Thursday, July 26, 2012

Deonte' Thomas's Research Experiences for Undergraduates - Summer 2012 - Part 2

Since my last blog post many exciting events and discoveries have occurred. I have to admit, after seeing what some of the other REUs were experiencing I became jealous. Going to field work on the beach, boat trips, working with Arctic cores and scuba diving are just a few of the great opportunities that have been afforded to students like me. Fortunately, Virginia Eller, a graduate student whom I work with has a father who is Captain of the Checkmate fishing boat.

A few weeks ago on a cool Sunday morning, my research team drove out to Destin, FL, to catch fish and collect water samples. Little did I know that my first time deep sea (Deep C) fishing would be a treat. We made our way about 26 miles offshore and fished at many different spots in between. The deck hand told us exactly what to do as we all stood around trying to listen intently and gain our sea legs at the same time. Sooner than I expected there was a baited fishing pole in my hand. I spread my feet apart and planted them firmly as I could on the deck and placed the back end of the rod in my fighting to keep my rod sturdy. As soon as I dropped the bait, I got hit and began to reel it in. I could feel the weight and the fight of the fish. It was the largest thing I ever caught. They told me it was in the red snapper family and called a mingo. For the next few hours I felt like a master fisherman, catching a red snapper, two lesser amberjack, and a king mackerel. The king mackerel put up the most fight and topped out as the biggest catch for me. Vincent Perrot, a post doctoral student from France, caught a wahoo, in the swordfish family.

Dr. Salters, knowing that wahoo and king mackerel had pretty high concentrations of mercury, thought it would be a good idea to test these two fish. Also, these fish were higher up in the food web than any other samples that we had acquired. The next day we freeze dried our wahoo and king mackerel samples. Once dried, I used a mortar and pestle to grind down samples and prepare them for acid digestion. We believed the freshness of the samples allowed them to digest perfectly. After preparing the samples, the last thing to do was run them through the Neptune, a multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) instrument, for tracing of isotopic composition mercury. After weeks of lab time and hours of tuning on the Neptune instrument the testing would be a cinch. After compiling data from our wahoo, king mackerel, standards, sediment proxy and previous coastal samples acquired from Alexandra Harper, another graduate student at FSU, we had results! Our data shows that mercury from aquatic life forms undergo mass dependent fractionation (MDF) and mass independent fractionation (MIF) for odd isotopes, while mercury in sediments only fractionate mass dependently. Also, mercury in coastal samples (shrimp, sea bass, pinfish, pigfish) show significantly less MIF than in oceanic samples (wahoo and king mackerel). Furthermore, oceanic samples are higher up in the food web and greater photo reduction is seen in residual mercury in the oceanic water column than the coast. We know that mercury is passed through the food web, and our study is more proof that it bioaccumulates and affects aquatic organism differently.

In addition to this fishing trip, I have been to the FSU Coastal and Marine Lab in St. Theresa, FL, one of the most biologically diverse places in North America. There I learned a lot about how industries that use the Gulf of Mexico as a resource are impacting it. Another great place was the Antarctic Research Facility, probably one of the coldest places in Florida and the largest storehouse for arctic core samples. Then the National High Magnetic Field Laboratory, where I work every day, is home to the strongest magnet. There is so much scientific diversity here. As my last week at the Mag Lab winds down I cannot help but to reminisce on all of the wonderful experiences. I am very appreciative of the exposure to geochemistry and marine sciences, the life of a researcher, beautiful places and great people.  
Sharing my research at the Mag Lab REU poster session.
Post Author: 
Deonte' Thomas


  1. Great writing, Deonte! My high school students really enjoyed it!

    Stan Cutler
    Lake Brantley HS

    1. I am very glad to hear that! I wasnt sure if anyone outside of my family members were reading my blog lol. It comforts my soul that dedicated and passionate teachers still exist. Thank you!