Wild Side Column: Living with the tides
We don't feel the tug of the moon as the world revolves but the oceans do. Each day, the moon's gravity makes tidal force that causes the Earth and its oceans to bulge toward the moon and on the side farthest from the moon. As the earth rotates, it passes through two of the bulges each day. The bulges of water are high tides. When we aren't in one of the bulges, we see low tide.
The Earth doesn't have a global ocean. Continents stand in the way. On some ocean coastlines, like in Belize, Central America, the tidal range is minimal, only about one foot. On other coasts, like in Alaska or the Maritime provinces in Canada, the tidal range is substantial, over 10 feet in places.
The sun also causes tides like the moon does but to a smaller degree. When the Earth, moon and sun line up during a full or new moon, the lunar and solar tides combine to make more extreme tides, called spring tides. When lunar and solar tides are at opposite, the result is lower tides, called neap tides.
Wind and weather also affect the tides. Strong offshore winds produce lower low tides and onshore winds can make higher water levels. High-pressure weather pushes down sea levels producing lower tides. Low-pressure systems, often associated with storms and hurricanes, can produce higher tides.
Here in Cedar Key, Florida we often see 3 to 4 feet of tidal range in a day. On the shallow Gulf Coast that's a lot of water affecting a lot of territory. Florida is flat and the ocean floor on the Gulf Coast is flat too. You can go offshore over 10 miles to find 30 feet of water.
Life in the Gulf and in the tidal creeks and marshes is adapted to the ebb and flow of the tides. It's remarkable how plants and animals can thrive being alternately flooded in salt water for part of the day and dried out or being subjected to freshwater river flow during low tide. That's why the Nature Coast of Florida is so productive of fish, shellfish and wildlife, with all the moving tidal water, inflowing rivers, tidal creeks, marshes, and shallow sea.
Those who make their living or recreate on the water on the Florida Gulf Coast, watch the tides as much as the weather. It's important to know where you are with respect to the tide when navigating along this coast. You can easily find yourself stuck up a creek where a paddle can do you no good when the tide goes out. There's no walking through tidal mud or salt marsh. You can feed the sand gnats, mosquitoes and alligators while you wait. There's a big sandbar just north and west of Cedar Key called Hard Luck, where all you can do is wait for the next tide if you get stuck out there.
I've been helping a friend from Cedar Key work on a house on Deer Island, between Cedar Key and Suwannee to the north. It's a beautiful island surrounded on the land side by channels and salt marsh and very shallow sand flats on the Gulf side.
My friend Scott can drive his shallow draft boat there at high speed regardless of the tide, knowing the deepest parts of the inside route among the islands and oyster bars.
On some days the tide is too low to go on the inside route so we go on the Gulf side and make an amphibious landing on the beach.
Since we arrived to spend the winter in Cedar Key, we have fallen into the habit of checking the tide chart in addition to the weather forecast. Fishing seems to be best on a rising tide when moving water sets up currents. Last Saturday Carol caught a dandy 26.5-inch long red drum along a current break by an oyster bar near Deer Island. The upper slot size limit is 27 inches so Carol's fish was a big one welcome for dinner.