Salt marsh is one of the signature landscape features of downtown Westport, but the proliferation of a tall, thin invasive wetland weed -- the phragmites australis -- is marring views of the Saugatuck River and taking a toll on plant and wildlife diversity.

"I feel like they're taking over, which they kind of are," said David Brant, executive director of the Aspetuck Land Trust, which has started to remove the phragmites from its 3.2-acre Taylortown Salt Marsh property off the Kings Highway bridge. "It's taking over our salt marshes and basically crowds out all the native plants, which decreases plant diversity, which decreases wildlife diversity because all of the native plants are a food source of birds and other native animals."

Dense growth of the fast-growing reed, which can reach to 12 feet tall, has resulted over time in the loss of a biologically-rich tidal marsh because the reeds block sunlight from reaching marsh soil. As a result, native plants do not mature and spread seeds.

This type of non-native phragmites was most likely introduced from Europe sometime in the distant past and is not a source of food for any native birds, bugs or other animals.

Earlier this year the land trust began the first phase of a three-year project to remove the weeds from more than 12 acres of salt marsh in the Saugatuck River estuary in downtown Westport. In the winter, the weeds are mowed, and in the summer they're sprayed with growth-curbing herbicides.

The mowing is done with an amphibious "Marshmaster" machine operated by the state Department of Energy and Environmental Protection, which is partnering with the land trust on this project.

Phragmites thrive in less salty water, which is why they're more pervasive in the upper riches of the Saugatuck River, where the fresh water is running south and diluting the salinity of the water from Long Island Sound.

Conservation Director Alicia Mozian is responsible for reviewing development projects that might produce fresh water that runs off into the Saugatuck River.

"The phrag is more likely to grow then, so we don't want runoff going into the river," Mozian said.

According to the land trust, removal of the phragmites will increase the populations of red-winged blackbirds, owls rails, egrets, snipe, woodcock, river otter and muskrats, as well as cattail, hibiscus and other native plants and grasses.

"We are literally going to transform the landscape there forever," Brant said. "We're removing all this noxious, monoculture invasive plant. In its place is going to grow all these diverse, more colorful plants that are going to be more beautiful and they're going to have more seeds on them and these are going to attract more wildlife.

"So we're opening up the views of the estuary, we are increasing the plant diversity and, ultimately, the wildlife diversity," he said.