Illegal stocking is a pervasive, global problem
Evaluating the full scope of illegal stocking is difficult due to the cryptic and diffuse nature of the problem. Only a few jurisdictions have attempted to quantify the number of incidents they have experienced. The magnitude and extensiveness of this crime is suggested by the growing intolerance of illegal introductions apparent in the actions of management agencies.
North America
In Maine illegal introductions have established northern pike, largemouth bass, smallmouth bass, black crappie Pomoxis nigromaculatus,bluegill Lepomis macrochirus, and green sunfish L. gibbosus in more than 150 lakes ( Boucher 2007). In the Upper Colorado RiverBasin, anglers have illegally established more than 46 populations of cool- and warmwater species in at least 22 reservoirs (Johnson et al. In review). Montana has documented more than 500 illegal introductions in almost 300 waters (Tipton 2007). In Wyoming, 50% of the unauthorized introductions during the last three decades were deliberate, illegal introductions (Rahel 2004). Illegal stocking of northern pike has allowed that species to invade over 130 lakes in southcentral Alaska and pike have ruined a multitude of coho, chinook and rainbow trout fisheries there.
Alabama (2003), West Virginia (2004) and North Carolina (2005) developed new regulations specifically to deal with the increasing number of unauthorized introductions in their states. Some of Georgia’s top smallmouth bass, sunfish, and bullhead fisheries were ruined by illegal stocking of spotted bass, blueback herring and flathead catfish. Illegally stocked flathead catfish are a threat to native fish populations in eastern Pennsylvania and North Carolina as well.
Maryland was in the news as reproducing populations of the southeast Asian snakehead were found in the state. In British Columbia, the Ministry of Environment has now closed 9 lakes to fishing after yellow perch were illegally stocked in them. Alberta is in the process of surveying stakeholders about unauthorized yellow perch introductions occurring throughout the Province. Ontario Federation of Anglers and Hunters partnered with OMNR to produce a massive invasive species outreach campaign with a strong illegal stocking component.
Europe
North American crayfish, sunbleak, topmouth gudgeon, and zander are some of the nonnative species illegally introduced and causing problems in the United Kingdom. The governement of England and Wales has developed eFishBusiness, an elaborate program to facilitate the legal movements of fish into, around and from England and Wales. Three arrests have been made of people smuggling live fish from France for stocking into the U.K. via the Channel Tunnel. In Ireland, anglers have illegally introduced exotic zebra mussels into ponds and lakes under the mistaken impression that it would improve water quality and fishing.
Australia
The government of Queensland developed a great education module for school children called Aquatic Invaders about the dangers of introducing nonnative fish. Tasmania has fines of up to $25,000 for illegal stocking of nonnative fish.
Africa and Asia
Please send us examples of unauthorized/illegal stocking to highlight here.
