I spent many summer days on Block Island back in the 70s. A colleague whom I worked with when I worked in NYC, the World Trade Center south tower, bought a home there just after WW2 at what later turned out to be a heck of a deal. She had five acres with a bass pond and a beautiful view of the ocean and the sound. She also had a grand nephew ,Jason, who was about 10 yrs old and needed someone to stay with him on the Island when his parents who also became friends with my wife and I ,couldn't. I got the house to use for me and my family in exchange for keeping Jason.. Jason liked to fish and I loved to fish.(tautog, bluefish and stripers in the surf with an occasional flounder or weakfish) So my wife and my two then little girls and I made several weekly stays over the course of several years. My job changed and we moved to another part of NY state and lost touch with Calla for a couple of years and then I heard that she had passed away . She was a very classy lady and I'm very grateful she shared her love of Block Island with us in this special way.
Right the water won't help the cycle at all. The bacteria that perform nitrification
( ammonia reduction) and denitrification are benthic they colonize the /surface of the rock and substrate primarily.