INVESTIGATIONS IN FISH CONTROL

80. Effects of Antimycin A and Rotenone 

on Macrobenthos in Ponds

81. Aquatic Macroinvertebrates in a Small Wisconsin 

Trout Stream Before, During, and Two Years After 

Treatment with the Fish Toxicant Antimycin

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 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.

(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 Toxicites 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.

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

80. Effects of Antimycin A and Rotenone 

on Macrobenthos in Ponds

By Larry J. Houf and Robert S. Campbell

81. Aquatic Macroinvertebrates in a Small Wisconsin 

Trout Stream Before, During, and Two Years After 

Treatment with the Fish Toxicant Antimycin

By Gerald Z. Jacob! and Donald J. Began

UNITED STATES DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE 

Washington, D.C. 1977

Effects of Antimycin A and Rotenone 

on Macrobenthos in Ponds

by 

Larry J. Houf and Robert S. Campbell

School of Forestry, Fisheries and Wildlife

Missouri Cooperative Fishery Research Unit

University of Missouri, Columbia, Missouri 54601

Abstract

Samples of macrobenthos, collected over a 14-month period from nine 0.03-ha experimental 

ponds at the Fish-Pesticide Research Laboratory, Columbia, Missouri, were analyzed to 

determine the long- and short-term effects of antimycin A and rotenone. The ponds were 

characterized by an abundance of bushy pondweed (Najas guadalupensis) and by the absence 

of fish. Treatment concentrations of 0.5 mg/1 of rotenone and 20 /ig/1 of antimycin and 

concentrations of 2.0 mg/1 of rotenone and 40 /j. g/1 of antimycin were applied. There were no 

effects on species diversity, emergence, seasonal dynamics, abundance, or relative numbers of 

taxa that could be attributed to either toxicant. Periods of spring emergence, summer buildup, 

and fall emergence of insects were closely associated with the seasonal development and 

decline of vegetation.

The short- and long-term effects on invertebrate 

macrobenthos of treating bodies of water with 

rotenone and antimycin A lack adequate documentation. Most benthic organisms appear to be unaffected 

by either toxicant at concentrations applied for fish 

eradication (Brown and Ball 1942; Walker et al. 1964; 

Gilderhus et al. 1969; Schoettger et al. 1967; Smith 

1972). However, there are reports of mortality among 

specific taxa exposed to low concentrations of 

rotenone (Gushing and Olive 1956; Brown and Ball 

1942) and to high concentrations of antimycin A (H. 

Howell et al. unpublished data; Walker et al. 1964; 

Lesser 1972).

The purposes of this study were to: (1) identify any 

short- or long-term changes in species abundance in 

pond benthos resulting from the application of 

rotenone or antimycin, (2) determine any difference 

in abundance of benthos which may result from use of 

different concentrations of toxicants, (3) determine 

the time required for affected populations of 

organisms to recover from rotenone and antimycin 

treatment, and (4) determine whether emergence of 

benthic organisms is affected by rotenone or antimycin treatment.

The complete qualitative and quantitative 

analyses of benthic collections, June-October 1971 

and April-August 1972, which are the basis for this 

paper, are presented in an appendix.

The appendix also provides analysis of the 

seasonal changes in benthic populations: summer 

and winter development, fall and spring emergence. 

This description of benthic community dynamics in 

these experimental ponds is distinctive because it 

concerns a habitat which is heavily vegetated and 

devoid of predatory fish populations. Dense vegetation provides unusual cover, abundant food, and 

more habitat niches than occur in nonvegetated 

bottom sediments. Vegetation also has the potential 

for causing low concentrations of dissolved oxygen, 

either directly through respiration or indirectly 

through decomposition. The absence of fish may 

modify species abundance and composition of the 

benthos because the populations are not subject to 

predation by fish.

Methods 

Description of Study Area

This study was conducted on nine similar ponds at 

the Fish-Pesticide Research Laboratory, Columbia, 

Missouri. Average dimensions of the standing water 

mass were 21.4 * 15.6 * 0.6 m; average surface area 

was 0.03 ha; and average volume was 251.3 m3 .Pond 

bottoms were sloped; water depths ranged from about 

0.3 to 1.2 m. The soil type was Mexico silt loam.

1
Experimental Design

The nine experimental ponds, A through I, differed 

in past use and in length of time they had held water. 

(Correspondence of pond lettering to the FishPesticide Research Laboratory numbering system is: 

A, 24; B, 16; C, 23; D, 18; E, 20; F, 19; G, 17; H, 22; and 

I, 21.) Before the study began, all ponds were drained 

for 2 weeks of drying, as a means of reducing species 

differences between ponds and establishing similar 

successional stages. A random treatment design 

provided two control ponds, three ponds for rotenone 

treatment, and four ponds for antimycin treatment. 

Sample sites were randomized as to location and 

depth in each pond after the pond was divided into 

16 3.0- x 4.5-m sampling rectangles.

Sampling Methods

From 1 June 1971 to 31 August 1972, 121 samples 

were collected and analyzed. Four samples per 

pond two from the shallow area and two from the 

deep area were collected at monthly intervals for the 

14-month period. From 1 June to 31 August each year, 

collections were made at 14-day intervals. In addition, more intensive sampling preceded and followed 

treatment: the interval in days was gradually 

decreased before treatment in the sequence 14,7,3,2, 

1, and treatment; and then gradually increased after 

treatment in the sequence 1, 2, 3, 7, and 14 days. The 

sampling device was a modified Ekman dredge, 

231 cm2 .

Samples were washed in the field through a screen 

with 11.8 meshes per linear centimeter. The vegetation, benthic organisms, and debris remaining on the 

screen were placed in jars containing 10% formalin. 

In the laboratory the macro-vegetation was removed 

and examined for benthic organisms, and the 

remaining detritus with organisms was placed in a 

saturated aqueous solution of Epsom salts 

(magnesium sulfate) and stirred so that the 

organisms floated to the surface. This is a modification of a flotation procedure described by Anderson 

(1959), in which sugar was replaced with Epsom salts.

Emergence cages one in each pond were 

operated from 7 to 30 April 1972. The wooden and 

nylon cages, 1.0 m square by 20 cm high, were 1 to 

4 m from shore over water about 1 m deep. Adult 

insects were removed from the covering screens at 

weekly intervals and preserved in 95% ethanol.

Computation of 

Species Diversity Index

A species diversity index derived from the information theory (Wilhm and Dorris 1968) was estimated by 

the formula

d - -2 (ni/ri) Iog 2 (ni/ri)

where d - estimate of diversity, n\ - number of 

individuals in the i^1 taxon, and n - total number of 

individuals in the sample.

Application of Toxicants

The ponds were treated in late August, near the 

usual time of pond treatment (September) in the 

Midwest. Concentrations of rotenone and the initial 

concentrations of antimycin were those recommended for fish eradication by Kinney (1968) and Lennon 

and Berger (1970), respectively.

All ponds were treated on the afternoon of 25 

August 1971. Sand formulated antimycin (Fintrol 5) 

was applied to ponds F, G, H, and I. An initial low 

treatment concentration of 1.5 /ug/1 was applied to 

ponds F and G, and an initial heavy treatment 

concentration of 10 /u,g/l to ponds H and I. 

Applications of emulsifiable rotenone (Noxfish; 5% 

active ingredient) were made in ponds C, D, and E. 

Ponds C and D received a low treatment concentration of 0.5 mg/1 and Pond E a heavy treatment of 

2.0 mg/1. Ponds A and B were untreated controls.

Although rotenone concentrations selected were 

adequate, the treatments with antimycin were 

ineffective in eradicating fish held in cages in the 

ponds with pH values greater than 9.0 (Table 1). After 

completing toxicity tests to determine adequate 

concentrations of antimycin (Table 2), we re-treated 

the ponds on 1 September 1971 at low concentrations 

of 20 ju,g/l (F and G) or high concentrations of 

40 jug/1 (H and I). The low concentration in ponds F 

and G produced a complete kill of all bluegills 

(Lepomis macrochirus); however, the high concentration in H and I yielded only a partial kill of bluegills 

130 to 180 mm long (Table 3). The lessened effect of 

the 40 fj. g/1 concentration was possibly related to the 

higher pH values in ponds H and I. The pH values 

were 9.0 in pond F and 9.5 in pond G at 1000 h, and 9.6 

in pond H and 9.7 in pond I at 1100 h.

Classification

The classification scheme for the Chironomidae 

follows Sublette and Sublette (1965), except that we 

assigned generic status to four of the subgenera of 

Sublette and Sublette: Dicrotendipes, Harnischia, 

Endochironomus, and Cryptochironomus.
Table 1. Numbers of confined bluegills of two sizes killed within 1,4, and 14 h after treatment of ponds with 

low and high concentrations of rotenone and antimycin.

Hours after treatment, total length of fish (mm), and (in 

parentheses) number of test fish in cages.

Pond

A

B

C

D

E

F

G

H

I

Treatment

Control

Control

Rotenone,

Rotenone,

Rotenone,

Antimycin

Antimycin

Antimycin

0.5 mg/1

0.5 mg/1

2.0 mg/1

, 1-5 p g/1

, 1.5 p g/1

, 10.0 ft g/1

Antimycin, 10.0 fi g/1

Results

i

50-100

(20)

0

0

5

5

12

0

0

1

2

4

130-180 50-100

(7)

0

0

0

0

2

2

0

0

0

Water Quality

(20)

0

1

20

16

20

5

1

2

3

all ponds (Table

reflect differences

14

130-180 50-100 130-180

(7)

1

0

5

2

5

2

0

0

0

(20) (7)

0

2

20

16

20

6

1

3

5

1

1

6

2

7

2

0

0

0

5). Differences in surface valu

in the time

varied from about 0900 to 1300.

of sampling, whi<

Pond G wasthe on

Chemical analysis of the water from the deep well 

supplying the ponds used in the present experiment 

was given by Kennedy et al. (1970). Seasonal 

fluctuations in pond water chemistry (Table 4) were 

similar in 1971 and 1972, and did not differ from those 

expected in small ponds in the Midwest. Seasonal 

changes in alkalinity were accentuated by the 

development of dense stands of macrophytes. During 

both summers, photosynthesis resulted in the elevation of pH to values greater than 9.5 in all ponds. The 

rotenone and antimycin treatments had no 

noticeable effect on water chemistry.

Dissolved oxygen concentrations in the experimental ponds were similar to those found in many small 

ponds in Missouri. Summer stagnation developed in

Table 2. Toxicity test: mortality of bluegills, total 

length 50-100 mm, exposed to different concentrations of sand formulated antimycin atpH9.3.

pond where anaerobiosis was detected; this condition 

was accompanied by the generation of hydrogen 

sulfide, the odor of which was evident from the pond

margin.

Taxa Identified

A distinctive characteristic of the experimental 

waters was the dense growth of vegetation

Table 3. Numbers of caged small (50-100 mm long) 

and large (130-180 mm) bluegills that died after 

re-treatment of ponds F-I with antimycin.

Concentration

(/ig/1)

5

10

15

20

40

Number

of fish

10

10

10

10

10

Hours after treatment

4

0

0

0

2

a

5

0

0

0

2

7

6

0

0

0

5

a

12

a

0

2

8

10

24

a

0

2

8

10

No count made.

Hours after treatment, length 

of fish (mm), and (in parentheses) 

numbers of test fish in cages 

c on

Pond

A

B

C

D

E

F

G

H

I

Treatment

Control

Control

Control

Control

Control

20 fj, g/1

20 p. g/1

40 fJi g/1

40 fJL g/1

50-100

(20)

0

0

0

0

0

20

20

19

7

\j

130-180

(8)

0

0

0

0

0

8

8

4

0

fj\j

50-100

(20)

0

0

0

0

0

20

20

20

20

130-180

(8)

0

0

0

0

0

8

8

5

2
Table 4. Range of values for water quality determinations, June through August, 1971 and 1972, for five 

ponds at the Fish-Pesticide Research Laboratory, Columbia, Missouri. 3-

Characteristic

Treatment and 

pond identification

Control

A

B

Rotenone

E

Antimycin

H

I

Temperature (°C)

PH

7.8-9.9

8.3-9.7

8.4-10.0

7.7-10.1

8.9-10.3

Surface

24-30

24-29

23-29

24-29

24-28

Bottom

21-28

22-28

21-28

22-28

21-26

Dissolved oxygen (mg/1)

Surface

5-16

5-13

6-16

4-14

4-15

Bottom

0.7-15

1-11

1-12

0.8-15

0.6-9

Hardness 

(mg/1 as 

Ca C0 3 )

80-141

74-169

75-155

70-132

65-122

Alkalinity 

(mg/1 as 

Ca C03 )

60-150

65-152

73-145

77-161

77-120

Hardness, alkalinity, and pH were determined only from surface samples; pH was measured at midmorning.

Table 5. Dissolved oxygen concentrations (mg/l) at 

surface (S) and bottom (B) in six ponds at the FishPesticide Research Laboratory, Columbia, Missouri, July-September 1971.

Date (1971) and 

site of sample

July 7

S 

B

July 20

S 

B

August 3

S 

B

August 21

S 

B

August 31

S 

B

September 14

S 

B

September 28

S 

B

Ponds

A

15.3 

2.5

16.0

1.5

16.0

1.5

13.0 

1.3

14.0 

0.7

17.2 

0.5

9.9 

6.7

B

12.8 

10.0

12.4 

10.7

12.9 

9.7

11.6 

9.6

13.1 

1.6

12.8 

6.0

11.6 

3.2

E

15.6 

11.0

14.2 

9.6

13.7 

2.5

9.3 

2.3

14.0 

2.0

11.1 

0.8

13.2 

2.0

H

10.4 

11.2

8.8 

8.8

11.4 

11.0

8.5 

6.8

11.2 

1.4

7.7 

6.5

11.6 

3.8

I

11.0

8.2

10.2 

7.9

14.4 

8.6

8.8 

0.6

10.8 

0.8

10.0 

2.1

12.2 

3.9

G

12.4 

5.4

10.5 

1.6

15.0 

1.0

8.0 

0.7

5.0 

0.0

1.3 

0.7

7.8 

4.6

throughout all of the ponds. Bushy pondweed (Najas 

guadalupensis) and chara (Chara sp.) were the most 

abundant plants. Others included water hyssop 

(Bacopa rotundifolia), smartweed (Polygonum sp.), 

arrowhead (Sagittaria sp.), spike rush (Eleocharis 

sp.), and sedge (Carex sp.).

Seventy-four animal taxa were identified (Table 6). 

Most abundant members of the communities were 

herbivorous mayflies (Caenis simulans and 

Callibaetis fluctuans), predaceous dragonflies 

(Enallagma civile and Ischnura verticalis), and 

predaceous midges (Sayomyia punctipennis, 

Ablabesmyia peleenis, and Procladius bellus). 

Other true midges were the filter feeding midges 

Tanytarsus sp. of the tribe Calopsectrini and 

Pseudochironomus richardsoni and Chironomus 

attenuatus of the tribe Chironomini. Other abundant 

members included ooze transporting oligochaetes 

and periphyton browsing snails (Physa sp., Gyraulus 

sp., and Helisoma sp.).

Effects on Abundance 

of Benthic Organisms

Inasmuch as the effects of treatment on benthic 

organisms were similar for both heavy and light 

applications of the toxicants, the data from heavy 

applications of rotenone (2 mg/1, pond E), and 

antimycin (4) jug/1, ponds H and I), have been 

selected as representative.

Rotenon Treatment, 2 mg/1

Short-term effects. No immediate short-term 

(August-September 1971) effects from application of
Table 6. Benthic organisms collected from research ponds A-I, Fish-Pesticide Research Laboratory, 

Columbia, Missouri, June 1971-August 1972. The numerically dominant members of each group are 

indicated with an asterisk; dominant groups in number and volume are indicated by two asterisks.

OLJGOCHAETA (aquatic earthworms)** 

INSECTA

EPHEMEROPTERA (mayflies)** 

Baetidae

Caenis simulans*

Callibaetis fluctuans* 

Ephemeridae

Hexagenia bilineata

ODONATA (dragonflies and damselflies)** 

Libellulidae

Tramea Carolina*

Libellula (2 species)*

Erythemis simplicicollis*

Plaihemis sp. 

Aeshnidae

Anax junius 

Coenagrionidae

Enallagma civile*

Ischnura verticalis*

Agria sp.

HEMIPTERA (true bugs) 

Mesoveliidae

Mesovelia mulsanti* 

Notonectidae

Notonecta sp. 

Veliidae

Microvelia sp.

Velia sp. 

Hebridae

Merragata sp. 

Hydrometridae

Hydrometra martini 

Belostomatidae

Belostoma

TRICHOPTERA (caddis flies) 

Leptoceridae

Oecetis inconspicua*

Leptocella sp.* 

Hydroptilidae

Oxyethira sp.* 

Phryganeidae

Phryganea

Agrypnia

COLEOPTERA (beetles) 

Hydrophilidae

Berosus sp.*

Tropisternus 

Dytiscidae

Laccophilus maculosa*

Bidessus lacustris

Hydroporus sp.

Agabus sp.

Ilybius sp.

Coptotomus

Haliplidae

Haliplus sp.*

Peltodytes 

Gyrinidae

Dineutus assimilis 

DIPTERA (true flies)** 

Chaoboridae (phantom midges)

Chaoborus americanus

Sayomyia punctipennis 

Chironomidae (true midges)

Pseudochironomus richardsoni*

Ablabesmyia peleenis*

Tanytarsus (2 species)*

Chironomus attenuates*

Procladius bellus*

P. subletti

Labrundinia pellosa

Larsia planesis

Dicrotendipes nervosus

D. modestus

Harnischia collator

H. monochromus

H. potamogeti

CUnotanypus pinquis

Tanypus punctipennis

T. neopunctipennis

Glyptotendipes barbipes

Endochironomus nigricans

Polypedilum simulans

P. trigonus

Lauterborniella varipennis

Psectrocladius dyari

Monopelia sp.

Cricotopus

Cryptochironomus fulvus

Corynoneura

Paratendipes 

Ceratopogonidae

Two unidentified species 

Stratiomyiidae

Odonotomyia sp. 

Tabanidae

Chrysops sp.

Tabanus sp. 

GASTROPODA (snails)**

Gyraulus*

Physa

Heliosoma 

PELECYPODA (clams)
2 mg/1 rotenone in pond E were observed. Major 

species of mayflies, dragonflies, damselflies, aquatic 

earthworms, snails, phantom midges (Chaoboridae), 

and true midges (Chironomidae), present before 

treatment were also present after treatment. 

Although most populations of Caenis simulans, 

Tramea Carolina, Enallagma civile, Ablabesmyia 

peleenis and Pseudochironomus richardsoni declined 

in abundance (Fig. 1), these downward trends had 

started before treatment. Results were similar in the 

ponds (C and D) treated with 0.5 mg/1 rotenone. The 

declines noted were the result of emergence of insects 

and summer stagnation, rather than toxicity of the 

chemical; trends in population density were similar 

in control and rotenone-treated ponds. Populations of 

Sayomyia punctipennis, Libellula sp., Erythemis

simplicicollis, Ischnura uerticalis, and Dicrotendipes 

showed no density reductions.

Long-term effects. Long-term effects of a rotenone 

treatment of 2 mg/1 (Pond E) were evaluated by 

comparing population densities in 1972 with those in 

1971. The same species were present in both summers 

and, generally, in the same relative abundance 

(Fig. 1).

Although the population densities in 1972 were 

somewhat variable with respect to the densities 

measured in 1971, there was no evidence that the 

rotenone treatment was responsible for these 

variations. Rather, differences appeared to be due to 

natural population fluctuations.

CONTROL PONDS: A- and B ROTENONE-TREATED POND: EPseudochironomus richardsoni

Jun I Jul lAug 

1971

I Jun I Jul I Aug 

1972

Jun I Jul I Aug' ISep 

1971

I Jun I Jul I Aug 

1972

Fig. 1. Changes in population densities of major species of aquatic insects in control ponds A and B, and rotenone-treated 

(2 mg/1) pond E, 1971 and 1972. Vertical line in August shows treatment date. Density values express numbers collected 

on any one collection date as a percentage of the total numbers of that species collected throughout the period of 

collection.
Antimycin Treatment, 40 /A g/1

Short-term effects. No dominant organisms 

which were present before treatment were eliminated 

by exposure to heavy (40 jug/1) applications of 

antimycin in Ponds H and I. These dominant species 

included representatives of the mayflies, dragonflies, 

damselflies, phantom midges, true midges, snails, 

and aquatic earthworms.

In general, a decline in population density was 

observed during a brief period after treatment, in both 

treated and control ponds (Fig. 2). In a few organisms 

this decline preceded treatment. These declining 

populations are, therefore, not a response to toxicants 

but to summer stagnation (Table 5) and emergence. 

Populations of Caenis simulans, Sayomyia punctipennis, and Ablabesmyia peleenis are examples.

The relatively minor variability among some populations in control ponds and treated ponds e.g., 

Tramea Carolina, Enallagma civile, and 

Pseudochironomus richardsoni does not negate this 

general observation.

Long-term effects. No long-term effects on the 

bottom fauna were observed after applications of 

40 fjig/l antimycin in Ponds H and I. This judgment 

is based on a comparison of the presence or absence 

and the densities of the major taxa in 1971 and 1972 

Caenis simulans, Tramea Carolina, Enallagma civile, 

Sayomyia punctipennis, Ablabesmyia peleenis, and 

Pseudochironomus richardsoni (Fig. 2) which were 

selected as representative. Species present in 1971 

were present in similar numbers in 1972.

CONTROL PONDS: A and B 

Caenis simulans

ANTIMYCIN-TREATED PONDS: H and

Pseudochironomus richardsoni

Jun I Jul I Aug 1 Sep I 

1971

I Jun I Jul I Aug 

1972

20 _| 

0

Jun I Jul I Aug Sep 

1971

| Jun | Jul I Aug 

1972

Fig. 2. Changes in population densities of major species of aquatic insects in control ponds A and B and the antimycintreated (40 ft g/1) ponds H and 1,1971 and 1972. Vertical line in August shows treatment date. Density values express 

numbers collected on any one collection date as a percentage of the total numbers of that species collected throughout the 

period of collection.
Effects on 

Insect Emergence

We conclude that there was no consistent evidence 

of toxicant interference with insect emergence, on the 

basis of comparisons of emergences in control ponds 

and in ponds treated at specified concentrations. The 

evaluation of emergence was made in 1972,6 months 

or more after pond treatment. Emergence behavior 

was considered to be representative in six selected 

species: Caenis simulans, Tramea Carolina, 

Enallagma civile, Sayomyia punctipennis, 

Pseudochironomus richardsoni, and Ablabesmyia 

peleenis (Table 7). The total emergence for the study 

period, April through June, was subdivided to show 

the percentage occurring in each month for each 

treatment, so that early or delayed emergence can be 

identified. Inspection of the table indicates that, 

although toxicants appeared to have a depressing 

effect in some treated ponds, comparison with control 

ponds in the same month shows that the decrease was 

instead a result of early emergence. For example,

fewer Pseudochironomus richardsoni or Enallagma 

civile emerged in June in treated ponds than in 

control ponds; however, April values indicate that 

emergence was early in the treated ponds and late in 

the control ponds.

Effects on 

Species Diversity

Species diversity appeared unchanged as a result of 

pond treatment by toxicants at specified concentrations. Diversity was judged by enumeration of the 

taxa and by calculation of species diversity indices in 

control and treated ponds.

The number of taxa present in each pond for 14 

samplings in 1971 and 1972 (Table 8) did not differ 

consistently between (a) pre- and post-treatment 

samples in 1971, (b) the years 1971 and 1972, or (c) 

control ponds and ponds treated with antimycin and 

rotenone. The mean number of taxa for all ponds 

combined was 21.3. The mean number for all 1971 and 

1972 samples for each pond was near this value.

Table 7. Emergence of insects in ponds treated with rotenone or antimycin, and in control ponds, April-June 

1972. Monthly values are expressed as percentage of the total emergence April-June for each species for 

each treatment.

Species, and month 

of emergence

Caenis simulans

April

May

June

Tramea Carolina

April

May

June

Enallagma civile

April

May

June

Sayomyia punctipennis

April

May

June

Ablabesmyia peleenis

April

May

June

Pseudochironomus richardsoni

April

May

June

Control 

ponds

0

0

100

0

0

100

0

0

100

0

67

33

8

50

42

35

11

54

Treatment

Rotenone

0

0

100

0

14

86

0

25

75

4

19

77

16

30

54

70

11

19

Antimycin

0

0

100

0

9

91

0

46

54

1

1

98

10

23

67

76

9

15
Table 8. The number of taxa present in control ponds and in ponds treated with high concentrations of 

rotenone or antimycin, Fish-Pesticide Research Laboratory, Columbia, Missouri, June 1971-August 1972.

Sampling 

date

1971

June 8

June 22

July 20

August 21

August 24

August 25

August 28

September 1

September 1

September 4

October 12

1972

April 15

June 8

June 27

July 25

August 29

Mean, all

samples

Control

Pond A

19

9

21

23

20

16

20

26

24

13

21

31

60

23.3

Pond B

16

16

17

21

24

16

16

16

25

13

20

22

17

18.4

Rotenone (2 mg/1)

Pond E

18

14

16

25

22

T

12

17

28

27

12

21

23

27

20.2

Q

Treatment

Antimycin

Pond H

23

24

24

23

27

T

19

RT

25

17

21

27

15

26

25

32

23.4

(40 fi g/1)

Pond I

19

20

25

30

T

14

RT

23

19

18

20

25

22

23

20

21.4

Q

^P J-MA** J-«M « J-. "D^p «« J.u«. _ J __ __ x Tl_ _ J_TT _ _ J T __ __ _ _ _ j _ _ _ j__ J __ :j.T_ J/\ _ /I _ _ J.^ __ _ ^* _ JZL __ j _ _ _ j __ __ A_ __ ! J.1. 1 A _ /" T = treatment; RT = re-treatment. Ponds Hand I were re-treated with 40 /j. g/1 antimycin after treatments with 10 /j.g/1 

proved to be insufficient to kill all caged fish in the pond.

Calculated species diversity indices for all sampling 

periods in 1971 and 1972 for each pond fell between 

the values 2.00 and 4.12 (Table 9).

Discussion

The results of this study justify the proposal that 

the toxicants antimycin and rotenone be retained as 

fish control agents because they are not detrimental 

to benthic communities when applied in proper 

dosages. The 14-month investigation of high and low 

concentrations revealed no short- or long-term effects 

on species abundance or on insect emergence. These 

conclusions are generally in agreement with published literature. Other studies have shown that 

species of major benthic groups have not been 

seriously affected by recommended treatment concentrations of 10 fj.g/1 antimycin (Walker et al. 1964, 

Gilderhus et al. 1969) or of 0.5 mg/1 of rotenone 

(Brown and Ball 1942). However, Brown and Ball did 

identify an initial reduction in the population of 

certain unidentified species of Chaoboridae. The 

chaoborid Sayomyia punctipennis in the present

study was not affected. Penick (1963) described a 

study by H.S. Swingle showing that S. punctipennis 

was unaffected by rotenone.

Our analysis of species diversity indices showed 

that treatment with toxicants at specified concentrations did not disturb benthic communities, either 

immediately after treatment or in the following year. 

With one exception, our indices fell within the range 

2.0 to 4.1. Wilhm (1970) suggested that indices below 

1.0 identify unstable, disturbed benthic communities 

and that indices between 3.0 and 4.0 identify 

undisturbed communities. Applying these criteria to 

our indices, we conclude that none of our experimental or control ponds supported disturbed communities. The random occurrence of indices between 

2.0 and 4.0 throughout control and treated ponds is 

further evidence that these ponds contained stable 

communities.

The value of species diversity indices as monitors of 

community stability was demonstrated by an inconsistently low index of 1.80 in pond G (treated with 

20 /xg/1 antimycin), which was associated with the 

development of anaerobic conditions (Table 5) and 

generation of hydrogen sulfide.
10

Table 9. Diversity indices for control ponds and ponds treated with high concentrations of rotenone or 

antimycin, Fish-Pesticide Research Laboratory, Columbia, Missouri, June 1971-August 1972.

Treatment a

Sampling 

date

1971

June 8

June 22

July 20

August 21

August 24

August 25

August 28

September 1

September 4

September 14

October 12

1972

April 15

June 8

June 27

July 25

August 29

Con

Pond A

2.00

2.75

2.70

3.60

2.81

3.21

3.05

2.45

2.83

2.06

2.21

4.12

3.26

trol

Pond B

2.38

2.25

3.19

3.60

3.56

2.40

2.68

2.62

3.42

2.93

2.54

2.77

3.33

Rotenone 2mg/l

Pond E

2.14

3.12

2.46

3.34

3.26

T

3.12

3.08

3.51

3.74

2.24

2.54

3.24

3.56

Antimycin

Pond H

2.52

2.70

3.68

3.62

3.80

T

3.06

RT

2.66

2.93

2.74

2.68

3.12

3.37

3.61

3.53

40/ig/l

Pond I

3.31

2.93

b

3.66

3.48

T

2.66

RT

3.76

2.87

3.12

3.57

2.74

2.97

2.38

3.02

T = treatment; RT = re-treatment. Ponds Hand I were retreated with 40 /tg/1 antimycin after treatments with 10 /tg/1 

proved to be insufficient to kill all caged fish in the pond.

Sample not analyzed.

Two environmental factors that influenced this 

study were the large beds of vegetation and the 

absence of fish. The lack of fish may modify species 

abundance and composition because of the accompanying marked reduction in predation on benthic 

organisms.

The invasion of all open water of all ponds by 

vegetation by late summer was accompanied by an 

increase in number of niches, which was in turn 

reflected in an increase in the species diversity index. 

Periods of spring emergence, summer buildup, and 

fall emergence of insects were closely tied to the 

seasonal development and decline of vegetation. 

Photosynthetic activity of vegetation resulted in high 

pH (above 9.5 in early afternoon), which caused 

inactivation and subsequent detoxification of antimycin, and made it necessary to increase the 

concentration of antimycin applied. Decomposition 

of plant material resulted in low dissolved oxygen 

concentrations in late summer (Table 5), which, in 

combination with insect emergence, resulted in a 

seasonal decline in insect abundance and a decrease 

in the diversity index.

An advantage of the toxicants antimycin and 

rotenone is that they are naturally occurring compounds whose persistence is prevented through 

biodegradation. Thus insects, which have the capacity for rapid recolonization, are not excluded from 

aquatic ecosystems for long periods even after 

overdoses of these toxicants.

Conclusions

1. No short- or long-term effects on abundance of 

dominant benthic species could be attributed to 

pond treatments with 0.5 and 2.0 mg/1 concentrations of rotenone or 20 and 40 yu g/1 concentrations of antimycin.

2. Species diversity within the benthic community, 

as evaluated by number of taxa and diversity 

indices, was not changed by rotenone or antimycin 

treatment.

3. Insect emergence was not affected by rotenone or 

antimycin treatments.

Acknowledgments

We thank R. E. Lennon and J. B. Hunn, Fish 

Control Laboratory, LaCrosse, Wisconsin, for direc-
11

tion and financial support; R. Schoettger, FishPesticide Research Laboratory, Columbia, Missouri, 

for supplying pond facilities; A. Witt, Jr. and R. O. 

Anderson, Missouri Cooperative Fishery Research 

Unit, Columbia, for consultation; and W. Enns, 

Department of Entomology, University of Missouri, 

for aid in identifying benthic insects. Additional 

financial support was provided by the Paul K. 

Wehmiller Fellowship.

This paper is a contribution from the Missouri 

Cooperative Fishery Research Unit, which is jointly 

supported by the Missouri Department of Conservation; the University of Missouri, Columbia; and the 

U.S. Fish and Wildlife Service.

References

Anderson, R.O. 1959. A modified flotation technique for 

sorting bottom fauna. Limnol. Oceanogr. 4:223-225.

Brown, D.C., and R.C. Ball. 1942. An experiment in the 

use of derris root (rotenone) on the fish and fish-food 

organisms of Third Sister Lake. Trans. Am. Fish. Soc. 

72:267-284.

Gushing, C.E., and J.R. Olive. 1956. Effects of toxaphene 

and rotenone upon macroscopic bottom fauna of two 

northern Colorado reservoirs. Trans. Am. Fish. Soc. 

86:294-301.

Gilderhus, P.A., B.L Berger, and R.E. Lennon. 1969. Field 

trials of antimycin A as a fish toxicant. U.S. Fish Wildl. 

Serv., Invest. Fish Control 27. 21 pp.

Kennedy, H.D., L.L. Eller, and D.F. Walsh. 1970. Chronic

effects of methoxychlor on bluegills and aquatic invertebrates. U.S. Fish Wildl. Serv., Tech. Pap. 53.18 pp. 

Kinney, E.C. 1968. Rotenone in fish pond management.

U.S. Fish Wildl. Serv., Fish. Leafl. 576 (revised). 7 pp. 

Lennon, R.E., and B.L. Berger. 1970. A resume on field

applications of antimycin A to control fish. U.S. Fish

Wildl. Serv., Invest. Fish Control 40. 19 pp. 

Lesser, B.R. 1972. The acute toxicities of antimycin A

and juglone to selected aquatic organisms. M.S. Thesis,

Univ. of Wisconsin, LaCrosse. 41 pp. 

Penick, S.B. and Company. 1963. Noxfish and ProNoxfish for fisheries management. S.B. Penick and

Company, New York. 35 pp. 

Schoettger, R.A., B.L. Berger, and P.A. Gilderhus. 1967.

Reclamation of Turquoise Lake, Leadville, Colorado.

U.S. Fish Wildl. Serv., Fish Control Laboratory,

LaCrosse, Wis. 20 pp. (Unpubl. manuscr.) 

Smith, D.W. 1972. Chemical reclamation of Fish Creek,

Montealm County, using Fintrol bars (antimycin).

Michigan Department of Natural Resources, Fisheries

Division. 5 pp. (Unpubl. manuscr.) 

Sublette, J.E., and M.S. Sublette. 1965. Family Chironomidae. Pages 142-181 in A catalog of the Diptera of North

America north of Mexico, U.S. Department of

Agriculture Handbook No. 276. 1696 pp. 

Walker, C.R., R.E. Lennon, and B.L. Berger. 1964.

Preliminary observations of toxicity of antimycin A to

fish and other aquatic animals. U.S. Fish Wildl. Serv.,

Invest. Fish Control 2 (Circ. 186). 18 pp. 

Wilhm, J.L. 1970. Range of diversity index in benthic

macroinvertebrate populations. J. Water Pollut. Control

Fed. 42:R221-R224. 

Wilhm, J.L., and T.C. Dorris. 1968. Biological

parameters for water quality criteria. BioStience

18:477-481.

13

Appendices

Appendix I, Community Dynamics in the Experimental Ponds, provides a description of the 

dynamics of benthic populations in ponds which are 

heavily vegetated and which lack fish. The absence of 

fish may modify species abundance and composition 

because of the accompanying marked reduction in 

predation on benthic organisms. The dense vegetation provides unusual cover, more niches, and 

presumably more food than may be available to 

benthos in nonvegetated habitats. Periods of spring 

emergence, summer buildup, and fall emergence of 

insects were closely associated with the seasonal 

development and decline of vegetation.

Appendix II, Changes in Density of Benthic

Organisms, presents the field data from all collections, plotted as number of organisms per square 

meter, June-October 1971 and April-August 1972, for 

control and toxicant-treated ponds. Values for 

representative species from these data (Figs. A3-A13) 

provided the basis for discussion and conclusions in 

the text.

Appendix III, Density of Midges Captured in 

Emergence Cages, shows the rate of capture 

(no./mVwk) of two genera of phantom midges and 24 

taxa of true midges in emergence cages, April-June 

1972, in two control ponds, in one pond treated with 

2.0 mg/1 of rotenone, and in two ponds treated with 

40 ft g/I of antimycin (Figs. A14-A18).

15

Appendix I

Community Dynamics in the 

Experimental Ponds

Our observations of seasonal changes in benthic 

populations describe community dynamics in ponds 

with extensive beds of vegetation and without fishes. 

Seasonal changes are presented in the following 

sequence: summer development, fall emergence, 

winter development, and spring emergence. These 

periods were not synchronous in all ponds but were 

closely approximated.

Summer development was characterized by rapid 

larval development, as a result of high temperature. 

This developmental period was disrupted in the first 

year of the study (1971) by the draining and refilling 

of the ponds in late April. Draining delayed the 

growth of macrophytes, increased bottom organic 

matter and subsequent growth of benthic algae, and 

later resulted in extremely dense populations of 

Chironomus attenuatus and Glyptotendipes barbipes. These species constituted almost the entire 

community of benthos. Their subsequent reduction 

followed the decline in benthic algae as developing 

beds of vegetation limited light penetration.

By mid-July most major genera typical of these 

pond communities (Table 6) were present, and the 

vegetation, which developed rapidly because the 

carbonate reserve was high, provided an abundant 

food source and a variety of niches for recolonization. 

This recolonization was hastened by the proximity of 

the study ponds to nearby ponds that had not been 

drained.

Distinctive trends occurred in the seasonal 

patterns of appearance and abundance for major 

members of the pond communities (Figs. Al and A2). 

The mayfly Caenis simulans, the dragonfly

Erythemis simplicicollis, and the damselfly Ischnura 

uerticalis showed late summer population increases. 

Of the true midges, Ablabesmyia peleenis, 

Pseudochironomus richardsoni, Tanytarsus, and 

Procladius subletti showed two emergence periods 

and a population buildup in midsummer.

The fall emergence period was characterized by a 

decline in larval populations. The decline was also 

associated with a partial decline and decomposition 

of vegetation, which caused high oxygen demand. 

The decline in midge larvae (Ablabesmyia peleenis, 

Pseudochironomus richardsoni, Procladius subletti, 

and Tanytarsus) was due to emergence (Appendix III, 

Figs. A14-A18). Reduction of other species was linked 

with stagnation.

The winter development period was characterized 

by slow larval development resulting from low 

temperature. Initially, the numbers of mayflies, 

dragonflies, and damselflies appeared to be large. 

Later, the numbers declined as larval size increased. 

A reverse trend characterized the true midges; 

densities were low in late October and high in early 

April (Appendix II, Figs. A3-A13).

The spring emergence period was characterized by 

intensified emergence of genera that pupate 

throughout the year, and also by the emergence of the 

genera that pupate once a year. The highly distinctive seasonal emergence pattern of the true midges 

(Chironomidae) is described for the months of April, 

May, and June in Table Al. The total emergence 

resulted in the smallest number of individuals and in 

the lowest values for species diversity indices found 

throughout the year.
16

MAYFLIES

Ca/fibaetis Caenis

DRAGONFLIES

Libel Iu la ««

Erythemis

DAMSELFLIES

PHANTOM MIDGES

Jan I Feb iMarlApr I May I Jun I JuMAug I Sep I Oct I Nov I Dec

Months

Fig. Al. Schematic presentation of trends in seasonal abundance of the most common 

dragonflies, damselflies, and phantom midges, collected from nine experimental ponds (A-I) 

near Columbia, Missouri, in 1971.
17

Ablabesmyia

Pseudochironomus

Tanytarsus

Clinotanypus

Chironomus

Jan IFeb I Mar I Apr I May I Jun ' Jul ' Aug 'Sep ' Oct 'Nov I Dec

Months

Fig. A2. Schematic presentation of trends in seasonal abundance of seven of the 

most common midges collected from nine experimental ponds (A-I) near Columbia, 

Missouri, in 1971.
18

Table Al. Seasonal emergence patterns for midges (Chironomidae) in experimental fish ponds A to I, FishPesticide Research Laboratory, Columbia, Missouri, April-June 1972. Presence of identifying letter 

indicates emergence from that pond.

Species April May June

Pseudochironomus richardsoni 

Tanytarsus sp. 

Dicrotendipes nervosus 

Procladius bellus 

Ablabesmyia peleenis 

Endochironomus nigricans 

Psectrocladius dyari

Lauterborniella varipennis 

Larsia planes is 

Clinotanypus pinguis

Polypedilum simulans 

Chironomus attenuates

ABEHI 

ABEHI 

--EHI 

ABEHI 

ABEHI 

 E 

TJ

A 

 E 

ABEHI 

ABEHI 

A-EHI 

-BEHI 

ABEHI 

A 

A -HI

ABEHI 

ABEHI 

ABEHAB 

TTHT

-EHI

ABEHI 

A-EHI 

ABEHI 

ABEHI 

ABEHI 

A HRTT

A TTH

ABEHI 

ABEHI 

ABEHI 

A __

TITTHT

ABEHI 

 HI
19

Appendix II

Changes in Density of Benthic Organisms in 

Heavily Vegetated Ponds Lacking Fish Populations, June-October 1971 and April-August 

1972

I I

Callibaetis

Caen is 

Liballula

Tramea 

Erythemis

Enallagma

Ischnura 

Sayomyia

-1000

L 0

OLIGOCHAETA

JUN JUL AUG 

1971

SEP OCT APR MAY JUN 

1972

JUL AUG

Fig. A3. Changes in density (no./m2) of mayflies (Callibaetis, Caenis), dragonflies (Libellula, Tramea, Erythemis), 

damselflies (Enallagma, Ischnura), phantom midge (Sayomyia), and aquatic earthworms (Oligochaeta) in 

control Pond A at the Fish-Pesticide Research Laboratory, Columbia, Missouri, June-October 1971 and AprilAugust 1972. The short vertical bars along the baseline indicate time of application of toxicants in the treated 

ponds.
20

TT

I I

Ablabesmyia

Pseudochironomus

Procladius 

Chironomus

Tanytarsus

r 1000

- 0

JUN JUL AUG 

1971

OCT MAY JUN 

1972

JUL AUG

Fig. A4. Changes in density (no./m2 ) of midges (Ablabesmyia, Pseudochironomus, 

Procladius, Chironomus, Tanytarsus) in control Pond A at the Fish-Pesticide 

Research Laboratory, Columbia, Missouri, June-October 1971 and April-August 

1972. The short vertical bars along the baseline indicate time of application of 

toxicants in the treated ponds.

^1000

L- 0

Callibaetis 

Caenis

Libellula

Tramea

Erythemis

Enallagma 

Ischnura

Sayomyia

Physa

Gyraulus

OLIGOCHAETA

AUG 

1971

SEP OCT APR MAY I JUN 

1972

1 JUL AUG

Fig. A5. Changes in density (no./m2 ) of mayflies (Callibaetis, Caenis), dragonflies 

(Libellula, Tramea, Erythemis), damselflies (Enallagma, Ischnura), phantom 

midge (Sayomyia), snails (Physa, Gyraulus) and aquatic earthworms 

(Oligochaeta) in control Pond B at the Fish-Pesticide Research Laboratory, 

Columbia, Missouri, June-October 1971 and April-August 1972. The short vertical 

bars along the baseline indicate time of application of toxicants in the treated 

ponds.
21

Ablabesmyia

Pseudochironomus

-1000

- 0

Tanytarsus

I

Tanytarsus

II

JUN' JUL AUG 

1971

SEP'OCT 1 APR' MAY ' JUN' JUT' AUG 

1972

 7 r

Fig. A6. Changes in density (no./m2) of midges Ablabesmyia, Pseudochironomus, 

Procladius, Chironomus, and two unidentified species of Tanytarsus in control 

Pond B at the Fish-Pesticide Research Laboratory, Columbia, Missouri, JuneOctober 1971 and April-August 1972. The short vertical bars along the baseline 

indicate time of application of toxicants in the treated ponds.

L- 0

JUN JUL AUG 

1971

OCT

Caltibaetis

Caen is

Libellula

Tramea

Erythemis

Enatlagma 

Ischnura

Sayomyia 

Physa

Gyraulus

OLIGOCHAETA

MAY ' JUN 

1972

JUL AUG

Fig. A7. Changes in density (no./m2) of mayflies (Collibaetis, Caenis), dragonflies 

(Libellula, Tramea, Erythemis), damselflies (Enallagma, Ischnura), phantom 

midge (Sayomyia), snails (Physa, Gyraulus) and aquatic earthworms (Oligochaeta) 

in Pond E, treated with 2 mg/1 of rotenone, at the Fish-Pesticide Research 

Laboratory, Columbia, Missouri, June-October 1971 and April-August 1972. The 

short vertical bars along the baseline indicate time of application of toxicants in the 

treated ponds.
22

r 1000

Ablabesmyia

Pseudochironomus

Glyptotendipes

Endochimnomus

Procladius 

Dicrotendipes

Chironomus

Tanypus 

Clinotanypus

JUN JUL ' AUG ' SEP ' OCT 

1971

MAY ' JUN ' JUL ' AUG 

1972

Fig. A8. Changes in density (no./m2) of midges Ablabesmyia, Pseudochironomus, 

Glyptotendipes, Endochironomus, Procladius, Dicrotendipes, Chironomus, 

Tanypus, Clinotanypus, and two unidentified species of Tanytarsus in Pond E, 

treated with 2 mg/1 rotenone, at the Fish-Pesticide Research Laboratory, Columbia, Missouri, June-October 1971 and April-August 1972. The short vertical bars 

along the baseline indicate time of application of toxicants in the treated ponds.

Cal/ibaetis

Caenis

Libellula

Tramea

Erythemis

Enallagma

Ischnura 

Sayomyia

Physa

Helisoma 

PELECYPODA

r- 1000

COLEOPTERA

JUN APR MAY JUN 

1972

JUL

Fig. A9. Changes in density (no./m2) of mayflies (Callibaetis, Caenis), dragonflies 

(Libellula, Tramea, Erythemis), damselflies (Enallagma, Ischnura), phantom 

midge (Sayomyia), snails (Physa, Helisoma), clam (Pelecypoda) and beetles 

(Coleoptera) in pond H treated with 40 /zg/1 of antimycin at the Fish-Pesticide 

Research Laboratory, Columbia, Missouri, June-October 1971 and April-August 

1972. The short vertical bars along the baseline indicate time of application of 

toxicants in the treated ponds.
23

OLIGOCHAETA

Gyraulus 

.-1000

- 0

JUN JUL AUG 

1971

OCT APR MAY JUN 

1972

JUL AUG

Fig. A10. Changes in density (no./m2) of aquatic earthworms (Oligochaeta) and 

snails (Gyraulus) in Pond H, treated with 40 yug/1 of antimycin, at the FishPesticide Research Laboratory, Columbia, Missouri, June-October 1971 and AprilAugust 1972. The short vertical bars along the baseline indicate time of 

application of toxicants in the treated ponds.

TT

Ablabesmyia

Pseudochironomus

Procladius 

Tanytarsus I

Tanytarsus - II 

Chironomus

Dicrotendipes 

C/inotanypus

,- 1000

- 0

JUL AUG 

1971

OCT APR MAY JUN 

1972

AUG

Fig. All. Changes in density (no./m2 ) of midges Ablabesmyia, 

Pseudochironomus, Procladius, Chironomus, Dicrotendipes, Clinotanypus, and 

two unidentified species of Tanytarsus in Pond H, treated with 40 jug/1 of 

antimycin, at the Fish-Pesticide Research Laboratory, Columbia, Missouri, JuneOctober 1971 and April-August 1972. The short vertical bars on the baseline 

indicate time of application of toxicants in the treated ponds.
24

Callibaetis 

Caen is

Libellula

Tramea 

Erythemis

Enallagma 

Ischnura 

Sayomyia 

Physa

Gyraulus

OLIGOCHAETA

i- 1000

JUN ' JUL 1 AUG'SEP' OCT 

1971

APR' MAY ' JUN « JUL 

1972

AUG

Fig. A12. Changes in density (no./m2) of mayflies (Callibaetis, Caenis), 

dragonflies (Libellula, Tramea, Erythemis), damselflies (Enallagma, Ischnura), 

phantom midge (Sayomyia), snails (Physa, Gyraulus), and aquatic earthworms 

(Oligochaeta) in Pond I, treated with 40 //g/1 of antimycin, at the Fish-Pesticide 

Research Laboratory, Columbia, Missouri, June-October 1971 and April-August 

1972. The short vertical bars along the baseline indicate time of application of 

toxicants in the treated ponds.

Ablabesmyia

Pseudochironomus

Procladius

Tanytarsus - I

Tanytarsus - II

JUN APR ' MAY ' JUN ' JUL ' AUG 

1972

Fig. A13. Changes in density (no./m2 ) of midges Ablabesmyia, Pseudochironomus, 

Procladius, Chironomus, Clinotanypus, Tanypus, Harnischia, and two unidentified species of Tanytarsus in Pond I, treated with 40 /ig/1 of antimycin, at the 

Fish-Pesticide Research Laboratory, Columbia, Missouri, June-October 1971 and 

April-August 1972. The short vertical bars along the baseline indicate time of 

application of toxicants in the treated ponds.
25

Appendix III

Density of Phantom Midges and True Midges

Captured in Emergence Cages in Two Control

and Three Treated Ponds, April-June 1972

Endochironomus nigricans 

Glyptotendipes baripes

Monopelia sp. 

Pseudochironomus richardsoni

Tanytarsus -1 

Dicrotendipes nervosus

Lauterborniella varipennis

Procladius bellus

Ablabesmyia peleenis

Larsia planesis

Clinotanypus pinguis

Polypedilum trigonus 

Harnischia collator

Chaoborus americanus

Sayomyia punctipennis

APRIL MAY JUNE

Fig. A14. Density (no./m2 per week) of phantom midges (Chaoborus and 

Sayomyia) and true midges (other taxa shown) captured in emergence cages in 

control Pond A at the Fish-Pesticide Research Laboratory, Columbia, Missouri, 

April-June 1972. (The figure includes one unidentified species of Tanytarsus.)
26

Labrundinia pellosa 

Pseudochironomus richardsoni 

Lauterborniella varipennis 

Dicrotendipes nervosus

Tanytarsus I

Tanytarsus II 

Procladius bellus 

Procladius subletti 

Ablabesmyia peleenis

Larsia planesis

Psectrocladius dyari 

Clinotanypus pinguis

Polypedilum simulans 

Harnischia collator 

Harnischia potomogeti

Sayomyia punctipennis

i- 40

L. 0

APRIL MAY JUNE

Fig. A15. Density (no./m2 per week) of phantom midges (Sayomyia) and true midges (other taxa 

shown) captured in emergence cages in control Pond B at the Fish-Pesticide Research 

Laboratory, Columbia, Missouri, April-June 1972. (The figure includes two unidentified species 

of Tanytarsus.)
27

Lauterborniella varipennis

Labrundinia pellosa 

Monopelia sp.

Pseudochironomus richardsoni

Dicrotendipes nervosus 

Dicrotendipes modestus 

Tanytarsus I

Tanytarsus - II

Procladius bellus

Procladius subletti 

Ablabesmyia peleenis

Larsia planesis

Psectrocladius dyari

Clinotanypus pinguis

Tanypus punctipennis 

Tanypus neopunctipennis 

Polypedilum simulans 

Polypedilum trigonus 

Harnischia collator 

Endochirpnomus nigricans 

Harnischia potomogeti

Sayomyia punctipennis

Chaoborus americanus

APRIL MAY JUNE

Fig. A16. Density (no./m2 per week) of phantom midges (Sayomyia, Chaoborus) and true 

midges (other taxa shown) captured in emergence cages in Pond E, treated with 2.0 mg/1 of 

rotenone, at the Fish-Pesticide Research Laboratory, Columbia, Missouri, April-June 1972. 

(The figure includes two unidentified species of Tanytarsus.)
28

Labrundinia pellosa 

Monopelia sp.

Dicrontendipes nervosus 

Dicrontendipes modestus 

Polypedilum trigonus

Pseudochironomus richardsoni

Chironomus sp. 

Tanytarsus -1

Lauterborniella varipennis

Procladius belfus

Polypedilum simulans 

Tanytarsus - If

Larsia planesis

Endochironomus nigricans 

Clinotanypus pinguis

Tanypus punctipennis 

Tanypus neopunctipennis 

Harnischia collator 

Harnischia monochromus

Ablabesmyia peleenis

Sayomyia punctipennis 

Chaoborus americanus

APRIL MAY JUNE

Fig. A17. Density (no./m2 per week) of phantom midges (Sayomyia, Chaoborus) and true 

midges (other taxa shown) captured in emergence cages in Pond H, treated with 40 yu g/1 of 

antimycin, at the Fish-Pesticide Research Laboratory, Columbia, Missouri, April-June 

1972. (The figure includes two unidentified species of Tanytarsus.)
29

Lauterborniella varipennis 

Monopelia sp.

Pseudochironomus richardsoni 

Dicrotendipes nervosus 

Dicrotendipes modestus

Labrundinia pellosa

Tanytarsus -1 

Tanytarsus - II

Procladius bellus 

Chironomus sp.

Ablabesmyia peleenis

Harnischia collator 

Harnischia monochromus

Larsia planesis

Polypedilum simulans 

Clinotanypus pinguis 

Tanypus punctipennis

Tanypus neopunctipennis

Sayomyia punctipennis

r-40

u 0

APRIL MAY JUNE

Fig. A18. Density (no./m2 per week) of phantom midge (Sayomyia) and true midges (other 

taxa shown) captured in emergence cages in Pond I, treated with 40 jug/1 of antimycin, at 

the Fish-Pesticide Research Laboratory, Columbia, Missouri, April-June 1972. (The figure 

includes two unidentified species of Tanytarsus.)

Aquatic Macroinvertebrates in a Small Wisconsin

Trout Stream Before, During, and Two Years After

Treatment with the Fish Toxicant Antimycin1

by 

Gerald Z. Jacob! and Donald J. Degan2

College of Natural Resources, University of Wisconsin 

Stevens Point, Wisconsin 54481

Abstract

Benthos and benthic drift were sampled periodically in Seas Branch Creek (Vernon County, 

Wisconsin) for 5 months before and for 2 years after the stream was treated with antimycin, and 

over the same period in nearby untreated Maple Dale Creek. During treatment on 4 October 

1972, antimycin concentrations varied from 17to44 /tg/1 at the two sampling station sin Seas 

Branch Creek. Populations of macroinvertebrates were drastically reduced 2 days after 

treatment, but all common taxa identified before treatment were present in the stream 1 year 

later. Estimated biomass reductions of living organisms 2 days after treatment were as high as 

50% for one caddis fly, Hydropsyche sp., and 75% for another, Brachycentrus americanus; 70% 

for a crane fly, Antocha sp.; and nearly 100% for a mayfly, Baetis cingulatus, and a scud, 

Gammarus pseudolimnaeus. Summer biomass of Antocha and Brachycentrus did not regain 

pretreatment levels during the second year. The mortality of the riffle beetle, Optioservus 

fastiditus, was approximately 20% 9 days after treatment. A crayfish, Orconectes propinquus, 

was not affected by the treatment. The biomass of Gammarus, Prosimulium (a black fly), 

Baetis, and Hydropsyche was high during both summers after treatment. After 1 year, and 

continuing into the second year, total benthic biomass approached or exceeded that before 

treatment.

The piscicide antimycin is used for several purposes in fishery management, including eradication 

of nongame fish species that are suspected of 

competing with game fish. Antimycin and rotenone 

are the only two chemicals registered for such use by 

the Environmental Protection Agency.

In 1972 the Wisconsin Department of Natural 

Resources, in rehabilitating Seas Branch Creek, used 

antimycin to eradicate populations of catostomids 

and cyprinids. After removal of the nongame species, 

the stream was restocked with brown trout (Salmo 

trutta). This project afforded us the opportunity to 

observe the reactions of fish food organisms to 

antimycin.

The purpose of our study was to observe and 

document changes in nontarget aquatic macroinvertebrate populations in this small trout 

stream after the application of antimycin. Short- and

long-term effects of treatment were shown by quantitative and qualitative variations in benthic biomass 

and changes in the composition and abundance of 

drift organisms.

The effects of antimycin on the invertebrate fauna 

have been previously investigated in lakes or ponds, 

but not (to our knowledge) in a natural trout stream. 

Callaham and Huish (1969) and Rabe and Wissman 

(1969) reported that 5.0 /ig/1 applications of antimycin severely reduced populations of zooplankton 

in lakes and ponds, whereas Walker et al. (1964), 

Gilderhus et al. (1969), and Houf and Hughey (1973) 

found that fish-killing concentrations of antimycin 

had no significant effect on lake plankton and 

benthos. Snow (1974) observed no gross long-term 

detrimental effects on zooplankton and benthos 6 

years after antimycin treatment in Rush Lake, 

Wisconsin.

1 This research was supported by the U.S. Fish and Wildlife 

Service (Fish Control Laboratory Contract 

14-16-0008-13679).

2 Present address: Iowa Conservation Commission, 

Backbone State Park, Strawberry Point, Iowa 52026.

Study Area

Seas Branch Creek is in central Vernon County, in 

the hilly, unglaciated area of southwestern Wisconsin (Fig. 1). It is an 8-km-long tributary of the West

1
Fig. 1. Locations of study stations SBl and SB2 on Seas 

Branch Creek, which was treated with antimycin on 4 

October 1972, and control station MD on untreated 

Maple Dale Creek. The triangles near SBl and MD 

indicate flood control reservoirs.

Fork of the Kickapoo River. A 5-ha permanent 

impoundment on the stream, 4 km above its mouth, 

serves as a flood control reservoir.

Because Seas Branch Creek was treated with 

antimycin at its source, a nearby stream, Maple Dale 

Creek, which has similar physical, chemical, and 

biological characteristics, was selected as a control. 

This stream, 4 km long, is a tributary of Bishop 

Branch Creek, which is also a tributary of the West 

Fork of the Kickapoo River. The confluence of Bishop 

Branch Creek with the Kickapoo is 9 km downstream 

from that of Seas Branch Creek. A flood control 

structure, with no permanent pool, is about 300 m 

above the sampling station on Maple Dale Creek.

The upstream Seas Branch Creek station (SBl) was 

50 m above the impoundment, in the middle of a riffle 

70 m long. At this station the stream averaged 1.5 m 

in width and 12 cm in depth, and had a mean annual 

discharge of 0.11 mVs. The downstream Seas 

Branch station (SB2) was 800 m below the impoundment and was at the lower end of a riffle 130 m long.

The stream here was 3.3 m wide and 18 cm deep, and 

had a mean annual discharge of 0.17 mVs. The 

Maple Dale Creek control station (MD) was 6 m 

above the confluence of Maple Dale and Cook Creeks 

at the lower end of a riffle 40 m long. The stream here 

was 2.5 m wide and 15 cm deep, and had a mean 

annual discharge of 0.15 mVs.

Water quality data were taken at each station 

throughout the study period (Tables 1, 2, and 3). 

Temperatures ranged from 0 to 20 C; average 

temperatures at SBl were 2 to 4 C lower than at SB2 

or MD, or both, during the summer before and the two 

summers after treatment. Water chemistry differed 

little at the stations before, during, or after treatment. 

Dissolved oxygen concentrations were high (8.5 to 

15.1 mg/1; 81 to 126% saturation). The calcareous 

composition of the numerous bluffs along both 

streams is reflected in the average water quality 

values: pH, 8.3; total alkalinity, 215 mg/1; and 

conductivity, 434 /A mhos. Turbidity was low, 

averaging 0.29 Jackson Turbidity Unit (JTU) during 

periods of normal flow (Tables 1, 2, and 3). Average 

discharge at all stations was about twice as high in 

1973 as in 1972 or 1974. Slow release of cold 

groundwater after high precipitation in 1973 may 

have been responsible for the lower water 

temperatures in 1973 and 1974.

The stream bed at all three stations was composed 

largely of rough, angulate stones, mostly 5 to 10 cm 

in diameter (some up to 30 cm). Small amounts of 

gravel and sand were present; interstitial organic 

litter was primarily autochthonous plant material. 

The stones at SB2 and MD were loose, but at SBl 

many were imbedded in clay. Water crowfoot (Ranunculus aquatilis), the dominant stream vegetation, 

covered 8 to 50% of the stream bed throughout the 

year at all three stations. Limited amounts of 

pondweed (Potamogeton sp.) were present in the 

control stream, and watercress (Nasturtium officinale) along the water's edge in the treatment 

stream.

Methods

Antimycin (Fintrol-concentrate formulation) was 

applied to Seas Branch Creek from 0000 to 0920 h on 

4 October 1972, under the direction of the Cold Water 

Research Group of the Wisconsin Department of 

Natural Resources. Errors in calculating dosages and 

equipment failure resulted in treatment values much 

higher than the intended concentrations of 10 /LI g/1. 

The concentration was 25 /j. g/1 for the first 3 h and 

40 fj. g/1 for the next 6-1/3 h at SBl and 17 jtg/1 for 

2 hand 44 ;u, g/1 for 7 h at SB2. Antimycin drip sites 

were about 270 m above each of the two stations.
Table 1. Physical and chemical data from the upper treatment station (SBl) of Seas Branch Creek, 1972-74.

Dissolved 02

Date

1972

15 May

15 June

15 July

15 Aug

3 Oct

6 Oct

13 Oct

1 Nov

1 Dec

1973

15 Jan

15 March

15 May

16 July

15 Sept

6 Oct

10 Oct

1974

20 April

17 May

30 July

2 Oct

Mean

Temp

Air

21

15

32

25

18

10

10

8

-6

-12

1

15

24

10

11

1

10

16

21

6

11.8

<°C)

Water

16

12

17

14

11

10

10

8

4

1

6

8

14

9

9

5

9

11

14

9

9.9

ppm

11.7

10.1

9.2

10.0

10.1

10.2

11.0

10.6

13.0

14.3

13.4

12.8

11.4

9.9

10.3

12.4

10.2

10.4

9.8

10.0

11.0

Percent 

saturation

122

96

98

100

95

94

102

93

102

104

111

112

115

90

95

100

90

97

98

90

100

pH

8.8

8.5

8.1

8.5

8.3

8.4

8.5

8.3

8.2

8.3

8.2

8.6

8.3

8.0

8.1

8.1

8.1

8.2

8.0

7.4

8.2

Total 

alkalinity 

(ppm)

186

194

186

203

215

223

213

215

207

203

210

218

203

198

236

209

210

215

233

207

209

Turbidity 

(JTU)

0.16

0.27

0.12

0.30

0.27

0.57

0.36

0.19

0.35

0.30

0.21

0.11

0.22

0.27

0.17

0.20

0.20

0.50

0.07

0.16

0.25

Conductance 

( fj mho/cm)

ND

440

440

420

520

500

480

420

400

400

380

450

460

440

450

410

350

420

400

410

430

Discharge

(mVs)

0.08

0.08

0.08

0.07

0.09

0.08

0.08

0.10

0.08

0.08

0.15

0.17

0.19

0.16

0.14

0.13

0.11

0.04

0.09

0.10

0.11

On 16 August 1972 the gate of the impoundment on 

Seas Branch Creek was opened and the reservoir 

drained to an area of 1 ha, where it was maintained 

until after treatment to reduce the amount of 

antimycin needed. When the gate was closed 2 days 

after treatment, the impoundment refilled in about 2 

weeks. This refilling reduced the water flow at SB2 by 

about one-half for most of that period.

Benthic samples were collected a total of 20 times 

during the 28-month study. On each sampling date, 

four samples were taken at SBl and five each at SB2 

and MD with a modified Hess circular 0.05-m2 bottom 

sampler (with a net of 7.5 meshes/cm), similar to that 

described by Waters and Knapp (1961). At each 

station one sample came from vegetation and the rest 

from the rubble substrate. The biomass of benthos in 

the vegetation samples was prorated into the total 

benthic biomass according to the estimated percentage of the riffle area covered with vegetation at each 

sampling period. This percentage was assigned 

subjectively on the basis of the estimated change in

vegetative cover in each riffle area from one sampling 

period to another.

Drifting organisms were collected in vertical nets of 

7.5 meshes/cm supported by a 0.1-m2 square frame 

attached to a board placed on the stream bottom. 

Three nets were used at SB2 and MD, and two at SBl 

to collect samples for 10 min, four or five times in each 

24-h period before treatment. Sampling times included sunrise, sunset, midday, and midnight, which 

represented times of major drift (Waters 1972). Drift 

samples were taken every 3 h for 24 h during 

treatment (starting 3 h before application of antimycin) and then every 6 h for 36 h thereafter. Total 

drift was calculated by the methods of Waters (1962). 

Current velocities were measured with a Gurley 

pigmy current meter, no. 625. Velocities were used to 

calculate discharge, which was then used to calculate 

drift rates.

Samples of invertebrates were strained with a 0.5- 

mm mesh soil screen and stored in 70% isopropyl 

alcohol. Organisms were separated from detritus and
Table 2. Physical and chemical data from the lower treatment station (SB2) of Seas Branch Creek, 1972-74.

Dissolved 02

Date

1972

15 May

15 June

15 July

15 Aug

3 Oct

6 Oct

13 Oct

1 Nov

1 Dec

1973

15 Jan

15 March

15 May

16 July

15 Sept

6 Oct

10 Nov

1974

20 April

17 May

30 July

2 Oct

Mean

Temp

Air

18

17

32

24

17

10

10

8

-6

-12

1

15

24

10

11

0

10

16

20

7

12.1

(°C)

Water

14

15

20

18

12

11

10

8

4

1

6

12

17

12

11

4

9

12

17

10

11.2

ppm

11.7

9.8

10.0

11.6

10.3

10.8

13.0

11.6

12.5

14.3

14.1

13.1

11.1

9.1

10.0

12.2

9.6

10.3

8.9

10.4

11.2

Percent 

saturation

115

100

114

125

98

102

119

102

100

103

117

125

118

85

95

98

85

100

95

95

105

pH

8.7

8.6

8.0

8.5

8.3

8.5

8.5

8.5

8.1

8.0

8.3

8.5

8.1

8.0

8.1

8.0

7.8

8.1

8.2

7.7

8.3

Total 

alkalinity 

(ppm)

186

199

190

201

220

220

240

203

215

224

185

197

204

220

214

214

202

217

220

232

210

Turbidity

(JTU)

0.11

0.16

0.73

0.44

0.52

0.30

0.42

0.20

0.19

0.40

7.20

0.58

0.51

0.42

0.21

0.31

0.16

0.20

0.10

0.35

0.35

Conductance 

(/* mho/cm)

ND

420

420

400

500

500

520

440

420

460

320

425

420

420

440

420

350

400

410

400

425

Discharge

(mVs)

0.10

0.11

0.12

0.10

0.16

0.15

0.05

0.20

0.15

0.12

0.22

0.24

0.26

0.29

0.31

0.28

0.18

0.06

0.08

0.16

0.17

identified, and body length was measured. Identifications were verified by the museum staff of the 

Smithsonian Institution, Washington, B.C. In estimating the biomass of individual organisms from 

the length, we followed Hynes (1961), Hynes and 

Coleman (1968), Hamilton (1969), and Jacobi (1969) 

in assuming that an insect's shape is that of a 

cylinder five times as long as wide, that its volume 

increases by the cube of the length, that its specific 

gravity is 1.05, and that 3.3 * 10" 5 g is the weight of a 

1-mm length unit. Insects were not weighed because 

weight loss varies widely after preservation (Howmiller 1972). Crayfish were wet-weighed after surface 

water had been removed by blotting.

Additional specimens from some of the major taxa 

were nonquantitatively collected from the treatment 

and control stream on 6, 13, and 19 October and 4 

November 1972, and the percentages of dead 

organisms noted (Table 4). We used these values to 

estimate the percentages of dead organisms in the 

benthic samples for these periods; biomass was

adjusted to show only the weight of living organisms. 

The taxa collected are given in Table 5; average 

monthly values for water temperature, discharge, 

vegetative cover, and total benthic biomass before 

and after treatment in Table 6; and the estimated 

biomass (g/m2) for each organism at each station on 

each collection date in Tables 7-9.

Results 

Total Benthos and Drift

The aquatic macroinvertebrates collected included 

33 identified to genus or genus and species, 5 to 

family, and 2 to order (Table 5). The dominant forms 

on the basis of pretreatment biomass (in order of 

abundance) were Hydropsyche (caddis fly), Orconectes propinquus (crayfish), Chironomidae 

(midges), Optioservus fastiditus (riffle beetle), Antocha (crane fly), Brachycentrus americanus 

(caddis fly), Gammarus pseudolimnaeus (scud),
Table 3. Physical and chemical data from the control station (MD) of Maple Dale Creek.

Dissolved &2

Date

1972

15 May

15 June

15 July

15 Aug

3 Oct

6 Oct

13 Oct

1 Nov

1 Dec

1973

15 Jan

15 March

15 May

16 July

15 Sept

6 Oct

10 Nov

1974

20 April

17 May

30 July

2 Oct

Mean

Temp

Air

18

15

28

28

16

13

6

9

-6

-11

1

15

24

15

11

1

16

18

21

7

12.3

<°C)

Water

18

13

20

20

13

11

10

8

4

0

5

15

19

10

10

5

13

13

17

7

11.6

ppm

8.5

11.6

10.2

11.0

10.1

8.6

11.0

10.9

13.8

15.1

14.5

12.4

9.9

10.4

11.8

13.1

10.1

11.2

9.7

12.3

11.3

Percent 

saturation

93

113

116

124

98

81

101

95

107

106

117

126

105

95

108

105

98

110

102

105

105

pH

8.6

8.6

8.6

8.5

8.4

8.5

8.5

8.5

8.3

8.2

8.4

8.7

8.1

8.1

8.1

8.1

8.4

8.3

8.3

7.6

8.3

Total 

alkalinity 

(ppm)

191

216

219

213

238

235

226

222

230

223

229

210

238

228

206

230

224

223

247

248

225

Turbidity 

(JTU)

0.40

0.23

0.23

0.13

ND

0.47

0.30

0.60

0.10

0.30

0.21

0.21

0.55

0.30

0.17

0.19

0.10

0.35

0.10

0.20

0.27

Conductance 

(fji mho/cm)

ND

420

470

420

ND

560

540

450

440

500

420

440

460

450

480

440

345

420

425

385

447

Discharge

(mVs)

0.09

0.08

0.10

0.07

0.13

0.11

0.09

0.15

0.11

0.10

0.33

0.25

0.16

0.20

0.17

0.17

0.17

0.06

0.12

0.10

0.14

Baetis cingulatus (mayfly), and Prosimulium sp. 

(black fly).

Drift rates increased noticeably during treatment 

at both stations, reaching 50 g/h at SB1 18 h after 

treatment and nearly 169 g/h at SB2 9 h after 

treatment (Fig. 2). Other increases in drift rates were 

associated with increased densities or emergence of 

the dominant taxa before and after treatment (Fig. 3). 

The high values for total drift at SB2 in July and 

October 1974 are attributed largely to scuds, which in 

these 2 months constituted 67% and 34% of the total 

benthic biomass.

Total benthic biomass decreased at SB1 and SB2 

(as well as at MD) immediately after treatment but 

attained a peak in the treated stream later in the fall, 

resuming the generally increasing trend that began 

in early fall (Fig. 4). One year after treatment, total 

benthic biomass in Seas Branch Creek approached or 

exceeded that found before treatment. This trend also 

was suggested during the second year after treatment, although the order of dominating taxa differed 

between years.

The decrease in benthos at the control station 

(MD) during the time of treatment probably reflects a 

sampling error, rather than a true decrease in density 

of organisms; the samples were collected from a riffle 

area which had been disturbed during earlier sampling. Neither drift samples (Fig. 3) nor nonquantitative benthic samples (Table 4) indicated abnormally high values for dead or drifting organisms 

at MD during the time of treatment.

To compare the pretreatment and posttreatment 

data, we calculated the average biomass (without 

crayfish) of samples collected annually at each 

station in May, July, and October (Table 6). Biomass 

reached maximum levels during these months, which 

span the major growing season. Vegetative cover 

more than doubled during the year after treatment at 

8B2 and during the second year after treatment at 

8B1, but changed little at the control station. Benthic 

biomass also followed this general pattern in the 

treatment stream but, again, remained nearly constant in the control stream (Table 6).
Table 4. Summary of total numbers of invertebrates 

collected and percentage dead at the three study 

stations on different dates after the antimycin 

treatment on 4 October 1972. (Dashes indicate no 

sample taken; P = present, but not counted).

Station

Date (1972) 

and taxon 1 

(L = larvae)

6 October3

Baetis

Brachycentrus

Gammarus

Hydropsyche

Optioservus (L)

Antocha (L)

Stenonema

Orconectes

13 October

Baetis

Brachycentrus

Gammarus

Hydropsyche

Optioservus (L)

Antocha (L)

Stenonema

Orconectes

19 October

Baetis

Brachycentrus

Gammarus

Hydropsyche

Optioservus (L)

Antocha (L)

Stenonema

Orconectes

4 November

Baetis

Brachycentrus

Gammarus

Hydropsyche

Optioservus (L)

Antocha (L)

Stenonema

Orconectes

SB1

Total 

no.

77

47

49

51

32

41

11

0

1

12

17

58

33

7

4

3

9

5

9

19

26

9

3

10

0

10

4

5

2

2

2

0

Dead

(%)

13

53

37

12

16

63

9

0

100

50

18

40

15

43

25

0

0

40

0

58

4

33

0

0

0

80

25

0

0

50

0

0

SB2

Total 

no.

13

31

19

6

2

4

10

0

50

4

100

35

8

6

4

0

20

3

7

25

2

2

4

0

P

P

P

P

P

P

P

Dead

(%)

85

74

100

33

0

0

0

0

98

50

89

20

100

83

0

0

100

0

100

0

100

50

0

0

0

0

0

0

0

0

0

MD

Total 

no.

32

100

27

48

27

4

1

0

16

31

50

50

25

25

4

3

28

55

69

55

53

41

10

3

_

Dead

(%)

0

1

4

0

0

0

0

0

0

3

2

0

0

12

0

0

0

2

2

2

2

7

0

0

_

Data for SB2 on 6 October were obtained from observations on organisms placed in small containers before 

treatment.

Amphipoda (Scuds)

Immediately after treatment, Gammarus 

pseudolimnaeus decreased in the benthic samples 

(Fig. 4), and increased markedly in the drift (Fig. 2). 

The number of drifting dead and dying organisms 

reached a maximum 12 h after treatment at SB2 and 

18 h after treatment at SB1 (Fig. 2). By the second 

day after treatment the mortality of scuds was 

apparently 100% at SB2 but only 37% at SB1 (Table 4). 

Estimated benthic biomass of scuds at both treatment locations remained low during the winter after 

treatment but increased in the following summer to 

values far exceeding those of the previous year (Fig. 

4). Scuds were abundant in the benthos during the 

summer after treatment; they were also dominant in 

July 1974 at both treatment stations, making up 56% 

and 67% of the biomass (without crayfish) at SB1 and 

SB2. A drift rate at SB2 of 5 g/h in September 1973 

and about 25 g/h in July and 24 g/h in October 1974 

reflected this increased density of organisms (Fig. 3).

In the control stream, the biomass of scuds never 

varied significantly from one sample period to 

another (Fig. 4), and drift rates were low throughout 

the year (Fig. 3).

Diptera (Crane fly, 

Midges, Black fly)

Benthic biomass of the crane fly Antocha was 

reduced sharply by the treatment at both SB1 and 

SB2 (Fig. 4), and no live specimens were collected in 

the drift immediately after treatment. The drift of 

dead crane flies reached a peak 18 h after treatment 

at SB1 and 12 h after treatment at SB2 (Fig. 2). No 

living crane fly larvae were taken in benthic samples 

for 2 weeks at SB2 (none were found 2 days after 

treatment), whereas the maximum mortality of 63% 

at SB 1 2 days after treatment decreased gradually to 

50% (one of two specimens collected) 1 month later 

(Table 4). Benthic biomass of crane flies was about 

four times greater at SB2 than at SB1 before 

treatment but remained low for 1 year after treatment 

at both stations. The estimated biomass was high in 

the samples collected at SB 1 in November 1973, but 

was again low in April and May 1974. Emerging 

adults were not found at SB1 during May 1974, but 

were present in drift samples at SB2 and MD. Despite 

the large numbers of larval crane flies in the samples 

collected at SB1 in November 1973, the population did
Table 5. Macroinvertebrate taxa collected in the treatment stream, Seas Branch Creek, and the control

stream, Maple Dale Creek.a

Arthropoda 

Insecta 

Diptera

Chironomidae (midges) 

Tipulidae (crane flies)

Antocha

Hexatoma 

Simuliidae (black flies)

Prosimulium 

Empididae (dance flies)

Hermerodromia 

Rhagonidae (snipe flies)

Atherix variegata 

Stratiomyidae (soldier flies)

Hedriodiscus 

Tabanidae (horseflies)

Tabanus

Chrysops

Ephemeroptera (mayflies) 

Baetidae

Baetis cingulatus 

Heptageniidae

Stenonema 

Ephemerellidae

Ephemerella 

Trichoptera (caddis flies) 

Brachycentridae

Brachycentrus americanus 

Hydropsychidae

Hydropsyche

Cheumatopsyche 

Hydroptilidae

Ochrotrichia 

Helicopsychidae

Helicopsyche borealis 

Glossosomatidae

Protoptila

Glossosoma 

Limnephilidae 

Plecoptera (stoneflies) 

Perlodidae

Isoperla 

Nemouridae 

Coleoptera (beetles) 

Elmidae (riffle beetles)

Optioservus fastiditus

Stenelmis sandersoni 

Dytiscidae (diving beetles)

Odonata

Zygoptera (damselflies) 

Hemiptera (bugs) 

Corixidae (water boatmen)

Sigaria mathesoni 

Belostomatidae (giant water bug)

Lethocerus

Gerridae (water striders) 

Gerris 

Trepobates 

Crustacea 

Amphipoda 

Gammaridae (scud)

Gammarus pseudolimnaeus 

Decapoda (crayfish) 

Astacidae

Orconectes propinquus 

Arachnoidea

Hydracarina (water mites) 

Mollusca

Gastropoda (snails) 

Basommatophora 

Physidae

Physa obrussoides 

Pelecypoda (clams) 

Heterodonta 

Sphaeriidae 

Pisidium 

Annelida

Hirudinea (leeches) 

Rhynchobdellida 

Glossiphoniidae

Glossiphonia complanata 

Arhynchobdellida 

Erpobdellidae

Erpobdella punctata 

Oligochaeta (worms) 

Pleisopora

Tubificidae 

Platyhelminthes 

Turbellaria (flatworms) 

Tricladida 

Planariidae

Dugesia 

Nematomorpha

Gordiida (horsehair worms) 

Gordiidae 

Gordius

All forms shown were collected in both the treatment and control stream, with four exceptions: Erpobdella, Helicopsyche, 

and Nemoura were only in the treatment stream and Pisidium only in the control stream.
Table 6. Average monthly (May, July, and October>a) water temperature, discharge, vegetative 

cover, and benthic biomass at Seas Branch Creek 

stations SBl and SB2 and control station MD 

before (1972) and after (1973,1974) the antimycin 

treatment of Seas Branch Creek.

Station Water

and temp

year (°C)

Discharge

(mVs)

Estimated Benthic

vegetative biomass

cover (%) (g/m2)

SBl

1972

1973

1974

SB2

1972

1973

1974

MD

1972

1973

1974

15

10

11

15

13

13

17

15

12

0.08

0.17

0.08

0.13

0.27

0.10

0.11

0.19

0.11

10

10

23

11

27

17

11

9

7

56.5

49.7

114.8

61.1

105.6

111.0

96.0

93.2

100.3

Before treatment on 3 October 1972 for all stations.

not recover from the treatment as indicated by the 

sharp (nearly complete) overwinter decline, the lack 

of adults in the succeeding summer drift, and the near 

absence of the organisms in October 1974 (2 years 

after treatment).

The rate of emergence of crane flies was high in 

spring and decreased from May through September 

at the control station; the sharp decrease in biomass 

between March and May 1974 (Fig. 4) was 

presumably a result of emergence. Larval drift rates 

were low throughout the year at both treatment 

stations, except for the increase at the time of 

treatment (Fig. 3).

Drift rates of Chironomidae at SB2 increased 

sharply 21 h after treatment, peaked 12 h later, then 

declined gradually into the next week; drift at SBl 

increased slightly 15 h after treatment (Fig. 2). The 

biomass at both SBl and SB2 decreased slightly 

during treatment, then increased sharply in 

December 1972 (Fig. 5). At this time, midges 

dominated the biomass (without crayfish) at both 

treatment stations, contributing 57% at SBl and 63% 

at SB2. Apparently the larvae rapidly occupied 

habitats vacated by more sensitive organisms. 

Biomass then decreased throughout the year to low 

levels that approached pretreatment values. High 

drift rates of midges at SB2 in the year after 

treatment (Fig. 3) were attributed to overlapping 

hatches of the various species present.

Benthic biomass values of Chironomidae were low 

and fluctuated throughout the year at station MD; an 

increase in biomass similar to that at SBl and SB2 

occurred here after the treatment date, but never 

reached the levels found at the treated stations (Fig. 

5). Drift rates were low throughout the year at MD; the 

nearly 5 g/h in May 1974 (Fig. 3) reflected the 

slightly higher benthic biomass present then (Fig. 5).

Antimycin had no direct effect on Prosimulium sp. 

because black flies had emerged before treatment. 

Biomass at SB2 remained low through November; an 

increase began in January that reached a maximum 

of 98 g/m2 in July 1973 (Fig. 5), or 65% of the benthic 

biomass (without crayfish). Drift rates, which 

previously were low (not illustrated) increased with 

this large increase of Prosimulium. Biomass at SBl 

also peaked in July. A residual population was 

present at MD, throughout the year, but never made 

up a significant portion of the total benthic biomass 

(Fig. 5).

The dance fly Hemerodromia sp. which was present 

at all three stations in small numbers (but ranging up 

to 8 g/m2 at station MD in January 1973) throughout 

the year (Tables 7-9) appeared to be unaffected by the 

treatment; few specimens were in the drift, and no 

dead ones were found.

Ephemeroptera (Mayflies)

Many dead nymphs of Baetis cingulatus were 

observed at the time of treatment at SBl, and drift 

rates doubled (Fig. 6). At SB2, where the water was 

warmer, a major emergence had taken place before 

the treatment. Benthic biomass of this species 

therefore declined at both stations after treatment 

(Fig. 5). The benthic biomass of B. cingulatus 

increased 20-fold 1 year after treatment at SB2 and 

also increased greatly at SBl earlier in the year (Fig. 

5). The decrease in biomass at all stations in 

November 1973 (Fig. 5) was apparently caused 

largely by earlier increased drift of late instar 

nymphs and subimagoes (Fig. 7). The very high 

biomass levels at SB2 during the second summer 

after treatment were related to increased vegetation 

and the larger population of the generation in the 

preceding year. The decrease in biomass in October 

1974 at SBl was presumably due to earlier emergence.

The two periods of maximum emergence of B. 

cingulatus at MD were in May to July and late 

September to November. Benthic biomass increased 

here for each generation (Fig. 5), and drift was high at 

the time of emergence, which coincided with the time 

of antimycin treatment (Figs. 6 and 7).

The mayfly Stenonema sp. was present at the three 

sampling stations throughout the study; biomass 

was highest in the second year after treatment.
Mortality during treatment appeared to be initially 

low or nil at SB2, but five of six organisms (83%) 

collected 10 days after treatment were dead (Table 4). 

Another mayfly, Ephemerella sp., was not collected 

in 1972 or 1973 but appeared in 1974 at SB1 in April, 

May, and October and at SB2 and MD in May.

Trichoptera (Caddis flies)

Benthic biomass of the caddis fly Brachycentrus 

americanus was reduced immediately after treatment 

(Fig. 8), and drift increased sharply (Figs. 6 and 7). At 

SB 1, drift did not occur until 12 h after treatment and 

reached a maximum 3 h later (Fig. 6). Mortality at 

this station was about 53% 2 days after treatment and 

80% 1 month later (Table 4). Drift at SB2 doubled 

shortly after treatment (Fig. 6) and continued to be 

high for at least 2 days. Mortality was 74% on the 

second day after treatment and 100% 2 weeks after 

treatment (Table 4). This species seemed to become 

disoriented during the antimycin treatment. At SB2 

many organisms moved about sluggishly and 

crawled onto stream vegetation and stones. About 

50% then abandoned their cases and died.

Biomass of B. americanus remained low at both 

treatment stations during the first year after treatment, but increased considerably at SB1 (not at SB2) 

during the second year after treatment (Fig. 8).

This species overwintered as larvae and emerged in 

May through August in Maple Dale Creek. An early 

emergence in May 1973 preceded a rapid increase in 

biomass of the following generation (Fig. 8).

For the caddis fly Hydropsyche sp., the number of 

dead and dying in the drift at SB2 reached a 

maximum 9 h after treatment and decreased during 

the next week (Fig. 6). Mortality then increased 

gradually to 100% on 19 October (Table 4). Few drift 

organisms were taken after treatment at SB1, and the 

number increased only slowly into the next week (Fig. 

6). Mortality here was initially low and reached a 

maximum of only 58% 2 weeks later (Table 4). 

Biomass of Hydropsyche was reduced at both 

stations during treatment and increased slightly 

during the months after treatment (Fig. 8). We 

attributed this increase to recolonization by drift. The 

population appeared to have recovered during the 

year after treatment. Biomass levels at both treatment stations during the second summer after 

treatment exceeded those before treatment.

In 1972, benthic biomass of Hydropsyche was 

markedly lower in samples taken at MD on 6 and 13 

October than on 3 October or 1 November (Fig. 8). 

However, as mentioned earlier, this decrease was 

attributed to a sampling error as no increase in drift 

rates or die-off was observed during this period. 

Larvae in the 3 October and 1 November samples

were in the same size group, indicating that no 

emergence had occurred.

Hydropsyche produced one generation per year; 

emergence extended from May through August. Drift 

rates increased at the times of emergence (Fig. 7). 

Benthic biomass at all three stations showed decreasing trends after emergence, followed by an increase 

as the new generation developed (Fig. 8). Samples 

contained a wide range of instars because of the 

prolonged hatching time, as was observed also by 

Hynes (1961). Biomass increased in the fall. Medium 

size specimens (5-10 mm long) dominated the 

October-November samples and large ones 

(10-13 mm long) the late winter and early spring 

collections.

Coleoptera (Riffle beetle)

No noticeable changes in benthic biomass or drift 

of Optioservus fastiditus occurred during treatment, 

although benthos collections 10 days after treatment 

suggested a 15% and 20% mortality at stations SB1 

and SB2, respectively (Table 4). The biomass of O. 

fastiditus, represented by concurrent populations of 

larvae and adults, reached a peak at all stations at 

about the same time in 1972 and 1973 (Fig. 8). After 

the reduction or disappearance of organisms sensitive to antimycin, the larvae contributed 

significantly to the total benthic biomass e.g., up to 

70% at SB2 on 13 October 1972 (Table 8).

Decapoda (Crayfish)

No dead or dying Orconectes propinquus were 

observed during or after the antimycin treatment 

(Table 4). Because this organism is highly mobile, it 

was difficult to accurately evaluate its population 

density (Tables 7, 8, and 9). Many young of the year 

(1.2-2.0 cm long) were found at SB2 from May, June, 

or July through October in all years (Table 8).

Discussion

The application of high concentrations of antimycin (17-44 jUg/1) resulted in an immediate 

increase in drift rates and a temporary reduction in 

populations of five of nine major taxa, Gammarus 

pseudolimnaeus, Antocha, Baetis cingulatus, 

Brachycentrus americanus, and Hydropsyche. Orconectes propinquus was not affected by the treatment. The biomass of other organisms, such as 

Chironomidae, Optioservus fastiditus, and 

Prosimulium, increased during the months after 

treatment. Total benthic biomass (all taxa combined) 

during the two summers after treatment approached 

or exceeded that of the summer before treatment.
10

Table 7. Benthic biomass (g/m2) for station SBl of Seas Branch Creek above the impoundment, before and 

after treatment of the stream with antimycin on October 4,1972. a

Taxon

Diptera

Chironomidae

Antocha

larvae

pupae

Prosimulium

larvae

pupae

Hemerodromia

Other

Epheremoptera

Baetis

Stenonema

Ephemerella

Trichoptera

Hydropsyche

Brachycentrus americanus

Ochrotrichia

Glossosoma

Other

Plecoptera

Isoperla

Coleoptera

Optioservus fastiditus

larvae

adult

Stenelmis sandersoni

Amphipoda

Gammarus pseudolimnaeus

Mollusca

Physa obrussoides

Hirudinea

Erpobdella punctata

Miscellaneous

Benthic Biomass

without Orconectes

Decapoda

Orconectes propinquus

Total Benthic1 Biomass

1972

15 May

11.5

4.3

2.9

T

T

0

0.1

0.1

0

0

17.4

0

0.3

0

0.2

T

1.1

0.3

0.1

0.6

0

0

0.3

39.2

4.2

43.4

15 June

4.0

1.7

0.8

0.3

0

0

0.2

1.0

0

0

17.0

0.4

0.3

0

0.2

0

2.4

0.1

0.1

6.9

0

0

T

35.4

0.1

35.5

15 July

8.1

4.6

0.5

0.7

T

0.2

3.6

0.9

0

0

7.0

2.8

0

0

0.6

0

3.9

0.3

0.2

1.9

0

0

0.2

35.5

16.7

52.2

15 Aug

2.3

2.3

0.4

0.5

T

0.1

2.8

2.1

0.1

0

11.7

1.5

0

0

0.1

0

7.4

1.0

0.2

2.8

0

0.3

0.1

35.7

11.9

47.6

3 Oct

2.2

3.2

0

0.1

T

3.7

7.1

5.2

0.6

0

54.7

1.6

0

0

0.1

T

13.4

0.9

0.7

1.3

0

0

0.1

94.9

0

94.9

6 Oct

T

0.9

0

0

T

1.2

0.5

0.3

0.9

0

28.3

0.4

0

0

0.5

T

5.3

0.5

0.1

0.4

0

0.9

0

40.2

1.4

41.6

13 Oct

0.4

0.2

0

0

0

1.0

1.3

0

0

0

12.6

0.5

0

0

0.2

0

7.0

0.5

0.2

0.4

0

0

0

24.3

0

24.3

1 Nov

6.7

0.1

0

0

0

1.1

4.0

0

0.2

0

9.0

0.1

0

0

T

0

12.7

0.3

0.3

0.4

0.1

T

T

35.0

0

35.0

1 Dec

102.1

0.3

0

0

0

1.5

40.0

0

0.5

0

16.9

1.3

0

0

0.1

0.2

15.8

0.7

0.1

0.1

0

0

T

179.6

4.0

183.6

T = less than 0.05 g.
11

Table 7 Continued

15 Jan

23.7

0.3

0

0.2

0

3.9

14.8

T

0.1

0

25.8

0.8

0

0

0.4

T

12.2

1.0

0.1

0.2

0.3

T

T

83.8

3.6

87.4

15 Mar

9.9

0.2

0

0.1

0

0.1

15.2

3.9

0

0

19.1

0.6

0

0

0.3

0.7

1.6

0.2

0

0.2

0

0

0

52.1

0

52.1

15 May

9.8

0.1

0

0

T

T

4.8

6.3

1.0

0

1.7

0

T

0

1.6

0.9

1.4

0.3

0

1.6

0

0

0.3

29.8

0

29.8

1973

16 July

11.8

0.1

0

24.5

0

0.2

0

1.3

0

0

0.4

1.6

0

T

0.2

0

0.8

0.2

0

0.6

T

T

0

41.7

0

41.7

1974

15 Sept

7.1

1.6

0

3.5

T

2.2

0.5

1.6

0.4

0

44.8

1.4

0

0

2.0

T

16.4

1.8

0.1

5.6

T

3.4

0.1

92.5

0

92.5

6 Oct

0.2

0.4

0

2.1

T

0.2

0

1.4

0.4

0

58.2

2.3

T

T

0.2

T

6.6

0.6

0

4.3

T

0.4

T

77.3

25.9

103.2

10 Nov

0.1

7.5

0

10.3

0

0.4

9.0

1.2

0.6

0

13.1

11.0

0

0

0

0.3

20.1

0.4

0.2

9.2

0

0.4

T

83.8

0

83.8

20 April

1.1

0.3

0

T

0

0

0

0.3

0.5

4.8

49.7

3.0

0

3.3

1.9

2.1

4.6

1.0

0

5.2

T

0

0

77.8

0

77.8

17 May

0.5

0.2

0

T

0

0

0.5

T

2.9

11.4

68.8

0

0

4.7

4.5

0.2

6.3

0.9

T

7.6

T

0.6

0

109.1

39.1

148.2

30 July

8.8

0.7

0

8.9

0

T

0

2.5

2.4

0

17.8

14.3

T

3.1

0.1

0

6.6

1.3

0

86.4

0

0.5

0

153.4

13.2

166.6

2 Oct

0.1

0.1

0

0.6

0

3.2

4.0

0.1

0.9

T

35.5

15.4

T

4.0

T

0

9.1

1.1

0

11.2

0.1

0

0

85.4

82.6

168.0
12

Table 8. Benthic biomass (g/m2) for station SB2 of Seas Branch Creek, below the impoundment, before and 

after treatment of the stream with antimycin on October 4,1972. a

Taxon

Diptera

Chironomidae

Antocha

larvae

pupae

Prosimulium

larvae

pupae

Hemerodromia

Other

Ephemeroptera

Baetis

Stenonema

Ephemerella

Trichoptera

Hydropsyche

Brachycentrus americanus

Ochrotrichia

Glossosoma

Other

Plecoptera

Isoperla

Coleoptera

Optioservus fastiditus

larvae

adult

Stenelmis sandersoni

Amphipoda

Gammarus pseudolimnaeus

Mollusca

Physa obrussoides

Hirudinea

Erpobdella punctata

Nematomorpha

Miscellaneous

Benthic Biomass

without Orconectes

Decapoda

Orconectes propinquus

Total Benthic Biomass

1972

15 May

13.8

3.4

0.5

0

0

0

0.6

0.1

0

0

6.7

0

T

0

1.1

0

0.4

T

T

4.9

0

4.6

0

1.8

37.9

23.3

61.2

15 June

31.0

1.3

0.9

0.5

0.1

T

0.2

1.3

0

0

12.1

12.4

0.1

0

0.6

0

5.4

0.1

0.1

4.9

0.1

13.0

0

0.4

84.5

6.0

90.5

15 July

15.4

2.9

0.2

0.2

T

0.5

T

1.5

0

0

17.4

12.4

0

0

0.3

0

8.6

T

0.5

1.7

0

0

0

T

61.6

7.1

68.7

15 Aug

28.6

16.1

0.4

T

T

0

0.2

0.4

0.1

0

30.1

11.0

0.1

0

T

0

7.3

0.1

0.5

2.4

T

3.5

0

0

100.8

34.0

134.8

3 Oct

0.8

12.3

0

0.2

T

0.3

0

T

0.2

0

34.2

17.0

0

0

T

0

12.3

0.1

0.6

2.3

0

3.5

T

0.1

83.9

52.7

136.6

6 Oct

2.3

6.7

0.1

0

T

3.0

0.4

0

0.1

0

19.7

11.5

0

0

0.1

0

17.7

0.1

0.5

0

0

0

T

0.1

62.3

21.4

83.7

13 Oct

5.2

0

0

0

T

0.1

0.1

0

0.1

0

4.1

0.9

0

0

0.3

0

40.5

0.3

1.2

0.1

T

4.3

0

0.1

57.3

5.3

62.6

1 Nov

20.0

0.3

0

0

0

1.2

16.3

0

0.2

0

7.2

1.6

0

0

0.5

0

45.7

0.2

0.5

T

T

0.4

0

0.3

94.4

49.1

143.5

1 Dec

111.4

0.3

0

0.1

0

1.2

1.8

0

0.3

0

10.4

2.6

0

0

0.2

0

43.3

0.2

0.8

0

0.4

0.1

T

3.1

176.2

0

176.2

a T = less than 0.05 g.
Table 8 Continued

13

15 Jan

50.5

0.1

0

0.7

0

2.9

3.6

T

0.1

0

4.7

0.3

0

0

3.0

0

18.5

0.1

0.2

0

0.4

0.1

0

2.0

87.2

12.6

99.8

15 Mar

39.3

T

0

3.4

0

T

11.0

0.9

0.1

0

4.5

0.5

0

0

1.6

0

9.4

0.2

0.1

T

T

2.8

0

0.7

74.5

8.9

83.4

15 May

55.3

0.5

0

1.9

0.1

0

0.3

3.4

0.1

0

3.8

0

0

0

0

T

1.5

0.2

T

0.1

T

20.6

0

0.4

88.2

5.3

93.5

1973

16 July

13.9

0.1

0

97.8

T

T

0

6.1

T

0

2.5

1.1

T

T

T

0

10.5

0.2

T

11.6

0.2

1.0

0

0

145.0

25.0

170.0

15 Sept

8.8

0.6

T

0.4

T

2.2

0.4

13.9

1.5

0

39.1

1.2

T

0

0

T

33.2

0.3

0.1

24.0

0.1

0.9

0

0

126.7

45.2

171.9

6 Oct

0.1

0.5

0

0.1

T

0.6

0.2

14.0

2.6

0

39.1

0.5

T

0

0

0

18.9

0.1

T

16.3

T

1.0

0

T

94.0

80.7

174.7

10 Nov

0.1

0.5

0

0.1

0

1.1

0

1.3

2.3

0

11.9

0.3

0

0

9.0

0

20.6

T

T

14.5

T

1.6

0

0

63.3

15.4

78.7

20 April

0.6

0.3

0

T

0

0

1.3

23.5

8.9

0

10.9

0.1

0

0

0

1.1

7.3

0.2

T

19.7

T

12.7

0

0

86.6

15.3

101.9

1974

17 May

3.2

1.1

0

3.1

0

0

0.4

37.7

8.4

1.5

50.9

0

0

0.3

0.1

0.2

8.2

0.4

0.3

20.8

0

2.9

0

0

139.5

16.7

156.2

30 July

0.4

0.4

0

1.3

0

T

1.2

6.0

1.1

0

6.6

2.4

0

0

0.3

0

10.2

0.6

0

71.4

0.3

5.1

0

0

107.3

27.9

135.2

2 Oct

0.1

1.5

0

T

0

0

9.2

7.6

1.4

0

18.7

3.3

0

0.3

0

0

14.3

0.8

0

29.3

0.2

T

0

0

86.7

13.1

99.8
14

Table 9. Benthic biomass (g/m2) for control station MD of Maple Dale Creek, before and after treatment of 

Seas Branch Creek with antimycin on October 4,1972. a

Taxon

Diptera

Chironomidae

Antocha

larvae

pupae

Prosimulium

larvae

pupae

Atherix

Hemerodromia

Other

Ephemeroptera

Baetis

Stenonema

Ephemerella

Trichoptera

Hydropsyche

Brachycentrus americanus

Ochrotrichia

Glossosoma

Other

Plecoptera

Isoperla

Coleoptera

Optioservus fastiditus

larvae

adult

Stenelmis sandersoni

Amphipoda

Gammarus pseudolimnaeus

Mollusca

Physa obrussoides

Hirudinea

Erpobdella punctata

Nematomorpha

Miscellaneous

Benthic Biomass

without Orconectes

Decapoda

Orconectes propinquus

Total Benthic Biomass

1972

15 May

5.0

1.6

0.7

0

0

0

0.4

0

T

0.4

0

9.8

0.1

0.1

0

0.8

0.3

1.4

0.1

0.1

0.7

0.3

0

0

0.1

21.9

26.3

48.2

15 June

10.7

0.4

0.2

0

0

0

0.2

0.7

0.2

0

0

6.3

1.0

T

0

0.3

0

4.0

0.2

0.5

2.3

0.2

7.7

0

0.4

35.3

32.4

67.7

15 July

3.6

12.7

0.3

0.2

T

0

0

T

0.4

0

0

14.7

1.8

0

0

T

0

4.6

0.2

0.3

0.8

T

2.6

0

0.1

42.3

7.2

49.5

15 Aug

6.3

10.9

1.8

0.3

T

6.3

0.4

T

0.2

T

0

60.3

3.3

0

0

0.1

0

4.2

0.4

0.4

0.4

0

0

0

0.1

95.4

41.6

137.0

3 Oct

1.0

11.9

0

0.1

T

4.9

1.1

0.1

0.7

0.3

0

172.9

6.9

0

0

0.6

T

21.2

1.1

0.5

0.5

T

0.1

0

0.2

224.1

30.0

254.1

6 Oct

0.7

13.0

0

T

T

2.3

0.9

0.2

0.5

T

0

40.2

6.1

0

0

0.4

T

13.6

0.4

0.8

0.1

0

0

0

T

79.2

0.2

79.4

13 Oct

1.6

7.1

0

T

0

2.1

0.5

0.9

0.1

T

0

6.0

3.9

0

0

0.6

0

17.8

0.2

0.6

0.5

0

0

T

T

41.9

1.1

43.0

1 Nov

2.0

13.1

0

0.2

0

2.0

2.2

0.1

0.2

0.2

0

164.9

13.1

0

0

0.1

0.2

19.7

0.1

0.4

0.2

0.1

0

T

0.1

218.9

0

218.9

1 Dec

21.9

7.9

0

0.2

0

8.3

3.4

T

0.5

0.1

0

40.3

2.8

0

0

0.1

0.4

11.4

0.1

0.2

1.3

0

0

0

0

98.9

16.0

114.9

T = less than 0.05 g. Continued
15

Table 9. Benthic biomass (g/m2) for control station MD of Maple Dale Creek, before and after treatment of

Seas Branch Creek with antimycin on October 4,1972. a

15 Jan

16.8

7.1

0

0.3

0

1.6

8.0

0.4

0.4

T

0

44.4

10.4

0

0

T

0.9

29.9

0.1

0.6

0.6

T

0

0

0.1

121.6

1.2

122.8

15 Mar

18.6

14.9

0

T

0

2.0

2.0

3.4

5.6

0.4

0

82.0

9.5

0

0

1.7

0.4

2.6

0.3

0.1

1.9

T

0.8

0

0.1

146.3

14.7

161.0

15 May

5.6

4.3

0

0

0

0

0.1

0.2

0.5

T

0

18.5

0

0

0

0.3

0.3

1.5

0.2

0

0

0

0

0

0

31.5

0

31.5

1973

16 July

1.6

5.9

0

0.3

0

0

0.3

0.6

1.3

0

0

14.1

11.1

0

T

0.1

0

16.3

1.0

T

1.0

0.1

0

0

0

53.7

8.8

62.5

15 Sept

2.7

8.8

T

1.5

0

1.3

1.5

0

3.6

0.1

0

79.7

32.9

0

0

0

0

50.6

0.4

T

1.6

T

0

0

T

184.7

42.7

227.4

6 Oct

0.8

9.9

0

0.4

0

0

2.6

0

3.3

T

0

128.2

25.6

0

0

T

T

20.7

1.2

T

1.4

T

0

0

T

194.1

22.8

216.9

10 Nov

0.2

6.1

0

T

0

0

1.6

0

0.4

T

0

56.5

31.9

0

0

0

0

27.0

0.4

T

2.0

0

0

0

0

126.1

0

126.1

20 April

11.4

6.6

0

0.4

0

0

0

0.4

0.1

0

0

62.3

3.4

0

0.1

0.1

1.5

9.3

0.6

0.1

0.3

0

0

0

0

96.6

6.6

103.2

1974

17 May

24.6

6.5

0

0.4

0.3

0

T

0

0.3

1.1

T

32.4

0

0

0.1

0

0.4

7.9

0.9

0.3

0.3

T

0

0

0

75.5

22.6

98.1

30 July

9.4

13.3

0

2.6

0

0

0

0

3.7

0.1

0

13.7

2.5

0

T

0.4

0

12.4

0.5

0.2

1.4

T

0

0

0

60.2

128.0

188.2

2 Oct

0.1

2.1

0

0.2

0

0

0

0

7.3

0

0

94.3

42.5

0

0.1

0

0

17.1

0.5

0

1.0

0

0

0

0

165.2

1.0

166.2
16

Gammorus pstudolimnttus

12 M 24 6 00 6 12 18 24 6 12 18 24 6 v 12 18 24 6

Oet 2| Oct 3 I Oct 4 I Oct 5 I Oct I2|

Sampling Time and Date

12 18 24 6 00 6 12 18 24 6 12 16 24 6

Oct 2 1 Oct 3 I Oct 4 I Oct 5 I

Sampling Time and Date

12 18 24 6 00 6 12 18 24 6 12 18 24 6 * 12 18 24 6

Oct 2| Oct 3 I Oct 4 I Oct 5 I Oct I2|

Sampling Time and Date

£«:

in 1.6

O 1.6

CD .6

Chfronomidae

Treatment 

I

12 16 24 6 00 6 12 18 24 6 12 18 24 6 v 12 16 24 6

Oct 2| Oct 3 | Oct 4 | Oet 5 I Oct 12)

Sampling Time and Date

Fig. 2. Drift of benthic macroinvertebrates (total, scuds, crane flies, and midges) at sampling stations in treated Seas 

Branch Creek (SBl, above impoundment; SB2, below impoundment), and in untreated Maple Dale Creek (MD), October 

1972. Numbers along the baseline show sampling times (6 = 0600 h, 12 = 1200 h, . . .) and arrows show time when 

antimycin reached the station.
».

 

3

I»

5 .

£

5-

A - No Somoll

- - A 1

l.ll

Troo

., 1

Toton "*"

. 1, ll

SB2

Total drift

.1. 1 1 1 .. ll

r SBl

1, .... ... ,..,

1,

M

L "

|,a.

|I

O toID

talar- °-

A -No Sampli Tokon

^i A *

MY JN JL tS S <

MD

- A A AJLJ1- 

SB2 

eaamana pnadatmnatat

. I

'

, - ,,, 

N DJAFMRAPMYJNJLA6S 

Month and Year Month and Year

A - NO Sompl. Takm

_ . ,

1

 1

MD

t . j | ^ L A | . 1 . 'I

0

882 1'"

AatocAo P 6^'

"g"

.2 *» 

i::

_ _ _

r

I,,,,,,.,,,. ,,,,,, i

N DJ4FMRAPMYJNJL40S 0 N AP MY JL 0

A -No Samplo Takm

, -1

Trtatmmt

*

.1 ...

.1, I

HTJNJLAGS 0 N 

I

C

1 ,

1.,, JA F H

MD

1

J

SB2

1SBl

> 4 1 4 <

R AP MY JN J

I

. 

LAGS 

Month and Year

I9T3

Month and Year

Fig. 3. Drift of benthic macroinvertebrates (total, scuds, crane flies, and midges) in treated Seas Branch Cre

and in untreated Maple Dale Creek (MD), 1972-74.
18

EzooTotol

MY T JN I JL 1 AG I 3 I 0 1 N D \ JA | F | MR | AP | MY | JM | JL | AG | 3 | 0 | N

Month and Year of Sampling

Gammarus pseudolimnaeus (scuds)

Month and Year of Sampling 

f\ Treatment Antocha (crane fly)

MD / / """" \\ I \ / \

/ «- ly v_y \ ^ \

-A /

| JL | AG | 3 I Tf'N ? D I A I F | Jl

Month and Year of Sampling

Fig. 4. Biomass of benthic macroinvertebrates (total, scuds, and crane flies) in treated Seas Branch 

Creek (SBl, SB2), and in untreated Maple Dale Creek (MD), 1972-74.
19

Chironomidoe (midges)

 1555 

Month and Year of Sampling

Month and Year of Sampling

Month and Year of Sampling

Fig. 5. Biomass of benthic macroinvertebrates (midges, black flies, and mayflies) in treated Seas Branch Creek (SB1, SB2), 

and in untreated Maple Dale Creek (MD), 1972-74. (Note the change in scale for biomass of black flies for values larger 

than 5 g/m2).
(grams/hour) Biomass Drift 

"s I

(13;

I?

fa,

cr e 

bS-

(grams/hour) Biomass Drift 

I

a

i

CO

Cd

88- 

o

COCd

(grams/hour) Biomass Drift 

g o 
";

l.5: 

1.0

I*:

"!,.=

 :

a-No SonoK TokM

.. 1, ,

Troolmont 

. _ , .

,1,1 1 vrjilws o li t M r *

MD

1 1

SBl

1.....,,

li te m JN JL w s

l.ll

|,

1

|

IL

-

-

t

I"

6

r

6-NoSomol. T.

ll,

<

Troo 

<

 . 

"i 

1

1" li, .1 :

K tne^euana omtrtcma |

(5 ^

g

«

A - No Somolo 1

1 II,.

Ill

Troo 

. .1

KM 

.. 

1

nonl 

- 

Month ond Year Month and Year 

Fig. 7. Drift of benthic macroinvertebrates (a mayfly and two caddis flies) in treated Seas Branch Creek (SBl, 

untreated Maple Dale Creek (MD), 1972-74.
22

Brachycentrus americanus (caddis fly)

Month and Year of Sampling

Hydropsyche (caddis fly)

MY | JN |~~JL [""AS| 8 | 0 | N | 5 |~~JA| F |~MR |~AP | MY | JN | JL | AG | S | 5 | N

__

Month and Year of Sampling

Optioservus fastiditus (riffle beetle)

MY | JN | JL JAG | S | 0 I N | D | JA | F I MR f AP |MY | JN | JL | AS | S | 0 | N | ___| AP | MY | [ JL | | 0

J973 ' l9M

Month and Year of Sampling

Fig. 8. Biomass of benthic macroin vertebrates (two caddis flies and a riffle beetle) in treated Seas Branch Creek (SBl, SB2), 

and in untreated Maple Dale Creek (MD), 1972-74.
23

Many benthic organisms are not specialized in food 

preference, and diets change according to the 

availability of algae (Chapman and Demory 1963). 

Additional food and space for Chironomidae, O. 

fastiditus, and Prosimulium could result from the 

reduction of other taxa of invertebrates, and of fish, 

and an increase in algae and in available plant 

surface area for attachment. The alga, Vaucheria sp., 

increased noticeably at SB2 1 week after treatment 

and reappeared in June 1973. Ranunculus present in 

July increased here also from a maximum of 15% 

stream-bed coverage before treatment to 50% in the 

year after treatment.

Recovery of invertebrates after treatment may 

have been hastened by the increase in stream 

vegetation. Particulate organic matter flushed 

downstream when the reservoir was draining may 

have been a source of nutrients. Nutrients also may 

have been made available by bacterial and fungal 

degradation of fish carcasses which littered the 

stream bottom after treatment. An increase in 

nutrients was observed by Richey et al. (1975) when 

kokanee salmon (Oncorhynchus nerka) died after 

spawning.

Chironomidae, Gammaruspsendolimnaeus, Baetis 

cingulatus, and Prosimulium, which had high 

turnover rates resulting from immature developmental periods of less than 1 year, returned more quickly 

than most other taxa to pretreatment biomass levels 

in the year following treatment. Populations of 

Antocha and Brachycentrus americanus, which have 

longer development times, had not recovered to 

pretreatment levels 1 year after treatment at the 

downstream station (SB2). Moffett (1936) observed a 

similar pattern in populations that were decimated 

by floods. Although both Antocha and B. americanus 

showed signs of recovery in November 1973, Antocha 

dropped back to low levels at SB1 during the second 

year.

Hildebrand (1971), who studied benthos disruptions by salmon spawning, believed that organisms 

with low drift rates in winter would not repopulate a 

stream until midsummer, when drift rates increased. 

Rapid recolonization in Seas Branch Creek could 

have taken place because treatment of areas adjacent 

to the mainstream was incomplete; e.g., mortality of 

Hydropsyche was high at SB2 but recovery was rapid 

after treatment. Repopulation could also have 

resulted from the insects' normal recolonization cycle 

which Mueller (1954) found to involve upstream flight 

of adults, ovoposition, population growth, and a later 

downstream drift of immatures in response to 

competition for food and space.

Because antimycin is short-lived, it would be 

desirable, although somewhat difficult, to treat a 

stream when adults of dominant or sensitive insects

are mating. If ovoposition took place after treatment, 

survival and perhaps higher biomass levels might 

result, as observed in Baetis cingulatus at the 

downstream Seas Branch station.

Acknowledgments

We thank K. B. Cumming, J. B. Hunn, and D. W. 

Coble for reviewing the manuscript; M. D. Jacobi for 

designing and implementing the computer program 

for benthic biomass; E. Avery of the Wisconsin 

Department of Natural Resources for field assistance; 

R. W. Baumann and colleagues at the Smithsonian 

Institution Natural History Museum for verification 

of identification of specimens; W. L. Hilsenhoff for 

identification of specimens; and members of the 

Westby Rod and Gun Club for allowing us to use their 

hatchery as a base of operation.

References

Callaham, M. A., and M. T. Huish. 1969. Effects of 

antimycin on plankton and benthic organisms. Proc. 

Annu. Conf. Southeast. Assoc. Game Fish Comm. 

22:255-263.

Chapman, D. W., and R. Demory. 1963. Seasonal 

changes in the food ingested by aquatic insect larvae and 

nymphs in two Oregon streams. Ecology 44:140-146.

Gilderhus, P. A., B. L. Berger, and R. E. Lennon. 1969. Field trials of antimcyin A as a fish 

toxicant. U.S. Fish Wildl. Serv., Invest. Fish Control 27. 

21pp.

Hamilton, A. L. 1969. On estimating annual production. 

Limnol. Oceanogr. 14(5):771-782.

Hildebrand, S. G. 1971. The effect of coho spawning on 

the benthic invertebrates of the Platte River, Benzie 

County, Michigan. Trans. Am. Fish. Soc. 100(l):61-68.

Houf, L. J., and R. E. Hughey. 1973. Benthic and 

zooplankton fauna for which no demonstratable shortterm or long-term effects of treatment with antimycin 

were observed. I. Benthos. II. Zooplankton. Missouri 

Cooperative Fishery Research Unit, University of 

Missouri, Columbia, Missouri. 2 pp. (Unpubl. manuscr.)

Howmiller, R. W. 1972. Effects of preservatives on 

weights of some common macrobenthic invertebrates. 

Trans. Am. Fish. Soc. 101(4):743-746.

Hynes, H. B. N. 1961. The invertebrate fauna of a Welsh 

mountain stream. Arch. Hydrobiol. 57(3):344-388.

Hynes, H. B. N., and M. J. Coleman. 1968. A simple 

method of assessing the annual production of stream 

benthos. Limnol. Oceanogr. 13:569-573.

Jacobi, G. Z. 1969. Benthic macroinvertebrate production: Estimation using a new artificial substrate 

sampler. Ph.D. Thesis. University of Utah, Salt Lake 

City. 44 pp.

Moffett, J. W. 1936. A quantitative study of the bottom 

fauna in some Utah streams variously affected by 

erosion. Bull. Utah Biol. Serv. 3(3):163.

Mueller, K. 1954. Investigations on the organic drift in 

North Swedish streams. Rep. Inst. Freshwater Res. 

Drottningholm 35:133-148.
24

Rabe, F. W., and R. C. Wissman. 1969. Some effects of 

antimycin in an oligotrophic lake. Prog. Fish-Cult. 

31(3):163.

Richey, J. E., M. A. Perkins, and C. R. Goldman. 1975. 

Effects of kokanee salmon (Oncorhynchus nerka) 

decomposition on the ecology of a subalpine stream. J. 

Fish. Res. Board Can. 32:817-820.

Snow, H. E. 1974. Notes on the zooplankton and benthos 

of Rush Lake, Douglas County, six years after application of antimycin. Wis. Dep. Nat. Resour. Rep. 79. 4 pp.

Walker, C. R., R. E. Lennon, and B. L. Berger. 1964. 

Preliminary observations on the toxicity of antimycin A 

to fish and other aquatic animals. U.S. Fish Wildl. Serv., 

Invest. Fish Control 2 (Circ. 186) 18 pp.

Waters, T. F. 1962. A method to estimate the production

rate of a stream bottom invertebrate. Trans. Am. Fish.

Soc. 91(3):243-250. 

Waters, T. F. 1972. The drift of stream insects. Annu.

Rev. Entomol. 17:253-272. 

Waters, T. F., and R. J. Knapp. 1961. An improved

stream bottom fauna sampler. Trans. Am. Fish. Soc.

90(2):225-226.
(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 arid 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.

72. Toxicity of Rotenone to Fish in Standardized Laboratory Tests, by L. L. Marking and T. D. 

Bills. 1976. 11 pp.

(Reports 73 through 76 are in one cover.)

73. Formalin: Its Toxicity to Nontarget Aquatic Organisms, Persistence, and Counteraction, by T. 

D. Bills, L. L. Marking, and J. H. Chandler, Jr. 1976. 7 pp.

74. Chlorine: Its Toxicity to Fish and Detoxification of Antimycin, by L. L. Marking and T. D. 

Bills. 1977. 6 pp.

75. Malachite Green: Its Toxicity to Aquatic Organisms, Persistence, and Removal with Activated 

Carbon, by T. D. Bills, L. L. Marking, and J. H. Chandler, Jr. 1977. 6 pp.

76. Toxicity of Furanace® to Fish, Aquatic Invertebrates, and Frog Eggs and Larvae, by L. L. 

Marking, T. D. Bills, and J. H. Chandler, Jr. 1977. 6 pp.

(Reports 77 through 79 are in one cover.)

77. Efficacy of 3-Trifluoromethyl-4-nitrophenol (TFM), 2',5-Dichloro-4'-nitrosalicylanilide (Bayer 

73), and a 98:2 Mixture as Lampricides in Laboratory Studies, by V. K. Dawson, K. B. 

Gumming, and P. A. Gilderhus. 1977. 11 pp.

78. Toxicity of the Molluscicide Bayer 73 and Residue Dynamics of Bayer 2353 in Aquatic 

Invertebrates, by H. O. Sanders. 1977. 7 pp.

79. Accumulation, Elimination, and Biotransformation of the Lampricide 2',5-Dichloro-4'- 

nitrosalicylanilide by Chironomus tentans, by J. A. Kawatski and A. E. Zittel. 1977. 8 pp.

Fish Control Laboratories

Fish and Wildlife Service

U.S. Department of the Interior

P.O. Box 818 

La Crosse, Wisconsin 54601
As the Nation's principal conservation agency, the Department of the 

Interior has responsibility for most of our nationally owned public lands 

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

and water resources, protecting our fish and wildlife, preserving the 

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 

and works to assure that their development is in the best interests of all 

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.

GPO 839-587

FISH CONTROL LABORATORIES 

U.S. FISH AND WILDLIFE SERVICE

P.O. BOX 818 

LA CROSSE, WISCONSIN 546O1

POSTAGE AND FEES PAID 

U.S. DEPARTMENT OF THE INTERIOR

INT423