Subject: How would you go about collecting samples of meiofauna in the sand?

How would you go about collecting samples of meiofauna in the sand?
I am trying to do a study on the meiofaunal life that live in the 
sands at a local beach.  I have tried to collect samples already, 
but have only been able to collect samples down two feet.  To collect 
them, I dug down with a shovel.  By the time I got down to two feet,
I had already hit the water table, and I could not dig down any 
farther. Am I digging too close to the water, or do I have to use some
sort of a core sampling device?  Please tell me how to go about this, 
because all of the samples I have been collecting have not been 
yielding any meiofauna.  I have also been separating them from the 
sand using a bath of freshwater and a 1 mm. sieve.  Thus, the majority 
of the sand would be left in the sieve, and the water and meiofauna
would go through into another bucket.  If this procedure is wrong, 
then please tell me what the right way is.  Thank you very much for 
your time.  

Re:How would you go about collecting samples of meiofauna in the sand?