NTL; 211 thru 228; 241 thru 262; Seismic Survey Mitigation Measures and Protected Species Observer Program NTL

OMB Control Number: 1010-0151
OMB Expiration Date: March 31, 2018
UNITED STATES DEPARTMENT OF THE INTERIOR
BUREAU OF OCEAN ENERGY MANAGEMENT (BOEM)
GULF OF MEXICO OUTER CONTINENTAL SHELF (OCS) REGION
BOEM NTL 2016-G02

Effective Date: 09/30/2016

NOTICE TO LESSEES AND OPERATORS (NTL) OF FEDERAL OIL, GAS, AND
SULFUR LEASES IN THE OCS, GULF OF MEXICO OCS REGION
Implementation of Seismic Survey Mitigation Measures
and
Protected Species Observer Program
This NTL supersedes and replaces NTL No. 2012-G02. This NTL does not introduce any new
types of mitigation measures; however, it clarifies how you should implement seismic survey
mitigation measures, including ramp-up procedures, the use of a minimum sound source,
airgun testing and protected species observation and reporting. This NTL also updates
regulatory citations and addresses and provides clarification on how measures identified in
this NTL will be implemented to assist BOEM, the Bureau of Safety and Environmental
Enforcement (BSEE), and operators in complying with the Endangered Species Act (ESA; 16
U.S.C. §§ 1531-1544) and Marine Mammal Protection Act (MMPA; 16 U.S.C. §§13611423h). The measures contained herein apply to all on­lease ancillary activity surveys you
conduct under 30 CFR Part 550 and all off-lease surveys you conduct under 30 CFR Part 551.
This NTL is being implemented through, and will become a binding requirement of new OCS
oil and gas leases issued by BOEM and conditions of approval on new and amended OCS
plans and seismic survey permits in the Gulf of Mexico. Where required as part of a lease or
authorization, even though this NTL is being issued by BOEM, you are required to make
certain reports to BSEE, as provided below.
Background
The use of an airgun or airgun arrays while conducting seismic operations may have an
impact on marine wildlife, including marine mammals and sea turtles. Some marine
mammals, such as the sperm whale (Physeter macrocephalus), and all sea turtles that inhabit
the Gulf of Mexico are protected under the Endangered Species Act (ESA). All marine
mammals are protected under the Marine Mammal Protection Act (MMPA).
BSEE and BOEM consult jointly with the National Oceanic and Atmospheric
Administration’s National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife
Service (FWS) under Section 7 of the ESA to ensure that BOEM or BSEE authorized
activities will not jeopardize the continued existence of ESA listed species nor result in
adverse modification of designated critical habitat. See 16 U.S.C. §1536. The Biological
Opinions that have been issued to the Bureaus (or their predecessor agency) include
mitigation measures, terms and conditions, and reasonable and prudent measures to ensure
that activities meet the requirements of Section 7 of the ESA. Incidental take of ESA listed
1

species is prohibited except as authorized pursuant to an Incidental Take Statement in the
Biological Opinions, subject to the conditions therein; incidental take of ESA listed marine
mammals cannot be authorized under the ESA unless also authorized under the MMPA. The
provisions of this NTL include mitigation measures, terms and conditions, and reasonable and
prudent measures identified in the Biological Opinions issued to the Bureaus or their
predecessors, as a result of ESA consultation. BSEE is tasked as the lead agency for
compliance with lessee or operator reporting requirements under the current Biological
Opinions applicable to both Bureaus. Therefore, while BOEM is issuing this NTL, reports
described in this NTL must be submitted to BSEE.
In order to protect marine mammals and sea turtles during seismic operations, NMFS requires
seismic operators to use ramp-up and visual observation procedures when conducting seismic
surveys. These procedures were developed through previous consultations with the Bureaus
and their predecessor agencies. Procedures for ramp-up, protected species observer training,
visual monitoring and reporting are described in detail in this NTL. These mitigation measures
apply to geophysical activities conducted under lease terms; for all seismic survey operations
conducted in waters deeper than 200 meters (656 feet) throughout the Gulf of Mexico; and, in
the Gulf of Mexico waters east of 88.0° W. longitude, for all seismic survey operations
conducted regardless of water depth. Performance of these mitigation measures will also be
applied as a condition of the approval of applications for geophysical permits. You must
demonstrate your compliance with these mitigation measures by submitting to BSEE certain
reports detailed in this NTL.
Definitions
Terms used in this NTL have the following meanings:
1. Airgun means a device that releases compressed air into the water column, creating
an acoustical energy pulse with the purpose of penetrating the seafloor.
2. Ramp-up (sometimes referred to as "soft start") means the gradual increase in
emitted sound levels from an airgun array by systematically turning on the full
complement of an array's airguns over a period of time.
3. Visual monitoring means the use of trained observers to scan the ocean surface
visually for the presence of marine mammals and sea turtles. These observers must
have successfully completed a visual observer training program as described below.
The area to be scanned visually includes, but is not limited to, the exclusion zone.
Visual monitoring of an exclusion zone and adjacent waters is intended to establish
and, when visual conditions allow, maintain a zone around the sound source and
seismic vessel that is clear of marine mammals and sea turtles, thereby reducing or
eliminating the potential for injury.
4. Exclusion zone means the area at and below the sea surface within a radius of 500
meters surrounding the center of an airgun array and the area within the immediate
vicinity of the survey vessel. Each survey vessel must maintain its own unique
exclusion zone.
5. Whales mean all marine mammals in the Gulf of Mexico except dolphins (see definition
below) and manatees. This includes all species of baleen whales (Suborder Mysticeti), all
species of beaked whales (Ziphius cavirostris and Mesoplodon sp.), sperm whales
(Physeter macrocepahalus), and pygmy and dwarf sperm whales (Kogia sp.). Of the
2

baleen whales, only the Bryde's whale (Balaenoptera edeni) is expected to be present in
the northern Gulf of Mexico and is considered uncommon. This species has primarily
been sighted in water depths less than 200 m in the eastern Gulf of Mexico. Sightings of
other baleen whale species are highly unlikely.
6. Dolphins mean all marine mammal species in the Family Delphinidae. In the Gulf of
Mexico, this includes, among others, killer whales, pilot whales, and all of the "dolphin"
species.
Ramp-up Procedures
The intent of ramp-up is to warn marine mammals and sea turtles of impending seismic
operations and to allow sufficient time for those animals to leave the immediate vicinity. For
all seismic surveys, including airgun testing, you must use the ramp-up procedures described
below to allow whales, other marine mammals, and sea turtles to depart the exclusion zone
before seismic surveying begins.
Measures to conduct ramp-up procedures during all seismic survey operations, including
airgun testing, are as follows:
1. Visually monitor the exclusion zone and adjacent waters for the presence of any
marine mammals and sea turtles for at least 30 minutes before initiating ramp-up
procedures. If none are detected, you may initiate ramp-up procedures. Do not initiate
ramp-up procedures at night or when you cannot visually monitor the exclusion zone
for marine mammals and sea turtles if your minimum source level drops below 160 dB
re 1 µPa-m (rms) (see measure 5). Altering the vessel's course to shallower water
depths (< 200m in the Central and Western Planning Areas) to circumvent ramp-up
requirements of the 200 meter isobath will be considered noncompliant.
2. Initiate ramp-up procedures by firing a single airgun. The preferred airgun to begin
with should be the smallest airgun, in terms of energy output (dB) and volume (in3)
3. Continue ramp-up by gradually activating additional airguns over a period of at
least 20 minutes, but no longer than 40 minutes, until the desired operating
level of the airgun array is obtained.
4. Immediately shut down all airguns ceasing seismic operations at any time a
whale is detected entering or within the exclusion zone. You may
recommence seismic operations and ramp-up of airguns only when the
exclusion zone has been visually inspected for at least 30 minutes to ensure
the absence of marine mammals and sea turtles.
5. You may reduce the source level of the airgun array, using the same shot
interval as the seismic survey, to maintain a minimum source level of 160 dB
re 1 µPa-m (rms) for the duration of certain activities. By maintaining the
minimum source level, you will not be required to conduct the 30-minute
visual clearance of the exclusion zone before ramping back up to full output.
Activities appropriate for maintaining the minimum source level are: (1) all
turns between transect lines, when a survey using the full array is being
conducted immediately prior to the tum and will be resumed immediately
after the tum; and (2) unscheduled, unavoidable maintenance of the airgun
array that requires the interruption of a survey to shut down the array. The
3

survey should be resumed immediately after the repairs are completed.
There may be other occasions when this practice is appropriate, but use of the
minimum source level to avoid the 30-minute visual clearance of the
exclusion zone is only for events that occur during a survey using the full
power array. The minimum sound source level is not to be used to allow a
later ramp-up after dark or in conditions when ramp-up would not otherwise
be allowed.
Protected Species Observer Program
Visual Observers
Visual observers who have completed a protected species observer training program as
described below are required on all seismic vessels conducting operations in water depths
greater than 200 meters (656 ft) throughout the Gulf of Mexico. Visual observers are required
on all seismic vessels conducting operations in OCS water depths less than 200 meters (656 ft)
in the Gulf of Mexico waters east of 88.0° W. longitude. At least two protected species visual
observers will be required on watch aboard seismic vessels at all times during daylight hours
(dawn to dusk) when seismic operations are being conducted, unless conditions (fog, rain,
darkness) make sea surface observations impossible. If conditions deteriorate during daylight
hours such that the sea surface observations are halted, visual observations must resume as soon
as conditions permit.
Operators may engage trained third party observers, may utilize crew members who have been
trained as observers, or may use a combination of both third party and trained crew observers.
During these observations, the following guidelines must be followed: (1) other than brief alerts
to bridge personnel of maritime hazards, no additional duties may be assigned to the observer
during his or her visual observation watch (if conditions warrant more look-outs when
navigating around or near maritime hazards, additional personnel must be used to ensure that
watching for protected species remains the primary focus of the on-watch observers), (2) no
observer will be allowed more than 4 consecutive hours on watch as a visual observer, (3) a
"break" time of no less than 2 hours must be allowed before an observer begins another visual
monitoring watch rotation (break time means no assigned observational duties), and (4) no
person (crew or third party) on watch as a visual observer will be assigned a combined watch
schedule of more than 12 hours in a 24-hour period. Due to the concentration and diligence
required during visual observation watches, operators who choose to use trained crew members
in these positions may select only those crew members who demonstrate willingness, as well as
ability to perform these duties.
Training
All visual observers must have completed a protected species observer training course. BOEM
and BSEE will not approve particular trainers or training programs. However, NMFS has
established basic training criteria which must be adhered to by any entity that offers observer
training. Operators may utilize observers trained by third parties, may send crew for training
conducted by third parties, or may develop their own training program. All training programs
offering to fulfill the observer training requirement must: (1) furnish to BSEE, at the address
listed in this NTL, a course information packet that includes the name and qualifications (i.e.,
4

experience, training completed, or educational background) of the instructor(s), the course
outline or syllabus, and course reference material; (2) furnish each trainee with a document
stating successful completion of the course; and (3) provide BSEE with names, affiliations, and
dates of course completion of trainees.
The training course must include the following elements:
I. Brief overview of the MMPA and the ESA as they relate to seismic acquisition and
protection of marine mammals and sea turtles in the Gulf of Mexico;
II. Brief overview of seismic acquisition operations in the Gulf of Mexico;
III. Overview of seismic mitigation measures (NTLs) and the protected species observer
program in the Gulf of Mexico;
IV. Discussion of the role and responsibilities of the protected species observer in the Gulf of
Mexico, including:
a) Legal requirements (why observers are needed and what they do)
b) Professional behavior (code of conduct)
c) Integrity
d) Authority of protected species observer to call for shut-down of seismic acquisition
operations
e) Assigned duties:
1) What can be asked of the observer
2) What cannot be asked of the observer
f) Reporting of violations and coercion
V. Identification of Gulf of Mexico marine mammals and sea turtles, with emphasis
on whales;
VI. Cues and search methods for locating marine mammals, especially whales, and sea
turtles; and
VII. Data collection and reporting requirements:
a) Forms and reports to BSEE via email at [email protected] on the 1st and
15th of each month; and
b) Whale in exclusion zone/shut-down report within 24 hours.
Visual Monitoring Methods
The observers on duty will look for whales, other marine mammals, and sea turtles using the
naked eye and hand-held binoculars provided by the seismic vessel operator. The observers will
stand watch in a suitable location that will not interfere with navigation or operation of the
vessel and that affords the observers an optimal view of the sea surface. The observers will
provide 360° coverage surrounding the seismic vessel and will adjust their positions
appropriately to ensure adequate coverage of the entire area. These observations must be
performed consistently, diligently, and free of distractions for the duration of the watch.
5

Visual monitoring will begin no less than 30 minutes prior to the beginning of ramp-up and
continue until seismic operations cease or sighting conditions do not allow observation of the
sea surface (e.g., fog, rain, darkness). If a marine mammal or sea turtle is observed, the observer
should note and monitor the position (including the latitude and longitude of the vessel and
relative bearing and estimated distance to the animal) until the animal dives or moves out of
visual range of the observer. You must make sure the observer continues to monitor for
additional animals that may surface in the area, as there are often numerous animals that may
surface at varying time intervals. At any time a whale is observed within an estimated 500
meters (1,640 feet) of the sound source array ("exclusion zone"), whether due to the whale's
movement, the vessel's movement, or because the whale surfaced inside the exclusion zone, the
observer will call for the immediate shut-down of the seismic operation, including airgun firing
(the vessel may continue on its course but all airgun discharges must cease). The vessel
operator must comply immediately with such a call by an on-watch visual observer. Any
disagreement or discussion about the presence of a marine mammal should occur only after
shut-down. When no marine mammals or sea turtles are sighted for at least a 30-minute period,
ramp- up of the source array may begin. Ramp-up cannot begin unless conditions allow the sea
surface to be visually inspected for marine mammals and sea turtles for 30 minutes prior to
commencement of ramp-up (unless the method described in the section entitled “Passive
Acoustic Monitoring” is used). Thus, ramp­ up cannot begin after dark or in conditions that
prohibit visual inspection (e.g., darkness, fog, rain) of the exclusion zone. Any shut-down due
to a whale(s) sighting within the exclusion zone must be followed by a 30-minute all-clear
period and then a standard, full ramp-up. Any shut-down for other reasons, including, but not
limited to, mechanical or electronic failure, resulting in the cessation of the sound source for a
period greater than 20 minutes, must also be followed by full ramp-up procedures. In
recognition of occasional, short periods of the cessation of airgun firing for a variety of reasons,
periods of airgun silence not exceeding 20 minutes in duration will not require ramp-up for the
resumption of seismic operations if: (1) visual surveys are continued diligently throughout the
silent period (requiring daylight and reasonable sighting conditions), and (2) no whales, other
marine mammals, or sea turtles are observed in the exclusion zone. If whales, other marine
mammals, or sea turtles are observed in the exclusion zone during the short silent period,
resumption of seismic survey operations must be preceded by ramp-up.
Reporting
The importance of accurate and complete reporting of the results of the mitigation
measures cannot be overstated. Only through diligent and careful reporting can BOEM,
BSEE, and subsequently NMFS, determine the need for and effectiveness of mitigation
measures. Information on observer effort and seismic operations are as important as
animal sighting and behavior data. In order to accommodate various vessels’ bridge
practices and preferences, vessel operators and observers may design data reporting
forms in whatever format they deem convenient and appropriate. Alternatively,
observers or vessel operators may adopt the United Kingdom's Joint Nature
Conservation Committee forms (available at their website www.jncc.gov.uk). At a
minimum, the following items should be recorded and included in reports to the BSEE:
Observer Effort Report: An observer effort report prepared each day during which seismic
acquisition operations are conducted. Furnish an observer effort report to BSEE on the 1st and
6

the 15th of each month that includes:
•
•
•
•
•
•
•
•

Vessel name
Observers’ names and affiliations
Survey type (e.g., site, 3D, 4D)
BOEM Permit Number (for "off-lease seismic surveys") or Plan Control Number
and OCS Lease Number (for "on-lease/ancillary seismic surveys")
Date
Time, latitude, and longitude when daily visual survey began
Time, latitude, and longitude when daily visual survey ended
Average environmental conditions while on visual survey, including
Wind speed and direction
Sea state (glassy, slight, choppy, rough or Beaufort scale)
Swell (low, medium, high or swell height in meters)
Overall visibility (poor, moderate, good)

Survey Report: A survey report must be prepared each day during which seismic
acquisition operations are conducted and the airguns are being discharged. You must
furnish a survey report to BSEE on the 1st and the 15th of each month during which
operations are being conducted that includes:
•
•
•
•
•
•
•
•
•
•
•
•
•

Vessel name
Survey type (e.g., site, 3D, 4D)
BOEM Permit Number (for "off-lease seismic surveys") or Plan Control Number
and OCS Lease Number (for "on-lease/ancillary seismic surveys")
Date
Time pre-ramp-up survey begins
What marine mammals and sea turtles were seen during pre-ramp-up survey?
Time ramp-up begins
Were whales seen during ramp-up?
Time airgun array is operating at the desired intensity
What marine mammals and sea turtles were seen during survey?
If whales were seen, was any action taken (i.e., survey delayed, guns shut down)?
Reason that whales might not have been seen (e.g., swell, glare, fog)
Time airgun array stops firing

Sighting Report: A sighting report must be prepared for each sighting of a marine mammal
(whale or dolphin) or sea turtle made during seismic acquisition operations. You must furnish a
sighting report to BSEE on the 1st and the 15th of each month during which operations are being
conducted that includes:
•
•
•

Vessel name
Survey type (e.g., site, 3D, 4D)
BOEM Permit Number (for "off-lease seismic surveys") or Plan Control Number
7

•
•
•
•
•
•
•
•
•
•
•
•
•

•
•
•
•
•
•

and OCS Lease Number (for "on-lease/ancillary seismic surveys")
Date
Time
Watch status (Were you on watch or was this sighting made opportunistically
by you or someone else?)
Observer or person who made the sighting,
Latitude and longitude of vessel
Bearing of vessel
Bearing and estimated range to animal(s) at first sighting,
Water depth (meters)
Species (or identification to lowest possible taxonomic level)
Certainty of identification (sure, most likely, best guess)
Total number of animals
Number of juveniles
Description (as many distinguishing features as possible of each individual
seen, including length, shape, color and pattern, scars or marks, shape and size
of dorsal fin, shape of head, and blow characteristics)
Direction of animal's travel - compass direction
Direction of animal's travel- related to the vessel (drawing preferably)
Behavior (as explicit and detailed as possible; note any observed changes
in behavior)
Activity of vessel
Airguns firing? (yes or no)
Closest distance (meters) to animals from center of airgun or airgun array
(whether firing or not)

Note: If this sighting was of a whale(s) within the exclusion zone that resulted in a shut­
down of the airguns, include in the sighting report the observed behavior of the whale(s) before
shut-down, the observed behavior following shut-down (specifically noting any change in
behavior), and the length of time between shut-down and subsequent ramp-up to resume the
seismic survey (note if seismic survey was not resumed as soon as possible following shutdown). Send this report to BSEE within 24 hours of the shut-down. These sightings should
also be included in the first regular semi-monthly report following the incident.
Additional information, important points, and comments are encouraged. All reports
must be submitted to BSEE on the 1st and the 15th of each month (with one exception
noted above). Forms should be scanned (or data typed) and sent via email to
[email protected].
Please note that these marine mammal and sea turtle reports are in addition to any reports
you submit under BOEM NTL No. 2005-G07, effective July 1, 2005, and all progress and
final reports required as a condition of your geophysical permit.
Borehole Seismic Surveys
Borehole seismic surveys differ from surface seismic surveys in a number of ways, including the
8

use of much smaller airgun arrays, having an average survey time of 12-24 hours, utilizing a
sound source that is not usually moving at 4-5 knots, and requiring the capability of moving the
receiver in the borehole between shots. Due to these differences, the following altered
mitigations apply only to borehole seismic surveys:
•

•

•

•

•
•

During daylight hours, when visual observations of the exclusion zone are being
performed as required in this NTL, borehole seismic operations will not be
required to ramp-up for shutdowns of 30 minutes or less in duration, as long as
no whales, other marine mammals, or sea turtles are observed in the exclusion
zone during the shutdown. If a whale, other marine mammal, or sea turtle is
sighted in the exclusion zone during the shut-down, ramp-up is required and may
begin only after visual surveys confirm that the exclusion zone has been clear for
30 minutes.
During nighttime or when conditions prohibit visual observation of the
exclusion zone, ramp-up will not be required for shutdowns of 20 minutes or
less in duration. For borehole seismic surveys that utilize passive acoustics
during nighttime and periods of poor visibility, ramp-up is not required for
shutdowns of 30 minutes or less.
Nighttime or poor visibility ramp-up is allowed for borehole seismic surveys
only when passive acoustics are used to ensure that no whales are present in
the exclusion zone (as for all other seismic surveys). Operators are strongly
encouraged to acquire the survey in daylight hours when possible.
Protected species observers must be used during daylight hours, as provided in
this NTL, and may be stationed either on the source boat or on the associated
drilling rig or platform if a clear view of the sea surface in the exclusion zone and
adjacent waters is available.
All other mitigations and provisions for seismic surveys as set forth in this NTL
will apply to borehole seismic surveys.
Reports should reference a Plan Control Number, OCS Lease Number,
Area/Block and Borehole Number or BOEM permit number, as applicable.

Passive Acoustic Monitoring
Whales, especially sperm whales, are very vocal marine mammals, and periods of silence
are usually short and most often occur when these animals are at the surface and may be
detected using visual observers. However, sperm whales are at the greatest risk of potential
injury from seismic airguns when they are submerged and under the airgun array. Passive
acoustic monitoring appears to be very effective at detecting submerged and diving sperm
whales, and some other marine mammal species, when they are not detectable by visual
observation. BOEM and BSEE strongly encourage operators to include passive acoustic
monitoring as part of their protected species observer program. Inclusion of passive
acoustic monitoring does not relieve an operator of any of the mitigations (including visual
observations) in this NTL with the following exception: monitoring for whales with a
passive acoustic array by an observer proficient in its use will allow ramp-up and the

9

subsequent start of a seismic survey during times of n.:dm:ed visibility (e.g., darkness. fog.
rain) when such ramp-up otherwisi.: would not be pi.:rmitti.:d using only vi sual obsavers. If
you use passive acoustic monitoring, include an assessment of the usefulness, effectiveness.
and problems encountered with the use of that method of marine mammal detection in the
reports described in this NTL A description of the passive acoustic system. the software
used, and the monitoring plan should also be reported to BSEE at the beginning of its use.

Paperwork Reduction Act of 1995 (PRA) Statement
The PRA (44 U.S.C. Chapter 35) requires us to inform you that we collect the information
described in this NTL to ensure that you conduct operations in a manner that will not jeopardiLe
threatened or endangered species or destroy or adversely modi(v critical habitat that has been
designated for those species. In addition. this NTL refers to information collection requirements
under 30 CFR 550 Subpart 8. We protect all proprietary information submitted according to the
Freedom oflnformation Act. 30 CFR 550.197. and 30 CFR 250. 197. An agency may not
conduct or sponsor a collection of infonnation unless it displays a currently valid Office of
Management and Budget (OMR) Control Number. OMB has approved the information
collection requirements in this NTL and associated regulations and assigned OMB Control
Number 1010-0151. Direct any comments regarding any aspect of this collection of information
to the Information Collection Clearance Officer, Bureau of Ocean Energy Management, 45600
Woodland Road, Sterling, VA 20166.

Issuance of Notices to Lessees
BOEM issues NTLs as guidance documents in accordance with 30 CFR 550. l 03 to clarify and
provide more detail about certain BOEM regulatory requirements and to outline the information
to be provided in various submittals. Under that authority. this NTL sets forth a policy on and an
interpretation of regulatory requirements to provide a clear and consistent approach for
complying with those requirements.

Contact
Any questions regarding this NTL should be submitted to: [email protected].
Submissions of sightings and other reporting under this NTL should be made to BSEE at:
mailto:protectedspecies@bsee. gov.

'7/&J/t'1
Michael Celata
Gulf of Mexico Regional Director
Bureau of Ocean Energy Management

Dated

10