Title

Diel Stream Phosphorous and Periphyton Polyphosphate Dynamics

Start Date

13-11-2015 8:00 PM

End Date

13-11-2015 9:59 PM

Description

Phosphorus (P), a key nutrient added to agricultural fertilizer to support plant growth, also supports the growth of algae in streams. Stream algae grow on aquatic substrata within communities of other microorganisms collectively referred to as periphyton mats. Recent evidence suggests that streams experience large 24-hour swings in P concentration (i.e. soluble reactive phosphorous, SRP) driven by shifting oxidation-reduction conditions, which can be stored by periphyton in the form of polyphosphates (polyP). The purpose of this study was to monitor (1) how stream SRP concentration varies over a 24-hour period, and (2) how stream periphyton respond to this variation with respect to polyP storage. We collected periphyton rock scrapings and water samples every four hours over a 24-hour period from Fishing Creek in Columbia County, PA. We also deployed an automatic sampler that took one water sample per hour. Our periphyton samples were analyzed for polyP, chlorophyll a, ash free dry mass, mat P, and extracellular enzymes. SRP concentration displayed no discernable cyclic diel pattern, though the concentrations did generally increase. Our hypothesis that SRP concentration would peak mid-day was partly supported, as on day 1 the highest concentration occurred at 2 PM. Further support on day 2 was lacking. Our hypothesis that periphyton polyP storage would peak in response to the lowest diel stream SRP concentration was not supported, as polyP peaked mid-day on day 2 when SRP was neither relatively high nor low. No cyclic diel pattern was observed in polyP storage, but a general pattern of increase occurred.

Type

Poster

Language

eng

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Nov 13th, 8:00 PM Nov 13th, 9:59 PM

Diel Stream Phosphorous and Periphyton Polyphosphate Dynamics

Elaine Langone Center, Terrace Room

Phosphorus (P), a key nutrient added to agricultural fertilizer to support plant growth, also supports the growth of algae in streams. Stream algae grow on aquatic substrata within communities of other microorganisms collectively referred to as periphyton mats. Recent evidence suggests that streams experience large 24-hour swings in P concentration (i.e. soluble reactive phosphorous, SRP) driven by shifting oxidation-reduction conditions, which can be stored by periphyton in the form of polyphosphates (polyP). The purpose of this study was to monitor (1) how stream SRP concentration varies over a 24-hour period, and (2) how stream periphyton respond to this variation with respect to polyP storage. We collected periphyton rock scrapings and water samples every four hours over a 24-hour period from Fishing Creek in Columbia County, PA. We also deployed an automatic sampler that took one water sample per hour. Our periphyton samples were analyzed for polyP, chlorophyll a, ash free dry mass, mat P, and extracellular enzymes. SRP concentration displayed no discernable cyclic diel pattern, though the concentrations did generally increase. Our hypothesis that SRP concentration would peak mid-day was partly supported, as on day 1 the highest concentration occurred at 2 PM. Further support on day 2 was lacking. Our hypothesis that periphyton polyP storage would peak in response to the lowest diel stream SRP concentration was not supported, as polyP peaked mid-day on day 2 when SRP was neither relatively high nor low. No cyclic diel pattern was observed in polyP storage, but a general pattern of increase occurred.