What was the Lake Guardian, a ship displaying the insignia of the United States Environmental Protection Agency, doing in Humber Bay? —Stan Bowen, Etobicoke

Guarding the lake, of course! Billing itself as “the only self-contained, non-polluting research ship on the Great Lakes,” the Lake Guardian has been making the rounds of our inland seas for 12 years. The ship sets sail every March, testing its way across the lakes, analyzing the data in its five on-board labs. This year, the Guardian visited the mouth of the Humber to study the effects of the zebra mussel and other non- indigenous species on local plankton and micro-organisms.

• Categories: Miscellaneous