[R] count data

[Sacha Viquerat]

hello dear list! I wonder about the layout of my csv for my study design:

i have 11 different sites.

each site had been visited 9 times.

on each visit, 6 distinctive water parameters had been taken ONCE on 
each visit (as continuous variables).

on each visit, the fish abundance was counted using a net at 3 different 
locations within the site (count data).

I know i will have to do an lmer using the nested locations as error 
term. Question is: how to organize my data, since i have abundances from 
the same 3 locations per site replicate but only one water parameter 
measurement per site replicate. to give you an idea, heres the basic 
look so far of my csv:


site    location    abundance    pH    no3    and so on...
A    1        12        7.1    0.003    ...
A    2        15        7.1    0.003    ...
A    3        18        7.1    0.003    ...
B    1        11        7.4    0.004    ...
B    2        8        7.4    0.004    ...
B    3        17        7.4    0.004    ...
A    1        13        7.2    0.001    ...
A    2        19        7.2    0.001    ...
A    3        21        7.2    0.001    ...
B    1        9        6.9    0.002    ...
B    2        5        6.9    0.002    ...
B    3        2        6.9    0.002    ...

i just made up the table to give an idea how the data looks like. the 
goal would be to analyze fish abundance ~ water parameters, does anyone 
have a suggestion?

thanks in advance!