Need to know which stats test to use?

[Jakerm1995]

I am currently confused as to which stats test to use. I am checking for the number of species orders found between managed and unmanaged dune slacks. I have already done a Simpson's index for diversity, but I assumed that for this assignment I would also need to do a significance test. I did an ANOVA and Tukey test, and no significant difference found in either. I am wondering if I am supposed to see no significant difference, and just leave it at that or whether or not doing it wrong and that I am supposed to do a different type of test. I hope this makes sense.

I have attached screenshots of both the tests and my data.

Any suggestions welcome, thanks for reading