Nicholas Zaring EBIO 4100 Winter Ecology Spring 2015 CU Mountain Research Station

Algae are single or multi cellular organisms that provide food and oxygen in aquatic communities. Winter = more snow and less light… Algae (diatoms) are photosynthetic organisms… What happens to abundance? Further, streams move at different speeds depending on location. What happens to abundance with the added pressure of stream speed? Pinnularia

Hypothesis: In Como Creek, algae abundance will be different in fast and slow moving streams as a consequence of water speed and its effect on attachment to substrate. Null Hypothesis: There is no significant difference in algae abundance in Como Creek when comparing fast and slow moving streams.

-R- selected -“Bloom and Bust” lifestyle, dependent on nutrients and season. -Mixing in upper layer -Settling in lower layer -Chlorophyll a+c, fucoxanthin, and a light brown/golden color. Diatoms!

A comparison of abundance using weight as a measure of mass, and microscopy as an indication of organisms present. At 2 different locations of Como Creek… Slow Portion = 4 samples each location Fast Portion = 4 samples each location Repeated on two different days, for a total of 16 samples in Como Creek.

The blue cap was used to isolate a consistent amount of algae on similar sized rocks. After scrubbing around the cap, the algae under the cap was collected in test tubes and brought back for analysis. Back at the station, the algae was filtered out, weighed, and observed through microscopy to document organisms present.

Comparison to other streams in the area? Methods of measurement, weight includes other materials due to scrubbing the rocks. Rock size varies, non-bias selection of rocks might provide different results. Snow cover on the creek was not able to be added as a variable.

P=.017

P=.012

Diatoms are more abundant in slow moving areas of Como Creek. Frustilia, a Diatom, makes up the majority of Algae found in Como Creek. Data analysis produced p values indicating that there is a significant difference between algae abundance in slow vs. fast moving areas of Como Creek.

SOME diatoms can move depending on light/nutrient needs. Frustilia is not one of these. Only ONE type of diatom found in my experiments has adaptations that allow it to better attach itself to substrate, Encyonema. One big implication, diatoms do not “choose” to live in a location, and their abundance is dictated by the flow of water.

Abundance is greater in slower moving streams, so what? A supported hypothesis that refutes the null. …current also exerts a shear stress on benthic algae, which can cause cell sloughing, and high flows disturb and scour the substrate. (Allan/Castillo 2007) Low stress can allow build up of diatoms on a substrate, while high stress wipes them clean and sends them elsewhere. If encyonema can attach to a substrate, and is not abundant, frustilia abundance is most probably a consequence of water flow. But, it leads to more questions!

There is a difference abundance of algae in Como Creek, dependent on stream speed. Frustilia is very abundant in Como Creek. More experiments should be done to determine how exactly these diatoms are affected by stream speed. Would abundance change in summer? Would species present change in summer? Given that the data suggest diatom abundance reliant on speed of creek, would it have mattered if there was snow cover?

Dr. Sarah Spaulding – U.S. Geological Survey/INSTAAR – any and all diatom questions. Derek Sweeney - logistics/experimental equipment. Professor T. Kittel – data/experiment analysis. Algae description and types. (n.d.). Retrieved February 22, 2015, from Allan, J., & Castillo, M. (2007). Stream ecology: Structure and function of running waters (2nd ed.). Dordrecht: Springer. Chapter 6: Periphyton Protocols. (n.d.). Retrieved February 22, 2015, from Smithsonian National Museum of Natural History. (n.d.). Retrieved February 22, 2015, from

Bioluminescence…