Seacucumbers were counted at the same 63 survey sites in three successive years (3 x 63 = 189 surveys in total). The distribution of counts per site are non-normal for each year. (Some sites have loads of seacucumber while most sites have few or none...they seem to have very patchy distributions). I would like to tell if there is a statistically significant difference between years for each of the 63 sites. I would also like to pool the sites into groups and compare if there is a significant difference between years for groups.

I think I need a non-parametric test for paired samples. The only thing close I can find is a Kruskal-Wallis one-way ANOVA, but this test requires that samples are independent, which they aren’t because the same sites are re-sampled.

I would be very grateful for suggestions on the best statistical test for this situation.

Seacucumbers were counted at the same 63 survey sites in three successive years (3 x 63 = 189 surveys in total). The distribution of counts per site are non-normal for each year. (Some sites have loads of seacucumber while most sites have few or none...they seem to have very patchy distributions). I would like to tell if there is a statistically significant difference between years for each of the 63 sites. I would also like to pool the sites into groups and compare if there is a significant difference between years for groups.

I think I need a non-parametric test for repeated measures. The only thing close I can find is a Kruskal-Wallis one-way ANOVA, but this test requires that samples are independent, which they aren’t because the same sites are re-sampled.

I would be very grateful for suggestions on the best statistical test for this situation.