Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Mole Crab Distribution

No description

Sungmee Park

on 7 June 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Mole Crab Distribution

Mole Crab Distribution in Intertidal Zone Methods 1. X by Y transect system (X=from ocean to where wave hits shore, 15 cm; Y=along shoreline, 30 cm
2. After wave receded, sand collected to first ridge of plastic container for each plot
3. No crabs = "o", Results p-value 0.0323 < 0.05
Refute null hypothesis that there is no difference in distribution of mole crabs at different shore heights
Mole Crabs live further from water Discussion Heights 1&2 are statistically different from Height 4
30-45 cm is distance that makes significant difference in mole crab distribution PROBLEMS: Torrey Pines State Reserve Beach
San Diego, CA
5/13/13 -Sungmee Park Histogram of Mean # of Mole Crabs based on Intertidal Zone Heights 4. 4 total X plots + 4 Y plots, 4 heights from water
5. 71 total crabs collected (41 females, 30 males)
6. Tested for normality + analyzed through one-way ANOVA (JMP) orange eggs Female Mole Crab X Y One-way ANOVA:
p-value: 0.0323 Null Hypothesis: The null hypothesis is that there will be no significant difference in distribution of E. analoga at different shore heights Hypothesis: The hypothesis is that E. analoga will aggregate further from the shore Why?: Main predator = fish, so avoid them by living further up to protect themselves and their clutch (if female) Important part of beach ecosystem (fish, birds, sea otters rely on them as food) & intermediate host for parasites + indicator for toxins like DDT and domoic acid Compared Means of Each Height:
B: 1, 2, 3 (not statistically different)
A: 3, 4 (not statistically different) -Harder to get mole crabs at height 1 (closest to water) due to wave activity
-For more accurate results, should study over different wave activity, water temperature, etc.
-Should scoop up sand at once vs. using hands to scoop up multiple times (crabs could have escaped)
Full transcript