| Summary | The Galapagos Marine Reserve is home to at least 50 species of sharks and rays. Although these species are protected in the marine reserve, they are vulnerable to industrial fishing outside the protected waters, to unintentional bycatch by local fishers inside the reserve, and to illegal fishing. We are using sharks in this case as a proxy for biodiversity/ecosystem health. |
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| Project | SESMAD |
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| Subtype | Natural Resource Unit |
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| Sector | Marine protected areas, Scientific Research and Conservation |
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| Biotic | Yes |
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| Explanation | |
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| Commons Aggregation | Guild |
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| Explanation | The GMR is home to 33 species of shark (see chapter by Hearn et al., 2014 for list - table 2.1) |
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| Commons Boundaries | Very unclear boundaries (1) |
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| Explanation | Many sharks are highly migratory and frequently travel out of the GMR boundaries, and to other eastern Pacific islands |
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| Commons Indicator | ["Ecosystem health and/or biodiversity"] |
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| Explanation | Sharks are high trophic level species, their high abundance is indicative of a healthy ecosystem. Hammerheads in particular have been shown through modeling studies to represent entire communities as an umbrella species (Hearn et al., 2013) |
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| Commons Unit Size | Large (4) |
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| Explanation | |
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| Environmental Medium | Oceanic |
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| Explanation | Oceanic |
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| Inter Annual Predictability | Moderate (2) |
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| Explanation | Migratory, but some species through to have important aggregation sites in GMR. Sharks are regularly recorded |
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| Intra Annual Predictability | Moderate (2) |
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| Explanation | Similar intra-annual patterns between hammerheads, whale, and Galapagos sharks in northern bioregion: greater abundance in cooler months of the year (May-October). In warmers months abundance is greatly reduced. |
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| Commons Renewability | Renewable (1) |
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| Explanation | But many species slow to reproduce |
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| Productivity | Poorly productive (1) |
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| Explanation | Many species are long lived and slow to reproduce |
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| Commons Accessibility | Somewhat accessible (2) |
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| Explanation | Accessible with the right equipment and regularly seen on dives |
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| Commons Heterogeneity | Moderate (2) |
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| Explanation | Many species of shark found throughout the GMR. Some are found more commonly in certain regions, however presence of any one sharks species is unpredictable. Most common species hammerhead and the Galapagos sharks. (Hearn et al., 2013) |
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| Commons Mobility | High (3) |
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| Explanation | Sharks highly mobile |
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| Commons Spatial Extent | 133000 |
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| Explanation | Coded as extent of GMR, but can migrate long distances to other eastern pacific islands |
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| Technical Substitute | No |
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| Explanation | |
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