If a goldfish grows to accommodate its environment, what can happen when it gets released into rivers, lakes and ponds? Freakishly large goldfish, the size of a dinner plate, have been caught in waterways in Minnesota and the Great Lakes region. Goldfish, alligators, pythons and most common aquarium plants are not native to Minnesota.
"We and many others are working to educate people about the alternatives to releasing these animals," said Marte Kitson, Minnesota Sea Grant's Environmental Literacy Extension Educator. "We're particularly happy to be working with a variety of partners to launch our newest alternative: Habitattitude Surrender events."
Goldfish were first introduced in the U.S. in 1878 by the U.S. Commission on Fisheries. The newly formed Commission offered free goldfish, brought from Japan, to residents in the District of Columbia. Throughout the 1880s and 1890s, the fish were bred in ponds in the District and Baltimore, and anyone who sent a request through a member of Congress could receive one along with a glass globe to keep it in. At its height, the campaign was distributing 20,000 fish annually. In the 20th century, goldfish became a common prize at county fairs.
The innocent fun associated with the flowery goldfish has resulted in unanticipated consequences. Dumped into waterways or washed out of private ponds, goldfish and koi find their way into rivers and lakes where they can hybridize with their common carp cousins that were brought to America from Europe in the early 19th century. As these hybridized fish root around in the sediment and scour the bottom of waterbodies to feed, they ruin habitat for native species. They “vacuum” up organic matter and leave very little behind for the foraging native fish. They can even eliminate frogs from an area by eating tadpoles.
One of the most sensational goldfish stories of the last several years happened in 2015 in Teller Lake #5, Colorado. Held up as a horrible warning of what can happen when released domestic fish run amok, the 12-acre lake made national headlines with its estimated population of 4,000 goldfish. Then, in a twist of fate, a pod of hungry white pelicans swooped down. In the aftermath of an epic feeding frenzy, wildlife officials found four live goldfish and a few regurgitated bodies. The pelicans saved taxpayers tens of thousands of dollars in clean-up efforts that might have included draining the lake or zapping it with electricity.
Minnesota Sea Grant partnered on two Surrender events in 2016, one in the Twin Cities and the other in Duluth. These events created convenient, humane options for owners to part with unwanted aquarium and water-garden pets and plants. Surrender events are a component of HabitattitudeTM, a national public awareness campaign to help aquarium and water garden owners become part of the solution to prevent the release of aquatic fish and plants. It's a cooperative effort embraced by pet and water garden industries and the campaign's logo and "don't release" message appears on fish bags, new aquariums and elsewhere. At the Twin Cities event, the Minnesota Aquarium Society accepted nearly 100 fish. The fish were bagged, tagged and auctioned to the highest bidder within hours. The proceeds from the auction supported the Society's efforts to promote excellence in fish keeping.
"Aquarists and water gardeners may release organisms for a variety of reasons," said Brad Swanson of the Minnesota Aquarium Society. "Fish might get too big or aggressive. Pets get ill. Owners move or lose interest. We are committed to providing a solution to this problem of aquariums being dumped into lakes and rivers."
According to Swanson, the most common non-native fish released into the environment are goldfish, common carp-koi and Oriental weatherloach.
In September, Minnesota Sea Grant collaborated with The Snake Pit, World of Fish and Animal Allies to organize a Surrender event in Duluth where a fish, five turtles and four snakes were given up for adoption.
"Those one or two fish can make a difference," says Kitson. Non-native species can become invasive, reproduce quickly and ruin habitat — and dinnertime — for native animals. Even if the released animals don't become invasive, their lives beyond the aquarium are perilous. Supporting this message, Minnesota Sea Grant staff also made the rounds at the Minnesota Water Garden Society's annual Twin Cities tour to educate visitors and pond owners about the importance of keeping koi and aquatic plants contained.
Minnesota Sea Grant is widely recognized for its broad partnerships and efforts to keep non-native aquatic plants and animals from spreading throughout the state. However, given a striking uptick in alligators roaming Cass County, Minnesota, this summer (three seen, two apprehended), there is obviously more work to be done.
By Jennifer Gasperini