transformation that
amazes who witness it for
first time — countless times
Above all else, salt marshes are ruled by the tides.
Coastal marshes are among only a handful of Earth’s natural ecosystems—the others being mangrove forests, beaches, and rocky seashores—subjected to these predictable daily inundations.
Animals that live in the marsh or regularly come to it for food and shelter must move to the tidal beat.
Here in South Carolina, the tides twice daily sweep into the rivers and sounds and then into smaller and smaller creeks—and then cover the entire marsh with a mixture of salt water from the sea and fresh water off the land. It’s a remarkable transformation that amazes those who witness it for the first time — and even those who have seen it countless times.
A professor once explained the process to me: “Tidal creeks and rivers,” she said, “assume dendritic patterns of smaller and smaller channels, which act both as tributaries during ebb tides and distributaries during flood tides.”
The world of the salt marsh : appreciating and protecting the tidal marshes
of the southeastern Atlantic coast by Charles Seabrook (Athens, GA: University of Georgia Press, 2012).
I grew up on the east coast.
The east coast of Lake Michigan that is.
It could also be identified as the West Coast of Lower Michigan.
The Big Lake, as we called it, to let folks know we weren’t talking about any of the uncountable number of small lakes in Western Lower Michigan.
There were no tides on the Big Lake and few lake side marshes as the Western side of Lower Michigan was made up of sand dunes over clay banks.
I thought I knew all you could know about big bodies of water.
Then I moved to the Low Country of South Carolina and learned about the Salt Marsh.
I learned about the salt marsh and the tides.
I learned about the “bite” of the East Coast, geographically known as the Georgia Bight (or South Atlantic Bight)—is a massive, inward-curving bend in the coastline that stretches roughly from Cape Hatteras, North Carolina, down to West Palm Beach, Florida, centering deeply along the coast of Georgia and South Carolina.
This distinct indentation has a profound, amplifier effect on the region’s high tides.
While most of the East Coast experiences a modest tidal range of 1 to 3 feet, the center of the Georgia Bight (including places like Savannah, Georgia, and Hilton Head Island, South Carolina) experiences normal daily tidal shifts of 6 to 8 feet, occasionally spiking to 8 to 10 feet during seasonal extremes.
Those daily tidal shifts of 6 to 8 feet, occasionally spiking to 8 to 10 feet during seasonal extremes are an amazing thing.
Always the same.
Always different.
With the tides on a 10 hour cycle, the times of high and low tide are different every day.
A beautiful huge stretch of beach at noon on one day will be a high tide at noon a few days later.
As Mr. Seabrook writes, “It’s a remarkable transformation that amazes those who witness it for the first time — and even those who have seen it countless times.“
