

M. salmoides

Yellow perch 

Perca flauescens

Walleye 

Stizostedion vitreum vitreum

LC 50 and 95% confidence interval ( jig/1) at

3 h

141 

114-174

358

212 

171-262

175 

160-191

61.5 

53.4-70.8

141 

124-160

50.0 

38.6-64.7

181 

160-204

388 

332-454

630

452-878

1,410 

1,139-1,745

389 

332-456

424 

335-537

277 

219-350

514 

449-588

150 

126-179

135 

103-176

6 h

106 

82.5-136

152 

105-219

156

137-177

86.9

40.0 

33.6-70.8

79.7 

69.2-91.8

28.3 

21.0-38.0

58.2 

52.5-64.5

270 

254-287

1,190 

917-1,453

218 

141-337

238 

186-304

840 

717-984

332 

249-443

336

245-461

165

360 

305-425

134 

120-149

52.4 

46.8-58.7

24 h

57.5 

50.4-65.5

71.6 

63.1-81.3

49.0

44.3-54.2

68.9 

56.2-84.4

35.0 

29.7-41.2

47.0 

42.2-52.3

26.9 

19.8-36.5

44.9 

31.4-64.3

84.0 

74.7-94.4

400 

291-549

67.2 

59.3-76.1

71.9 

64.0-80.8

665 

516-856

400 

234-684

218 

197-241

149 

124-178

93.2

85.1-102

200 

131-305

92.0 

80.1-106

16.5 

15.2-17.9

96 h

30.0 

23.7-38.0

62.0 

54.8-70.2

36.9 

33.9-40.2

46.0 

32.6-64.9

21.5 

15.5-29.8

44.3 

41.1-47.7

26.9 

19.8-36.5

33.0 

26.6-41.0

497 

412-600

50.0 

41.1-60.8

142 

115-176

57.0 

51.9-62.6

68.0 

54.0-85.6

389 

298-507

164 

138-196

141 

114-174

141 

133-149

79.0 

70.7-88.2

142 

115-176

70.0 

59.8-82.0
Table 2. Toxicity of Noxfish® to rainbow trout in water of different temperatures, hardnesses, and pH's.

Temp

7

12

17

12

12

12

12

12

12

12

Water 

hardness

Soft

Soft

Soft

Very soft

Soft

Hard

Very hard

Soft

Soft

Soft ,

LC 5o and 95% confidence interval (fig/I) at

pH

7.5

7.5

7.5

8.0

8.0

8.0

8.0

6.5

8.5

9.5

3 h

>400

175 

160-191

73.0 

59.8-89.1

122 

108-138

90.0 

81.1-99.9

112 

95.1-132

113 

92.7-138

169 

151-189

133 

108-163

124 

106-145

6 h

276

237-322

86.9

73.0 

59.8-89.1

61.9

54.9-70.2

62.0 

51.6-74.5

81.9 

64.5-104

66.9 

55.0-81.4

129 

107-155

98.0 

87.4-110

75.0 

63.2-89.0

24 h

158 

134-186

68.9 

56.2-84.4

43.4 

30.9-60.9

54.4 

45.9-64.4

56.5 

48.2-66.3

55.1 

43.9-69.

53.0 

44.3-63.4

78.5 

69.6-88.6

80.0 

70.3-91.0

54.0 

45.9-63.6

96 h

70.0 

62.5-78.4

46.0 

32.6-64.9

43.4 

30.9-60.9

54.4 

45.9-64.4

56.5 

48.2-66.3

55.1 

43.9-69.1

53.0 

44.3-63.4

69.5 

63.7-75.9

62.1 

51.7-74.5

35.5

28.7-43.9
Table 3. Toxicity of Noxfish® to channel catfish at selected temperatures, hardnesses, and pH's.

Temp

12

17

22

12

12

12

12

12

12

12

Water 

hardness

Soft

Soft

Soft

Very soft

Soft

Hard

Very hard

Soft

Soft

Soft

LC 50 and 95% confidence interval (/ig/1) at

pH

7.5

7.5

7.5

8.0

8.0

8.0

8.0

6.5

8.5

9.5

3 h

1,720 

1,381-2,141

1,410 

1,139-1,745

739 

672-813

1,420 

1,080-1,868

1,640 

1,341-2,005

1,220 

1,023-1,454

1,160 

996-1,351

1,530 

1,175-1,991

899 

689-1,173

629 

548-721

6 h

1,000 

784-1,276

840 

717-984

449 

352-572

640 

464-883

890 

677-1,171

942 

756-1,173

1,000 

782-1,279

865 

692-1081

735 

608-889

625 

546-715

24 h

539 

377-770

400 

234-684

164 

137-196

476 

346-655

450 

341-593

400 

312-513

359 

282-457

500 

326-767

565 

454-704

550 

444-681

96 h

200 

164-244

164 

138-196

164 

137-196

328 

290-370

237 

199-282

308 

237-400

318 

240-421

200 

158-254

309 

237-403

248 

184-335
Table 4. Toxicity of Noxfish® to bluegills at selected temperatures, hardnesses, and pH's.

Temp

12

17

22

12

12

12

12

12

12

12

Water 

hardness

Soft

Soft

Soft

Very soft

Soft

Hard

Very hard

Soft

Soft

Soft

LC5o and 95% confidence interval (//g/1) at

pH

7.5

7.5

7.5

8.0

8.0

8.0

8.0

6.5

8.5

9.5

3 h

450 

353-573

424 

335-537

268 

240-300

334 

194-575

450 

317-639

300 

196-460

295 

211-413

291 

207-409

255 

204-319

196 

162-237

6 h

270 

217-335

336 

245-461

227 

194-266

219 

183-262

319 

241-422

284 

200-403

194 

148-255

228 

194-267

192 

170-217

152 

134-173

24 h

141 

114-174

149 

124-178

140 

107-183

142 

129-157

152 

135-172

146 

131-162

138 

125-152

150 

124-181

122 

108-138

122 

108-138

96 h

141 

114-174

141 

133-149

132 

122-143

132 

118-147

137 

123-153

132 

118-147

132 

121-144

138 

110-173

122 

108-128

122 

108-138

Although the difference in toxicity was not significant at each hardness increment, the difference was 

significant in very soft as compared to hard or very 

hard water.

Table 5. Toxicity of Noxfish® to newly fertilized

eggs of rainbow trout in reconstituted water of

different hardnesses at 12 C.

Water 

hardness

Very soft

Soft

Hard

Very hard

96-hLC 50 (mg/l) 

and 96% confidence interval

5.60

3.55-8.83

4.42

3.28-5.96

3.20

2.31-4.43

2.50

2.16-2.90

Persistence of 

Noxfish in Water

The toxicity to bluegills of Noxfish solutions aged 

for 1, 2, and 3 weeks decreased through each week of 

aging. At 12 C the 96-h LC 50 's were 133 //g/1 in 

freshly prepared solutions and 254 // g/1 in solutions 

aged for 3 weeks (Table 6). The toxicity decreased

Table 6. Toxicity (96-h LC50 's and 95% confidence

intervals in fig/1) to bluegills of fresh and aged

solutions of Noxfish® in soft water (deactivation

indices shown in parentheses).

Temi

(°C)

12

17

> 

0

133

117-151

(1.00)

90.0

64.1-126

(1.00)

Aging time (weeks)

1

117

92.3-148

(1.30)

2

213

193-236

(1.60)

190

159-228

(2.11)

3

254

215-300

(1.91)

288

247-336

(3.20)

Half-life

(days)

22

13
X

UJ

o

23

H-

<2 

>

HO 

< 

UJ

o

7 

TIME

14 21 

I N DAY S

Fig. 1. Detoxification rate for Noxfish® in soft water at 12 C [O] and 17 C [X].
more rapidly at 17 C than at 12 C; the half-lives were 

13 and 22 days, respectively (Fig. 1).

Detoxification of Noxfish

Static tests with green sunfish showed that 

potassium permanganate immediately detoxified 

Noxfish, as indicated by the marked loss of activity in 

unaged solutions of Noxfish and KMnC>4 (Table 7). 

For instance, the 96-h LC 50 at pH 7.5 was 0.241 mg/1 

for Noxfish alone and 1.71 mg/1 for Noxfish plus 

1.0 mg/1 of KMnQ4 . The solutions of Noxfish and 

KMnC>4 that were aged for 50 min before the fish were 

added had lost some additional activity (96-h LC 50 , 

3.09). The immediate detoxification in unaged 

solutions was probably a reflection of the effective 

exposure time, i.e., the time required for Noxfish to 

produce a lethal effect. The KMnO4 detoxified 

Noxfish in water at all pH's tested.

Chlorine was far less effective than KMnC>4 for 

detoxifying Noxfish in laboratory tests. There was 

little immediate detoxification in unaged solutions 

and little detoxification during 6 h of aging. For 

instance, at pH 7.5 the 96-h LC 50 was 0.293 mg/1 for 

Noxfish alone and 0.429 mg/1 for Noxfish plus

0.5 mg/1 of chlorine (Table 8). In a 6-h aging period, 

Noxfish was detoxified more efficiently at pH 9.5 

than at pH's 7.5 and 8.5.

Toxicity of Different 

Formulations of Rotenone

Pro-Noxfish, a synergized formulation containing 

2.5% rotenone, was more toxic to rainbow trout than 

the Noxfish formulation or powdered rotenone when 

concentrations were calculated on the basis of 

rotenone content. The comparative 96-h LCso's 

(// g/1) were as follows: Pro-Noxfish, 1.02; Noxfish, 

3.05; and powdered rotenone, 4.20 (Table 9). There 

was no significant difference in toxicity between 

Noxfish and rotenone powder formulations.

Toxicity in 

Flow-through Tests

In 4-day flow-through exposures, Noxfish was more 

toxic to chinook salmon and yellow perch than to carp 

or white suckers (Table 10). Toxicity did not increase 

with exposure time after 4 days, except for carp (in 

which toxicity increased through 20 days). Noxfish

Table 7. Toxicity and detoxification of Noxfish® in static tests with green sunfish in water containing 1.0

mg/l of KMnO4 at 12 C.

Compound and (for 

compounds combined) 

interaction time (min) a

Noxfish + KMnO 4

96-h LC 50 and 95% confidence interval (mg/1) at

pH 6.5 pH 7.5 pH 8.5

Length of time Noxfish and KMn0 4 were added before fish were introduced.

pH 9.5

KMnO4

Noxfish

3.47

3.12-3.87

0.184

0.161-0.211

3.03

2.69-3.41

0.241

0.203-0.287

1.41

1.14-1.74

0.158

0.114-0.219

3.08

2.32-4.08

0.378

0.317-0.451

0 1.32 

1.04-1.68

10 1.17 

0.948-1.44

20 1.41 

1.14-1.74

30 1.82 

1.54-2.15

40 2.00 

1.64-2.44

50 1.93 

1.61-2.31

1.71 

1.49-1.96

1.41 

1.14-1.74

2.89 

2.28-3.36

2.89 

2.28-3.66

2.28 

1.82-2.85

3.09 

2.74-3.49

2.10 

1.91-2.31

1.81 

1.54-2.13

2.38 

2.24-2.53

3.10 

2.69-3.58

3.09 

2.88-3.32

3.59 

3.19-4.03

1.55 

1.16-2.08

1.36 

1.07-1.70

1.64 

1.38-1.94

1.91 

1.59-2.29

1.41 

1.14-1.74

1.81 

1.53-2.13
Table 8. Toxicity and detoxification of Noxfish® in static tests with green sunfish in water containing

0.5 mg/l of chlorine at 12 C.

Compound and (for 

compounds combined) 

interaction time (h) a

Chlorine

Noxfish

Noxfish + chlorine

0

0.5

1.0

2.0

4.0

6.0

96-h

pH 7.5

0.840 

0.703-1.00

0.293 

0.264-0.325

0.429 

0.359-0.512

0.348 

0.299-0.405

0.483 

0.406-0.575

0.412 

0.337-0.504

0.494 

0.438-0.557

0.494 

0.438-0.557

LC so and 95% confidence interval (mg/l) at

pH 8.5

0.820 

0.588-1.14

0.338 

0.304-0.376

0.300 

0.242-0.372

0.492 

0.427-0.567

0.380 

0.318-0.455

0.400 

0.339-0.473

0.489 

0.432-0.554

0.454 

0.390-0.529

pH 9.5

0.709 

0.567-0.887

0.329 

0.294-0.368

0.488 

0.426-0.559

0.900 

0.677-1.20

0.689 

0.584-0.813

0.770 

0.689-0.862

1.37 

0.988-1.90

Length of time Noxfish and chlorine were added before fish were introduced.

Table 9. Toxicity of three formulations of rotenone to rainbow trout in soft water at 12 C.

Preparation

Pro-Noxfish®

Noxfish®

Powdered 

rotenone

% active 

rotenone

2.5

5.0

33.0

LC 5o and 95% confidence interval (//g/1) at

1 h

13.0 

8.15-20.7

25.5 

16.1-40.5

16.5 

14.3-19.1

3 h

4.53 

3.28-5.65

8.70 

6.90-11.0

8.09 

6.37-10.3

6 h

2.98 

2.43-3.65

5.50 

4.87-6.20

6.60 

5.41-8.02

24 h

1.82 

1.60-2.08

3.25 

2.78-3.81

3.82 

3.30-4.46

96 h

1.02 

0.917-1.15

3.05 

2.85-3.27

3.20 

2.09-3.70
10

Table 10. Toxicity of Noxfish® to four species offish in flow-through toxicity tests at 12 C.

Species

Chinook 

salmon

Carp

White 

sucker

Yellow 

perch

1 day

112 

97.7-128

160 

121-211

LC5o and 95%

4 days

71.0 

55.3-99.1

142 

122-165

144 

122-170

60.0 

53.3-67.6

confidence interval (//g/1) at

10 days

62.0 

52.1-73.7

96.0 

78.0-118

129 

118-141

50.0 

36.8-68.0

20 days

59.0 

49.5-70.3

67.0

57.4-78.3

112 

95.5-131

46.0 

32.7-64.8

30 days

68.0 

57.7-80.1

112 

95.5-131

was consistently and significantly more toxic to all 

four species in static than in flow-through tests 

(Table 11).

Discussion

The literature on toxicity of rotenone to fish 

suggests that concentrations used in fishery management are generally higher than those known to be 

lethal in laboratory tests; that toxicity depends on 

temperature, water hardness, pH, and physical 

characteristics; and that many different application 

rates may be effective for the same target species of 

fish (Schnick 1974; Meyer 1966).

Since laboratory procedures are usually more 

standardized than field procedures, laboratory data 

are expected to be more consistent than field data. 

Although the LCso's of less than 0.2 mg/1 for

Table 11. Comparison of acute toxicities of Noxfish® to four species offish in 96-h flow-through and 

static tests in carbon filtered municipal water at 

12 C.

Species LC 5o and 95% confidence interval (j/g/1)

Static Flow-through

Chinook salmon

Carp

White sucker

Yellow perch

34.7

26.9-44.7

19.0

12.1-29.9

17.9

12.8-25.1

30.0

23.6-38.2

71.0

55.3-99.1

142

122-165

144

122-170

60.0

53.3-67.6

Noxfish against rainbow trout, channel catfish, and 

bluegills reported by Bridges and Cope (1965) were 

similar to ours, applications of at least 1 mg/1 have 

been repeatedly recommended for eliminating these 

species. Spitler (1970) reported that 1.6 mg/1 of 

Noxfish was not effective and that as much as 5 mg/1 

was sometimes needed. The difference in laboratory 

and field data is due to several factors. Laboratory 

data generally indicate concentrations that produce 

50% mortality (LC 5o), whereas field concentrations 

are based on eliminating 100% of the target fish. 

Organisms, particulate matter, and sunlight contribute to the tendency toward faster detoxification of 

chemicals in natural waters than in the laboratory. 

Furthermore, because uniform concentrations are 

much more difficult to obtain in the field, additional 

amounts of toxicants are generally applied to ensure 

a lethal concentration throughout a body of water.

Although some of the reports are conflicting, 

rotenone is generally more effective at high than at 

low temperatures (Gersdorff 1943; Almquist 1959; 

Ball 1948; Hooper 1955), in acid than in alkaline 

waters (Leonard 1939; Foye 1964), and in soft than in 

hard water (Foye 1964). In many of these studies, 

however, efficacy was based on survival time of the 

fish rather than on the concentration of the toxicant. 

Our laboratory data show only slight changes in the 

toxicity of rotenone at different temperatures, 

hardnesses, or pH's. Consequently, concentrations 

used in the field should be based on the results of onsite toxicity tests (Burress 1975) rather than on 

extrapolations of laboratory or field data.

Most studies in laboratory or field have shown 

that goldfish and black bullheads are the species 

most resistant to rotenone. Individual fish of a 

species may be exceptionally resistant (Meyer 1966) 

an observation that may explain some incomplete 

fish kills and the need to apply a concentration
11

greater than that indicated in laboratory tests.

The detoxifiers KMnO 4 and chlorine were toxic to 

fish at concentrations only slightly greater than 

those needed to detoxify rotenone. For example, 

against green sunfish in water at pH 8.5, the 96-h 

LC 50 for KMnO 4 was 1.41 mg/1 and that for chlorine 

was 0.82 mg/1. These results support Engstrom-Heg 

and Loeb (1968) and Engstrom-Heg (1972), who 

cautioned that high concentrations of KMnO 4 may 

become toxic and may have to be reduced with sodium 

thiosulfate or other agents. Therefore, detoxifiers 

should be used only when necessary and in only the 

quantities needed.

References

Almquist, E. 1959. Observations on the effect of rotenone

emulsives on fish food organisms. Inst. Freshwater Res.

Drottningholm Rep. 40:146-160. 

Baker, P. H., and A. J. Cordone. 1969. Distribution, size

composition, and relative abundance of the Piute

sculpin, Cottus &eZdmgzzEigenmannandEigenmann,in

Lake Tahoe. Calif. Fish Game 55(4):285-297. 

Ball, R. C. 1948. A summary of experiments in Michigan

lakes on the elimination of fish populations with

rotenone, 1934-1942. Trans. Am. Fish. Soc.

75(1945):139-146. 

Bridges, W. R., and O. B. Cope. 1965. The relative

toxicities of similar formulations of pyrethrum and

rotenone to fish and immature stoneflies. Pyrethrum

Post 8(l):3-5. 

Burress, R. M. 1975. Development and evaluation of onsite toxicity test procedures for fishery investigations.

U.S. Fish Wildl. Serv. Invest. Fish Control 68. 8 pp. 

Committee on Methods for Toxicity Tests with Aquatic

Organisms. 1975. Methods for acute toxicity tests

with fish, macroinvertebrates, and amphibians. Ecol.

Res. Ser. EPA [Environ. Prot. Agency]-660/3-75-009. 61

pp. 

Engstrom-Heg, R. 1972. Kinetics of rotenone-potassium

permanganate reactions as applied to the protection of

trout streams. N.Y. Fish Game J. 19(l):47-58. 

Engstrom-Heg, R., and H. A. Loeb. 1968. Chemical

detoxification of rotenone: a simple case of oxidation?

N.Y. Conserv. Dep., Bur. Fish, N.Y. Fish News 27:3-7. 

Foye, R. E. 1964. Chemical reclamation of forty-eight

ponds in Maine. Prog. Fish-Cult. 26(4):181-185. 

Gersdorff, W. A. 1943. Effect of change of temperature on

relative toxicity of rotenone and phenol. J. Agric. Res.

67(2):65-80.

Hooper, F. F. 1955. Eradication of fish by chemical

treatment. Mich. Dep. Conserv., Fish Div. Pam. No. 19.6

pp. 

Hunn, J. B., R. A. Schoettger, and E. W.

Whealdon. 1968. Observations on the handling and

maintenance of bioassay fish. Prog. Fish-Cult.

30(3): 164-167. 

Lennon, R. E. 1967. Clearance and registration of

chemical tools for fisheries. Prog. Fish-Cult.

29(4): 187-193. 

Lennon, R. E., and C. R. Walker. 1964. Laboratories and

methods for screening fish-control chemicals. U.S. Fish

Wildl. Serv. Invest. Fish Control 1 (Circ. 185). 15 pp. 

Lennon, R. E., J. B. Hunn, R. A. Schnick, and R. M.

Burress. 1970. Reclamation of ponds, lakes, and

streams with fish toxicants: a review. FAO Fish. Tech.

Pap. No. 100. 99 pp. 

Leonard, J. W. 1939. Notes on the use of derris as a fish

poison. Trans. Am. Fish. Soc. 68(1938):269-279. 

Litchfield, J. T., Jr., and F. Wilcoxon. 1949. A simplified

method of evaluating dose-effect experiments. J. Pharmacol. Exp. Ther. 96(2):99-113. 

Marking, L.L. 1969. Toxicological assays with fish. Bull.

Wildl. Dis. Assoc. 5:291-294. 

Marking, L. L. 1972. Methods of estimating the half-life

of biological activity of toxic chemicals in water. U.S.

Fish Wildl. Serv. Invest. Fish Control 46. 9 pp. 

Marking, L. L. 1975. Toxicological protocol for the

development of piscicides. Pages 26-31 in P. H. Eschmeyer, ed. Rehabilitation of fish populations with

toxicants: a symposium. Am. Fish. Soc., North Central

Div., Spec. Publ. No. 4. 

Marking, L. L., and T. D. Bills. 1975. Toxicity of

potassium permanganate to fish and its effectiveness for

detoxifying antimycin. Trans. Am. Fish. Soc.

104(3):579-583. 

Meyer, F. A. 1966. Chemical control of undesirable

fishes. Pages 498-510 in A. Calhoun, ed. Inland fisheries

management. Calif. Dep. Fish Game, Sacramento. 

Mount, D. I., and W. A. Brungs. 1967. A simplified dosing

apparatus for fish toxicological studies. Water Res.

1:21-29. 

Olson, L. E., and L. L. Marking. 1973. Toxicity of TFM

(lampricide) to six early life stages of rainbow trout

(Salmo gairdneri). J. Fish. Res. Board Can. 30:1047-1052. 

Schnick, R. A. 1974. A review of the literature on use of

rotenone in fisheries. U.S. Fish Wildl. Serv. Lit. Rev.

74-15. NTIS [Natl. Tech. Inf. Serv.] No. PB-235 4547AS.

130 pp. 

Spitler, R. J. 1970. An analysis of rotenone treatments

for estimation of fish populations in southern Michigan

lakes, 1957-1967. Mich. Acad. 3(l):77-82.



(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. 7 pp.

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.

71. Field Tests of Isobornyl Thiocyanoacetate (Thanite) for Live Collection of Fishes, by R. M. 

Burress, P. A. Gilderhus, and K. B. Gumming. 1976. 13 pp.

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