Marine mammal and sea turtle density
estimates
MRA for the
Navy Northeast OPAREA: Atlantic City, Narragansett Bay, and
Boston

The
GMI Marine Sciences Group analyze and integrate both raw data and
published reports to provide a comprehensive source of existing
information on the description of the environment within specified
marine regions worldwide. The information found within an MRA is
vital for environmental planning and for use in environmental
compliance documentation, for example the description of the
affected environment. Areas addressed include the physical
environment (oceanographic parameters and habitats), the biological
environment (e.g., protected and commercial marine species), and
some socioeconomic considerations (e.g., location of dive sites and
fishing hotspots). More than 100 hardcopy maps accompany each
report, and associated geodatabases developed for the MRAs depict
physical oceanography, bathymetry (2D, 3D), commercial fisheries,
marine mammal distributions, sea turtle distributions, threatened
and endangered species, EFHs, marine protected areas (MPAs), and
recreational activities.
An MRA also identifies data and information gaps and provides a prioritized list of recommendations for future research. These assessments also serve as the groundwork for future environmental documentation and regulatory consultations (e.g., EAs, EISs, BAs, and Section 7 consultations).
To date, we have produced (or are producing) the following MRAs:
Density
estimates have been prepared for marine mammals and sea turtles in
the following areas:
GMI has developed methodology that uses occurrence polygons based on Sightings Per Unit Effort (SPUE) calculations as the basis for geographic stratification of the survey data to generate seasonal density estimates using standard line transect methodology and the program DISTANCE.
Federal activities affecting marine mammals and threatened or endangered sea turtles are governed by the Endangered Species Act (ESA), the Marine Mammal Protection Act (MMPA), and the NEPA/Executive Order 12114 (EO 12114). The data generated for this technical report serves as the basis for future documentation under these statutes. This information is vital for environmental planning and the development of environmental compliance documentation (e.g. biological and environmental assessments) that must be prepared in accordance with NEPA/EO 12114, MMPA and ESA.
These technical reports used available survey data to estimate marine mammal and sea turtle densities. The available data was not only spatially and temporally disparate, but gathered under varying protocols for varying purposes. The information on sightings, distribution, and density estimates were aggregated and re-analyzed, using the authors’ judgments, assignments, and extrapolations. By doing this, shortcomings in any one data set or method were offset through the assembly of a relatively large body of information. This aggregated information was characterized as more robust and likely more accurate than the information drawn from any one of its contributing components.
A comprehensive compilation, assessment, and interpretation of the best available data and information on protected and commercial marine species, marine habitats, and oceanographic features present in the Navy’s northeast U.S. (Atlantic City, Narragansett Bay, and Boston) operating areas and their surrounding regions was this project’s aim. The information in this extensive marine resources assessment report is the basis from which future Navy operations and training exercises will be planned to better mitigate potential impacts to protected species or habitats.
Systematic searches for relevant scientific data and literature were conducted. Once sources vital to the production of this assessment were identified, the information, data, or literature were obtained, reviewed, catalogued, and stored in a bibliographic database. Sources included academic and research institutions, state and federal agencies, the Internet, electronic databases, and marine resource experts. The compiled geospatial data were the foundation of this assessment and the extensive datasets were archived in a geographic information system (GIS) that was also used to manage, analyze, manipulate, and visualize the geo-spatial data. More than 175 map figures were produced for this assessment.