Journal article
Cross-shelf distribution of copepods and the role of event-scale winds in a northern California upwelling zone
Deep-sea research. Part II, Topical studies in oceanography, Vol.53(25), pp.3078-3098
2006
Handle:
https://hdl.handle.net/2376/114463
Abstract
Cross-shelf distribution and abundance of copepod nauplii and copepodids were measured during three summer upwelling seasons (2000–2002) in a coastal upwelling zone off northern California. These 3 years varied considerably in the intensity of winds, abundance of chlorophyll, and water temperature. The cruises in 2000 were characterized by relaxation conditions, with generally high levels of chlorophyll and high water temperature. The cruises in 2001 and 2002 were dominated by strong and persistent upwelling events, leading to lower chlorophyll and water temperatures. The copepod assemblage was dominated by
Oithona spp.,
Acartia spp. and
Pseudocalanus spp., with
Metridia pacifica (
lucens),
Microsetella rosea,
Oncaea spp. and
Tortanus discaudatus also common during all 3 years. The cross-shelf distribution of copepods was generally shifted offshore during upwelling and onshore during relaxation events, although some variability between species occurred. Abundance of all life stages generally exhibited a negative correlation with cross-shelf transport averaged over at least 1–4 days and lagged by 0–3 days, indicating lower abundances during and immediately after active upwelling. However, copepod nauplii seemed to respond positively to wind events lasting 1–5 days followed by a period of relaxation lasting 6 or 7 days. These rapid rates of change in abundance are probably too great to be due to in situ growth and reproduction alone; physical processes must also play a role. These results suggest a highly dynamic relationship between copepods and upwelling events off northern California, with species-specific responses to upwelling to be expected.
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Details
- Title
- Cross-shelf distribution of copepods and the role of event-scale winds in a northern California upwelling zone
- Creators
- Katherine M Papastephanou - Department of Biology and the Romberg Tiburon Center for Environmental Studies, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 94132, USAStephen M Bollens - Department of Biology and the Romberg Tiburon Center for Environmental Studies, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 94132, USAAnne M Slaughter - Department of Biology and the Romberg Tiburon Center for Environmental Studies, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 94132, USA
- Publication Details
- Deep-sea research. Part II, Topical studies in oceanography, Vol.53(25), pp.3078-3098
- Academic Unit
- Environment, School of the (CAS)
- Publisher
- Elsevier Ltd
- Identifiers
- 99900547862701842
- Language
- English
- Resource Type
- Journal article