September/October 2021 - 121

G U E S T
EDI TORIAL
JOHN DUSCHANG, ENVIRONMENTAL SCIENCES AND
PLANNING DIRECTOR, AND JOE CASSONE, FISHERIES AND
ENVIRONMENTAL SCIENTIST, HDR
Assessing Marine Life Noise Impacts to Aid Pile Projects
As consulting environmental and
fisheries scientists, we often marvel at
the technical acumen and long-term
project planning of the professionals
that design and build the foundations
for the infrastructure projects that we
have worked on, including the
Governor Mario M. Cuomo Bridge over
the Hudson River in New York. Given
enough information, project teams can
anticipate and overcome many design
challenges to deliver projects within
schedule and on budget. Often, though,
there is a major risk to schedules and
budgets that teams may not fully
account for: the permitting and project
modifications related to elevated
underwater noise produced by pile
installation. The same value of
foresight, which is expressed in the
quote, " It wasn't raining when Noah
built the ark, " applies to evaluating
foundation pile installations for their
potential to impact fish, marine
mammals and sea turtles.
In fact, assessing and mitigating
underwater noise impacts for marine
projects has become central to their
environmental permitting and compliance
process. If not properly planned
for in the early stages of project
development , issues related to
underwater noise can wreak havoc on
budgets, schedules and designs.
Potential implications of underwater
noise impact can include costly
model ing effor t s , t ime-of-year
restrictions on pile driving, restrictions
on the number of concurrent pile
driving locations, underwater noise
mitigation measures, and modifications
to project design and to permit
approvals that are critical to a project's
planned schedule. A better understanding
of the realities related to the
evaluation and mitigation of underwater
noise and early integration of this
information into the project planning
and budgeting process will benefit
project owners, designers
and contractors.
Species of Interest
Impacts related to underwater
noise can involve consultation
under the Endangered
Species Act (ESA),
Ma g n u s o n S t e v e n s o n
Fisheries Protection Act
(Essential Fish Habitat) and
Marine Mammal Protection
Act. The species of interest
will vary regionally and by
consultation process, with
some examples including:
* Endangered Species: Atlantic sturgeon,
shortnose sturgeon, Atlantic
salmon, Chinook salmon, North
Atlantic right whale, sea turtles
Pile Driving Impacts
The noise produced by pile driving can
result in a range of potential impacts to
marine life. The noise can result in
injury or mortality to fish due to burst
capillaries or barotrauma for fish with
swim bladders. The swim bladder is an
air-filled organ that helps fish regulate
their buoyancy - and for some species,
HDR deploys monitoring equipment for endangered sturgeon near
Cuomo Bridge (credit, New York State Thruway Authority)
* Commercially and Recreationally
Important Fish: Atlantic cod, black
sea bass, striped bass, snapper,
grouper
* Migratory and/or Forage Fish:
Alewife, blueback herring, American
shad, menhaden
* Marine Mammals: Whales, dolphins,
porpoise, seals, manatees
detect sound. The sound wave produced
by pile driving can result in rapid
compression and expansion of the
swim bladder, causing injuries to
internal organs.
Marine life exposed to pile driving
noise also have the potential to undergo
changes in hearing or hearing loss.
Underwater noise can also result in
behavioral impacts to marine life and
result in the masking of biologically
relevant sounds or avoidance of the
ensonified area. Those avoidance
behaviors become a concern when
there is potential to interrupt feeding or
DEEP FOUNDATIONS * SEPT/OCT 2021 * 121
September/October 2021

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