HomeMy WebLinkAbout5774230v1 (Summary Report- Nutter Comments)12/8/2022
Town of Barnstable
Conservation Commission
367 Main Street
Hyannis, MA 02601
Subject: 102 Bluff Point Drive, Cotuit
Dear Commissioners,
Per your request, Megalodon Environmental, LLC (Megalodon) in collaboration with Sullivan
Engineering & Consulting is pleased to provide you with the following Report Results from the
approved Scope of Work dated April 29, 2022.
The Sea Legs has been operating off the beach area since 2014, at which time the Commission
waived jurisdiction at this site. The vessel was not able to be used this summer awaiting a repair
part, and was not part of this additional study.
The Iguana has been operating off the beach area since 2020. The Commission requested
continued studies to better evaluate the potential impacts should there be a “growing request for
them”, but again waived jurisdiction “unless there are major problems that are developed”.
Prior shellfish surveys carried out by Natural Resources had not observed any negative impacts to
the shellfish habitat or populations.
These additional study items were performed as requested by the Commission.
PRELIMINARY SCOPE OF WORK
TASK 1 – RESEARCH
As set forth in the Shellfish Habitat Assessment Report, submitted herewith, Megaldon
Environmental reviewed the available literature on the impacts of recreational vehicles on shellfish.
The studies reviewed support the conclusion that there is no evidence that operation of an
amphibious vehicle has a significant impact on shellfish populations.
TASK 2 – WEIGHT / PRESSURE
Ground Pressure of Average Male Walking Foot = 16 psi.
The Iguana has a weight of 8,377 lbs spread on 2 – 10” x 6’-6” tracts.
Pressure = 5.4 psi.
The SeaLegs has a weight of 3,241 lbs spread on 3 – 25” x 12” wheels with an estimated contact
area of 8” x 8”.
Pressure = 16.8 psi
Megalodon Environmental LLC
Use or disclosure of data contained on this sheet is subject to the restriction on the first page of this document.
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TASK 3 – SHELLFISH HABITAT ASSESSMENT
A copy of the Shellfish Habitat Assessment Report prepared by Megalodon Environmental is
enclosed. As described in the report, Megalodon performed shellfish habitat assessments in June
and in September of 2022. In the June assessment, thirty two quahogs and two whelks were
identified. In the September assessment, thirty seven quahogs and three softshell clams were
identified. As set forth in more detail in Megalodon’s report, the presence of multiple quahogs
suggests that the amphibious vehicle is not having a significant negative impact to this shellfish
species and softshell clams are not commonly present in the area in which the amphibious vehicle
operates.
TASK 4 – SEDIMENT ANALYIS
The attached grain size analysis shows no significant changes between the traveled path and
baseline areas to the east and west.
Nuclear Density testing showed no significant changes between the traveled path and the baseline
areas to the east and west with results ranging from 83.0% to 83.8%.
TASK 5 – PHYSICAL TESTING
In addition to the Shellfish Habitat Assessment performed by Megalodon, the Natural Resource
Department elected to conduct their own study by transplanting soft shell clams to the site and
driving an amphibious vehicle directly over them. The Natural Resource Department placed 100 soft
shell clams (60 adults / 40 <1”) in 6 test plots – 3 in test traveled way and 3 in control site at low
tidal, mid tidal, and upper tidal. A total of 600 soft shell clams were transplanted on the site from
other locations.
Approximately 2% of transplants were impacted by Natural Resources’ recovery operations.
Approximately 4% of the transplants were estimated to be impacted by the vessel.
Approximately 50% of the transplants were not recovered by natural conditions.
According to Natural Resources, in typical shellfish harvesting activities, approximately 17% of soft
shell clams are impacted.
Accordingly, the percentage of transplants impacted during the study was significantly less than
what would be expected to be impacted through typical shellfish harvesting and through natural
conditions. Therefore, no significant impacts on the soft shell clam population were observed as a
result of the study.
Moreover, as noted in Task 3, soft shell clams are not commonly found in the area in which the
vessel operates.
TASK 6 - SUMMARY
The additional studies continue to show no significant negative impacts to the shellfish habitat or
populations. As noted above, the quahog population increased slightly in the study area over the
course of the season. Soft shell clams are not commonly found in the study area, but to the extent
they were to be present in this area, the impacts from the amphibious vehicle are less than would
be anticipated from shellfish harvesting activities and less than those lost by natural occurrence.
Megalodon Environmental LLC
Use or disclosure of data contained on this sheet is subject to the restriction on the first page of this document.
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We believe the applicant has met all requirements of the Commission, and the prior authorizations
should be considered finalized.
At this time there is no way to identify potential longer term impacts, and given site specificity, no
way to identify how the impacts may differ at other sites.
The applicant is happy to continue to collaborate with the Commission and Natural Resources is
their studies for future applicants.
Thank you,
Pamela Neubert Ph.D. John O’Dea, P.E.
Principal Scientist Principal Engineer
Megalodon Environmental LLC Sullivan Engineering
and Consulting, Inc.
megalodonev@gmail.com john@sullivanengin.com
5774230.1