A major operator in Alberta's oilsands is appealing a $278,000 regulatory fine it was issued after hundreds of birds died in one of its toxic tailings ponds. 

Canadian Natural Resources Ltd. was sanctioned last year by the Alberta Energy Regulator for not stopping the birds from nesting on an island that emerged from a pond at the Horizon oilsands mine, about 60 kilometres north of Fort McMurray.  

Throughout the spring and summer of 2022, more than 400 California gulls died from exposure to the …