HomeMy WebLinkAboutGreen Dunes Shellfish ReportShellfishHabitat Evaluation
Performed by Paul G. Caruso
DBA Cape Coastal Resources
42 Matthew Way, Marstons Mills, MA
Location of survey:Green Dunes
Date:3/28/2025
Proposed project:Dock and float
Waterbody:Halls Creek
Job number: 2025-8
Time of site visit: 1530 to 1630
Time/height of low tide: 01700\-0.10’
Site description
The site is a developed upland lotwith 2 houses undergoing renovation. The lot has a steep coastal bank sloping to a narrowfringing saltmarsh vegetated primarily with Spartinaalterniflora
on a tributary of Halls Creek. The salt marsh ends at a well-definededge at the low tide mark. (Figure 1).The soft muddy bottom slopes gradually until about -2.0 feet MLW then grades
back up to the other bank of the creek. The subtidal areas below -1.0 MLW are almost entirely coveredby thered algae (gracerlaria).
Methods
Fivesampling transects were made from MHW to50 feet past the end of the proposed float using a lined basket rake from a canoe. Transects were placed 25 and 50 feet either side of the
lot centerline for a total sample box width of 100 feet and length of 90 feet (9,000 square feet). Samples were taken every 10 feet from mean high waterto the seaward extent of the sample
box. Total sampled area equals 50 square feet. This sample size exceeds the required 0.05% of the sample area (45 square feet). See attached sample box plot.
Findings
Other than a few ribbed mussels on the marsh face and one loose oyster at the centerline marsh face only 1live quahog wasencountered at Sample A-3. Given the nature of the substrates
encountered and the anoxic condition of the sediments nolive shellfish were expected to be sampled. Additionally no living SAV (eelgrass or widgeon grass) was noted in the sample area.
Discussion
The project as proposed should have little or no impact on shellfish habitat as the area of the proposed structures and vessel use represent poor quality bivalve shellfish habitat.
Figure1. Site conditions looking north
Figure 2.View west depicting coastal bank, transect staking and centerline of proposed structures.
Table 1
Sediments
south
Transect Line
north
Sample #
A
B
C
D
E
0
peat
peat
peat
peat
peat
peat=marsh sod
1
peat
peat
peat
peat
peat
FM=firm mud
2
M
M
M
M
M
M=soft mud
3
FM
M
M
M
M
4
M
M
M
M
M
5
M
M
M
M
M
6
M
M
M
M
M
7
M
M
M
M
M
8
M
M
M
M
M
9
M
M
M
M
M
Table 2
Standing Stock
south
Transect Line
north
Sample #
A
B
C
D
E
0
NULL
NULL
NULL
NULL
NULL
RM= ribbed mussel
1
0
RM
RM
0
RM
Q=quahog
2
0
0
OY
0
0
OY=oyster
3
Q
0
0
0
0
4
0
0
0
0
0
5
0
0
0
0
0
6
0
0
0
0
0
7
0
0
0
0
0
8
0
0
0
0
0
9
0
0
0
0
0