The Town of Oyster Bay, local and national environmental groups, and independent and large shellfish harvesters all agree a study on the environmental effects of mechanical shellfish dredging in Oyster Bay is needed. But they’ve yet to agree on how to pay for it.

The North Oyster Bay Baymen’s Association, which represents independent harvesters, say mechanical dredging by Frank M. Flower & Sons is destroying the bottom of Oyster Bay and reducing the number of shellfish they are catching in adjacent bay waters.

Flower, which for decades has held a lease with the town to harvest shellfish in more than 1,800 acres in Oyster Bay and Cold Spring Harbor, says dredging is not harming the bay.

The baymen and Flower have battled for years over dredging, both in and out of court, with mutual allegations of harassment on and off the water.

Now, the town is joining the baymen’s calls for a thorough study. Town Clerk James Altadonna said he’s concerned by video footage of brown plumes of sediment trailing Flower boats and is worried that “the bay will be so disturbed by the dredging that it won’t be able to heal itself.”

San Francisco-based environmental group Earthjustice, which generally views mechanical dredging as harmful, has, at the request of the baymen, begun examining the effects of dredging in Oyster Bay, most of which occurs within Oyster Bay National Wildlife Refuge.

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Flower attorney James Cammarata said Flower would consider paying for a study if the town requests one. Altadonna said the town would welcome Flower’s funding, as long as the town oversees the study and “as long as it’s done with no influence from either the baymen or Flower, so we can truly have an independent study.”

Flower’s clam-harvesting technique involves shooting water onto the bay bottom to loosen sediment, and then using a metal basket to scoop up clams, company general manager Joseph Vinarski said Wednesday morning on a Flower boat as workers lowered the device into the bay.

Oysters are harvested either with the metal device or with a vacuum technique that sucks up shellfish.

Baymen’s Association President William Painter said the plume of sediment from dredging “annihilates” fish, especially recently spawned shellfish. He said much of the bay bottom now “looks like a desert.”

Vinarski said that’s untrue. If shellfish production is decimated, “wouldn’t we be putting ourselves out of business?” he asked.

The state Department of Environmental Conservation said in a statement that the number and diversity of shellfish harvested in the bay and other factors suggest “that the health of Oyster Bay is good.”

A 2011 National Oceanic and Atmospheric Administration report concluded that effects of dredging near shorelines “are generally short-lived” and that they are “minor” when compared with natural disturbances, such as storms. But NOAA said the impact varies depending on the location and the equipment used.

Chris Amato, an Earthjustice attorney, said the frequency, duration and type of dredging also help determine the effect on a particular body of water.