Sunday, April 17, 2011
From Alberta Sustainable Resource Development Homepage:
Edmonton... The long winter with cold temperatures and heavy snowfall may cause low oxygen levels and winter kills of fish, especially in shallow lakes. Albertans can assist the government’s monitoring of fish populations by reporting any fish kills seen on lakes after spring break-up.
Many small, shallow lakes in Alberta, whether they contain native fish or stocked trout, can suffer winter kills. Thicker ice and above average snowfall minimize light penetration, reducing aquatic plant activity, which is a source of new oxygen in winter. In shallow lakes, the combination of decomposing plants using oxygen and a long winter can also result in low oxygen levels. Larger, deeper lakes may be able to better sustain the oxygen levels necessary for fish survival over winter.
Fish and wildlife staff have been monitoring oxygen levels on selected lakes in the province. They will continue to monitor fish populations and make adjustments as necessary. Albertans are encouraged to contact Fish and Wildlife offices of Sustainable Resource Development, if they see dead fish after spring ice break-up. Phone 310-0000 (toll-free within Alberta) to contact the nearest office.