Mar 09, 2004 — The St. Lawrence Seaway is scheduled to open another shipping season on March 25th. Observers warn letting giant freighters into the St. Lawrence too early can damage riverside ecology and homes. They also worry about the nightmare scenario of an oil spill trapped under ice. As David Sommerstein reports, the Seaway has made compromises over how it chooses an opening date, but critics still fear economics trumps the environment.