Subject: What causes small 'springs' of water to come up from the beach?

A few weeks ago, I was walking down a beach during a storm (heat lightning, 
large waves, etc)  A "shelf" had formed from the wave action and the tide was 
high.  I heard a loud bubbling sound.  Looking closer, I saw small "springs" 
or "giesers" of water coming up from the sand.  They were about an inch in 
diameter.  I dug deeper to see if it was some sort of organism, but my digging 
only increased the size of the upwelling.  The "springs" were quite numerous.  
Despite searching on the internet, I could not find the name of these things, 
or what causes them.  

Re: What causes small 'springs' of water to come up from the beach?