The effect of glyphosate and gamma cyhalothrin on the total number of viable Daphnia magna and the average number of offspring per Daphnia specimen
School Name
Spring Valley High School
Grade Level
10th Grade
Presentation Topic
Zoology
Presentation Type
Non-Mentored
Abstract
If chemicals leach into local water supplies and groundwater through irrigation systems and runoff, they can harm aquatic organisms, such as Daphnia magna. This research assessed the results of these chemical substances and how they could affect Daphnia magna in the surrounding environment. It was hypothesized that Daphnia magna exposed to systemic products, rather than contact products, would yield the highest average reproductive rates and the greatest survivorship of adult Daphnia specimens. There was a control group, Compare-N-Save Concentrate Grass & Weed Killer (glyphosate, systemic) group, and Spectracide Triazicide Insect Killer (gamma cyhalothrin, contact) group. The total number of viable adult Daphnia specimens and the average number of offspring reproduced per adult Daphnia were recorded daily until all of the organisms died. A multivariate test was run with F(12,166) = 6.248 p < 0.05 Wilks’ Λ = 0.475, partial η2 = 0.311 to find that the herbicide or pesticide/concentration had a significance of .000, and from there, a one-way MANOVA test was run for the two dependent variables. After the MANOVA was run, a post-hoc Scheffé Test was conducted at α = 0.05 to determine where there was a significant difference between the herbicide or pesticide/concentration and the average number of offspring reproduced, and a Tamhane-T2 test was run for the total number of viable Daphnia magna. Grouping information using the Scheffé Test showed that significant differences lie between 5 pairs of means for the average number of offspring, while the Tamhane-T2 test showed only 1 difference in means for the number of viable Daphnia. The hypothesis that the systemic product would result in more offspring and greater survivorship was not supported because the glyphosate had the lowest average number of offspring reproduced, and 2 out of the 3 glyphosate groups had averages of 0 offspring.
Recommended Citation
Ravindra, Bridgette, "The effect of glyphosate and gamma cyhalothrin on the total number of viable Daphnia magna and the average number of offspring per Daphnia specimen" (2017). South Carolina Junior Academy of Science. 263.
https://scholarexchange.furman.edu/scjas/2017/all/263
Location
Wall 211
Start Date
3-25-2017 10:45 AM
Presentation Format
Oral and Written
Group Project
No
The effect of glyphosate and gamma cyhalothrin on the total number of viable Daphnia magna and the average number of offspring per Daphnia specimen
Wall 211
If chemicals leach into local water supplies and groundwater through irrigation systems and runoff, they can harm aquatic organisms, such as Daphnia magna. This research assessed the results of these chemical substances and how they could affect Daphnia magna in the surrounding environment. It was hypothesized that Daphnia magna exposed to systemic products, rather than contact products, would yield the highest average reproductive rates and the greatest survivorship of adult Daphnia specimens. There was a control group, Compare-N-Save Concentrate Grass & Weed Killer (glyphosate, systemic) group, and Spectracide Triazicide Insect Killer (gamma cyhalothrin, contact) group. The total number of viable adult Daphnia specimens and the average number of offspring reproduced per adult Daphnia were recorded daily until all of the organisms died. A multivariate test was run with F(12,166) = 6.248 p < 0.05 Wilks’ Λ = 0.475, partial η2 = 0.311 to find that the herbicide or pesticide/concentration had a significance of .000, and from there, a one-way MANOVA test was run for the two dependent variables. After the MANOVA was run, a post-hoc Scheffé Test was conducted at α = 0.05 to determine where there was a significant difference between the herbicide or pesticide/concentration and the average number of offspring reproduced, and a Tamhane-T2 test was run for the total number of viable Daphnia magna. Grouping information using the Scheffé Test showed that significant differences lie between 5 pairs of means for the average number of offspring, while the Tamhane-T2 test showed only 1 difference in means for the number of viable Daphnia. The hypothesis that the systemic product would result in more offspring and greater survivorship was not supported because the glyphosate had the lowest average number of offspring reproduced, and 2 out of the 3 glyphosate groups had averages of 0 offspring.