Climate, seabirds, forage, and upwelling ecosystems

Upwelling ecosystems provide vital services to society, yet are at risk due to increasing stratification, acidification, and deoxygenation, and changes in mixing. Unprecedented variation in fisheries and other aspects of the pelagic ecosystem of the central California Current System (CCS) has prompted renewed attention on upwelling, its drivers, and change relative to global warming. I review the unusual ecosystem variability that prompted new explanations for change focused on the timing and intensity of upwelling off California. Winds appear to be changing in other upwelling ecosystems as well. The extent to which biophysical changes in the CCS results apply to other upwelling systems is now under investigation (California �" Benguela Joint Investigation). Upwelling-favorable winds appear to be increasing in sectors of each ecosystem, but in the CCS forage fish productivity has been affected, whereas in the Benguela, redistributions appear to be the dominant patterns of response with cascading effects to seabirds.

Speaker: William Sydeman, Farallon Institute