### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)** 



### 1 Carney, 1983; Kettle et al., 1987;

deNoyelles et al., 1989; deNoyelles et al., 1994 500 365 Single Mesocoms, experimental ponds Decrease in cover by emerged, floating,

and submerged aquatic plants (>90% decline in Typha; 100% decline in SAV). Macro > 1 yr (no recovery observed) From 805-d study where ponds formerly treated with formulated product at 20 μg/L were increased to 500 μg/L; exposure concentrations derived from graph during the second year of the study. Y



### 2 Carney, 1983; Kettle et al., 1987;

deNoyelles et al., 1989; deNoyelles et al., 1994; deNoyelles and Kettle, 1980; Dewey, 1986 20 365 Single Mesocoms, experimental ponds Decrease in cover by floating and

submerged aquatic plants (40% decline in Typha; 50% decline in SAV; 50% decline in Najas). Macro > 1 yr (no recovery observed) From 805-d study; study concentrations from first year of study. Y



### 3 deNoyelles et al., 1982; deNoyelles et

al., 1989 500 63 Single Mesocoms, experimental ponds Decrease (> 90% decline) in

phytoplankton 14C-uptake and biomass. 100% decline in SAV. Change (observed after 14 days) in species composition of phytoplankton. Phyto and Macro > 63 d (no recovery reported for

shift in species composition; recovery in phytoplankton biomass and production occurred>3 weeks) From 136 day study; according to study authors, ponds were intensely monitored for first 63 days, then sampled monthly thereafter until day 136; however, exposure concentration information is not available past 63 days. Y



### 4 deNoyelles et al., 1989; Carney, 1983 100 365 Single Mesocoms, experimental ponds Decrease in cover by emerged and

submerged aquatic plants (75% decline in Typha; 80% decline in SAV). Macro > 1 yr (no recovery observed) From 805-d study; study concentrations from first year of study where ponds were dosed with atrazine at 100 μg/L. Y



### 5 deNoyelles et al., 1989; Carney, 1983 200 340 Single Mesocoms, experimental ponds 75-80% decline in Typha;>90% decline

in SAV. Macro > 1 yr (no recovery observed) From 805-d study; study concentrations from second year of study. Y



### 7 Hamilton et al., 1987 80 56 Multiple Lake enclosure 60% decrease in density; 20% decrease in number of periphyton species; 80% decrease in periphyton biomass. Change (shift observed after 2nd day of exposure) in species composition. Peri 49-50 d recovery for periphyton density and biomass; no recovery for periphyton numbers and shift in species composition. Results from 1983 study cited in the paper.

Y



### 8 Hamilton et al., 1987 140 56 Multiple Lake enclosure 60% decrease in density; 30% decrease in number of periphyton species; 75% decrease in biomass. Change (shift observed after 3rd day of exposure) in species composition. Peri >56 d recovery for periphyton density and biomass; no recovery for periphyton numbers and shift in species composition. Results from 1982 study cited in the paper; no significant effects in endpoints other than species composition observed although decreases were evident. Y



### 9 Hamilton et al., 1988 100 96 Multiple Lake enclosure Change in species composition (93% change in phytoplankton composition occurring on day 49 of study). Phyto >323 days Duration of Hamilton studies was 323 days after first atrazine application; however, measured atrazine concentrations were available only up to 96 days. Exposure profile includes two applications of atrazine at 100 μg/L (35 days apart). Y



### 10 Herman et al., 1986; Hamilton et al.,

1989 100 96 Multiple Lake enclosure 40% decrease in POC at day 34; 80% decline in14C-uptake at day 57; 10% - 20% decrease in DO, periphyton biomass (50%), chlorophyll (50%), productivity (70%), and community composition (100% decrease in Cyanophyta).

Increase in secchi depth (30%), dissolved inorganic carbon (60%), and nitrite nitrogen (100%). Peri 90 d; 14 d; >294 d; >294 d (POC recovery at 99 d;14C-uptake recovery at 135 d; species comp recovery at >323 d).

DO, secchi depth, and dissolved inorganic carbon recovered by the next spring (329 days); no recovery was observed for the other parameters evaluated. Duration of Hamilton studies was 323 days after first atrazine application; however, measured atrazine concentrations were available only up to 96 days. Exposure profile includes two applications of atrazine at 100 μg/L (35 days apart). Y 

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

13 Stay et al., 1985 430 53 Single Microcosms, laboratory Taub (pickle jars) 60-70% decrease in DO; 90% decrease

in14C-uptake; <100% decrease in primary productivity (went negative); and 80% decrease in ratio of14C to chla. Phyto > 53 d (no recovery observed) Daphnid bloom occurred between days 18 and 35 of the study and strongly interacted with the effects of the atrazine treatments. Only atrazine-related effects that occurred prior to the daphnid bloom on day 18 are considered. Full duration of study was 60 days with atrazine addition at day 7. Y



### 14 Stay et al., 1985 820 53 Single Microcosms, laboratory Taub (pickle jars) 60-70% decrease in DO; 90% decrease

in14C-uptake; <100% decrease in primary productivity (went negative); and 80% decrease in ratio of14C to chla. Phyto > 53 d Daphnid bloom occurred between days 18 and 35 of the study and strongly interacted with the effects of the atrazine treatments. Only atrazine-related effects that occurred prior to the daphnid bloom on day 18 are considered. Full duration of study was 60 days with atrazine addition at day 7. Y



### 15 Stay et al., 1985 3980 53 Single Microcosms, laboratory Taub (pickle jars) 60-70% decrease in DO; 90% decrease

in14C-uptake; <100% decrease in primary productivity (went negative); and 80% decrease in ratio of14C to chla. Phyto > 53 d Daphnid bloom occurred between days 18 and 35 of the study and strongly interacted with the effects of the atrazine treatments. Only atrazine-related effects that occurred prior to the daphnid bloom on day 18 are considered. Full duration of study was 60 days with atrazine addition at day 7. Y



### 17 Brockway et al., 1984 100 7 Single Microcosms, lab stagnant 40% decrease in net oxygen

production. Phyto > 7 d Effect occurred at day 1; exposure levels are nominal. Y



### 18 Brockway et al., 1984 500 12 Single Microcosms, lab stagnant 90% decrease in net oxygen

production. Phyto >12 d Effect occurred at day 1; exposure levels are nominal. Y



### 19 Brockway et al., 1984 5000 12 Single Microcosms, lab stagnant 100% decrease in net oxygen

production. Phyto > 12 d Effect occurred at day 1; exposure levels are nominal. Y



### 22 Detenback et al., 1996 15 15 Constant Artificial flowthrough swamp Decrease in DO and gross productivity

(23% decrease in DO; reduction in gross productivity (p<0.05) not reported). Increase in nutrients (15% increase in PO4; 15% increase in ammonium). Peri Recovery not reported. Atrazine detected in the control wetlands; duration of exposure is 15 days.

Y



### 23 Detenback et al., 1996 25 43 Constant Artificial flowthrough swamp Decrease in periphyton respiration and

net productivity (reduction in respiration and net primary productivity (p<0.05) not reported). Peri Recovery not reported. Atrazine detected in the control wetlands; duration of exposure is 43 days. Y



### 24 Detenback et al., 1996 50 32 Constant Artificial flowthrough swamp Decrease (reduction in net productivity

(p <0.05)) not reported. Increase in nutrients (40% increase in PO4; 100% increase in ammonium). Peri Recovery not reported. Atrazine detected in the control wetlands; duration of exposure is 32 days.

Y



### 25 Detenback et al., 1996 79 17 Constant Artificial flowthrough swamp Decrease (reduction in net productivity

(p <0.05)) not reported. Increase in nutrients (50% increase in PO4; 250% increase in ammonium). Peri Recovery not reported. Atrazine detected in the control wetlands; duration of exposure is 17 days.
Y

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

26 Hamala and Kollig, 1985 100 14 Constant Microcosm, lab flowing Decrease in primary production (100%

reduction in productivity (became negative); 25% reduction in number of species; 50% reduction in biomass). Change in species composition (35% decrease in chlorophyta abundance observed at day 14). Peri >14 d to > 21 d Period of exposure was 14 days with a 21 day recovery period following exposure.

Y



### 27 Johnson, 1986 1000 30 Single Microcosm, lab stagnant Decrease in macrophyte biomass

(50%); primary production (90%); increase in alkalinity (approx. 2-fold).

Slight decrease in pH (10%) and increase in conductivity (20%). Macro >30 d Atrazine concentrations were not measured; nominal values were used. Effect occurred at day 2 (primary productivity) and day 30 (biomass; only measurement time). Y



### 28 Kosinski, 1984; Kosinski and Merkle,

1984 10 21 Single Artificial streams, recirculating 40% decrease in apparent primary

productivity; slight decrease in biovolume. Peri >21 d (primary production); <7 days (biovolume) Atrazine dissipated from the streams at a half-life of 3.2 days. Effect occurred at day 7; magnitude of effect for primary productivity estimated using study figures. Results from the two publications (Kosinski 1984 and Kosinski and Merkle 1984) were combined because they appeared to be from the same set of experiments. Y



### 29 Kosinski, 1984; Kosinski and Merkle,

1984 1000 21 Single Artificial streams, recirculating 50% decrease in apparent primary

productivity; 10% reduction in biovolume. Peri > 21 d (primary productivity); 14 d (biovolume) Atrazine dissipated from the streams at a half-life of 3.2 days. Effect occurred at day 7; magnitude of effect for primary productivity estimated using study figures. Y



### 30 Kosinski, 1984; Kosinski and Merkle,

1984 10000 21 Single Artificial streams, recirculating 70% decrease in apparent primary

productivity; 20% to 25% reduction in biovolume. Peri > 21 d Atrazine dissipated from the streams at a half-life of 3.2 days. Effect occurred at day 7; magnitude of effect for primary productivity estimated using study figures. Y



### 31 Krieger et al., 1988 24 12 Constant Artificial streams, recirculating Decrease in biomass (24% reduction)

and chlorophyll-a (30% reduction).

Slight decrease (21%, not statistically significant) in nitrate uptake.

No effect on dissolved silica uptake or phosphorus uptake rate. Peri None Effect observed at last study day.

Y



### 32 Krieger et al., 1988 134 12 Constant Artificial streams, recirculating Decrease in biomass (31% reduction),

chlorophyll-a (44% reduction), and nitrate uptake (25%).

No effect on dissolved silica uptake; possible slight effect (8%) on phosphorus uptake rate. Peri None Effect observed at last study day.

Y

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

33 Moorhead and Kosinski, 1986 1000 7 Single Artificial streams, recirculating Community productivity was decreased

by approximately 8-fold relative to controls.

Water quality parameters (conductivity, alkalinity, soluble reactive phosphorus, and pH), respiration, and changes in algal abundance were not affected. Peri >7 d Effect on community productivity remained at the end of the 7 day study. Effect occurred at day 0.

Y



### 34 Pratt et al., 1988 337 21 Constant Microcosms, laboratory flowing Statistically significant decreases in DO

(30%), number of species (15%), chlorophyll-a (90%), protein biomass of protozoa (40%), potassium (45%), magnesium (20%), and calcium (15%). Peri > 21 d Unclear what species were tested - whole community endpoints were evaluated. Colonization and diversity endpoints were associated with protozoa. Effect occurred at day 21. Y



### 35 Stay et al., 1989 204 (initial measured) 42 Single Microcosms, laboratory Leffler 30% decrease in pH; 80% decrease in

primary production; no effect on dark respiration or heterotrophic activity. Phyto 42 - >42 d Magnitude of effect estimated from graphs. Y



### 36 Stay et al., 1989 500 42 Single Microcosms, laboratory Leffler 30% decrease in pH; 120% decrease in

primary production; no effect on dark respiration or heterotrophic activity. Phyto > 42 d Magnitude of effect estimated from graphs. Y



### 37 Stay et al., 1989 1000 42 Single Microcosms, laboratory Leffler Decrease in pH and primary production

(magnitude not specified); no effect on dark respiration or heterotrophic activity. Phyto > 42 d Magnitude of effect estimated from graphs; values for 1000 μg/L were not presented but were reported to be similar to the 500 μg/L test concentration. Y



### 38 Stay et al., 1989 5000 42 Single Microcosms, laboratory Leffler Decrease in pH and primary production

(magnitude not specified); no effect on dark respiration or heterotrophic activity. Phyto > 42 d Magnitude of effect estimated from graphs; values for 5000 μg/L were not presented but were reported to be similar to the 500 μg/L test concentration. Y



### 39 Brockway et al., 1984 50 55 Constant Microcosms, lab continuous flow Approx. 30% decrease in oxygen

production and 50% increase in dissolved nitrate concentration. Phyto >55 d Exposure was 50 μg/L (day 0 to 55) + 0 μg/L (removal of atrazine from the system at day 56) + 50 μg/L (day 63 to 70); recovery was associated with removal of atrazine at day 55, and recovery occurred relatively rapidly. Effect occurred at day 7; exposure levels are nominal. Y



### 40 Brockway et al., 1984 100 15 Constant Microcosms, lab continuous flow Approx. 40% decrease in oxygen

production and approx. 65% increase in dissolved nitrate concentration. Phyto >15 d Exposure was complex - 100 μg/L was tested after exposure to 0.5 μg/L and 50 μg/L. Treatment was as follows: 0.5 μg/L (days 0 to 28) + 50 μg/L (day 29) + 100 μg/L (day 35) + 0 μg/L (removal of atrazine from the system at day 50) + 100 μg/L (day 63). Effect occurred on the first day of treatment with 100 μg/L. Y



### 41 deNoyelles et al., 1989 100 360 Single Mesocoms, experimental ponds Decrease (>90% decline) in 14C-uptake

and biomass of phytoplankton. Phyto >21 d Effect observed immediately (within first 3 wks) in both 136-d and 805-d studies during the first year. Recovery observed> 3 weeks. Y



### 42 deNoyelles et al., 1989 200 360 Single Mesocoms, experimental ponds Decrease (>90% decline) in 14C-uptake

and biomass of phytoplankton. Phyto >21 d Effect observed immediately (within first 3 wks) in both 136-d and 805-d studies during the first year. Recovery observed

>3 weeks. Y

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

44 Kosinski, 1984; Kosinski and Merkle,

1984 100 21 Single Artificial streams, recirculating 30% decrease in apparent primary

productivity; no affect on biovolume. Peri < 3 d Effect occurred at day 0 and recovery occurred by day 3. Y



### 45 Moorhead and Kosinski, 1986 10000 7 Single Artificial streams, recirculating Community productivity was decreased

by approximately 18-fold relative to controls and Nitzschia abundance was reduced by approx. 60%.

Water quality parameters (conductivity, alkalinity, soluble reactive phosphorus, and pH), respiration, and changes in non-Nitzschia algal abundance were not affected. Peri >7 d Effect occurred at day 0 (day of dosing).

Y



### 46 Moorhead and Kosinski,1986 100 7 Single Artificial streams, recirculating Community productivity was decreased

by approximately 8-fold relative to controls.

Water quality parameters (conductivity, alkalinity, soluble reactive phosphorus, and pH), respiration, and changes in algal abundance were not affected. Peri 7 d Effect occurred at day 0.

Y



### 47 Stay et al., 1985 53 53 Single Microcosms, laboratory Taub (pickle jars) 40% reduction in14C-uptake; 15-20%

reduction in DO; 60% reduction in net primary productivity; and ~50% reduction in14C-uptake/chl-a. Phyto 21 - 32 d; 53 d Daphnid bloom occurred between days 18 and 35 of the study and strongly interacted with the effects of the atrazine treatments. Only atrazine-related effects that occurred prior to the daphnid bloom on day 18 are considered. Full duration of study was 60 days with atrazine addition at day 7. Y



### 48 Stay et al., 1985 84 53 Single Microcosms, laboratory Taub (pickle jars) 55% reduction in14C-uptake; 20-30%

reduction in DO; 55% reduction in net primary productivity; and ~55% reduction in14C-uptake/chl-a. Phyto 28 - 32 d; 53 d Daphnid bloom occurred between days 18 and 35 of the study and strongly interacted with the effects of the atrazine treatments. Only atrazine-related effects that occurred prior to the daphnid bloom on day 18 are considered. Full duration of study was 60 days with atrazine addition at day 7. Y



### 49 Stay et al., 1985 170 53 Single Microcosms, laboratory Taub (pickle jars) 70% reduction in14C-uptake; 45-55%

reduction in DO; 100% reduction in net primary productivity; and ~65% reduction in14C-uptake/chl-a. Phyto 28 - 32 d; 53 d Daphnid bloom occurred between days 18 and 35 of the study and strongly interacted with the effects of the atrazine treatments. Only atrazine-related effects that occurred prior to the daphnid bloom on day 18 are considered. Full duration of study was 60 days with atrazine addition at day 7. Y



### 50 Stay et al., 1989 100 42 Single Microcosms, laboratory Leffler Decrease in pH (20%) and primary

production (50%).

Dark respiration and heterotrophic activity were not affected by treatment. Phyto 7 - >42 d Recovery did not appear to occur for the primary production endpoint. Effect occurred at day 0; magnitude of effect was estimated from study figures. Y



### 51 Brockway et al., 1984 50 12 Single Microcosms, lab stagnant Approx. 25% reduction in oxygen

production. Phyto > 12 d Effect occurred at day 1. Y

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

52 deNoyelles et al., 1982; deNoyelles et

al., 1989 20 63 Single Mesocoms, experimental ponds Decrease (50% decline) in 14C-uptake

and biomass of phytoplankton. Phyto >3 wks for biomass and14Cuptake Although full exposure period was 136-d, atrazine exposure concentrations are available for only 63 days. Y



### 53 Johnson, 1986 10 30 Single Microcosm, lab stagnant No effect on macrophyte biomass,

conductivity, pH, or alkalinity.

Slight (20%) decrease in gross primary productivity at the first measurement. However, this observation did not appear to be related to atrazine treatment. Macro 7 d Exposure levels were not measured and atrazine was introduced as a formulated product associated with soil. Primary productivity was lower than controls from day 2 to 7. N



### 54 Johnson, 1986 100 30 Single Microcosm, lab stagnant No effect on macrophyte biomass,

conductivity, pH, or alkalinity.

Slight (30%) decrease in gross primary productivity. However, this observation did not appear to be related to atrazine treatment. Macro 7 d Exposure levels were not measured and atrazine was introduced as a formulated product associated with soil. Primary productivity was lower than controls from day 2 to 7. N



### 58 Lampert et al., 1989 1 18 Single Lake enclosure 50% decrease in chlorophyll-a and oxygen saturation. Phyto >18 d Reductions in oxygen may have been related to daphnid mortality. However, chlorophyll-a reductions were considered to be treatment related. Y



### 58b Lampert et al., 1989 0.1 21 to 42 Single Lake enclosure Decrease in photosynthesis rate (1 of 2 replicates in coldwater experiment only, 60% decline) and oxygen saturation (approx. 40% reduction).

No clear effect on chlorophyll-a levels. Phyto >42 d (oxygen) >25 d (photosynthetic rate) Endpoints evaluated include chlorophyll-a levels, oxygen levels, and photosynthetic rate. Recovery was observed for the photosynthetic rate in some enclosures. Y



### 59 Pratt et al., 1988 32 (mean measured) 21 Constant Microcosms, laboratory flowing 35% decrease in DO (statistically

significant); slight reductions in magnesium and calcium levels.

No effect on number of species, chlorophyll-a, protein biomass of protozoa, or potassium. Peri > 21 d

--

Y



### 60 Pratt et al., 1988 110 (mean measured) 21 Constant Microcosms, laboratory flowing 35% decrease in DO; 60% reduction in

chlorophyll-a (not statistically significant); slight reductions in magnesium and calcium levels.

No effect on potassium, number of species, or protein biomass of protozoa. Peri > 21 d

--

Y



### 61 Stay et al., 1989 20 42 Single Microcosms, laboratory Leffler Slight (10%) decrease in primary

production.

No effect on pH, respiration, or heterotrophic activity. Phyto 1-10 d

--

N



### 62 van den Brink et al., 1995 5 35 Constant Microcosms, laboratory Slight decrease in photosynthetic

activity, as indicated by higher conductivity and alkalinity, and lower DO and pH. Phyto Not applicable

--
N



### 63 Brockway et al., 1984 0.5 7 Single Microcosms, lab stagnant No effect on oxygen production. Phyto Not applicable

-- N

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

64 Brockway et al., 1984 5 7 Single Microcosms, lab stagnant No effect on oxygen production. Phyto Not applicable

-- N



### 65 Brockway et al., 1984 0.5 29 Constant Microcosms, lab continuous flow No effect on oxygen production. Phyto Not applicable 0.5 μg/L exposure occurred for 29 days, then exposure was increased to 50 μg/L; exposure levels are nominal. N



### 66 Brockway et al., 1984 5 70 Constant Microcosms, lab continuous flow Oxygen production was slightly reduced

from days 10 to 45. Oxygen production was typically within 90% of controls, but was approximately 80% of controls for about 7 days during the first month of the study. Phyto Approx. 45 d

--

N



### 67 Gruessner and Watzin, 1996 5 14 Single with decreasing

conc. Microcosm, lab No effect on chl-a of periphyton on artificial substrate. Peri Not applicable Concentration of atrazine reduced to 1μg/L by day 14; on day 3, 15% of the treated water was removed and replaced with untreated stream water. On days 6 and 7 about 50% of the water was replaced; 15% of the water was replaced again on day 11. N



### 68 Gustavson and Wängberg, 1995 1 20 Single Lake enclosure No effect on community tolerance. Phyto and Peri Not applicable

-- N



### 69 Gustavson and Wängberg, 1995 10 20 Single Lake enclosure No effect on community tolerance. Phyto and Peri Not applicable

-- N



### 70 Gustavson and Wängberg,1995 20 20 Single Lake enclosure No effect on community tolerance. Phyto and Peri Not applicable

-- N



### 71 Jurgensen and Hoagland, 1990 2 28 2 short pulses of 24-hours @ day 1 and 14 Stream

enclosures No effect on cell density or biomass. Peri Not applicable Study results may have been confounded by a storm event and by the high detection limit of the analytical methods used in this study (50 μg/L). N



### 72 Jurgensen and Hoagland, 1990 30 28 2 short pulses of 24-hours @ day 1 and 14 Stream

enclosures No effect on cell density or biomass. Peri Not applicable Study results may have been confounded by a storm event and by the high detection limit of the analytical methods used in this study (50 μg/L). N



### 73 Jurgensen and Hoagland, 1990 100 28 2 short pulses of 24-hours @ day 1 and 14 Stream

enclosures No effect on cell density or biomass. Peri Not applicable Study results may have been confounded by a storm event and by the high detection limit of the analytical methods used in this study (50 μg/L). N



### 75 Lynch et al., 1985 25 30 (4 30-d exposures with 60-d intervals b/w exposures) Constant/

Multiple (see comment) Artificial

streams, laboratory No effect on standing biomass, rate of

primary production, or community respiration. Peri Not applicable DMSO was used as a solvent, and possible solvent effects were noted. Atrazine concentrations were not analytically confirmed. Streams were treated in four 30-day phases with 60 day recovery time between each 30 day exposure. N



### 76 Pratt et al., 1988 3.2 (mean measured) 21 Constant Microcosms, laboratory flowing No effect on DO, chlorophyll-a, protein

biomass of protozoa, number of species, magnesium, calcium, or potassium. Peri Not applicable

--
N



### 77 Pratt et al., 1988 10 (mean measured) 21 Constant Microcosms, laboratory flowing No effect on DO, chlorophyll-a, protein

biomass of protozoa, number of species, magnesium, calcium, or potassium. Peri Not applicable

--

N

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

78 Rohr and Crumrine, 2005 25 30 Multiple Mesocosms, experimental ponds Reduction in periphyton chlorophyll

-a

(15.2%). Peri Recovery not reported Initial dose of atrazine was 25 μg/L, (nominal) then after two weeks the ponds were redosed with 25 μg/L (nominal). Thus the exposure for the first two weeks was 25 μg/L (nominal) and the authors assumed the exposure for the second two weeks was 50 μg/L (nominal). Y



### 79 Rohr et al., 2008 117 28 Single Mesocosms, experimental ponds Reduction in phytoplankton chlorophylla (65%) and increase in periphyton chlorophyll-a (49%). Peri and Phyto Recovery not reported Chlorophyll was measured only at study termination. Study authors attribute increase in periphyton chlorophyll-a to reduction in phytoplankton, which facilitates increased nutrient availability and light penetration to periphyton. Y



### 80 Relyea, 2009 6.4 36 Single Outdoor
mesocosms, experimental ponds No effect to phytoplankton chlorophylla, periphyton biomass, and dissolved oxygen. Peri and Phyto Not applicable Solvent concentration reported for control only. N



### 81 Knauert et al., 2008; Knauert et al.,

2009 84 173 Multiple Outdoor
mesocosms, experimental ponds Inhibition of phytoplankton

photosynthetic activity (51.4%) at day 2. Average inhibition of photosynthetic activity from day 0-34 was 45.6%. Change in phytoplankton community structure. Phyto No recovery (compared to control ponds, atrazine resulted in statistically significant effects on photosynthesis and differences in phytoplankton species composition until the end of the experiment at day 173). Study duration included 34 days of constant atrazine exposure followed by a post-exposure period of approximately 5 months (139 days) where atrazine dissipated in the water column. The total duration of the study was 173 days. In order to maintain constant atrazine concentrations, atrazine was reapplied to the ponds only once on day 20. Atrazine caused a statistically significant reduction in photosynthetic activity of phytoplankton at day 2 of the study. Changes in phytoplankton community structure began at day 12. Y



### 82 Berard et al., 1999a, Berard et al.,

1999b, Berard and Benninghoff, 2001, Sequin et al., 2001b, Leboulanger et al., 2001 10 10 to 23 Single Experimental outdoor microcosms Change in phytoplankton biomass and

community structure (species and higher taxonomic groupings composition, species diversity (Shannon index), and Bray-Curtis index). Phyto Recovery not reported Reported atrazine concentration in source lake is relatively low compared to treatment concentration, although background measurements were not taken during the experiment and may have been higher. Study authors indicate that experiments were conducted for 10- 23 days (just before the stationary phase of phytoplankton growth). Endpoints were measured at the end of the experiments; the type and magnitude of effects varied among the experiments and effects were observed across the range of experimental durations. Y



### 83 Seguin et al., 2001a 30 40 Single Outdoor
mesocosms, experimental ponds Increase (61%) in periphyton

chlorophyll-aconcentration at Day 40. Peri Recovery not reported Increased chlorophyll observed only at study termination. Also examined effects of nicosulfuran in separate treatments. N



### 84 Seguin et al., 2001a 2 40 Single Outdoor
mesocosms, experimental ponds No effect Peri Not applicable Non-significant increase (14%) in periphyton chlorophyll-a concentration at day 40. Also examined effects of nicosulfuran in separate treatments. N

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

85 Seguin et al., 2001b 30 40 Single Experimental outdoor

mesocosms Change in phytoplankton community

structure (change in Bray-Curtis index starting on day 2 and increased Chrysophyceae abundance of unknown magnitude on day 40). Phyto Recovery not reported Also examined effects of nicosulfuran in separate treatments.

Y



### 86 Seguin et al., 2001b 2 40 Single Experimental outdoor

mesocosms Increased Chrysophyceae abundance

on day 40 (unknown magnitude). Phyto Recovery not reported Effect on abundance observed at study termination. Also examined effects of nicosulfuran in separate treatments. Y



### 87 Seguin et al., 2002 30 25 Single Experimental outdoor

mesocosms Decrease in chlorophyll-a(22%) and

dry weight (30%); change in community structure and Bray-Curtis similarity index; decrease in DO (20%). Phyto No Changes in biomass (chlorophyll-aand dry weight) were evident at day 9, changes in community structure began at day 11, changes in Bray-Curtis began day 9, and changes in DO about day 3. Although DO showed an apparent recovery about day 12, it diverged from the control again starting about day 17through the end of the experiment. Shortterm toxicity data from the atrazinetreated mesocosm communities was not considered for the data summary table due to the uncertainty surrounding exposure concentrations. Y



### 88 Downing et al., 2004 148 7 Single Laboratory microcosms Decrease in chlorophyll-a(30-40%),

primary productivity (~60%), and change in phytoplankton composition (~20% decrease in diatoms, ~25% decrease in bluegreen algae, ~30% decrease in green algae, ~75% decrease in brown algae, ~30% decrease in total phytoplankton). Phyto Recovery not reported Initial test concentrations are based on the average of reported measured day 0 values from the October 1999 and February 2000 experiments (112 - 184 μg/L); the corresponding nominal test concentration is 200 μg/L. Chlorothalnil and endosulfan were also investigated separately. Y



### 89 Downing et al., 2004 24.3 7 Single Laboratory microcosms Decrease in chlorophyll-a(~35%) and

change in phytoplankton composition (~15% decrease in diatoms, ~5% decrease in green algae, ~25% decrease in brown algae, ~10% decrease in total phytoplankton). Phyto Recovery not reported Initial test concentrations are based on the average of reported measured day 0 values from the October 1999 and February 2000 experiments (23.8 - 24.8 μg/L) ); the corresponding nominal concentration is 20 μg/L. Chlorothalnil and endosulfan were also investigated separately. Y



### 90 Boone and James, 2003 207 25 Single Outdoor
mesocosms, experimental ponds No clear treatment-related effects. Phyto Not applicable Main purpose of the study was to evaluate effects of atrazine and carbaryl on amphibians. Chlorophyll content was measured as a potential indirect effect (effect on food availability) to amphibians. Control levels were higher than all treatment levels (regardless of whether or not atrazine was present) at day 12 in Experiment 1. However, there were no apparent decreases in chlorophyll in any treatment with atrazine and chlorophyll in the atrazine-only treatment was higher than the control on day 25. N

### Endpoint

**Number Reference(s)**  **Initial Test Concentra**  **tion (μg/L) Duration** 

**(d) Single /** 

**Constant / Multiple**  **Ecosystem Results**  **Plant Group**  **Recovery Comments**  **Effect (Y/N)**  

### Cosm Endpoint Table Taken from August 2011 Memo, Organized by Number of Endpoint

95 Diana et al., 2000 20 51 Single Outdoor microcosms No clear treatment-related effects. Macro and Phyto Not applicable Atrazine concentrations were onlydetermined at 0 and 21 days posttreatment. Chlorophyll was measured through day 42 and macrophytes biomass was measured at the end of the experiment (day 51). N



### 96 Diana et al., 2000 196 51 Single Outdoor microcosms 98% decrease in macrophyte biomass;

3-fold increase in phytoplankton chlorophyll-a on day 14; approximate 60% reduction in pre-dusk DO levels at day 1. Macro and Phyto No – chlorophyll-a increase was

observed from day 14 to study termination; DO did not recover, and biomass was only measured at study termination. Atrazine concentrations were onlydetermined at 0 and 21 days posttreatment. Chlorophyll was measured through day 42 and macrophytes biomass was measured at the end of the experiment (day 51). Y



### 97 Diana et al., 2000 2036 51 Single Outdoor microcosms 99% decrease in macrophyte biomass;

2-fold increase in phytoplankton chlorophyll-a; approximate 80% reduction in pre-dusk DO levels at day 1. Macro and Phyto No - biomass was only measured

at study termination, and DO levels did not recover. However, chlorophyll concentrations were similar to control by day 42. Atrazine concentrations were onlydetermined at 0 and 21 days posttreatment. Chlorophyll was measured through day 42 and macrophytes biomass was measured at the end of the experiment (day 51). Y



### 98 McGregor et al., 2008 25 42 Single Outdoor microcosms No effect on dissolved oxygen. Macro and Phyto Not applicable DO was measured through day 40. Study focused on macrophytes, however DO measurements would have included effects on phytoplankton present in the microcosms. Effects on macrophyte biomass were also reported in the study; however, no effect levels were reported for biomass effects. N



### 99 McGregor et al., 2008 50 42 Single Outdoor microcosms No effect on dissolved oxygen. Macro and Phyto Not applicable DO was measured through day 40. Study focused on macrophytes, however DO measurements would have included effects on phytoplankton present in the microcosms. Effects on macrophyte biomass were also reported in the study; however, no effect levels were reported for biomass effects. N



### 100 McGregor et al., 2008 100 42 Single Outdoor microcosms 35% decrease in DO at day 1. Macro and Phyto No DO was measured through day 40. Study focused on macrophytes, however DO measurements would have included effects on phytoplankton present in the microcosms. Effects on macrophyte biomass were also reported in the study; however, no effect levels were reported for biomass effects. Y



### 101 McGregor et al., 2008 250 42 Single Outdoor microcosms 50% decrease in DO at day 1. Macro and Phyto No DO was measured through day 40. Study focused on macrophytes, however DO measurements would have included effects on phytoplankton present in the microcosms. Effects on macrophyte biomass were also reported in the study; however, no effect levels were reported for biomass effects. Y



### *Duration corresponds to the number of days for which atrazine exposure concentrations are available. Study durations that are longer than the period of time for which atrazine concentrations are available are specified in the "Comments" column.