Wiper Caught in Lake Ontario

While fishing in Lake Ontario off the Pickering Nuclear Generating Station (PNGS) this past mid-January, Oakville angler Tim Rourke landed a large “Wiper”, a cross between a White Bass (Morone chrysops) and Striped Bass (M. saxatilis). Rourke boated a 6.8 kilogram specimen of one of the province’s least-known hybrid fish on that balmy -12°C day. The warm-water discharge from the PNGS attracts a variety of species, especially in cold weather. Trout and salmon are common, but anglers can also catch bass, walleye, pike, panfish and drum.

Erling Holm, Assistant Curator of Fishes with the Department of Natural History at the Royal Ontario Museum (ROM), identified the catch as a “Wiper” by photograph, based on the large size, the strong striping pattern with broken lines, and the deep body. Wipers also usually have two patches of teeth at the back of the tongue that are adjacent to each other, which Rourke’s fish has. White bass have one patch and striped bass have two patches that are separated. Holm added that “This is the third wiper that I know of that came from Lake Ontario around Pickering. One smaller fish was caught in 2005 and a second fish, as large or larger than Rourke’s, was caught by the Toronto Region Conservation Authority in 2008 during routine monitoring. Also, Fisheries and Oceans Canada caught two wipers in Hamilton Harbour in 2009. And who knows how many have been caught and not reported.”

The origin of the “Wipers” is a mystery. Because Striped Bass are not native, nor known from Ontario waters, natural hybridization is unlikely. Perhaps they originate from fish markets, or it might also be possible that someone is intentionally stocking them from another aquaculture source. It is, however, illegal to transport live angler·caught fish overland (other than baitfish) and also unlawful to release fish into any waterbody other than the one from which it was caught (this includes baitfish), cautions Mark Robbins provincial enforcement specialist with the Ministry of Natural Resources. There are no current regulations specific to white bass or striped bass (or their hybrids) for Lake Ontario Fisheries Management Zone 20, but all general angling rules apply.

Despite its large size, Rourke’s 6.8 kilogram fish is not an Ontario record. The current provincial Wiper record is 9.6 kilograms, caught on May 14, 2006, in the Detroit River near Windsor. (Original article published in Ontario OUT OF DOORS Volume 43, Issue 3, April 2011; written by Ray Blades, Associate Editor)