Hi, I would like to know your opinion about the best statistical approach to use in the following case:

- 10 sampling points distributed along an area;
- One sampling moment;
- Abundance data of the occurring macroinvertebrate species in each sampling point;
- Goal: calculate if the macroinvertebrate communities differ significantly along the area in terms of the occurring species' abundance
- Data showed no normal distribution nor homoscedasticity

Followed approaches:

A - Kruskal-Wallis' test (significant result) and after a Dunn's test, that accused a significant difference between only two sampling points;

B - Mann-Whitney's Test which determined a significant difference of a sampling point in relation to all other sampling points.

Since the results are different according to the followed approach, in your opinion what is the right approach? Or is there a better approach that I should follow?

I thank you in advance for your attention!