HomeMy WebLinkAbout104 Great Bay Bay Road Shellfish Survey ConCom 1
TO: Conservation Commission
FROM: Natural Resources, Town of Barnstable
DATE: January 6, 2024
RE: APPLICATION: Seasonal Pier, Ramp, and Float
APPLICANT: Jeanne D. Barbieri, Trustee
7 Longmeadow Drive
Westwood, MA 02090
LOCATION: 104 Great Bay Road
Osterville, MA 02655
REPRESENTATIVE: John O’Dea
Sullivan Engineering & Consulting, Inc.
711 Main Street, P.O. Box 659
Osterville, MA 02655
SHELLFISH SURVEY RESULTS: A shellfish survey was conducted on January 4, 2024
by Shellfish Biologist Elizabeth Lewis and Shellfish Technician Devon Nunez. Low tide
occurred at 12:04 P.M. (+1.8) with the survey occurring between 11:30 A.M. and 12:15
P.M. Much of the intertidal zone was not exposed during the survey period. 33 sample
plots (1 sq. ft.) were examined for substrate type, shellfish, and habitat suitability. The
plots were located at transect intervals of 10 feet from the shoreward stake along the
centerline of the footprint of the proposed pier. This formed transect B. 10 feet on either
side of the center of the footprint and again at every 10 feet, formed two more transects
labelled A and C. A diagram is located below for your reference (Figure 1). Sample plots
correlate with the distance in feet from the beginning stake and transect.
Due to the higher low tide and not being able to dig deep enough to expose softshell
clams (Mya arenaria), siphon holes were counted as an estimate of the number of
softshells located within each plot. Below is a picture from the site to show how defined
these siphon holes are to determine number of softshell clams in each plot (Figure 2).
With this, it is a low end estimate because many times with any sand, the holes may fill
in. The sediment in this zone consists of large grain sand with areas of patchy seaweed
creating a thin, filmy layer. An average of 4.25 softshells were found per square foot
Town of Barnstable
Marine and Environmental Affairs Department
1189 Phinney’s Lane, Centerville, MA 02632
Derek Lawson, Director
508-790-6273 / Fax 508-790-6275
www.townofbarnstable.us
Animal Control 508-790-6274 Natural Resources 508-790-6272
Harbormaster 508-790-6273 Sandy Neck 508-790-6272
Marinas 508-790-6273 Sandy Neck Gatehouse 508 -362-8300
Moorings 508-790-6273
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between 0 and 40 feet. This would be considered productive habitat and the sediment
type is ideal for softshells.
At 40 feet and beyond, shellfish were harvested using a basket rake with 3/8” lined mesh
to retain any seed shellfish. Quahogs, Mercenaria mercenaria, were sporadically found in
this area out to 100 ft. ranging in size from 1 inch to well over 3 inches. A total of 14
quahogs were found. Sediment consisted of sand mixed with organic material and a thin
layer of mud/silt on top. Attached is the corresponding shellfish survey data sheet.
ADDITIONAL COMMENTS: The proposed project is located within North Bay DMF
SC23.3 and is designated as conditionally approved currently in the open status. The area
is rated a 10/10 by the 2011 Habitat Assessment Group. This area has access from shore
for recreational shellfishers and is a common place to harvest softshell clams during the
open season. Softshell clam populations are also found subtidally making this area
conducive to pumping for commercial shellfishers.
Wild quahogs are plentiful throughout the area. Additionally, just one pier over, Natural
Resources planted quahogs under predator exclusion nets with moderate success (years
ago). During the duration of the survey, we observed two commercial quahog draggers
just 20 feet away from the staked end of the pier. This area is quite productive for both
softshell clams and quahogs. The sediment type is conducive to both the settlement and
recruitment of these two species and is significant habitat. This shoreline is regularly
planted to supplement the wild quahog populations though none of the samples indicated
farm raised quahogs (notatas).
With the bottom of North Bay continuing to be compromised with added stressors and
productive areas becoming more important to protect, this is one of those areas to protect.
Few houses are left in North Bay without piers and North Bay is reaching buildout
capacity. Since this habitat is so valuable (10/10 rating), a pier would impact the
shellfishery in this location and alter the habitat of the area. Considering the maximum
depth of the pier is 2.5ft on an average low tide, there are times where on a minus low
tide, the float would hardly be above the sediment and has potential to sit on bottom.
Each time that float goes down as the tide comes back in it will create a suction and alter
the sediment below scouring out an area by the float. 131 ft. pier is very long and
destructive just to reach 2.5 ft. of water when the sediment of the area is sandy and hard
allowing for easy water access from the shore to use kayaks or dinghies. The level of
harm to the habitat far outweighs any benefits.
Sincerely,
Elizabeth A. Lewis, Shellfish Biologist
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Figure 1. Diagram of plots surveyed
10ft. 10ft.
A B C
0ft
= stake 10 ft.
10
20
30
40
50
100
Figure 2. Softshell Clam Siphon Holes at 0 ft.
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Figure 3. Sample Quahogs
Figure 4. Healthy Seed Quahog