Outdoors: UT student finds tiny discarded pets can become much larger problem
Jul. 20—LUNA PIER, Mich. — It created quite a stir recently when a University of Toledo student landed a huge goldfish while fishing in Lake Erie.
Walleye, perch, bass, pike, catfish, and sheepshead — yes — but big goldfish in Lake Erie?
Count UT senior Ashlen Gangway among those amazed and maybe a bit flabbergasted by that revelation. A summer evening of fishing with her boyfriend was punctuated by her hooking and landing what looked like a bulbous, carrot-colored rugby ball with fins.
"I knew I had a pretty decent-sized fish and once we saw it was a goldfish we were definitely pretty shocked," the Bedford resident said. "My boyfriend kept yelling 'don't lose it, don't lose it' so it was a relief to get it in the net."
Gangway said that once the goldfish, which she estimated at about 3 1/2 pounds, was out of the water, her catch became the focus of most of the other anglers on the popular public fishing pier here.
"We've caught pike there and some largemouth bass, sheepshead, perch, and white bass, but this big goldfish coming out of the lake got everyone's attention," she said. "The other fishermen were just as surprised as we were, and some of them came running down to get a picture of it."
While the catch certainly astonished the angler and the other fishermen assembled on the pier, pulling a large, bright orange invasive species from the lake did not surprise the biologists that closely monitor the fish populations in Erie.
"We have crews that survey Lake Erie's waters and we have detected them for years, so there's an established population of goldfish present," said Seth J. Herbst, Aquatic Species & Regulatory Affairs Unit Manager for the Fisheries Division of the Michigan Department of Natural Resources. "And commercial fishermen pick them up every once in a while and they let us know. There are multiple class sizes of goldfish out there in the lake."
Since goldfish are not native to these waters — or the Great Lakes region, or the North American continent, or the Western Hemisphere — where did these goldfish come from?
"We can't say with 100 percent confidence just how they got there, but we can draw the conclusion of the most likely route — the pet trade," Herbst said. "That is by far the most likely source of goldfish anywhere they are found in public waters."
The PhDs call this "organisms in trade" but the more direct label is pet dumping. That cute little goldfish that cost less than a buck at Walmart eventually outgrows its glass bowl or aquarium, the owner doesn't want to deal with the food, waste, maintenance, and space required, and "releases" that fish in the nearest waterway.
This is a bastardization of the "Born Free" concept, based on a movie in which a couple raised an orphaned lion cub and eventually released it back into the wild. That lion was let loose in a large national park in Kenya — a habitat where the lion species is native.
Most of the invasive species issues in the U.S. result from releasing animals, or introducing plants, in a part of the world where they are not native and are often destructive. Whether it is goldfish in Lake Erie, Burmese pythons in The Everglades, garlic mustard in our parks, or kudzu seemingly everywhere, introducing invasive animals and plants creates massive problems.
In the case of the goldfish, native to East Asia and a member of the carp family, they adapt well to our waters, compete with prized native sport fish for food, and reproduce prolifically.
A close relative, the European carp, also called the German carp, has been here so long that it is referred to as the "common carp." It is believed to have been introduced in the 1830s by a New Yorker who wanted to create a commercial fishery in the Hudson River. This carp is now established in all 48 contiguous states.
Herbst said the goldfish in Lake Erie work the bottom of the lake feeding primarily on aquatic insects and competing with native fish for those food sources.
"They root around a lot, and the insects they are eating put them in direct competition with a lot of our native species, including juvenile yellow perch and walleye," he said. "There is also the negative impact of them feeding on the bottom, increasing water turbidity and creating water clarity issues that mean less plant growth."
That reduction in plant growth has a significant negative impact on the ecosystem since many native fish rely on those plants for breeding sites and protection from predators. Lake Erie is far from alone in that club of waters dealing with invasive goldfish issues.
A lake near Boulder, Colo., recently was found to be infested with thousands of goldfish just three years after someone had dumped a few of the fish in those waters. In Minnesota's Carver County, just southwest of Minneapolis, several lakes have been found to hold huge populations of goldfish. Biologists estimate they have removed 30,000 to 50,000 goldfish from Big Woods Lake and Lake Hazeltine.
At the time of her goldfish encounter, Gangway, a 21-year-old psychology major, was not sure what to do with the fish so she ultimately released it. But she said in the days since she caught that goldfish she has learned a lot about the problems such invasive species can create.
"At first I was so surprised by all of the attention this caused, but now I know that goldfish don't belong in Lake Erie and that they can harm our native fish," she said. "People need to realize how big they can get and the kind of problems they can cause."
Herbst said that people with pet fish they no longer want to care for should contact pet shops or other pet owners to take the fish, but these fish should never be released into our waters. If an angler catches a non-native fish, the catch should be reported to the MDNR and the fish should not be released.
"This goldfish issue is just one example of a bigger problem since there are so many pathways for introducing invasive species," he said. "This is a worldwide problem, and this local case highlights the need for people to take a role in protecting our natural resources."
