The long-awaited dredging of the Annisquam River now is expected to extend into a second season to accommodate the removal of more material, protect the river's winter flounder habitat and reduce interaction with lobstermen and lobster gear during the disposal of dredged material, according to the U.S. Army Corps of Engineers.
Erika Mark, the Army Corps project manager, on Tuesday said public comments by the state Division of Marine Fisheries — which were supported by the Massachusetts Lobstermen's Association and other elements of the commercial fishing industry— prompted the Corps to reshape the schedule for restoring the federal channel to appropriate navigable depths.
All dredging and disposal will be completed by private contractors. The Army Corps put the project out to bid last week and plans to open submitted bids on Aug. 2.
The original work schedule, released last winter, stated the dredging of 140,000 cubic yards of sand and gravel from the river would begin this October and take about four months to complete.
But concerns over impacts on the winter flounder habitat and commercial lobstering industry during the late autumn and early winter – as well as the opportunity to fold in an additional dredging element — convinced the project's coordinators to consider extending work into 2021 to compensate for scheduling restrictions.
"Now it will likely require a second season," Mark said.
Mark said extending work will raise the project price tag from the original $6 million, but that all costs will continue to be borne by the Army Corps. She did not have an estimate for the additional costs.
The initial schedule called for dredging about 140,000 cubic yards of sandy material and gravel to eliminate shoals from the federal channel and parts of the Lobster Cove anchorage.
Most of the sandy material — about 32,599 cubic yards — will be transported to the Ipswich Bay Nearshore Disposal Site about 1.5 miles north of Farm Point and Wingaersheek and Coffin beaches. The site has an average depth of 32 feet.
The remainder — about 7,500 cubic yards of the sandy material and all the gravel — will be deposited at the Gloucester Historic Disposal Site, which is about seven-tenths of a mile due south of the beginning of the Dog Bar breakwater, in 80 to 120 feet of water.
And that worried the Division of Marine Fisheries and lobstermen.
"The Gloucester dredge disposal site is within an important area for the lobster fishery," DMF Executive Director David Pearce said in the agency's letter to the Army Corps of Engineers. "Throughout the spring and summer, egg-bearing females are particularly vulnerable. Adult lobsters are in highest abundance in the fall and the Gloucester fishery is most active during this time."
More lobster is landed in Gloucester than any other port in the state.
DMF said disposal at the Gloucester site only should occur in December and January "to minimize interaction with lobstering."
"The MLA supports DMF's recommendation to protect the resource," said Beth Casoni, MLA executive director.
DMF also recommended no dredging work or disposal at the Ipswich Bay site from Feb. 15, 2020, to June 30, 2020 "for the protection of winter flounder and diadromous fish."
Diadromous fish migrate between fresh and salt water and the Annisquam provides passage for the several species of spawning diadromous fish heading into the Little River, including rainbow smelt, blueback herring, alewife and others, DMF said.
Mark said the reconfiguration of the work schedule allowed project coordinators to fold in another dredging option not included in the project's initial plan.
That option calls for the additional dredging of about 50,000 cubic yards of silt from portions of the river.
"If we choose to include that option, we will definitely go into a second season," Mark said.
The second season also could complicate the removal of 100 to 150 city-owned moorings in the areas of the river to be dredged.
"If it goes into a second year, obviously we'll have to take some out this year and some out next year," Gloucester Harbormaster T.J. Ciarametaro said. "As of right now, I have a good idea about which need to be moved."
Contact Sean Horgan at 978-675-2714, or email@example.com. Follow him on Twitter at @SeanGDT.