Record Details
The distribution of epiphytic diatoms in Yaquina Estuary, Oregon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The distribution of epiphytic diatoms in Yaquina Estuary, Oregon |
| Names |
Main, Stephen Paul
(creator) McIntire, C. David (advisor) |
| Date Issued | 1972-05-31 (iso8601) |
| Note | Graduation date: 1973 |
| Abstract | Epiphytic diatom assemblages in the intertidal zone of Yaquina Bay and estuary were obtained from the following host macrophytes: Zostera marina, Fucus evanescens, and species of Enteromorpha, Polysiphonia, and Ulva. Samples were collected in September 1970 and in January and May 1971 from seven stations approximately evenly spaced between the marine lower bay (mean daily salinity 28-34 ⁰/oo) and the more freshwater areas 12 miles upriver (mean daily salinity 2-19 ⁰/oo). Differences in species composition and relative abundance (community structure) for samples from different depths and different stations were related to environmental gradients and to differences in host macrophyte. A total of 30, 439 diatoms identified and counted in 58 samples was separated into 221 taxa (species or varieties), 42 of which were found in only one sample, with 33 of these being represented by only one specimen. The most abundant epiphytic diatom taxa in September were Navicula diserta, Synedra fasciculata, Navicula no. 2, Fragilaria striatula var. californica, and Cocconeis scutellum var. parva. In January, Navicula diserta, Cocconeis scutellum var. parva, Nitzschia frustulum var. perpusilla, Cocconeis scutellum, and Navicula no. 2 and, in May-, Cocconeis scutellum var. parva, Navicula diserta, Nitzschia frustulum var. perpusilla, Thalassionema nitzschioides, and Thalassiosira salvadoriana were most abundant. The abundant taxa with the most even distributions among the samples were Navicula diserta, Nitzschia frustulum var. perpusilla, Navicula gregaria, N. no. 2, Synedra fasciculata, Plagiogramma vanheurckii, Thalassiosira aestivalis, and Nitzschia no. 2. Host-epiphyte specificity was not apparent. Seasonal, horizontal, or vertical environmental factors were not related to species composition parameters calculated for these samples. The community structures of subsamples within samples often differed as greatly as did the community structures of assemblages from nearby host macrophytes of different taxa. Differences in community structure between assemblages in September and May were related to horizontal salinity gradients and to vertical exposure and insolation gradients. In January, these differences between assemblages were instead related to biological factors apparently involving host-epiphyte interaction. The condition of the host macrophyte thallus in winter may be the basis for this interaction. Cluster analyses produced clusters of diatoms associated with combinations of environmental factors rather than host macrophytes. |
| Genre | Thesis/Dissertation |
| Topic | Estuarine ecology -- Oregon -- Yaquina River Estuary |
| Identifier | http://hdl.handle.net/1957/44831 |
