Oscars are native to Africa and popular as ornamental pet fish in the U.S. These oscars grew too large for their owners to maintain and were briefly sheltered at the Marineland Pet Center in Onalaska, WI. The La Crosse NFWCO later took possession of these unwanted pets to prevent their possible release into the wild. Photo credit: USFWS.

The tinfoil barb is a freshwater fish native to Southeast Asia and is popular as an ornamental pet in the U.S. This fish grew too large for its owner to maintain and was briefly sheltered at the Marineland Pet Center in Onalaska, WI. The La Crosse NFWCO later took possession of this unwanted pet to prevent its possible release into the wild. Photo credit: USFWS.

Reports of large, exotic fish caught by anglers, commercial fishers, and fishery resource managers in public waters have become all too common across the country in recent years.  The causes for most of these unexpected and environmentally troubling landings are hobbyists (aquarium owners and water gardeners) who can no longer care for their ornamental fish (e.g., pacu, koi) that grew to an unmanageable size and were purposely released into nearby surface waters as a quick solution.  Pet owners should know that the release of these fish (and the disease pathogens that may infect them) could adversely impact native fish with serious consequences for sport and commercial fisheries.  Faced with a dilemma like this, fish hobbyists need to learn of approved alternatives to the illegal abandonment of their aquatic pets in the wild.  One such option, now offered in western Wisconsin, is a government-business partnership that was established in 2006 by the La Crosse National Fish and Wildlife Conservation Office (NFWCO).  Several pet retailers in this region (that do not offer these frequently problematic fish for sale) have agreed to accept and quarantine large, unwanted pet fish from owners who can no longer care for them.  Because there is virtually no market for these businesses to re-sell such large fish to other pet owners, the La Crosse NFWCO will accept custody of these unwanted fish and humanely euthanize them at no cost.

Due to this unique partnership with local businesses, the Marineland Pet Center in Onalaska, Wis., recently accepted five large hobby fish from owners who no longer wanted to care for them.  On October 17, La Crosse NFWCO biologist Mark Steingraeber took possession of these tropical species which included four oscars (7 to 11 inches total length) and one tinfoil barb (12 inches total length).  These fish were humanely euthanized with Finquel® (tricaine methanesulfonate), a U.S. Food and Drug Administration-approved anesthetic for aquatic cold-blooded vertebrates, and cryopreserved later that day.  This brings the current tally of species turned-in to this program to four.  Since its inception in 2006, this unique partnership has prevented the possible release of twenty-two large, unwanted pet fish into Coulee Region surface waters.  Several of these fish have been prepared by a taxidermist and are now part of an exhibit used at La Crosse NFWCO outreach events to increase awareness of potentially problematic pet fish and acceptable alternatives to the release of these animals in the wild.