Day Three


Rock 1                                            Rock 2                                            Rock 3
      rock 1 day 3               rock 2 day 3                rock 3 day 3       
Rock  4                                                                                         Rock 5
                           rock 4 day 3                                        rock 5 day 3


Table 4.1 Comparison of the amount of  Batillaria Minima on the five rocks.  Percent cover of the rock above and under were estimated. Measurements taken include concentration around the rock and area of the rock.  By multiplying the respective percent cover by the area of each rock, I calculated the approximate area of snails above and under each rock.

Day 3
  concentration around cm % cover under % cover above  area of rock cm^2 area of snails under rock cm^2 area of snails above rock
Rock 1 n/a 90% 5% 56 50.4 2.8
Rock 2 n/a 60% 10% 92 55.2 9.2
Rock 3 n/a 70% 1% 84 58.8 0.84
Rock 4 n/a 70% 1% 220 154 2.2
Rock 5 n/a 60% 1% 55 33 0.55


                                 Table 4.2                                                                                                                                                 
Group Mean (%) Standard Error
Above Rock Area 3.118 1.576681325
Under Rock Area 70.28 21.3930456

Figure 4.1. This graph shows the difference in the percent cover above and under the rocks.  The means of each value are plotted with bars denoting the variance in each sample .   graph 3

                            

Table 4.3.  A single factor ANOVA was performed to determine if the percent cover above the rock differed significantly from the percent cover under the rock. Astericks (*) mark differences that are significant (p < .05).


Anova: Single Factor
SUMMARY
Groups Count Sum Average Variance
area of snails under rock cm^2 5 351.4 70.28 2288.312
area of snails on top of rock 5 15.59 3.118 12.42962
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 11276.8356 1 11276.8356 9.80278317 0.0139954* 5.31765506
Within Groups 9202.96648 8 1150.37081
Total 20479.8021 9        




                                                                                                                                                              
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