Meiofauna Analysis

             Sediment samples were obtained from two beaches, Nahant and Niles Beach. The meiofauna was extracted from the samples and looked at through a microscope and counted. It was observed that there was a significant abundance of nematodes at Nahant and maybe one or two harpacticoid copepods.  However, the core sample from Niles beach contained more species of meiofauna. Some of the different species found consisted of nematodes, harpacticoid copepods, and flatworms.  An observational analysis that was made from this was that there was a significant difference in Harpacticoid copepods and nematodes based on the means of the species seen in each of the samples.(Chart 1 and Chart 2)

            However, this did not prove that the hypothesis that Niles would contain more meiofauna than Nahant was correct. Further test needed to be performed in order to confirm the Hypothesis. T-test and F-test on each of the species was performed in order to determine the variance between the species of meiofauna in the samples. T-test for paired two sample means where performed to determine if the means between beaches where different. If the means where different the p-value was looked at to see if it was greater than .05. If the P value was greater than .05 it can be concluded that there were equal variance between the two. In order to further test the variances an F-Test Two Sample for Variances was done to each of the species in the beaches to determine if the variances were equal or unequal again. If the P value was greater than .05 then it could be concluded that the variances were equal, and if the P value was less than .05 it could be conculded that the variances were unequal. To confirm equal or unequal variances T-test Two Sample Assuming Equal Variances, or T-Test Two Sample Assuming Unequal Variances were performed.

            Results (Table1) of this showed that harpacticoid copepods were the only species of meiofauna that was significantly different with a p value of 8.18181E-07. Showing Niles Beach contained more diversity of meiofauna than Nahant because it had a significantly larger amount of copepods. Nematode ( Table 1) results were found to have equal variances; therefore both beaches were similar in the abundance of nematodes.

            (Charts 1 and 2) visually were able to represent the abundance of meiofauna between the two beaches. These charts showed that Nahant contained mainly nematodes, and Niles beach contained more of a variety.  The means of species were represented in (chart 3), which further confirmed that Niles contained a higher diversity of meiofauna. Therefore, the initial hypothesis that Niles Beach would have more meiofauna than Nahant was correct because of the observed sea life.

Sediment Analysis proves otherwise:

Niles beach having greater taxa went against the positive correlation of grain size and meiofauna abundance, "the number of major taxa is positively correlated with grain size (Rodriguez, p.68) because Nahant was the beach that had the larger grain sizes (Charts 4 and 5). This is suggested by the fact that the greater the grain size and exposure rate, the higher concentration of interstitial oxygen in the sediment.(Rodriguez, p. 68)  Therefore, because the interstitial space between sediment particles is larger, oxygen can travel deeper allowing meiofauna to go deeper into the sediment. The reason the data showed more diversity at Niles verses Nahant could be due the fact that the core sampling method used could not get deep enough to find all the meiofauna at Nahant.  Nahant could have had more meiofauna, but deeper core samples would need to be taken for further analysis from each of the beaches.