Date of Award


Degree Name

MS in Biological Sciences


Biological Sciences


Lars Tomanek


Alkylphenol ethoxylates (APEs) are widely used in industrial and household products as surfactants. APEs degrade into more toxic ethoxylates, such as 4-nonylphenol (NP), which has been shown to be an endocrine disruptor and enhance the growth of tumor cells. Nonylphenol is wider spread in Pacific estuaries than originally thought. Organisms in Morro Bay, California contain some of the highest concentrations of NP reported, while containing few other contaminants. As a benthic mud-dwelling fish, the arrow goby (Clevelandia ios) may be exposed to high levels of NP due to high contaminant sequestration rates in anaerobic mud. While ecotoxicology suggests that nonylphenol is in high concentration within C. ios tissues along with tissue level biological abnormalities, the molecular effects of nonylphenol on these fish have yet to be investigated. Utilizing proteomic techniques including two-dimensional gel electrophoresis and subsequent identification via MALDI-TOF/TOF mass spectrometry, there is evidence for change in expression of proteins involved in energy metabolism, biotransformation, regulation and cellular structure.