Section 1 Introduction - National Marine Fisheries Service - NOAA

NBK at Bangor EHW-1 Pile Replacement Project Final Marine Mammal Monitoring Report
The wharf is a U-shaped concrete structure built in 1977 for ordnance handling operations in
support of the Trident Submarine squadron home ported at NBK at Bangor (DoN 2011). EHW-1
consists of two 100-foot (ft) (30.5 meters [m]) access trestles and a main pier deck, which
measures approximately 700 ft (213 m) in length and is approximately 500 ft (183 m) wide. The
wharf is supported by both 16-inch and 24-inch diameter hollow, octagonal, pre-cast concrete
piles (approximately 130 ft [40 m] in length) (DON 2011). Marine mammal monitoring was
focused in the immediate vicinity of the structure within the WRA, and in the waters
immediately adjacent, where sound pressure levels (SPL) associated with pile installation and
removal activities could potentially be transmitted.
Project Staffing
Staff for the EHW-1 PRP included the project manager, the monitoring coordinator (MC),
marine mammal observers (MMOs), and acoustic technicians (Table 1). MMOs were
experienced in marine mammal identification and had extensive knowledge of the biology and
behavior of locally-occurring species. Acoustic technicians had prior experience conducting
acoustic monitoring during pile driving construction projects. All MMOs were dedicated to
observation of marine mammals and served no other function while conducting observations.
Marine Mammal Monitoring Platforms
Vessel-based Monitoring
Four vessels served as observation platforms and marine transportation. These boats included
three 21- to 24-ft (6.4- to 7.3-m) aluminum-hulled jet boats and one 32-ft (9.8-m) fiberglass
monohull boat (leased from Tetra Tech EC, Inc). Vessels were equipped with Global
Positioning Systems (GPS), very high frequency (VHF) radios and depth sounders, and all
captains were United States Coast Guard (USCG)-certified. All captains were familiar with
Puget Sound waterways and the unique characteristics of the region. Vessels were equipped
with elevated observation platforms which provided maximum viewing capability. The jet boats
observation platforms were approximately 2 to 3 ft (0.6 to 0.9 m) above the water line, while the
larger boat had an observation platform that was approximately 8 ft (2.4 m) above the water line.
EHW-1 was originally intended to start at the opening of the fish window and occur concurrently
with TPP. This would allow a sharing of monitoring assets between the two projects which were
located next to each other. However, materials and operational delays prevented EHW-1 repairs
from being initiated on time. As a result, by the time it started, several weeks of far-field
recordings had been conducted for the TPP and sufficient data had already been collected to
characterize small to large piles and determine propagation characteristics. Therefore for
EHW-1, it was determined that one far-field vessel, versus the initial three vessels, would be
sufficient to continue with acoustic recordings and would not substantially affect the
effectiveness of marine mammal monitoring. This was consistent with the language in the
EHW-1 Acoustic Plan which stated that “if the acoustic recordings indicate the actual zone of
influence is significantly smaller than the modeled area, some far-field monitoring locations may
be removed or consolidated if they are unnecessary for effective marine mammal monitoring.”
Bangor, Washington 4