Round Goby
Neogobius melanostomus

How to identify them

Round gobies and tubenose gobies are small bottom-dwelling fish. They don't have a swim bladder so they sink in water. They have large pectoral fins and an unusual single, fused pelvic fin that is shaped like a suction cup. Tubenose gobies have a tiny tube extending from each nostril.

Where did they come from?

Gobies came from the Caspian Sea region of Europe. They were first found in the Great Lakes in 1990 in the St. Clair River in Michigan.

How did they get here?

Gobies hitched a ride in ballast water of ocean going vessels. First deposited in Lake St. Clair, they are now present in all the Great Lakes to various degrees and are extending their range.

How can they spread?

Gobies can spread on their own by swimming and through population expansion. They reproduce quickly and can become quite abundant. They can be inadvertently spread by anglers if they use gobies as bait.

What are their effects?

Round gobies are fierce competitors for food. They out-compete our native bottom dwelling fish such as sculpins and log perch, forcing them out of their living spaces and spawning sites. Gobies are also voracious egg predators. They get so numerous that even smallmouth bass that guard their eggs cannot successfully defend their nests from the onslaught of hungry gobies. Smallmouth bass pulled off their nests by anglers in the spring may find few if any eggs remaining  when they return to their nests upon release. Gobies also consume eggs of other fish that broadcast their eggs or build nests in the cobble substrate preferred by gobies. These fish might include walleye, sunfish, lake trout and other salmonids.

Gobies can reproduce up to six times a summer, allowing their populations to expand rapidly. As they become abundant in near shore areas they may be a nuisance to anglers fishing with worms or other invertebrates. They are bait stealers, often getting caught in the process. As a non-target, abundant species they become a nuisance, though can be fast and fun action for kids.

Where are they found?

Gobies are most commonly found in cobbled areas near shore, but do range into water as deep as 50 feet.

Prevention

Unless they happed to spread as larvae or eggs, preventing the spread of gobies is simple: don't use them as bait and be certain they are not included in the minnows sold to you as bait. In many jurisdictions it is illegal to possess a live goby.

If you catch a round or tubenose goby, please freeze it or keep it chilled and report it to your local DNR or Sea Grant office. The specimen is needed for verification.