The California Current System is a coastal upwelling biome, as found along the eastern margins of all major ocean basins. These are among the more productive ecosystems in the world ocean. The California Current Ecosystem (CCE) LTER site (centered on 32.9° N, 120.3° W) is investigating nonlinear transitions in the California Current coastal pelagic ecosystem, with particular attention to long-term forcing by a secular warming trend, multi-decadal oscillations (e.g., PDO and NPGO), and ENSO in altering the structure and dynamics of the pelagic ecosystem. Low-frequency ecosystem transitions over the past 60 years have been well characterized by the CalCOFI program, but the LTER site is now developing a specific mechanistic understanding of the processes underlying these transitions. Our multi-faceted research program includes:
i) experimental cruises to investigate key processes of growth, grazing, advective transport, and demographic responses of mesozooplankton to altered nitracline depth and other aspects of hydrographic structure
ii) time series observations from quarterly shipboard measurements, continuously deployed ocean gliders, satellite remote sensing, and two shore-based measurement locations
iii) models, including models coupling planktonic food web processes to 4-D ocean circulation, allometrically scaled process models, and control volume property flux calculations
iv) an ocean informatics program to serve data to the scientific community and beyond
v) education and outreach to schoolchildren and the broader public.
This poster will highlight some of the approaches taken in CCE to understanding the processes underlying large-scale ecosystem transitions.