Physical Oceanographic Influences on Larval Transport and Settlement

Collaborators:

• Steve Wing - University of Otago
• Lance Morgan - Marine Convervation Biology Institute
• John Largier - Scripps Institution of Oceanography
• David Kaplan - University of California, Davis
• Carolyn Lundquist - NIWA, New Zealand
• Jennifer Diehl

Current Funding:

California Sea Grant

Focus:

Effects of coastal circulation on temporal and spatial variability in settlement of crabs, sea urchins and rockfish.

The primary mechanism uncovered by this research is the combination of retention of planktonic larvae in the lee of Pt. Reyes (Fig.1) Wing, et al. 1988), and northward, onshore transport during relaxation of upwelling winds (Wing, et al. 1995a,b). These changes take place on daily time scales, with several days to weeks of upwelling followed by briefer periods of relaxation. They are important to management because they lead to a specific spatial pattern of larval settlement (Fig.2) that is useful in the design of marine reserves. This pattern is also present in the recent settlement observed in red sea urchin size distributions at various points along the coast (Morgan, et al. 2000b) (Fig.3) . There is substantial interannual variability in this mechanism (Wing, et al. in prep.) that is related to ENSO conditions (Fig.4) (Lundquist, et al 2001). Understanding the links between this mechanism and variability at larger spatial and temporal scales is one of the outstanding problems in this area (Botsford 2001).