Annapolis wade-in assesses water clarity in early June. Credit: Jack Greer.

THE FIRST WEEKEND IN JUNE, and it's going to be a scorcher. Predictions along the Chesapeake are for temperatures in the high 90s and a heat index of 105.

But this morning there's a breeze coming off the Bay, where water temperatures are just climbing out of the 60s. From a distance the water still looks cool and clear.

This is wade-in day on Back Creek in Annapolis, Maryland. A small band has gathered to try the waters, to see how far they can get and still spot their feet. In tan shorts, leaning on her hiking stick, Mayor Ellen Moyer stands at the center of the ring. She's been the mayor of Annapolis since 2001 and is today's presiding politician. There's not much political going on, though, just a dozen or so citizens standing around in wading attire. They're here to play their part in a spring ritual acted out creek by creek and river by river all around the Chesapeake.

It's a tradition started by Bernie Fowler back in 1988 in a river well south of here.

Fowler, now 85, is a former state senator and a consummate local politician. He's also the recognized champion of the Patuxent River. Twenty years ago he came up with the idea of an annual wade-in to attract public attention to what he saw happening to his home waters. He'd watched the river grow murky for years, and upset that no one seemed to care, he started wading. To anyone who listened, he told the story of how as a young man he would wade up to his armpits and still see Bay grasses and blue crabs scuttling on the bottom.

Now every June, Fowler wears white tennis shoes and wades out until he can't see them anymore. A small crowd wades with him, in solidarity. Most years they don't have to wade very far. The yearly event in rural Calvert County attracts Maryland political heavyweights like Senator Barbara Mikulski and Congressman Steny Hoyer. It gets a lot of press.

Back Creek keeps a lower profile. But today the local lights are here. The head of the Chesapeake Ecology Center on Clay Street, in the urban heart of Annapolis. An official from the Maryland Department of Natural Resources (DNR). The environmental reporter for the local paper, The Capital. Everyone is taking photographs of everyone else.

At the appointed hour Mayor Moyer and her band line up facing the creek and start walking. A mallard splashes off toward the old McNasby's oyster plant, now home to the Annapolis Maritime Museum. As Moyer and friends wade on, the water climbs their ankles, their knees, their thighs. "It's cold!" she sings out. She'd probably like to stop soon — she's up to her waist — but she can still see her feet.

Soon her shirt is getting wet, and the two young girls next to her are practically swimming. Finally she stops, and Claudia Donegan, the designated helper from DNR, plunks down her meter stick. It disappears under water. "You're going to need a bigger stick," someone shouts. Donegan takes Moyer's hiking stick, marks off a meter with one hand and then lifts the measuring rod with the other to gauge the water's surface. "Forty-three inches!" she calls out.

Someone pulls out a tape measure and confirms the depth.

This is the deepest record yet for their Back Creek wade-in, and even better than the 30 inches recorded in nearby Weems Creek earlier that morning.

Moyer turns back toward shore. She says she's glad she took her cell phone out of her pocket. The two young girls dive the other way, out into the creek, and start swimming. The water drips from their arms as they glide.

From the dock that runs along the old oyster house, the water looks pretty clear. White oyster shells glimmer in the shallows. Rocks set offshore to break the energy of waves rolling in from the southeast show clear outlines even as they descend toward the bottom. Donegan reaches down and plucks a wisp of green floating past her thighs. "Horned pondweed," she says. It looks crisp, healthy.

"We've seen a fair amount of horned pondweed this year," she says. "And redhead grass." Everyone nods and stares. For a moment it seems that the grasses may be coming back, that the long shadow that darkens the Bay each summer is lifting.

As June turns to July, the water loses its luster. The good news fades, and once again summer brings a murkiness that obscures the bottom, even in shallow water. Like an annual migration, summer's shadow returns, and with it unanswered questions. Will the promise of this year's wade-in ever be fulfilled? Will the shadow that darkens the Bay each year ever be lifted?

— Jack Greer