University of Alabama researchers are tagging 750 amberjack to track their movements and population size in the Gulf of Mexico and offering harvesters $250 for each fish that they catch, the Associated Press reports.   Also known as yellowtail, the Seriola dumerili are overfished in the gulf but not in the south Atlantic Ocean, and the study aims to determine how the two separately managed stocks are connected, as part of an effort to better promote sustainability of the stocks, the university said in a statement [...]