Wildlife Impacts Assessments and Lessons Learned
from Offshore Wind Pilot Projects in the
Gulf of Maine, New England, and Mid-Atlantic
Introduction
Avian Surveys
Potential wildlife impacts are a concern in proposed offshore
wind project areas. As part of addressing this concern,
specific information on one or more resources may be
requested by Bureau of Ocean Energy Management (BOEM)
for lease authorizations, Construction and Operation Plans
(COP), and General Activities Plans (GAP). In addition,
the U.S. Fish and Wildlife Service and others may request
information on public trust resources in order to issue federal
permits. To meet these requirements, endangered species
and site characterization surveys are an important first step in
developing the needed baseline data.
Survey Area
American kestrel (Falco sparverius),
landed on survey vessel 14 nm from shore
• Sufficient coverage to addresses clearly defined baseline study expectations (a
minimum of 10% coverage of the assessment area is recommended)
• Larger than the area of the proposed offshore wind facility to allow flexibility and
avoidance of potential impacts including a one-nautical-mile buffer
Data Components of a Survey
• Evaluate and characterize migratory bird and local bird populations
• Key metrics include flight heights, spatial distributions, and estimated density
Theoretical offshore wind
park with avoidance buffers
In February 2013, BOEM issued avian survey guidelines for site characterization
assessments. These guidelines recommend the following:
• Pre-survey Coordination. Recommends that developers submit a draft avian survey
plan and hold a follow-up pre-survey meeting.
• Quarterly Progress Reports.
• Comprehensive Annual Report.
• Data Management. Encourages developers to share data on publically available data
servers.
Laughing gull (Larus atricilla)
Potential effects of offshore wind facilities include birds and
bats colliding with, and being displaced by, the facilities. This
presents the need to identify ways to avoid impacts and
comply with regulations.
To address this need, a study of birds and bats at proposed
offshore wind energy facility locations is conducted before
and after construction. The study must also take into account
permitting, conservation, and best management practices
(BMP). Several study methods are available that allow all
these requests to be met. These include the use of existing
data as well as conducting on-site surveys.
• Survey Methodology. Suggests surveys sample the proposed lease area for two
annual cycles (e.g., spring to spring). Recommends all lease blocks be surveyed for
commercial wind project, including a one-nautical-mile buffer around proposed blocks.
Land-based full spectrum acoustic
monitoring system for birds and bats
Survey Methods:
Aerial versus Vessel-based
Other Survey Methods
BOEM, USFWS, and state agencies have been willing to
accept either aerial or vessel-based surveys for diurnal
avian activity at pilot offshore projects in the North Atlantic.
Currently, BOEM recommends vessel-based or traditional
aerial surveys, with a provision to accept other types of aerial
surveys on a case-by-case basis.
In addition to traditional visual survey techniques for diurnal avian species,
other types of surveys may be requested to address specific agency
concerns. Agency concerns in the North Atlantic have included individual
species (e.g., roseate tern), species groups (e.g., bats), and nocturnal avian
migrants. Developing assessment methods and gathering baseline data
that addresses agency concerns may be an important part of a project’s site
characterization efforts.
Aerial Surveys:
Traditional visual surveys
from aircraft have been
used, but emerging
technological approaches
such as aerial videography
and photography using
high-definition cameras may
become standard procedure
in the future. Aerial surveys
may be more cost effective
and efficient for larger
scale projects, although
this depends on location,
distance from land, and the
resources that require study.
Where to Start
Townsend’s big-eared bat
(Corynorhinus townsendii)
Other survey methods used to obtain baseline
data for wildlife impacts assessments include:
Vessel-based Surveys:
1.A Critical Issues Assessment is an important first step
toward determining key wildlife issues in a given proposed
lease area. Publically available information for most
offshore locations can be used, although it may be limited.
Types of publically available information include:
Vessel-based surveys
have been more widely
implemented; therefore,
there is a larger data set on
which to compare results.
Vessel-based surveys may
be more appropriate for
small pilot scale projects.
• Non-governmental organization research
• BOEM or DOE funded research projects
For example, USFWS requested information
on nocturnal migrants, primarily bats, at pilot
offshore wind projects in the North Atlantic.
This is a challenging request because of the
limitations of deploying traditional nocturnal
migration census equipment (e.g., radar, thermal
imaging, and acoustics) at sea. However,
NEXRAD data are freely available for some
areas where coverage extends offshore. In
other cases, it may be possible to collect data
using thermal imaging or acoustic monitoring
equipment from survey vessels, met buoy, or met
tower platforms. Bat acoustic monitoring data
has been recorded from vessels and buoys with
good results.
Visual Observation
Acoustic Monitoring
• Shore-based surveys
• Avian acoustic monitoring
• Bat acoustic monitoring
Radar
• X-band and S-band avian radar
• Vertical profiling radar
Video
• Aerial videography
• Infrared videography (CSTAR)
• Academic or agency funded research
• Historical data sources
Avian/Bat Assessment Results
Conclusion
2. Following an initial assessment of critical wildlife issues,
consultation with regulatory authorities is recommended.
Obtaining information on biological conditions in or near the
proposed lease area prior to consultation can help facilitate
this step.
Avian and bat assessment results should include the
following components:
3. Public trust resources including birds may be protected
under one or more laws, thus requiring consultations with
multiple federal agencies. At a minimum,
developers should consult with the U.S.
Fish and Wildlife Service (USFWS),
National Oceanic Atmospheric
Administration, Army Corps of
Engineers, and BOEM.
• Flight heights and associated risk evaluations
Baseline wildlife impact
studies should be developed
in coordination with BOEM,
USFWS, other agencies and
stakeholders. Traditional diurnal
visual assessments may be
inappropriate for some species or
species groups; therefore, different
study methods are recommended
for certain project locations. The
integration of pre-construction
baseline data and future postconstruction assessments should
be considered when developing
site characterization surveys. In
addition, the magnitude of the
potential impact of the proposed
project should dictate the scale
of the pre- and post-construction
surveys.
• NEXRAD
4. State natural resource agencies
may have jurisdiction over
resources that may be impacted
by offshore development. This may
include state-listed wildlife covered
under the state endangered species law.
Forster’s terns (Sterna forsteri)
• Spatial and temporal assessments
• Species composition, with special focus on rare species
• Detectability estimates and corrections (distance
sampling and data analysis with Distance software)
• Weather data
Results may be compared to other regional efforts;
however, the scale of the assessment for individual
offshore wind projects may be focused on a
small area with a high level of effort as compared
to other regional survey efforts. Validation and
comparison of data between survey efforts in a
given region may yield a more comprehensive
understanding of offshore avian and bat
communities.
Density estimates of waterfowl using Inverse Distance Weighting interpolation
For more information:
Aaron Svedlow, Biologist
(207) 879-9496
[email protected]
Jennifer Daniels, Director of Offshore Energy
(617) 443-7526
[email protected]