Exploratory Marine Species Density Models in the Mediterranean Sea

Laura Mannocci, Jason J. Roberts and Patrick N. Halpin / Marine Geospatial Ecology Laboratory / Duke University

Observatoire PELAGIS, Tethys Research Institute, Institute for Environmental Protection and Research, Blue World Institute of Marine Research and Conservation, Universitat De València, ALNITAK Marine Research Center, ALNILAM Research and Conservation, EcoOcéan Institut, International Fund for Animal Welfare, Marine Conservation Research

Marine Geospatial Ecology LabObservatoire PELAGISTethys Research InstituteInstitute for Environmental Protection and ResearchBlue World Institute of Marine Research and ConservationUniversitat De ValenciaALNITAK Marine Research Center & ALNILAM Research and ConservationEcoOcean InstitutInternational Fund for Animal WelfareMarine Conservation Research

Contact:
Jason Roberts (jason.roberts@duke.edu), Laura Mannocci (laura.mannocci@gmail.com), Pat Halpin (phalpin@duke.edu)
Updated

Overview

In 2018, together with our collaborators, we prepared exploratory density surface models for eight species of the cetaceans inhabiting the Mediterranean Sea using line transect surveys collected by seven organizations over the period 1999-2016. This work was funded by the U.S. Navy to assist with assessing risk to protected marine mammals resulting from military readiness activities. The output of the project consists of raster files suitable for use with geographic information systems and similar analysis software, plus a report documenting the development of the models. These are all considered public information that are freely redistributable under the Creative Commons Attribution 4.0 International License mentioned below. However, we kindly request that you contact us (emails listed below) when redistributing these materials so that we are aware of how they are used.

The next comprehensive revision that will update all models for this region is scheduled for spring of 2024.

Mediterranean Density Models Download

Download all models in a single zip file: Mannocci_et_al_2018_Med_Densities.zip (11 MB)

Model results are organized in subdirectories by species. Within each subdirectory there are several files:

*_density.img - Raster giving the estimated density, expressed as the number of individual animals per grid cell. The cells are 25 square km, so the unit of density is individuals per 25 km2. Therefore, to convert to individuals per 1 km, divide the cell values by 25. As discussed in the report, for all species other than fin whale, the density value represents the estimated annual mean (the year-round average). For fin whales, the year is split into "summer" and "winter" periods, as defined in section 4.3.6 of the report.

*_cv.img - Raster giving the estimated coefficient of variation of the density estimates. These values are unitless and were computed as standard error divided by density.

*_qualitative_uncertainty.img - Binary raster specifying whether the density prediction for the cell required interpolation (0) or extrapolation (1), as defined in section 3.5.4 of the report.

Similar zip files are available per-species in the table below.

Modeled Taxon Scientific Name Version Released Links
Common bottlenose dolphin Tursiops truncatus 1 2018-02-18 DownloadHistory
Cuvier's beaked whale Ziphius cavirostris 1 2018-02-18 DownloadHistory
Fin whale Balaenoptera physalus 1 2018-02-18 DownloadHistory
Long-finned pilot whale Globicephala melas 1 2018-02-18 DownloadHistory
Risso's dolphin Grampus griseus 1 2018-02-18 DownloadHistory
Short-beaked common dolphin Delphinus delphis 1 2018-02-18 DownloadHistory
Sperm whale Physeter macrocephalus 1 2018-02-18 DownloadHistory
Striped dolphin Stenella coeruleoalba 1 2018-02-18 DownloadHistory

Citation

Mannocci L, Roberts JJ, Halpin PN (2018) Development of Exploratory Marine Species Density Models in the Mediterranean Sea. Final Report. Report prepared for Naval Facilities Engineering Command, Atlantic under Contract No. N62470-15-D-8006, Task Order TO37, by the Duke University Marine Geospatial Ecology Lab, Durham, North Carolina. March 2018.

Contact Us

If you have any questions about this model or its files, please contact Laura Mannocci (laura.mannocci@gmail.com), Jason Roberts (jason.roberts@duke.edu), and Pat Halpin (phalpin@duke.edu).

This document and the accompanying files are Copyright (C) 2018 by the Duke University Marine Geospatial Ecology Laboratory and are licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).

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