Date of Award

Spring 5-17-2014

Degree Type

Thesis

Degree Name

MS Biology

Department

Biology

Advisor

Carolyn S Bentivegna, Ph.D

Committee Member

Daniel B. Nichols, Ph.D

Committee Member

Edward G. Tall, Ph.D.

Committee Member

Jane L. Ko, Ph.D

Keywords

Fish oil, Spectroscopy, Method development, BP oil spill, menhaden fish tissues, environmental health

Abstract

The DeepWater Horizon (DWH) oil spill contaminated a large area in the Gulf of Mexico in summer 2010. It is likely that many aquatic species in the Gulf were affected by the spill. Crude oil contains polycyclic aromatic hydrocarbon (PAHs). Some PAHs are carcinogenic to fish and humans. The purpose of this project was to develop menhaden fish oil as a biomonitoring tool for crude oil contaminants such as PAHs using scanning fluorescence spectroscopy (SFS). Menhaden (Genus Brevoortia) is one of the most ecologically and economically important marine fish species along the Atlantic and Gulf coast; however, it is also one of the least studied. Menhaden are a filtering feeding fish and very important to aquatic ecosystems as the principle prey species for higher trophic level organisms, such as bluefish and tuna. Menhaden are also important to the bait and reduction industries, including the production of omega-3-fatty acid fish oil tablet supplement. It was hypothesized that their body oil would accumulate crude oil contaminants such as PAHs. Fish oil was obtained by separating fish muscle and skin from internal organs.

Crude oil contamination has commonly been tracked by measuring PAHs in fish bile and or tissues using fluorescence. Vitamins are fluorescent compounds, and it is possible that these vitamins are confounding factors when trying to measure PAHs in biological samples using fluorescence. In order to evaluate this, SFS was used to detect PAHs and vitamin standards alone and when combined with fish oil. Fish oil was obtained from several “over the counter” brands (such as Nature’s Bounty), a prescription brand (Lovaza), a commercial product (menhaden oil from DayBrook Industries) and wild menhaden collected from the Delaware Bay, NJ, James River, VA, Vermillion Bay, LA and Barataria Bay, LA in 2010 and/or 2011. Barataria Bay received heavy oiling from the DWH spill from April to August 2010. Vitamins and PAH standards were bought commercially. The fish oils and standards were analyzed using a SpectraMax M5 which provided a 2D scan and a Fluorolog 3 which provided a 3D scan.

Results indicated the presence of both PAH-like and vitamin-like compounds in fish oils. 2D spectra showed peaks in wild fish samples at Em350/Ex280, Em350/Ex290, Em450/Ex320 and Em450/Ex350. Comparisons to standards indicated that the peak at Em350/Ex290 could be vitamin E, the one at Em350/Ex280 could be albumin and/or naphthol, the one at Em450/Ex320 could be vitamin A and the one at EM450/Ex350 could be high MW PAHs. The presence of most of these compounds was supported by 3D spectra, which were better able to distinguish between standards than 2D spectra. Only vitamin A in wild fish oils was not confirmed by 3D spectra. Commercial fish oils contained mostly vitamin E. Lovaza (LV) appeared to contain vitamin A and Nature’s Bounty (NB) appeared to contain low MW PAH-like compounds. Spectra were also generated for DWH crude oil and for bile from DWH exposed killifish. 2D and 3D spectra for these samples were highly similar to several wild fish oil samples including three NJ collections and the one from Barataria Bay, LA collected in spring 2011. Overall, results indicated that vitamins and protein may be confounding factors when detecting naphthol-like PAHs in fish oil using fluorescence technologies. Some wild fish oils appeared to contain PAH-like compounds while others did not, indicating that menhaden fish oil is a promising biomonitoring tool. However, PAHs accumulated from crude oil could not be distinguished from those acquired from urbanization.


 
 

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