Strong concerns exist that the European eel population might be devastated by a new threat: "Anguillicola crassus", a foreign parasitic nematode. This parasite from East Asia (the original host is "A. japonica") appeared in European eel populations in the early 1980s. Since 1995, it also appeared in the United States (Texas and South Carolina), most likely due to uncontrolled aquaculture eel shipments. In Europe, eel populations are already from 30% to 100% infected with the nematode. Recently, this parasite was shown to inhibit the function of the swimbladder as a hydrostatic organ. As open ocean voyagers, eels need the carrying capacity of the swimbladder (which makes up 3–6% of the eel's body weight) to cross the ocean on stored energy alone.