Onset of Dormancy in the Copepod Calanus pacificus californicus off Southern California

Our long-range objectives are to understand and, as feasible, predict the distribution and abundance of pelagic organisms, particularly in regard to their physical environment and its changes. The objective of the proposed research is to identify the mechanism that controls onset of dormancy in open-ocean copepods and thus explain spatial and temporal variation in dormancy response. Specifically, we are developing a method that can be used to identify the conditions under which copepods prepare for dormancy in the field. This research will contribute to the following questions: (1) How does dormancy response affect population dynamics of open-ocean copepods? (2) What effect do shortand long-term environmental changes have on dormancy response of open-ocean copepods? (3) Do latitudinal differences in dormancy response of populations with broad ranges result from latitudinal differences in environmental stimuli alone (i.e. is population response to stimuli the same throughout the range)? (4) What controls the buildup and dispersal of deep aggregations of dormant copepods?