NEWPORT BEACH — Some call it a weed. A scourge on the bay. Others, mainly fish, can't live without it.

Eelgrass, a type of seagrass found throughout Southern California bays, lines the shore in many parts of Newport Harbor and provides refuge and food for marine life. Because of strict environmental regulations, homeowners avoid disturbing the plant. Many haven't dredged their shorelines for years, and their boats and floating docks have begun to run aground.

Trying to strike a delicate balance between the recreational and environmental value of the bay, the city is proposing a novel plan to manage eelgrass. City officials are negotiating with federal and state regulators to allow homeowners to dredge under their docks without costly mitigation. But part of the plan relies on growing the unpredictable grass in other parts of Newport Harbor using methods never tested in Southern California.

"We are trying to make things work for our residents, yet recognize the importance of eelgrass," said Chris Miller, the city's harbor resources manager.

Federally protected under the Clean Water Act, eelgrass has many ecological benefits. Besides the shelter and food it provides, it filters excess nutrients from fertilizers and other material washed into the bay. It also oxygenates water and sediment, and removes excess carbon dioxide through photosynthesis.

With long, ribbon-like blades, eelgrass provides small fish and invertebrates a refuge from predators. Crabs and other herbivores also eat it, and some smaller species attach to it for survival. Sand bass, California halibut and other fish use it as a nursery.

"We don't want to see a loss of eelgrass habitat in Newport Bay," said Bryant Chesney, a biologist at the National Marine Fisheries Service office in Long Beach.

Because of its benefits, National Marine Fisheries Service guidelines require dock owners to evaluate, transplant and monitor growth of the delicate grass. This process can cost tens of thousands of dollars.

Since regulators began strictly enforcing rules about 10 years ago, hardly any homeowners have dredged under their docks, local officials say.

To obtain a dredging permit, dock owners have to ensure the plant thrives for five years after dredging. If it doesn't survive, they're required to plant anew.

"It's a blank check," said Mark Sites, owner of Intracoastal Dredging, based in Newport Beach. "I haven't found many people that want to take on that responsibility."

Donna DiBari, a homeowner of 25 years on Balboa Island's South Bay Front, isn't one of them. She used to dredge around and under her dock every two years, she said, until the Army Corps of Engineers, the California Coastal Commission and other groups required strict mitigation.

Now the planks of her dock crack during low tide, when the sand pushes against the dock and it torques. Her dockhand refuses to repair the planks because they keep breaking, she says.

Furthermore, paint cracks and flakes off from the stress. A recent paint job cost $7,500.

"I can understand [eelgrass] does help the bay," she said, "but when you're prohibiting the owner of a dock to dredge — that's unreasonable."

The water's so shallow in front of her home that the ground scratches the instruments of DiBari's 30-foot Navigator powerboat, and she can no longer keep it there. Like many dock owners, DiBari leases space to other boaters. Now she can no longer lease to sailboat owners because their keels hit sand.

"We're a boating harbor, a recreation harbor. We need to be able to maintain and use our boats," said Miller.

While hitting ground is a problem for boats, many swimmers can't stand touching eelgrass, either.

"I hate it. It's messy and full of gunk," said Allan Beek, 83, who grew up on Balboa Island and has despised eelgrass for much of his life.

The Beek family owns the Balboa Island Ferry, whose propellers churn enough water to prevent eelgrass from growing there, his brother Seymour said. Seymour Beek owns a home and dock near the ferry and eelgrass thrives there. He hasn't dredged for about eight years. Sand now pushes up against his dock and boats during extreme low tides.