Where will they go? : Cryptomonas erosa vertical distribution in a poorly mixed water column with nutrient and light gradients
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Authors
Amrhein, Kelly
Issue Date
2007
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
In inland lakes, light and nutrients form gradients within the water column.
Mathematical models have been used to show that algae can form thin layers within the
water column at some depth to maximize light and nutrient intake. Biomass within the
water column creates a shading effect of light. Light decreases exponentially with depth
in lakes. Nutrients decrease as algae deplete the resources. Nutrients decrease linearly as
depth increases in lakes below the algal layer. Here we aim to prove this theory with a
system where nutrients and light are controlled. Five towers with identical light
conditions, and varying nutrient concentrations, were built to house the algal species
Cryptomonas erosa. We hypothesized that the system with the greatest nutrients
available would show a peak in biomass at a shallower point than in the tower with fewer
nutrients. In the towers with the greatest nutrient levels, C. erosa formed a layer
shallower in the tower than in a tower with fewer nutrients as expected, and it showed a
deeper peak in biomass in the system with less nutrients. In all of the systems a surface
aggregation was formed. In Towers B, C, D, and E, this surface aggregation had more
biomass than other locations in the tower. Growth rates for the C. erosa were extremely
low in this experient Future researchers may look into different variables that could
have affected this low growth rate, and may decided to use a different algal species. The
idea of towers is useful to researchers looking to study algal relationships year round in a
laboratory environment.
Description
vi, 37 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.