Large-volume (20-liter) bioassays were carried out in order to
assess the effects of major nutrients and micro-nutrients on
natural phytoplankton populations in water collected from a site
close to the mouth of Yaquina Bay, Oregon. Seven long-term
experiments were conducted during the years 1975-1976. A stripping
technique employing activated carbon was used to reduce the trace
metal and dissolved organic load of a portion of the water. Various
combinations of major nutrients (nitrate, phosphate, and silicate)
and micro-nutrients (trace metals and vitamins) were added to both
the carbon-stripped and the non-carbon-stripped water in order to
assess the effects of various nutrient substances on the growth
rate, biomass yield, and species composition of the phytoplankton
populations which developed from small natural inocula.
The major nutrients and the micro-nutrients appear to have
fundamentally different effects on the species composition and
population growth characteristics of the phytoplankton. The
micro-nutrients had marked systematic effects on the species composition
of the phytoplankton populations which developed in the
experimental vessels, while the major nutrients had minimal effects
on species composition. The micro-nutrients appeared essential for
the achievement of maximal population growth rates and minimal lags,
while the major nutrients had no effect on growth rates or lags.
Both the major nutrients and micro-nutrients had significant
effects on the final biomass yields. There were seasonal variations
in the control of final biomass yields by major nutrients and micro-nutrients. / Graduation date: 1977
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28662 |
| Date | 28 April 1977 |
| Creators | Frey, Bruce E. |
| Contributors | Small, Lawrence F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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