Wednesday, May 30, 2012

Dead zone research diversity 

     A recent unique invention called The Experimental Anoxia Generating Unit (EAGU) simulates oxygen deprivation and creates an artificial ocean dead zone by sealing off a particular volume of water approximately 80 feet below the ocean surface. Attached to the plexiglass are a camera and sensors to measure pH and oxygen concentration levels. The data collected from this unit will be used to discover the animal behaviors that could provide warning signs to possible future dead zones.
     On the Canadian shores, a much less conventional technique was used to research the presence of scavengers in oxygen deprived waters. Scientists lowered dead pigs with cameras and oxygen-measuring equipment attached down to the seafloor. There, the waters contained approximately 7% dissolved oxygen, a lower concentration than scientists expected to harbor living animals. They watched as crabs arrived to take advantage of the free meal, but they had their limits. Most crabs tolerated this environment for 1 or 2 days before abandoning the pig. These surprising results gave hope to researchers for the survival of at least some animals to help clean up the ocean floors and help prevent the increased oxygen consumption of bacterial decomposition. University of Victoria Canada professor Dr. Verena Tunnicliffe explains, "If some of these animals can survive, with a little bit of oxygen coming in, perhaps they can get down there and start that clean-up. There's lots of food down there now."
     A more traditional form of research is called monitoring, where scientists collect measurements of oxygen concentration, algae presence and water salinity. Field studies include sediment core sampling and the resulting lab work includes measuring gas concentrations in water and air and determining the chemical make up of the sediment. This allows them to plot information to assess how the size of dead zones changes each year and predict future trends of these ecosystems. Also, the data can be organized in computer models to calculate the movement and dissipation of ocean dead zones over long and short periods of time.

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