Presentation Title

The Story Diatoms Tell: Assessing the LA River with bioindicators

Faculty Mentor

Dr. Russell DiFiori

Start Date

17-11-2018 8:30 AM

End Date

17-11-2018 10:30 AM

Location

CREVELING 59

Session

POSTER 1

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

The Story Diatoms Tell: Assessing Health of the LA River with Bioindicators

Author: Valerie Hsiao, Natural Sciences, Pasadena City College

Mentor: Dr. Russell DiFiori, Natural Sciences, Pasadena City College

One of the major challenges aquatic ecosystems face is eutrophication, the result of runoff polluted by nutrients containing nitrates and phosphates. The LA river runs near or through very urbanized parts of LA and has many water quality issues to be resolved. Motile diatoms are significant bioindicators for an “impaired” watershed (Hausman, S., et al, 2016). Using bioindicators are effective in the assessment of water quality because it gives insight to different stress factors that remain, even after pollutants have dissipated. This is paramount in understanding how environmental factors have direct impact on ecology and aquatic organisms. In this study, the goal was to evaluate the use of diatom community composition to assess the water quality. The correlation between diatom diversity and water chemistry was analyzed by collecting epilithic samples at four sites along the LA river: i) Millard Canyon, ii) Lower Arroyo, iii) Marsh Park, and iv) Switzer. Diatom density and diversity were documented microscopically, and each site was assessed against the Biological Condition Gradient (Davies and Jackson, 2006). Moving from mostly natural to fully urban, water quality varied, on a scale from 1) natural to 6) highly disturbed. It was hypothesized that diversity will be dominated by motile biraphid species, Kobayasiella bicurneus and Kobayasiella jagii (Diatoms of North America, n.d.) at more urbanized sites due to increased susceptibility to nutrient pollutants.

References:

Davies, S.P. & Jackson, S.K. (2006). The Biological Condition Gradient: A Descriptive Model for Interpreting Change in Aquatic Ecosystems. Ecological Applications, vol 16, No. 4: 1251-1266

Hausman, S., et al. (2016). A diatom-based biological condition gradient (BCG) approach for assessing impairment and developing nutrient criteria for streams. Science of the Total Environment, vol 562: 914-927.

Diatoms of North America. (n.d). Taxa by Morphology. Retrieved from https://diatoms.org/morphology

Keywords:

  1. Diatom
  2. Motile
  3. Biological Condition Gradient
  4. Eutrophication
  5. Los Angeles River
  6. Nutrient
  7. Watershed
  8. Biodiversity
  9. Density
  10. Biraphid

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Nov 17th, 8:30 AM Nov 17th, 10:30 AM

The Story Diatoms Tell: Assessing the LA River with bioindicators

CREVELING 59

The Story Diatoms Tell: Assessing Health of the LA River with Bioindicators

Author: Valerie Hsiao, Natural Sciences, Pasadena City College

Mentor: Dr. Russell DiFiori, Natural Sciences, Pasadena City College

One of the major challenges aquatic ecosystems face is eutrophication, the result of runoff polluted by nutrients containing nitrates and phosphates. The LA river runs near or through very urbanized parts of LA and has many water quality issues to be resolved. Motile diatoms are significant bioindicators for an “impaired” watershed (Hausman, S., et al, 2016). Using bioindicators are effective in the assessment of water quality because it gives insight to different stress factors that remain, even after pollutants have dissipated. This is paramount in understanding how environmental factors have direct impact on ecology and aquatic organisms. In this study, the goal was to evaluate the use of diatom community composition to assess the water quality. The correlation between diatom diversity and water chemistry was analyzed by collecting epilithic samples at four sites along the LA river: i) Millard Canyon, ii) Lower Arroyo, iii) Marsh Park, and iv) Switzer. Diatom density and diversity were documented microscopically, and each site was assessed against the Biological Condition Gradient (Davies and Jackson, 2006). Moving from mostly natural to fully urban, water quality varied, on a scale from 1) natural to 6) highly disturbed. It was hypothesized that diversity will be dominated by motile biraphid species, Kobayasiella bicurneus and Kobayasiella jagii (Diatoms of North America, n.d.) at more urbanized sites due to increased susceptibility to nutrient pollutants.

References:

Davies, S.P. & Jackson, S.K. (2006). The Biological Condition Gradient: A Descriptive Model for Interpreting Change in Aquatic Ecosystems. Ecological Applications, vol 16, No. 4: 1251-1266

Hausman, S., et al. (2016). A diatom-based biological condition gradient (BCG) approach for assessing impairment and developing nutrient criteria for streams. Science of the Total Environment, vol 562: 914-927.

Diatoms of North America. (n.d). Taxa by Morphology. Retrieved from https://diatoms.org/morphology

Keywords:

  1. Diatom
  2. Motile
  3. Biological Condition Gradient
  4. Eutrophication
  5. Los Angeles River
  6. Nutrient
  7. Watershed
  8. Biodiversity
  9. Density
  10. Biraphid