fairfolio
Saved Projects

Lumbriculus variegatus and Man-Made Hazards: What Is the Tipping Point?

CSEF · 2016 Environmental Science Honorable_mention Award

Hunter C. Crawford-Shelmadine · Carlmont High School, Belmont, San Mateo County

Overview

Objectives/Goals The purpose of this experiment is to test how exposure to pesticide, fertilizer, oxybenzone sunscreen, zinc oxide reef safe sunscreen, or acidity at different concentrations effect the blood flow rate of Lumbriculus variegatus and then to repeat the experiment using different combinations of these man-made stressors to better understand how exposure to multiple stressors changes the results. Methods/Materials Build custom slide to contain worm for viewing. Mix concentrations (control .05 .1 .5 1 2.5 5%) for each stressor (above). Place worm in solution for 15 minutes. Remove worm. Count blood flow contractions (bpm) for 60 sec w/40x microscope. You need an assistant to time. Record data and repeat for each solution. Record qualitative observations. Results # PESTICIDE: The presence of pesticide in any .01% combination was lethal but not individually. In a .05% solution, pesticide & oxybenzone sunscreen was lethal, pesticide & fertilizer had a statistically significant reduction in bpm. # FERTILIZER: The addition of fertilizer when mixed with pesticides resulted in a lethal combination, but when mixed with oxybenzone sunscreen did not have a consistent impact to the bpm. # ACIDITY: Lowering to pH6 only had a minor measurable impact when added to the pesticide and fertilizer mixture. There was a statistically significant drop in bpm in the 0.05% concentration. # ZINC OXIDE REEF SAFE SUNSCREEN: The addition of this sunscreen did not have a positive or negative impact on the Lumbriculus variegatus in any combination. # OXYBENZONE SUNSCREEN: The presence of oxybenzone in the water trapped the worms in a thick film which increased BPM whereas virtually all other stressors decreased BPM. # OTHER RESULTS: exposure to fertilizer & pesticide (ind) turned their red colorful insides to gray. After 15 hours of exposure to each stressor, all were alive in .05% & .1% zinc and fertilizer but 100% dead in other solutions. Conclusions/Discussion My hypothesis states that when I measure the effect of a single man-made stressor on Lumbriculus variegatus and compare those results to when they are exposed to multiple man-made stressors, the multiple man-made stressors will have a greater impact on the Lumbriculus variegatus. My hypothesis is partially correct. Only certain combinations of man-made stressors had a statistically significant greater impact on the Lumbriculus variegatus than did the stressor(s) have by itself.

Summary statement

My experiment shows that certain man-made stressors (toxins/chemicals) in combination do have a greater impact (often lethal) on aquatic life than when exposed to the man-made stressor by itself.

Help received

My science teacher, Mr. Raffa, provide input & feedback on experimental design and was a great support throughout the project.

Awards (1)

  • Honorable Mention

Competition history

  • CSEF 2016 Environmental Science · Entry S1106

Resources

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

Source: California Science & Engineering Fair public projects

Save projects to your library

Sign in with Google to keep track of projects you find interesting, organized into folders. An account also raises your daily allowance for “Has this been done?”, and lets you create a key for the MCP server with a much higher limit than anonymous use. Browsing stays public.

Continue with Google