Award: OCE-0417616

"Nonlinear transitions in the California Current Coastal Pelagic Ecosystem" This research addressed the processes that lead to long-term variability in coastal ocean plankton, fish, and seabird communities in a major coastal upwelling ecosystem. Secondarily, the research examined the relationship of such changes in the upper ocean to variations to sinking particle fluxes that support life in deep-sea bottom dwelling communities. The research characterized long-term variations in ocean processes in the California Current System, recognizing three interacting time scales of change: progressive, long-term variation in the coastal ocean associated with ocean warming over the past 60 years; decadal-scale variation associated with the Pacific Decadal Oscillation and the newly discovered North Pacific Gyre Oscillation; and interannual-scale variation associated primarily with the El Nino-Southern Oscillation. The research found important changes in upper ocean plankton communities associated with all three time scales of ocean variation. This research has further demonstrated that slow, progressive changes in the physical ocean environment can lead to relatively rapid, abrupt changes in biological communities. This research also found that different regions of the coastal ocean respond differently to environmental forcing, with the offshore upwelling in the California Current having intensified over the past 6 decades, while inshore upwelling has not shown significant change. Because the size structure of the plankton communities differ in the offshore and inshore regions, and key fish populations are size-selective predators, these spatial differences in ocean changes have favored the growth of some fish populations over others. Our work has also shown that commercially harvested fish populations show greater sensitivity to environmental fluctuations than unharvested populations. The California Current Ecosystem Long-Term Ecological Research site has contributed to the training of >45 graduate students and 16 postdoctoral investigators, provided intensive summer research experiences to 19 undergraduate students, and created opportunities for >55 others to participate in at-sea research. Four certified teachers have participated in a Teacher-at-Sea program, and they and several other teachers have developed ocean science lesson plans in parallel with state and national educational standards. Numerous school children from diverse school districts have benefitted from publication of our childrenÆs book, visited our research site, and participated in field science experiences with our outreach partner organization, thus expanding the pipeline of new scientific talent in the United States. Last Modified: 12/30/2011 Submitted by: Mark D Ohman