Record Details
Macroscale to local scale variation in rocky intertidal community structure and dynamics in relation to coastal upwelling
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Macroscale to local scale variation in rocky intertidal community structure and dynamics in relation to coastal upwelling |
| Names |
Freidenburg, Tess L.
(creator) Menge, Bruce A. (advisor) Lubchenco, Jane (advisor) |
| Date Issued | 2002-05-24 (iso8601) |
| Note | Graduation date: 2003 |
| Abstract | Understanding how large-scale processes (>100 kms) influence ecological communities is currently a major focus in ecology. In marine systems, coastal upwelling, a large-scale oceanographic process in which surface water pushed offshore by winds is replaced by cold, nutrient-rich water from depth, appears to cause variation in rocky intertidal communities. Along the central Oregon coast upwelling occurs intermittently during the summer while on the southern coast it begins earlier in the spring and is less variable throughout the summer. Coastal upwelling can affect rocky intertidal communities by altering the delivery of nutrients, larvae, and phytoplankton. I conducted three studies on both the southern and central Oregon coast to understand how differences in upwelling affect rocky intertidal community structure and dynamics. In the first study, I examined the recruitment and growth rates of sessile invertebrates (mussels and barnacles). Recruitment of both mussels and barnacles, and growth of mussels were consistently higher on the central Oregon coast than the southern coast. Upwelled water is nutrient-rich, so differences in upwelling are likely to affect growth rates of macroalgae. In the second study, I tested this hypothesis by monitoring the growth of two species of intertidal kelp at both central and southern coast sites. During El Niño years, when upwelling is sharply reduced on the central Oregon coast, algae may fare better at sites on the southern coast where upwelling is less affected. However, during years when upwelling is strong all along the coast, nutrient limitation does not appear to differentially affect macroalgal growth rates. Finally, in the third study, I examined the influence of upwelling on the interactions between microalgal primary producers and herbivorous limpets. I conclude that this interaction is complex and varies both within and between upwelling regions. My research suggests that a transition in upwelling from weak and sporadic on the central Oregon coast to stronger and more persistent on the southern Oregon coast drives the striking differences in rocky intertidal community structure and dynamics between these areas. |
| Genre | Thesis/Dissertation |
| Topic | Intertidal ecology -- Oregon -- Oregon -- Pacific Coast |
| Identifier | http://hdl.handle.net/1957/31529 |
