FAILURE TO REDUCE MOOSE-VEHICLE ACCIDENTS AFTER A PARTIAL DRAINAGE OF ROADSIDE SALT POOLS IN QUÉBEC

Abstract

Salt pools along highways are considered a major cause of increased moose-vehicle collisions during June and July in Québec, Ontario and New Hampshire. About 60 moose are killed each year on the 189 km of Highways 175 and 169 which cross the Laurentides Wildlife Reserve in south central Québec. An attempt was made in 1979 to reduce accidents by drying up roadside salt pools. Some 71 % of salt pools found along a 52 km section of Highway 175 were treated by improving roadside ditch drainage or connecting marshy pools to water courses. In 1981 and 1982, 94 % of the treated pools were once again filled with water. Although mean pool depth was reduced, this did not result in the lowering of salinities or of the frequency of pool attendance by moose. Moose road mortality was not significantly modified by the drainage work. To be effective in reducing moose-vehicle collisions, roadside pools have to be completely and permanently eliminated. When it is not feasible or practical to drain all the water of a pool, other techniques tested elsewhere, like the covering of the pool with grates or diversion of a roadside stream through the salt pool to cause dilution, may be used in conjunction with drainage work. These could include long-lasting repellents or replacement of NaCl by CaCl₂ as a road deicer.