Presentation Title

Measuring Water Quality Using Diatoms in the Santa Ana River

Start Date

November 2016

End Date

November 2016

Location

HUB 302-40

Type of Presentation

Poster

Abstract

For decades, diatoms have been used to assess water quality because they are highly sensitive to changes in environmental conditions. Diatomic indices are typically calculated by identifying and counting species using a microscope, which is inefficient and prone to error. Therefore, a different identification method using DNA sequences has recently been under investigation. In our experiment, we identified species by sequencing DNA in order to observe preliminary trends between species composition and water quality of the Santa Ana River.

We collected diatom samples upstream, downstream, and at the outflow of a water treatment facility on the Santa Ana River. DNA was extracted and sequenced using diatom-specific primers. We then performed principal coordinate analyses (PCoA) comparing the samples with all organisms and with only stramenopile sequences. Unlike the PCoA with all organisms, which separated samples by location, the PCoA exclusively for stramenopiles showed less of a trend. In addition, we used the Biological Diatom Index (IBD) to determine the eutrophication levels of different extraction sites.

To explain the inconclusive results of the PCoA and the IBD, we examined the proportion of diatoms in each sample and found that many samples downstream had a significantly smaller proportion of diatoms than those upstream. This trend opens up the possibility for further studies on diatoms and water quality using more environmental data and improved yield of extractions.

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Nov 12th, 1:00 PM Nov 12th, 2:00 PM

Measuring Water Quality Using Diatoms in the Santa Ana River

HUB 302-40

For decades, diatoms have been used to assess water quality because they are highly sensitive to changes in environmental conditions. Diatomic indices are typically calculated by identifying and counting species using a microscope, which is inefficient and prone to error. Therefore, a different identification method using DNA sequences has recently been under investigation. In our experiment, we identified species by sequencing DNA in order to observe preliminary trends between species composition and water quality of the Santa Ana River.

We collected diatom samples upstream, downstream, and at the outflow of a water treatment facility on the Santa Ana River. DNA was extracted and sequenced using diatom-specific primers. We then performed principal coordinate analyses (PCoA) comparing the samples with all organisms and with only stramenopile sequences. Unlike the PCoA with all organisms, which separated samples by location, the PCoA exclusively for stramenopiles showed less of a trend. In addition, we used the Biological Diatom Index (IBD) to determine the eutrophication levels of different extraction sites.

To explain the inconclusive results of the PCoA and the IBD, we examined the proportion of diatoms in each sample and found that many samples downstream had a significantly smaller proportion of diatoms than those upstream. This trend opens up the possibility for further studies on diatoms and water quality using more environmental data and improved yield of extractions.