Standing amid the marshes of Petaluma's Shollenberger Park, Jeff McCreary points out the Northern shoveler ducks, the gadwalls, the cinnamon teals and the Canada geese.

And he's confident that his organization, Ducks Unlimited, has had a positive influence on the waterfowl's apparently contented existence in the wetlands, tucked between the Petaluma River and office parks.

McCreary, a Penngrove native who grew up in and around Petaluma, is the director of conservation programs for the nonprofit group that has helped conserve almost 5 million acres of land in the United States for waterfowl habitat.

He toured the park trails this week, examining the results of a recent Ducks Unlimited project to help construct two water control structures in the popular hiking and birding area. Also on his mind was California's ongoing drought and World Water Day, marked Saturday, March 22 annually around the globe.

This year's focus is on water and its link to energy and energy production. But in California and the North Bay, a lack of water is the concern.

"Water in the West is everything," he said. "This year epitomizes the record drought. What we're concerned about from a conservation standpoint is, what does that mean to waterfowl?"

While Shollenberger Park appears healthy and well-populated with various birds and other wildlife species, McCreary said the drought may become more evident in the next year by virtue of water shortages in the Central Valley.

There, wetlands may take a back seat to the water needs of farmers. That could create dryer habitats, forcing waterfowl to migrate further north in search of wetlands like Shollenberger.

The North Bay is an important stopover for migratory birds on the Pacific Flyway. In the past 200 years, many wetlands, particularly along San Pablo Bay, have been diked, drained and converted to fields or salt ponds.

Last year, Ducks Unlimited, which headquartered in Memphis, and the Sonoma Land Trust announced a large grant to help fund the Sears Point project, which will create habitat for canvasbacks and mallards as well as 22 fish species, including Chinook salmon.

In Petaluma, local nature lovers have seen changes too. Four years ago, local biologist Gerald Moore and his wife Mary Edith, of the Petaluma Wetlands Alliance, noticed a side channel along Shollenberger's main trail had dried up.

"That had never happened before," Moore said. "We were kind of disturbed because we couldn't figure out what was going on."

So he crawled around the creek and found dried cattails and a choked-off canal, where rain and runoff was supposed to flow.

"Everything was out of balance," he said. "We had a problem we needed to solve."

Moore contacted Ducks Unlimited because of their habitat conservation focus and asked for help. Two weeks later, McCreary and an engineer visited.

"That engineer hopped around those water gates and all around the ponds," Moore recalled. "He poked around for almost an hour. He said, 'You guys diagnosed this right. You've got to get rid of all these cattails in the channel and put in new water gates.'"

As the group walked further, they talked about how to get it done, knowing the city of Petaluma had no extra money.

"Halfway around the trial, he says, 'Why don't we help you get this done?'" Moore said.

At the time, Ducks Unlimited was working on a 1,700-acre wetlands restoration project along Highway 37 and could add the Shollenberger project to the list. The organization helped obtain $52,000 from the North American Wetlands Conservation Act and $25,000 from the U.S. Fish and Wildlife Service.

After three years of navigating the permitting process, last year two "weirs," or water control structures, were rebuilt at Shollenberger.

One helps balance fresh water in the channel and salty water from the marshes on the other side of the trail. The other is along the southern end of the ponds.

Phase two of the project, McCreary said, is to clean up those cattails that have overgrown the channel.

"More birds use the Central Valley and the Bay Area than almost any other place in the world in the winter," he said. "Projects like these have multiple benefits. That's the power of doing this."

(You can reach Staff Writer Lori A. Carter at 762-7297 or lori.carter@pressdemocrat.com.)