On Tue, 23 Mar 2010 10:47:03 -0400, wrote:

On Tue, 23 Mar 2010 08:44:56 -0400, John H
wrote:

I'm not familiar with your area. The bad is an estuary so it should be
mostly freshwater. It's a huge body of water so the tides can only
affect a small portion of the bay, right?

The Bay is tidal clear up past Baltimo

http://www.dnr.state.md.us/fisheries...ndex.asp#frame

The Potomac River is also tidal. Although 'fresh water' on top, the channel is
salt water on the bottom.
If you look at that link I posted you will see the water level is
affected by the tide but it is really brackish water being pushed in
and out. The real salty water (above 20 PPT) is concentrated down in
the south end by the ocean.
http://web.vims.edu/physical/WEB/PRE...lt.htm?svr=www

Although generally it is always saltier on the bottom it doesn't look
like there is much salt in the river upstream of around Port Tobacco.

That indicates to me there is a whole lot of fresh water entering the
bay from the tributaries and will not really allow much intrusion from
the ocean. The wedge effect seems to be limited to the southern part
of the bay.

You're absolutely correct. That's the problem with the bay, the polutants from
all the rivers and streams that dump into it.
--
John H

For a great time, go here first... http://tinyurl.com/ygqxs5v