Prior to analyses, we tested the data concerning their normality (Shapiro-Wilk test) and 173 homoscedasticity (Levene's test) (Zar, 1999). Environmental factors (BT= bottom water temperature; ST= surface water temperature; BS= bottom water salinity; %OM= percentage of associated organic matter content; and Phi= sediment texture) were compared between years using a Mann-Whitney test (significance level = 5%). We compared BT, ST, BS, %OM and Phi values among bays, sampling stations and seasons of the year (Summer: January to March, and so on) by means a Kruskal-Wallis test, followed by a post-hoc Dunn test.
Comparisons of the total abundance of specimens among the studied bays, and samplingstations were carried out using a Kruskal-Wallis test, followed by a post-hoc Dunn test (significance level= 5%).


Redundancy Analysis (RDA) 
library(vegan)					
crabbio=read.table("bioticdata.txt", header=TRUE, sep="")	#biotic data input
crababio=read.table("abioticdata.txt", header=TRUE, sep="") #abiotic data input
rdasousa=rda(crabbio,crababio) #Redundancy Analysis 
summary(rdasousa)	#statistical summary
plot(rdasousa)	  #plot