Red Tide Cysts Not A Red Light For Estuary Dredge Disposal

By: Ed Maroney

Topics: Dredging

An aerial view of Nauset Inlet, with Town Cove on the upper right and Nauset Beach in the upper left.  COURTESY PHOTO

ORLEANS The Nauset Estuary Stakeholder Group will meet via Zoom tonight (July 9) at 5 to hear some good news regarding the long-sought and oft-delayed effort to dredge the estuary and restore its utility for commercial and recreational boaters.

The likely presence of red tide cysts in some of the material to be dredged presented concerns about their possible spread when the materials were relocated. A pilot project was set up north of the Nauset Beach parking lot and the results are in. Minutes of the Orleans Dredge Advisory Committee for June 22 state that Leslie Fields of Woods Hole Group reported that “the project appears to demonstrate that the cysts will die due to one or more of the effects of freezing, fresh water or drying out of the cysts. It will be necessary to ‘turn over’ the pile of dredged material periodically (with a loader) to accelerate the desiccation of the cysts.”

A different outcome would have complicated the disposal of spoils from the estuary dredging. As it is, Fields advised that the north-of-the-beach site “will not accommodate all of the sand that is dredged from Nauset Marsh, assuming the channel behind the barrier beach is part of the dredging project.”

The question of the extent of the dredging, and the width of the new channel, are unresolved matters for the stakeholder group, which includes select board members from Eastham and Orleans as well as members of relevant interest groups. Dredge advisory committee chair Charlie Carlson said he’d “love it” if Eastham officials approved a 100-foot channel. “If they won't approve going ahead with a hundred feet, at least we could get permits for it,” he said. “If experience shows 50 feet’s not working, we could go to 100 feet right away.”

Stakeholder group member Steve Smith, also a member of the dredge advisory committee, added that a 50-foot channel in Town Cove would be inadequate. The former channel “was clearly about 150 feet wide,” he said. “Fifty feet in Town Cove is not only an unreasonably small width of channel, but it’s not safe for navigation with all the kids and their sailboat races. To have them plus kayakers plus the crew (teams), it’s just too small.”

The stakeholders meeting tonight on dredging the estuary will include an update on the permitting process and a review of dredging options and disposal site alternatives, as well as a look at resource area impacts on shellfish and eelgrass. To join the meeting, go to Zoom and enter ID#838 3332 0290.

As complicated as the estuary dredging project is, it’s just one of the issues being addressed by the Orleans Dredge Advisory Committee, which had back to back meetings June 22 and 29 last month. That group is also looking at dredging parts of Pleasant Bay and finding locations for the spoils while it investigates whether the town should buy its own dredge, rely on the county’s equipment, or contract out work.

Minutes from the June 22 committee meeting about Pleasant Bay dredging note Fields said “previously permitted disposal locations are no longer suitable, in most cases because the land is now marsh. Therefore the town will need to spend about $8,000 per site for engineering and permitting work.” Negotiations for use of privately-owned sites are essential.

There are potential town-owned sites, Carlson said at the June 29 meeting. Pah Wah Point “has town-owned property separate and apart from 141 Portaminicut… the only other town-owned property available is at Kent’s Point,” he said. “I don’t know how much material might be accepted there… Putting aside those two locations, everything else is private.”

Carlson said he had checked whether any Orleans Conservation Trust property could be used but came up empty. There’s some possibility that the new Sipson Island Trust might have an appropriate location, but “we need to give those folks another week or two to get their feet on the ground,” he said.

“That leaves us with Quanset Pond,” Carlson said. “We only have private landowners, who need to be contacted. We need Leslie to estimate the amount of area she needs before we start reaching out.” Committee member Bill Amaru, a longtime fisherman, recalled that “the peninsula that forms sort of the arm that protects Quanset is very small compared to what it was. It used to go all the way over to the opening of the channel that leads into the pond, back in the ‘70s. I wonder if it would be possible to find out the old dimensions of that spit and replace it with the spoils. It would create a new habitat for additional grass to grow on and protect the bay from strong winds.”

Member Ginny Farber cautioned against having discussions with private landowners before securing the “blessing” of the select board, to whom the committee is advisory. Carlson said he will speak to Town Administrator John Kelly first.

Carlson will also check with Kelly about whether additional funds will be needed from this fall’s special town meeting to study dredging the Mill Pond channel. At the committee’s June 22 meeting, Fields reported that Woods Hole Group and the Woods Hole Oceanographic Institution had concluded “there is little likelihood the red tide cysts in the Mill Pond will have an adverse impact on Nauset Marsh if the Mill Pond channel is dredged.”