As we canoed along a narrow, winding stretch of Old Lyme’s Lieutenant River at low tide the other day, wave after wave of fiddler crabs scuttled up muddy banks and darted into holes that pockmarked a crustacean metropolis.

“Look at them all! I had no idea there were this many crabs on the planet,” I called over my shoulder to my son Tom, paddling in the stern.

“Pretty amazing,” he replied.

Had the claw-clacking critters been as big as Godzilla, we humans would have been the ones fleeing for our lives, but happily for us, the puny crabs were about as menacing as Monarch butterflies.

Wildlife also abounded overhead: gulls circled, osprey swooped, terns dove — even a bald eagle glided imperiously above the reeds. Meanwhile, egrets silently stalked the shoreline shallows, poised to snatch a snack.

No wonder the fiddlers were skittish; life is tough at the bottom of the food chain.

The Lieutenant is one of the region’s most appealing short rivers, flowing 3.7 miles south from a spring near Saunders Hollow Road toward the vibrant, lush Connecticut River delta abutting Long Island Sound. The proliferation of birds and marine life inhabiting this sprawling expanse of wetlands, tidal marshes, beaches and islands inspired The Nature Conservancy to proclaim the lower Connecticut River one of “The World’s Last Great Places.”

The Lieutenant also has long attracted photographers and painters, including members of the Lyme Art Colony. Their American Impressionist movement in the early 20th century first flourished in an Old Lyme boarding house with sweeping views of the river that is now the Florence Griswold Museum, a National Historic Landmark.

Tom and I launched from a dirt road north of Route 1 not far from the museum (there are two other public launch sites with easy access to the Lieutenant — one off Shore Road and another at the end of Smith Neck Road).

Soon after passing beneath the Route 1 and I-95 overpasses and an Amtrak railroad bridge, we entered a secluded world of serpentine river channels lined with tall Phragmites.

“Look around us,” Tom said. “Not a single manmade structure.”

The Lieutenant bends sharply west just south of the railroad tracks, but we chose a route to the east through a channel leading to an estuary also fed by the Duck River. A separate canal cut through Marvin Island to the south, and several other watery passages extend like fingers though the tall grasses. Most of them dead end at low tide; you could easily lose your way here.

After a few twists and turns, we swept past the Great Island Wildlife Area/Roger Tory Peterson Natural Area Preserve, named for the late ornithologist/author/illustrator who lived in Old Lyme. We then crossed the mouth of the Blackhall River at Griswold Point and approached Long Island Sound.

A blustery southwest breeze kicked up whitecaps — not the best conditions for an open canoe — so after a short foray into the froth, we steered back north, propelled by the wind and a resurgent flood tide.

For the return trip, we steered into an arm of the Connecticut called the Back River, which passes between Great and Marvin islands.

It got kind of bumpy once we re-entered the main Connecticut River, and I was quite happy a mile or so later when we finally ducked back into the protected waters of the Lieutenant to complete a round-trip voyage of about nine miles.

Taking one last glimpse of the river before loading our boat on the car, I could see how the flowing water and bucolic setting helped inspire such artists as Henry Ward Ranger and Childe Hassam more than a century ago.

Our afternoon outing reinforced the truism: Nature’s influences are indeed timeless.