The following pages are a series of photo's along with explanations and descriptions of our observations concerning tidal influence in and around Horseshoe Pond. They are arranged in a series of pages in order to expedite up loading.
This first series of photo's are of Horseshoe Pond a couple hundred yards above the dam in the small cove on the Birch Island conservation area side of the pond. They were taken during a three day period this September 2002 at the end of a new moon tide cycle. Through this 10 day tide cycle the high tides ranged from 5.0 feet on the 4th to 4.8 on the twelfth. There was tidal movement into the pond at each high tide above 4.8 feet. The high tides for this period were as follows according to tide charts from Maine Harbors for the Wareham River.
This first photo is high tide in the pond
This second photo is after the tide has begun going out, ( note mud along shore in top of photo)
This third photo is further into the outgoing tide
This fourth photo shows the tide fully out of the pond on the day after the above photos were taken
This photo is from the same spot as the others but at a different angle. To the right hand side of this photo is the shoreline shown in the previous photo's.
What appears to happen here is that as the tide comes into the pond it prevents the river from flowing out. Due to this action the pond fills to such a level that it does not have time to completely empty before the next high tide. Therefore when the second high tide comes in it fills the pond even further. This goes on for as many days as the tide consecutively runs above about 4.8 feet. It is not until the tide cycle falls below 4.8 feet for at least a 24 hour period that the pond fully drains out to become freshwater.
In affect the pond has two tides. One which fluctuates between six hour tide cycles which is less noticeable ( this is what you see in the top three photos which were taken the same day). And another which fluctuates significantly when the moon cycle first begins and again when it ends several days later (this affect is in the last photo).