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. 2011 Aug 16;108(33):13600-5.
doi: 10.1073/pnas.1101525108. Epub 2011 Aug 1.

Global distribution and conservation of marine mammals

Sandra Pompa  1 , Paul R Ehrlich, Gerardo Ceballos
Affiliations

Global distribution and conservation of marine mammals

Sandra Pompa et al. Proc Natl Acad Sci U S A. .

Erratum in

  • Proc Natl Acad Sci U S A. 2011 Sep 20;108(38):16133

Abstract

We identified 20 global key conservation sites for all marine (123) and freshwater (6) mammal species based on their geographic ranges. We created geographic range maps for all 129 species and a Geographic Information System database for a 46,184 1° x 1° grid-cells, ∼10,000-km(2). Patterns of species richness, endemism, and risk were variable among all species and species groups. Interestingly, marine mammal species richness was correlated strongly with areas of human impact across the oceans. Key conservation sites in the global geographic grid were determined either by their species richness or by their irreplaceability or uniqueness, because of the presence of endemic species. Nine key conservation sites, comprising the 2.5% of the grid cells with the highest species richness, were found, mostly in temperate latitudes, and hold 84% of marine mammal species. In addition, we identified 11 irreplaceable key conservation sites, six of which were found in freshwater bodies and five in marine regions. These key conservation sites represent critical areas of conservation value at a global level and can serve as a first step for adopting global strategies with explicit geographic conservation targets for Marine Protected Areas.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Geographic distribution of marine mammals of the world. (A) Box plot with the conservative estimates of geographic range sizes by family. The thick black horizontal lines represent the average family range; the thin line inside the box marks the median family range; the top and bottom edges of the box are the first quartile (bottom edge) and the third quartile (upper edge) of the family range; bars derived from the box represent the maximum range value (upper bar) and the minimum range value (lower bar). Black dots represent outlier species. (B) Latitudinal trends in marine mammal species richness. Note that, as with terrestrial mammals, species richness is greater with decreasing latitude. However, in marine mammals the number of species is relatively similar from 30° N to 40° south, very different from the distribution of land mammal species.
Fig. 2.
Fig. 2.
Patterns of geographic distribution and key conservation sites for marine mammals. (A) The distribution of marine species richness is very heterogeneous. The most diverse 10,000-km2 cells have 37 species. The number of species in each cell is shown in the column on the left. The map shows the nine key conservation sites selected as being among the top 2.5% of cells in species richness. These areas include strictly marine species exclusively. (B) Irreplaceable key conservation sites were selected so that all marine mammals are represented in a conservation network.
Fig. 3.
Fig. 3.
Patterns of geographic distribution of species richness in different orders of marine mammals. (A) Pinnipeds (e.g., sea lions). (B) Mysticetes (e.g., blue whale). (C). Odontocetes (e.g., dolphins). Note the highly contrasting patterns and the higher species richness in Odontocetes. The number of species in each cell is shown in the column on the left.
Fig. 4.
Fig. 4.
Patterns of geographic distribution of marine mammal species that are at risk for extinction. The species included are those considered vulnerable, endangered, or critically endangered by the International Union for the Conservation of Nature (25). The number of species in each cell is shown in the column on the left.
Fig. 5.
Fig. 5.
Conservation targets covering (A) 10%, (B) 15%, (C) 20%, and (D) 25% of the marine mammal distributions using the Marxan optimization algorithm to optimize the number of grid cells and its geographic location.
See this image and copyright information in PMC

Comment in

References

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