Section 1 Introduction - National Marine Fisheries Service - NOAA

NBK at Bangor EHW-1 Pile Replacement Project Final Marine Mammal Monitoring Report
order to provide a series of project-specific, weather, species, and behavioral codes to enter into
the sightings sheets on a per sighting basis (Appendix D). At the end of each day, sighting
sheets from each monitoring boat were scanned electronically for storage in PDF format. All
data were also recorded in spreadsheet format and archived electronically. Standard equipment
for each boat included binoculars (7 x 50) with installed reticles, a hand-held GPS unit, VHF
radio, clipboard/notebook, and site-specific marine mammal identification guide (Whales and
Other Marine Mammals of Washington and Oregon, Eder and Sheldon 2001).
To minimize the probability of multiple observers counting a single animal twice (and
potentially overestimating takes) sightings were tracked on a continuous basis by an observer on
one vessel, and then “handed off” to an observer on a second vessel if the animal(s) headed in
the direction of the second vessel. Observers kept detailed sighting data and, whenever possible,
indicated in their field notes if an animal was a resight and which observer had seen it previously
(see Appendix E). Every attempt was made to protect marine mammals from Level A (injury)
Harassment via continuous monitoring of the behavioral harassment and near-field injury zones.
One hundred percent coverage of the Level B [behavioral] harassment zone during vibratory pile
installation and removal was not possible due to the large area involved and limited number of
monitoring vessels. For this reason, the Navy and NMFS agreed that the monitored area would
be a subset of this zone and extend 1.5 miles (2.4 km) from the pile. The measured harassment
zone was more than twice as large as the monitored zone, and for this reason potential missed
takes were estimated for the ensonified, unmonitored zone (see “Extrapolated Level B Takes”
section). As with any survey effort, the efficacy of visual detection of marine mammals
depended on several factors, including the observer’s ability to detect the animal, the
environmental conditions (visibility and sea state), and the position of the monitoring platforms.
Visual Monitoring Protocol
Pre-Activity Monitoring. Prior to the start of pile operations, the shutdown and buffer zones
were monitored for 30 minutes to document the presence of marine mammals. The following
monitoring methodology was implemented prior to commencing pile installation/removal
activities:
Near-field observers on boats and existing piers monitored the shutdown zone and buffer
zones. They ensured that no marine mammals were seen within the shutdown zone
before pile driving began.
If marine mammals were present within or approaching the shutdown zone prior to pile
driving or the soft-start 2 , the monitoring continued and the start of pile driving was
delayed until the animals left the shutdown zone voluntarily.
If marine mammals were not within the shutdown zone (i.e., the zone was deemed clear
of marine mammals), the observers radioed the MC who then notified the Pile Driving
Engineer Lead that pile driving could commence.
2 For a vibratory hammer, the soft start requires the contractor to initiate noise from the vibratory hammer for 15 seconds at
reduced energy followed by a 1-minute waiting period. This procedure was repeated two additional times.
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