In 2013, the California current was dominated by
strong coastal upwelling and high productivity. Indices
of total cumulative upwelling for particular coastal
locations reached some of the highest values on record.
Chlorophyll a levels were high throughout spring and
summer. Catches of upwelling-related fish species were
also high. After a moderate drop in upwelling during fall
2013, the California current system underwent a major
change in phase. Three major basin-scale indicators, the
PDO, the NPGO, and the ENSO-MEI, all changed
phase at some point during the winter of 2013/14. The
PDO changed to positive values, indicative of warmer
waters in the North Pacific; the NPGO to negative values,
indicative of lower productivity along the coast; and
the MEI to positive values, indicative of an oncoming
El Niño. Whereas the majority of the California Current
system appears to have transitioned to an El Niño
state by August 2014, based on decreases in upwelling
and chlorophyll a concentration, and increases in SST,
there still remained pockets of moderate upwelling,
cold water, and high chlorophyll a biomass at various central
coast locations, unlike patterns seen during the
more major El Niños (e.g., the 97–98 event). Catches of
rockfish, market squid, euphausiids, and juvenile sanddab
remained high along the central coast, whereas catches
of sardine and anchovy were low throughout the CCS.
2014 appears to be heading towards a moderate El Niño
state, with some remaining patchy regions of upwelling-driven
productivity along the coast. Superimposed on
this pattern, three major regions have experienced possibly
non-El Niño-related warming since winter: the
Bering Sea, the Gulf of Alaska, and offshore of southern
California. It is unclear how this warming may interact
with the predicted El Niño, but the result will likely be
reduced growth or reproduction for many key fisheries
species