[Qwapisking]

have you considered that due to the pollution levels of the surrounding waters of nyc that the specific gravity of the polluted water will affect only the area surrounding nyc? good question for karine.

[RoosterRedux]

The problem with that is that the currents around Manhattan and its proximity to the ocean keep the water changing and not static.

I used to live near the East River on the Upper East Side and can remember boats stuggling against the powerful current there. I think the water stays relatively fresh where the currents are active and strong.