EVR1001L Fall 2018 Lab 5 Frogs and Atrazine Ecotoxicology Lab Report Materials and Methods For this lab 2 aquariums were set up and contained a mixture of 100L freshwater and 10 of Holtfreter s solution That solution contained 344g of NaCl 5 0g of KCI 0 34g of CaCl2 0 81g of NaHCO3 Both of the tanks were filled one of the tanks is the control and the other is treatment tank 0 25mL Atrazine was added to the treatment tank through a Eppendorf Pipette then the tadpoles are fed This experiment is carried on for 4 years to allow the growing cycle of the tadpoles to continue The frog s sex is observed then document and the information is gathered Results Tables and Graphs Table 1 Testosterone levels and sex data obtained from the experiment where tadpoles were exposed Tadpole Treatment Your Data Actual Tadpole Sex Your Data Observed Frog Sex Your Data Testosterone Level Entire Class Data 1 Control Male Male Mean Standard 16 42 Deviation Control 2 Control Male Male 30 38 mean Calculated 3 Control Male Male 4 Control 5 Control Male Male Male Male 6 Atrazine Female Female 20 72601 Calculated std 36 22 dev 7 81838048 15 44 14 68 1 05 Mean Standard 7 Atrazine Male Male 8 Atrazine Male Male 9 Atrazine Male Male Deviation Control Calculated mean 7 15 3 31927 Calculated std 3 13 dev 2 60709361 2 36 10 Atrazine Male Male 1 24 Figure 1 contains the testosterone levels in the tadpoles in the experiment Testoserone Level Testosterone Levels in Tadpoles Frogs 40 35 30 25 20 15 10 5 0 1 2 3 4 5 Tadpole Frog Control Atrazine Discussion and Conclusions There were some observations I was able to make from looking and observing the treated frogs and the control frogs While the observed sex of the frogs and the actual sex of the tadpoles frogs were the same I did notice a huge difference in their testosterone level Frog one s testosterone was 16 42 the second s was 30 38 the third was 36 22 the fourth s was 15 44 and lastly the fifth s was 14 68 Frogs tadpoles one five were the frogs that were in the control tank and their testosterone levels were never affected The treatment tanks tadpole frogs testosterone levels were measured and their numbers were extremely different than the control tanks The tadpoles frogs in the control tank was measured frog six s testosterone level was 1 05 seven s was 7 15 eight s was 3 13 nine s was 2 36 and ten s was 1 24 While the low testosterone is explained for one of the tadpoles frogs because it was a female the others observed and actual sex was in fact male So the atrazine that was put into the treatment tank did have an effect on the tadpole frogs testosterone levels From my control treatment data no percentage of frogs changed from male to female While in the atrazine treatment data 20 changed into females 20 meaning one out of the five tadpole frogs changed into females When looking at the rest of the classes data from some of the atrazine experiments I observed that the frogs changing from female to male At least 20 of the frogs in the atrazine treatment tank changed sex There was sometimes where no frogs in the treatment tank changed sex this was only observed twice in the classes data In the control tanks none of the frogs appeared to change from male to female The classes testosterone data looked very similar to mine From the control tanks the levels ranged from 5 0 35 0 just like my control tanks did The classes data of the frog s testosterone levels in the treatment tanks ranged from 0 0 7 0 The classes data of the testosterone levels in the treated tanks are significantly different from the control tanks Atrazine does not naturally occur in nature it is a human made herbicide It has been discovered that if one is exposed to atrazine for a certain amount of time it has negative impacts Because it is a pesticide frogs and other amphibians are exposed to it in their environment and it has been found to have negative impacts on them It is shown to affect the hormone system and because frogs are small animals it has more an affect on them and that has been observed There are also health issues that come with exposure to atrazine It has been observed that it can delay puberty and cause males to develop female sex characteristics and has also been shown to have reproductive effects