Story has it,gobys arrived via an ocean ships takin in ballast water from the caspian sea,then dumped in the great lakes by accident.zebra mussels and quagga mussels showed up at the same time hmm. 1990 was the year that erie perch in my opinion had a blessing,more forage base,from goby introduction. Perch were small an not worth fishing for,before the gobys showed up,after the 1980s.