Working Group: Climate Change and Top Predators

This working group formed to begin addressing the unprecedented threats and uncertainty faced by pelagic ocean predators. A major challenge for developing conservation strategies for large mobile predators such as turtles, tunas, sharks, billfish, and seabirds is that they traverse vast distances and geographic boundaries. By combining and integrating climate change expertise from oceanographers with expertise on pelagic predators from the Tagging of Pacific Pelagics (TOPP) program, this working group sought to bridge a key information gap in how these threatened species are responding to climate change.

Specifically, this group reviewed and synthesized available data and generated comprehensive models in order to improve our understanding of which pelagic predator species are at the greatest risk and identify habitats critical for conservation in the eastern Pacific.

Findings

This working group published their findings in Nature Climate Change in September 2012. The results of comprehensive modeling work combining the TOPP database of 4,300 electronic tags and output from a global climate model—led by COS visiting fellow Elliott Hazen—predicted a slow but steady northward migration of North Pacific ecosystems (up to 1000km by 2100). Even with these open ocean shifts, biodiversity in the California Current is expected to remain high due to predicted steadiness or increases in upwelling intensity. The northward migration of habitats may alter migration and feeding patterns for large pelagic predators such as sea lions, sharks, sea turtles, and seabirds. Consequently some species groups such as tunas will likely prosper while other groups such as sharks are predicted to decline. Media coverage of the paper was widespread, from the Washington Post and USA Today, to the Tehran Times.

Broader Impacts

The understanding gained by this working group is critical to initially assess risk and vulnerability of large pelagic predators to climate change so that managers can proactively target strategies for species most at risk. For already stressed species, increased migration times and loss of pelagic habitat could exacerbate population declines or inhibit recovery. These findings can serve as a benchmark to better understand the processes and outcomes required for conserving these species and a launching point to recommend protection of pelagic habitats.

Bluefin Tuna. Photo Credit: Flicker Creative Commons.

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