Record Details
Plankton and nutrient ecology of the Columbia River estuary
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Plankton and nutrient ecology of the Columbia River estuary |
| Names |
Haertel, Lois Steben
(creator) Osterberg, Charles (advisor) |
| Date Issued | 1969-07-24 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Monthly samples of nutrients, phytoplankton and zooplankton were taken in the Columbia River estuary over a period of 16 months in order to determine distribution with season and salinity, and interrelationships between plankton and nutrients. Nitrate and phosphate levels in the river water entering the estuary are high in the winter and show depletion during the summer. Silicate levels are high in the river water at all seasons. Nitrate and phosphate levels are high in the entering ocean water during summer offshore upwelling. The nutrient levels in the estuary generally show a linear relationship with salinity, resulting from the levels of nutrients in the entering river and ocean water. Superimposed upon this linear relationship is a tendency for the nutrients to be enriched in the bottom waters of the central part of the estuary. The estuary phytoplankton are primarily composed of freshwater forms, and probably represent a downstream extension of the river flora. Regression analysis of phytoplankton levels vs. light, nutrients, and river flow indicates that light probably limits phytoplankton abundance on most dates. The zooplankton of the estuary are composed of three groups, preferring fresh, oligohaline, and polyhaline waters respectively. Regression analysis indicates a strong correlation between abundance of the freshwater group and river temperature. The factors controlling the abundance of the oligohaline and polyhaline groups are less obvious. The oligohaline group, principally Eurytemora affinis, reaches the greatest population density (100,000/m³ or more). Regression analysis indicates a close correlation between Eurytemora abundance and phosphate levels. This indicates a strong potential for zooplankton regeneration of phosphate necessary for phytoplankton growth. |
| Genre | Thesis/Dissertation |
| Topic | Plankton -- Columbia River Estuary (Or. and Wash.) |
| Identifier | http://hdl.handle.net/1957/28955 |
