ABSTRACT
Over the last 20 years, the assembly and synthesis of an enormous amount of new information on ocean processes has greatly improved our understanding of oceanographic processes that operate on spatial and temporal scales ranging from small to large (Hilborn et al. 2003). We are also learning more about how oceanographic processes along with habitat heterogeneity affect the spatial distribution of marine populations. At one end of the spectrum are processes like the Pacific Decadal Oscillation (PDA) and North Atlantic Oscillation that involve long periods where wind,
sea surface, and temperature are favorable to certain fish assemblages, followed by "flips" in conditions that then favor other assemblages (Mantua et al. 1997). At an intermediate scale are processes like El Ninos that operate on an intra-annual basis and that dominate the strength and locations of upwelling conditions (Cury et al. 1995) . At the smaller scale are nearshore and short term coastal events such as the springtime currents and winds that blow and then relax periodically.
