I thought a lot (probably too long) about how and what the best way to collect data for my project would be. At first, I wasn’t exactly sure how to implement the sampling methods and sample placement examples into my project. I initially wanted to haphazardly choose a rock at a certain site since I couldn’t randomly choose a coordinate at McNeill since not every location within a site will have barnacles. After doing the virtual forest tutorial in Module 3 I decided I would assign each rock at a site a number and randomly choose a rock to sample.
What I ended up doing was choosing a random rock (sample placement) at one of the sites (random number generator) and then used quadrats (sampling method) to calculate abundance of barnacles and ultimately barnacle density (response variable) at the particular site (predictor variable). The placement for the quadrats along the rock was haphazardly chosen as I figured that would work best with varying rock shapes and sizes. I chose 10 replicates for the rock as I felt that covered an appropriate area along the rock. I am considering increasing this number and maybe sampling both sides of the rock. I opted for quadrats rather than counting the entire number of barnacles as this would be extremely time consuming and I think density will be a good indicator of overall abundance. An important note to consider for future data analyses will be dead vs alive barnacles. For the purpose of this study I assume an “empty” barnacle is dead and that all others are “alive”. There is a possibility that some “full” barnacles could be dead but I will keep this counting technique consistent throughout data collection.
I didn’t have any problems implementing my sampling strategy once I decided on one to use. The data in general wasn’t too surprising, I expected density to be relatively low at this site however I won’t be able to compare until I gather more data at other sites. I am excited to record densities at other sites to compare these differences. As of right now, I am going to use the same approach going forward with future sites while considering some points stated above.
Hi Noah,
Sounds like an interesting research topic!
You say that your predictor variable is a particular site, and that as expected, the site you chose to sample had a low density of barnacles. What factors are you considering when predicting that a certain area will have higher or lower barnacle density? Do you have any predictions about which sites will have the highest density of barnacles?
Another question I had was whether you are accounting for the water levels in each sampling location – do you think this will have an impact on the results you get?
Look forward to reading more about your project.