California Current & Barnacle larvae transport
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Transcript of California Current & Barnacle larvae transport
California Current &Barnacle larvae transport
Mikaela ProvostPhysical Oceanography 12/2/2010
California Current
-Eastern edge of the North Pacific Gyre.
-Moves south along the western coast of North America bringing cool water from Alaska to Baja California.
What sustains the CA current?
- Westerlie winds drive the California current
Upwelling is characteristic
pfeg.noaa.gov
- Ekman transport offshore yields strong upwelling along the CA coast, supporting a high level of marine biodiversity
Sea Surface Temperature
- Cool water, an indicator of upwelling.
- Transport can be as much as 300 m3/sec
- Strongest upwelling in summer
Currents and barnacle recruitmentQuestion facing many marine ecologists:
Observe large fluctuations in the abundance of barnacle stock populations, and yet the environment seems to be highly productive.
Each data point represents a total of 7 days of settlement of acorn barnacles on six 10 cm x 10 cm plates.
Upwelling Intensity & Population Variability
- Higher recruitment associated with weaker cases of upwelling.
- Intertidal barnacle larvae carried offshore with strong upwelling, lower probability of encountering adult habitat for settlement.
Reasons for variation in barnacle populations:
ReferencesAlexander and Roughgarden. 1996. Larval Transport and Population Dynamics of Intertidal Barnacles: A Coupled Benthic/Oceanic Model. Ecological Monographs 66: 259-275
Farrell etal. 1991. Cross-shelf transport causes recruitment to intertidal populations in central California. Limnological Oceanography 36: 279-288.
Shkedy and Roughgarden. 1997. Barnacle recruitment and population dynamics predicted from coastal upwelling. Oikos 80: 487-498.
http://mlo.stanford.edu/barnacles.htm