Archive for October 2013
We all notice the rise and fall of waterways with the tides, but what drives that motion and how does it affect our favorite places along the coast? Join Leslie and Christian for a good discussion about tides, this time on The Paddler’s Planet. Tides are a rising and falling of the sea caused by the combined effects of gravity from the moon and sun and the rotation of the Earth. As the planet rotates gravity pulls water toward the moon and creates a bulge on that side of the Earth and a corresponding dip in sea level behind it. Many coastal areas have two high and two low tides per day; other places, like along the U.S. Gulf coast, have one high and one low per day.
The range of tides varies with the shape of the coast and the offshore bottom. Along the Chesapeake Bay tides may only range up and down about one and a half feet. But along the Georgia coast that range may be six feet or more, helping to create broad beaches and vast expanses of salt marsh.
Tides drive coastal ecology, with an incoming tide carrying tiny larvae of fish and invertebrates into marshes where they can take shelter and feed and grow. As tides recede, they pull decaying plant matter from marshes and carry that into bays, bringing nutrients to the coastal waters. On rocky coasts tide pools hold water at low tide, providing a refuge for animals that could otherwise dry-out and perish.
As paddlers we must be aware of tides. If paddling in a new area it’s especially important to check the tides ahead of time. Unprepared paddlers have been caught struggling against strong tidal currents or even left high and dry.
Learn more about how the movement of tides is vital to the health of our coastal waters, this week on The Paddler’s Planet.
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Hey there! This is Leslie Kolovich, and joining me today is 14 year old Ryan Maloney from Carlsbad California.