Waterways Committee Supports Kelp Project In Nantucket Sound

By: William F. Galvin

Topics: Agriculture & Farming

Sugar kelp.  UNIVERSITY OF MAINE

HARWICH — The waterways committee is supporting a pilot program growing kelp off Herring River this winter, with the understanding that project proponent Mark Kelleher will work with Harbormaster John Rendon to resolve any potential navigation issues.

Kelleher will be doing business as Kelpeher Farms and presently is going through the permitting process to locate two kelp arrays outside Herring River. One would be located a quarter mile outside the mouth of the river and the other would be to the west side of the Kill Pond Buoy. The inshore array would consist of one line 250 feet long and a second one with two lines, each 250 feet long, about 10 feet apart.

Sugar kelp (saccharin latissima) has been a food source in Asia for centuries and is growing in popularity in the United States. The sweet-tasting seaweed is native to New England waters and in the right conditions can grow in massive abundance. Nitrogen, which can degrade the health of the marine environment, is one of those nutrients, and kelp will remove it from the marine environment.

Kelleher was before the waterways committee last week and said his proposal is to install two anchor blocks and buoys and extend a horizontal line for 250 feet between the moorings. Using intermittent buoys, the line will be suspended seven feet below the surface so as not to interfere with vessels moving through the areas. The locations he has chosen have a depth of approximately 24 feet.

He pointed out the timing of the project is the fall and winter season when boat traffic is at a minimum. The plan is to install the equipment in October and add twine with microscopic kelp to the lines in November.

“It absorbs the nitrogen and the real burst of growth comes as the days get longer,” he said of the coming spring. The kelp can grow as much as 12 feet in length if there is enough nitrogen in the waters. The two locations have been chosen to measure the nitrogen available there.

The Herring River corridor contains high concentrations of nitrogen, essentially a pollutant, which it is hoped will feed the growth of the kelp. If the pilot program experiment is successful, he said he'd be back seeking more area for the kelp farm.

Kelleher said a kelp farm is an economic benefit to the town and a way of developing another food source for people to eat. He said he is working in consultation with Bren Smith, a vertical ocean farmer, who has had great success in growing kelp off the Connecticut shoreline.

Kelleher was looking for the waterways committee's support as he prepares to go before the conservation commission in early August for permitting. Kelleher said he has permit applications pending before the state Division of Marine Fisheries and the Army Corps of Engineers.

The lines would be removed after the harvest in May, but he wanted to leave the 160-pound terminal anchors in their locations year-round. Rendon said there is little traffic in those waters during the winter period when the kelp will be growing, but he did have concerns about leaving the anchors year-round.

The anchors would be marked by buoys. Waterways Committee Chairman Matt Hart said boaters do not expect to see buoys there and it could be confusing in the fog. There were questions the buoys would cause confusion with boaters using radar to pick up the Kill Pond navigation aid.

Fred Clancy also raised questions about ice in Nantucket Sound over the winter. Kelleher said he would use bar buoys so the ice does not lift the anchors.

Rendon said there are a lot of unknowns about the proposal, but added it is interesting and could be good for the town. He pointed out a kelp farm has been approved off Chatham.

“I'm supportive of it, but I'd like to see you remove those blocks during the boating season,” Rendon said of the anchors. He said 160-pound blocks are a manageable weight to remove and recommended they be pulled during the harvest.

There were also questions about the lines used for the farm impacting marine life. Kelleher said he will be using breakaway links and lines with appropriate breaking strength consistent with aquaculture gear prescribed in the Atlantic Large Whale Take Reduction Plan.

Natural Resources Director Heinz Proft said he has met with Kelleher a couple of times and he pointed out this is more of a study at this point to determine growth potential.

“We don't know what it is yet, but it sounds interesting,” Hart said.

The committee unanimously approved a motion to accept the proposal contingent upon the harbormaster's input. If any problems occur with the project the group asked that it be brought back to the committee for additional review.