So, what's the big deal? Well, the article I got this from says it takes a long time for the ice to melt and this could cause some serious future problems for those living on and around the lakes.
Already, the impact of this icy blockade can be felt. On March 25, five days after the official beginning of spring, the Soo Locks separating Lake Superior from the lower Great Lakes opened for the season. But after a long and harsh winter, Lake Superior's nearly 32,000 square miles were still nearly entirely covered in ice. It would be another eleven days before the first commercial vessel fought its way across Lake Superior with the aid of several dedicated ice breakers and down through the locks.
Read more @ Why It's a Big Deal That Half of the Great Lakes Are Still Covered in Ice - Stephanie Garlock - The Atlantic Cities