Aim: To investigate whether periwinkles prefer different environments on the rock to survive on.
Null Hypothesis: There will be no statistically significant difference between the areas that periwinkles preferably inhabit on a rocky shore.
Location: Jetty Beach a sheltered beach
Method:
Null Hypothesis: There will be no statistically significant difference between the areas that periwinkles preferably inhabit on a rocky shore.
Location: Jetty Beach a sheltered beach
Method:
- We laid down a tape measure along a point on the shore.
- We then used a random number generator to select 5 areas where we would collect our data as to where the periwinkles would be found.-
- When we reached each point we laid a 1m by 1m quadrant down over the point in the centre.
- We then proceeded to count the different areas where the periwinkles were observed. We set out 6 different locational areas we were going to measure. These were; Rocks, Pools, Pool edges, Crevices, Seaweed or Other.
- We tallied up how many periwinkles we observed in each locational area and then accumulated each of the 5 sites results together and inserted our data into a table.
- We then carried out a chi squared test to see if there was any statistically significant difference in where we found the periwinkles.
The chi squared value we obtained was 155.383. We then have to compare this with the critical value which depends upon degrees of freedom and levels of significance/ certainty. Our significance value was p=0.05.)
Our calculated Chi square value of 155.383 is greater than the critical value of 11.070 and therefore we reject the null hypothesis of no statistically significant even distribution at the 5% statistical level.
we therefore can accept that there is a preferable habitat for the periwinkle to live on the rocky shore.
Our calculated Chi square value of 155.383 is greater than the critical value of 11.070 and therefore we reject the null hypothesis of no statistically significant even distribution at the 5% statistical level.
we therefore can accept that there is a preferable habitat for the periwinkle to live on the rocky shore.