Besides the round goby, other new threats are the ruffe, a Eurasian fish that could hurt the Great Lakes' yellow perch, and the spiny water flea, a zooplankton that eats the same food as small fish and could disrupt the ecosystem. Domske keeps samples of the round goby in her UB office, a reminder of what havoc such a little creature is capable of causing. A European fish brought to the Great Lakes by oceangoing ships, the goby was first seen here in the eastern end of Lake Erie last fishing season. By fall they were quite abundant. They were showing up in the stomachs of major predators.
Gobies are the rabbits of the undersea world.
Females spawn up to six times in the spring and summer, every 20 days, compared to competing species that reproduce but once a season. At first blush, it might seem like a good thing that gobies are here, seeing how their preferred diet is the zebra mussel. But it's just as simple-minded to root for the goby, in Domske's view, as it is to think that zebra mussels are good for Lake Erie because the water is now 600 times clearer than before they arrived. But it is not healthier. The clearer water comes from the remarkable filtering ability of zebra mussels, which filter murky water as they eat their way through food sought by native species, as well as the lake bottom.