[SPSS] Comparison of Fish abundances over 3 inter-tidal zones and 4 sites.

#1
Hi there,

I'm relatively new to statistical analysis so bare with me...

I have a research project that aims to find whether fish species abundance/richness varies over 3 habitats and 4 sites. The 3 habitats or zones include mangrove, mangrove fringe and sea grass. 9 transects were taken (3 in each zone) giving a total of 36 transects over the 4 sites. All sites were individually picked however Sites A & B differ from C & D slightly in that A & B are considered pristine whereas C & D are degraded.

Just wondering if anyone could suggest which statistical method would be most suitable to use, I have attempted a couple of Two-way ANOVA's however I am not confident with the results obtained.

My null hypothesis are as follows:
H0 = There is no variation in fish species abundance across the 4 sites
H0 = There is no variation in fish species richness across the 4 sites
H0 = There is no variation in fish species abundance between the 3 habitats
H0 = There is no variation in fish species richness between the 3 habitats

Any help would be much appreciated...thank you for your time,
Shaan
 
#2
I didn't understand what was nested in what, or if there was any nesting. (A typical example of an OP that was not understood and not answered.) But it was some time ago that Shaan wrote that so she is probably gone from this site.

Helbob, start your own thread if you want to discuss your layout.
 
#3
I have similar data. 4 sites, 3 seagrass, 1 sand, sampled day and night on different months over a couple years. and my hypotheses are very similar.

I have done Bray Curtis MDS and cluster plots using Primer for each month to try and show if there is difference in fish abundance between site. there was only clustering in one months data set. I have also done GzLM on fish length data in SPSS to try and show if fish length is linked to site or time but think I have done it wrong so cant advise at all on that.