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Town of Chilmark seeks Corps permit to place structures in navigable waters for mussel cultivation in Chilmark

Published May 24, 2011

CONCORD, Mass. – The Town of Chilmark is seeking a permit from the U.S. Army Corps of Engineers in conjunction with work to place structures in navigable waters for mussel cultivation in Chilmark, Mass.


The proposed project includes work in navigable waters to place structures below the mean high water line for the placement of 10 submerged longline structures in groups of two in series below the mean high water line within a 15-acre subtidal area for mussel cultivation. Each longline will consist of a 1.12-inch polysteel longline anchored by two 4,000 kg concrete deadweight anchors. Each group of two longlines will require three anchors as they will be in series and will share a middle anchor. Additional intermediate 30 kilogram concrete block anchors may be installed at 7 meter intervals along each longline to hang to the bottom.


Buoyancy will be achieved with two 24-inch diameter circular plastic submerged floats located at each end of the horizontal section of the longlines as well as intermediate 16-inch diameter circular plastic floats spaced as needed along the horizontal sections. The distance between anchors will be 165 meters and the horizontal longline length between end floats will be 117 meters. The submerged depth for the longlines will be 8 meters. At the water’s surface, there will be five marking buoys per longline.


Seed mussels socked into biodegradable cotton sleeves with a rope core will be attached to the longline in continuous lengths of up to 600 meter per longline, with the pattern consisting of alternating long and short loops descending 8 or 9 meters in depth from the longline. As mussels increase in weight, additional buoyancy will be added to the submerged longline to maintain proper depth using additional plastic floats attached to the longline.


A Corps permit was previously issued to the Town of Chilmark in October 2009 for one pilot longline within the 15-acre area. The Town has now requested the deployment of nine additional longlines within the 15-acre area for a total of 10 longlines. The Town also requested that the 15-acre area be rotated 90 degrees and that the 10 longlines be deployed in groups of two in series to take advantage of the prevailing longshore current and to allow each group of two longlines to share a middle anchor. The groups of two longlines will be deployed in series parallel to the prevailing current with the necessary distance between the lines to allow the passage and maneuvers necessary for service vessels to work the lines.


One longline was also previously permitted under the original permit at a 10-acre site in Rhode Island Sound approximately 3 miles offshore of Chilmark, Mass. No additional longlines have been requested for the 10-acre site.

The proposed project will impact 15 acres of Essential Fish Habitat for various species and life stages. Habitat at the Rhode Island Sound site consists of hard bottom with some sand and habitat at the Vineyard Sound site consists of sandy substrate. Loss of this habitat may adversely affect these species. However, the Corps has made a preliminary determination that the site-specific adverse effect will not be substantial. Further consultation with the National Marine Fisheries Service regarding Essential Fish Habitat conservation recommendations is being conducted and will be concluded prior to the final permit decision.


The application for the federal permit was filed with the Corps of Engineers in compliance with Section 10 of the Rivers and Harbors Act, which provides for federal regulation of any work in, or affecting navigable waters of the United States. The public notice can be viewed on the Corps website at Select Regulatory/Permitting and then weekly public notices.


Public comments on the Corps permit review (File # NAE-2009-349) should be forwarded no later than June 7, 2011 to the U.S. Army Corps of Engineers, New England District, Regulatory Division (ATTN: Kevin Kotelly), 696 Virginia Road, Concord, MA 01742-2751. Additional information is available from Permit Project Manager Kevin Kotelly at 978-318-8703 or toll free 800-343-4789 or 800-362-4367 (if calling from within Massachusetts) or by email to:

Tim Dugan

Release no. 2011-053