Tony Pratt: ‘Life is a series of cycles’
“The ocean never stops,” says Tony Pratt. “It’s a perpetual motion machine.” His enthusiasm bubbles forth as he marvels at the wonder of Cape Henlopen. “Look at those magnificent sand bars!”
As recently as 1970, sand was rolling in the opposite direction, away from the Point. “That changed; now the beach is going out rather than eroding.”
The cape point naturally wants to collapse and create a barrier island, he says, but the man-made stone breakwater and outflowing beach have created a bottleneck for exiting water transporting sand against the process. “This is a success story!”
Just as Lewes Canal was once open water, he said, so will Delaware beaches “drown from the bay side.”
Our sightline is incredibly clear as a high-pressure front with low temperatures moves out; we see all the way to Slaughter Beach. “Cool air holds less moisture than warm air,” Tony explains. When atmospherics are just the opposite, you can’t make out Cape May, because warm air atop cold water forms vapor that obscures the view.
Looking into the distance, he laments how the former bounty of the bay, itself a result of tidal dynamics, has been squandered. “Clams were once plentiful. Bluefish, flounder, sea trout. All lost to overfishing.”
A seasoned veteran was duly impressed when I mentioned I would be walking with Tony. “The leading sand guy in the world,” were his words.
Tony more modestly calls himself “a shoreline and waterway administrator,” now retired after 30-plus years with the Delaware Department of Natural Resources and Environmental Control.
These days, he still works as a consultant, advising clients like Henlopen Acres on how to keep its marina from silting over and Bethany on how to handle frequent flooding - “Rain fills up the streets and can’t get out; the typical solution is to raise the roads, which only compounds the problem.”
Tony likens his life to the beaches he studies, a succession of cycles. One began at Hampshire College, fabled for its experimental approach to education (and where, we discovered, he was a student at the same time I was a young professor), when he stumbled upon one of the original books on coastal morphology and barrier island development. That launched his career, starting with a gig raising oysters and clams in a greenhouse.
He explains how 220,000 yards of sand gets delivered to the Cape every day, describing it as, “the end of a conveyor belt moving north from Fenwick dumping onto the beach. A slow geologic migration; 75,000 cubic feet to Bethany, 120,000 to Dewey, 200,000 to Rehoboth.” Shoreline drift.
In technical terms, our beaches are “cuspate forelands,” the product of continued accretion and propagation caused by prevailing wind and waves bringing sediment together from opposite directions.
“The mystery is where all the sand comes from. That’s the missing piece in the puzzle. The black box.”
Which gets him talking about waves. “The waves we have here are all caused by wind coming from multiple different directions at the same time.” On this day we have southerlies from Bermuda.
“Wind interacts with the surface of the water, transferring energy to create ripples. The back edge acts as a foil or a sail that captures more wind, and that makes the wave grow.”
This is the physics of orbital motion, “a perfect circle of energy,” he says.
This process can unfold over incredible distances. “We’ve probably had waves that started on the African coast.”
When waves hit bottom parallel to the shore, the sand bars at the Point are 8 to 10 feet offshore, so the waves elongate and crash. Tensile strength can’t keep them intact anymore. Local waves typically “spill,” curling over onto themselves.
The distinctive dunes of Cape Henlopen are the legacy of powerful nor’easters. Collisions with beach grass dislodge transported sand granules (they are capable of dropping three feet), fueling another magical cycle. More sand breeds more grass, which traps more sand … on and on.
“What do you see,” I ask as we wrap up, “when you’re here?”
“I see the brownish color of the waves as they crest; that’s sand in suspension. I see white sand in the nearest dune; it’s been dry for a long time. Slightly darker strips mean ocean waves have gotten to it. Calm energy builds up sand. Heavy energy claws it back.”
And then he repeats the essential truth he’s come to learn: “Life is a series of cycles.”