Tuesday, June 21, 2011

A good day in Maine

For me, every day is a good day. Of course some are better than others. But yesterday excelled.

I had the pleasure to fish the Kennebec River from Augusta to Hallowell, with a friend who also happens to be my boss. This humble man knows the river as I know my woodlot…that is, intimately.

Harry gave me a detailed history of what we saw along the shore, as well as what fish populated the river and when and how they came to be. But he also added something that shattered one of my long-held beliefs.

Specifically, I had always thought that on any tidal river, the water was at least partially saline, or brackish, as far upstream as tidal influence held sway. For instance, I would have testified that the Kennebec, as far as the first dam in Waterville, had at least some salt content. After all, the water rises and falls according to the tide.

Not so, according to someone who has studied and researched this topic for some time. Harry explained it to me this way.

While the salt water flows in with the tide, a flowing, freshwater river exerts a like influence. “The river never stops flowing,” Harry said.

It works this way. Fresh water from a river (or even a stream, on a smaller scale) meets salt water from the sea. The salt water pushes in with the tide, an inexorable force. But there comes a point where, although the tide continues to push in, the two waters do not mix. Fresh water pools up and because the tidal push is so great, the fresh water rises upstream, even in purely freshwater sections of river.

So the head of salty influence on any flowing water is yet to be determined. I plan on doing a taste test on several local streams and rivers. And no, I won’t drink the water but I shall stick my finger in and then give a perfunctory lick in order to see if it exhibits any saltiness.

Consider the map of Maine. Look at any coastal town, village or city. Frequently, you will see a place named, rather generically, “Head of Tide.” I always thought that this referred to the line of demarcation between fresh and salt water. It doesn’t.

Let’s add something else to the mix here. Tides are not all the same, ever. The moon exerts a certain pull, or lack of. And this affects the strength and consequent height of any given tide. Add winds, either onshore or offshore and we have a very unpredictable subject.

Clamdiggers are well aware of this. Although the tide chart indicates a negative tide, just the ticket for exposing far-out portions of clamflats, an onshore wind can thwart the moon’s influence, making it a poor day for clamming. The reverse is also true. A stiff, offshore wind can make a marginal tide into an exquisite one.

Every day, I try and learn something new. Yesterday, I learned enough to boggle my mind. Which is why I like being around those who have more knowledge than me or who are just plain better informed and even smarter.

It’s a dull individual indeed, who does not rejoice in adding to his or her personal body of knowledge. For me, it makes life worth living and I truly believe, keeps me young, at least in mind.

2 comments:

  1. Thanks Tom. I loved reading this.
    Its a sight to behold seeing the ocean water running into the fresh water while snorkling. The ocean water holds an oily apperance while the fresh water is clear.
    We experenced this while snorkling somewhere near Cancun Mexico. The oily water (ocean) was much warmer than the fresh water. Wow. We had a great guide that day. Marie and Luxy

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  2. Now I have learned something as well! Thanks!

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