A ship discharging its ballast water (Photo courtesy of the US Geological Survey)
Ships should be bringing in fewer unwanted
pests into the Great Lakes. Both Canada and the
U-S are now requiring ships to flush out their
ballast water tanks before entering the lakes.
Tracy Samilton reports:
Transcript
Ships should be bringing in fewer unwanted pests into the Great
Lakes. Both Canada and the U.S. are now requiring ships to flush out their
ballast water tanks before entering the lakes. Tracy Samilton reports:
Ships need to take on ballast water to keep them stable. When they pump in
water from freshwater foreign ports, they also suck up pests.
Since 2006,
Canada has required ships to flush their tanks with salty ocean water
before entering the Great Lakes. The U.S. adopted the requirement at the
start of this year.
Collister Johnson is with the U.S. side of the St.
Lawrence Seaway, which connects the Atlantic Ocean to the Great
Lakes. He says the rule will eliminate almost 99% of freshwater
pests in ballast tanks.
“If they’re exposed to salt water, especially full strength sea water, they
are effectively killed.”
Samilton: “Why didn’t we do this before?”
Johnson: (laughs) “I don’t know.”
It won’t completely eliminate the problem because some aquatic pests can
still survive in the sediment in the bottom of ballast tanks.
For The Environment Report I’m Tracy Samilton.