Climate Change Impacts to North Pacific Pelagic Habitat Are Projected to Lower Carrying Capacity
Abstract
We use output from a suite of CMIP5 earth system models to explore the impacts of climate change on marine fisheries over the 21st century. Ocean temperatures from both the historical and RCP 8.5 projections are integrated over the upper 200 m of the water column to characterize thermal habitat in the epipelagic realm. We find that across all models the projected temperature increases lead to a redistribution of thermal habitat: temperatures that currently represent the majority of North Pacific pelagic habitat are replaced by temperatures several degrees warmer. Additionally, all models project the emergence of new thermal habitat that exceeds present-day maximum temperatures. Spatially, present-day thermal habitat retreats northward and contracts eastward as warmer habitat in the southern and western North Pacific expands. In addition to these changes in thermal habitat, zooplankton densities are projected to decline across much of the North Pacific. Taken together, warming temperatures and declining zooplankton densities create the potential for mismatches in metabolic demand and supply through the 21st century. We find that carrying capacity for tropical tunas and other commercially valuable pelagic fish may be especially vulnerable to the impacts of climate change. The waters projected to see the greatest redistribution of thermal habitat and greatest declines in zooplankton densities are primarily those targeted by the Hawaii-based and international longline fleets. Fishery managers around the North Pacific will need to incorporate these impacts of climate change into future management strategies.
- Publication:
-
American Geophysical Union, Ocean Sciences Meeting
- Pub Date:
- February 2016
- Bibcode:
- 2016AGUOSPC11A..06W
- Keywords:
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- 1616 Climate variability;
- GLOBAL CHANGEDE: 1635 Oceans;
- GLOBAL CHANGEDE: 1637 Regional climate change;
- GLOBAL CHANGEDE: 4815 Ecosystems;
- structure;
- dynamics;
- and modeling;
- OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL