Title

The Toxicity of Reef Safe V. Non Reef Safe Sunscreen on Mortality of Daphnia major

Author(s)

Catherine Barron

School Name

Heathwood Hall Episcopal School

Grade Level

11th Grade

Presentation Topic

Environmental Science

Presentation Type

Non-Mentored

Abstract

The purpose of this experiment is to determine whether or not reef safe sunscreen is less toxic than regular sunscreen. This was tested by calculating the mortality rate in Daphnia. The hypothesis for this experiment is, if the toxicity of the 2 sunscreens are tested on Daphnia (0 nanograms, 10 nanograms, 100 nanograms, 1000 nanograms, 2000 nanograms), then the non-reef safe sunscreen will be more toxic than the reef safe sunscreen. The independent variable is the concentrations of sunscreen and dependent variable is the mortality rate of Daphnia. The solutions of sunscreen were made using serial dilutions sense the amount of sunscreen in each solution was so small. Five Daphnia were placed into each petri dish, and there were three petri dishes per solution for both types of sunscreen. The number remaining alive were counted over the course of two days after they were placed in petri dishes. A line graph and the percent mortality rate per group was calculated. No distinctive patterns occurred in the date, but there was a higher death rate in the non reef safe groups than in the reef safe groups. The data is inconclusive so the null hypothesis cannot be rejected.

Location

Furman Hall 227

Start Date

3-28-2020 9:00 AM

Presentation Format

Oral and Written

Group Project

No

COinS
 
Mar 28th, 9:00 AM

The Toxicity of Reef Safe V. Non Reef Safe Sunscreen on Mortality of Daphnia major

Furman Hall 227

The purpose of this experiment is to determine whether or not reef safe sunscreen is less toxic than regular sunscreen. This was tested by calculating the mortality rate in Daphnia. The hypothesis for this experiment is, if the toxicity of the 2 sunscreens are tested on Daphnia (0 nanograms, 10 nanograms, 100 nanograms, 1000 nanograms, 2000 nanograms), then the non-reef safe sunscreen will be more toxic than the reef safe sunscreen. The independent variable is the concentrations of sunscreen and dependent variable is the mortality rate of Daphnia. The solutions of sunscreen were made using serial dilutions sense the amount of sunscreen in each solution was so small. Five Daphnia were placed into each petri dish, and there were three petri dishes per solution for both types of sunscreen. The number remaining alive were counted over the course of two days after they were placed in petri dishes. A line graph and the percent mortality rate per group was calculated. No distinctive patterns occurred in the date, but there was a higher death rate in the non reef safe groups than in the reef safe groups. The data is inconclusive so the null hypothesis cannot be rejected.