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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

TOXICITY OF SEDIMENTS CONTAINING COAL-TAR PAVEMENT SEALANTS TO NOTOPHTHALMUS VIRIDESCENS AND AMBYSTOMA MACULATUM, SURROGATE SPECIES FOR EURYCEA SOSORUM

Bommarito, Thomas 01 January 2009 (has links)
The Barton Springs salamander (Eurycea sosorum) is a federally endangered species that is endemic to Barton Springs in Austin, Texas. Development within the Barton Springs watershed threatens the continued existence of E. sosorum. A factor that may be contributing to its decline is contamination from polycyclic aromatic hydrocarbons (PAHs). Nearby asphalt parking lots paved with coal-tar and asphalt sealants can be sources of PAHs. Unaltered parent compounds of PAHs can have toxic effects, but oxidation and ultraviolet radiation can create degradation products 100 times more toxic than the parent compounds. The objective of this project was to determine if PAHs are potentially harmful to E. sosorum using two surrogate species. Adult eastern newts (Notophthalmus viridescens) and larval spotted salamanders (Ambystoma maculatum) were exposed to sediments with nominal concentrations of total PAHs that ranged from 0 to 1500 mg/kg under UV (290 - 400 nm) and visible (400 - 700 nm) light to determine concentration/response relationships. No statistically significant mortality occurred under any treatment. Exposure to both coal-tar sealant and UV light resulted in sublethal effects such as decreased righting ability and swimming speed. Difficulty in performing such movements would make it difficult to catch prey and increase susceptibility to predation. Exposure to UV light also resulted in elevated numbers of micronucleated erythrocytes and white blood cells. This study shows that simultaneous exposure to PAHs and UV light result in sublethal effects that could make the population of E. sosorum vulnerable to further decline.

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