When was the scientific study regarding the collapse of the ecosystem published ?
In 2009 , Eduardo Spivak tallied the number of scientific papers published about different crab species over the previous 23 years , and found that " Neohelice granulata " was the sixth most studied crab species , after " Carcinus maenas " , " Callinectes sapidus " , " Scylla serrata " , " Cancer pagurus " and " Metacarcinus magister " , but ahead of the invasive and edible Chinese mitten crab ( " Eriocheir sinensis " ) and the commercially important " snow crab " , " Chionoecetes opilio " .