From The Cape Cod Times
CHATHAM — Every fall, eiders flock to Chatham Harbor and settle in for six months of snacking on mussels, one of their favorite foods.
But this year, the thousands of sea ducks will get a booming welcome.
Three air cannons will fire every 20 to 30 minutes during the daytime from three rafts in the harbor located near the prime mussel beds that fishermen want to harvest come spring.
Part of the test is to see if the cannon will also disturb nearby waterfront homeowners and guests at the posh Chatham Bars Inn.
The hope is that the ducks will move away from the irritating noise to mussel beds in ocean waters where they can dine in peace, said David Likos, vice chairman of the shellfish advisory committee.
"We definitely think these cannon will have an effect," he told selectmen Tuesday.
Big money at stake
At stake is possibly $800,000 worth of mussels, the value of the crop that survived to be harvested in 2007-08 as well as an estimated $500,000 worth of young softshell clams, also a favorite eider dish. It's money that could help the town's shrinking commercial shellfish industry. The number of commercial permit holders has dwindled from 540 in 1993 to 279 last year, according to town reports.
Last year, the ducks wiped out a potentially record crop of mussels, Likos said.
Given the importance of the shellfishing industry to the town, "I think it's worth the experiment," Selectman Tim Roper said.
He was among the three Chatham selectmen who unanimously approved the test, with conditions, including notifying the inn and other property owners "so when they hear this, they won't all jump out of their skins," Selectman Florence Seldin said. "We realize the importance of the shellfishing industry as well as the residents."
The committee wanted to use the cannons from November to March but "a weeklong test is probably prudent," said Robert Duncanson, director of the town's Department of Health and Environment. He promised to react quickly to any complaints.
"If that means turning them off, or relocating them, we'd do it as quickly as possible. I suspect, once we get (the cannon) deployed, if we get complaints, we'll get them right away," he said.
The committee also agreed to notify the Massachusetts Audubon Society, which oversees the plovers and terns that will nest next spring on Tern Island near two of the proposed cannon locations.
First time on Cape
No starting date for the test was given. The town must spend an estimated $400 to $500 for two cannons, to be paid for with a portion of commercial permit fees. Chatham's commercial fishermen have offered to buy a third cannon.
Two cannons would be moored a quarter to four-tenths of a mile east of the fish pier, and the third north of the new inlet, about two-thirds of a mile from the mainland, Likos said.
"You hook up a can of propane (to the cannon) like you normally would to your barbecue," he said. "The barrel can be adjusted to regulate the loudness of the pop."
The cannons have not been used elsewhere on the Cape, according to the committee's research, and nobody really knows what the "pop" will sound like offshore, where sounds can be muffled or amplified, depending on wind and waves. The noise from the cannon shots hits 100 to 125 decibels, far less than the 155 decibels of a shotgun blast, Likos said.
"I think the noise is somewhat like a lawn mower," he said, and, given the distance from shore, the cannon "would sound like an eggbeater. ... It's going to be a shot off in the distance."
The eiders themselves are naturally noisy, according to Likos, who played a video of a scene off Scatteree Landing as a boat came by and scared thousands into the air.
"In about 20 minutes, they found their way back to the landing but the noise they make is almost deafening. It's incredibly loud," he said.
Because of the unknown impact of the noise, Robert Oliver of Old Harbor Road, which is near two cannon sites, asked the selectmen to shoot off a cannon before approving their placement and to consider the impact on the Chatham Bars Inn and the owners who rent their homes.
"This is interesting and I'm not necessarily opposed," he said. "I don't live very far from these locations and I'm concerned. And if I'm concerned, other people will be also."
Eiders and humans have competed for the same Chatham shellfish before. The eiders fly in from Labrador, where they breed, to winter in Chatham, Likos said.
In 1953, the town hired boats for $10 a day to drive around and disperse the ducks, which did save many thousands of bushels of mussels.
Nowadays, the cost of labor and gas is too expensive, although the committee is encouraging boaters and fishermen to drive through flocks as they pass.
In 1956, the town got federal permission to kill eiders, but "we're only interested in dispersing, not in killing them," he said.
Another year, the town got federal permission to use pyrotechnics and powerboats to disperse the eiders. The rockets worked for a while but then "the ducks got used to the noise," Likos said.
The town already fires rockets, called "screamers," from a shotgun three or four times a day at the disposal area to scare away gulls. But it's too expensive and labor-intensive, Likos said.