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Coastal Centre concerned about plastic pollution in Lake Huron
Owen Sound Sun Times (7/17)
Everyone has a role to play in turning the tide on the growing problem of plastic pollution in the Great Lakes. That's the message from Ontario's Lake Huron Centre for Coastal Conservation outreach specialist, who is working to educate people on simple ways to help combat the issue.

Elementary Adventure Day outing provides hands-on fun
The Ashland Daily Press (7/12)
Just over half-a-dozen youngsters gathered at the Northern Great Lakes Visitor Center, in Wisconsin, to participate in the first of this year’s three 4-H Elementary Adventure Day’s.

Summer interns help to research Lake Erie issues
The Toledo Blade (7/5)
Eleven college and university students from across the United States are studying freshwater lake issues this summer at the University of Toledo’s Lake Erie Center.

Anglers enlisted in water fight
Great Lakes Echo (6/29)
A recent study by researchers at Cornell University, in N.Y., revealed that anglers in the Great Lakes region are aware of and concerned about the threat of aquatic invasive species (AIS).

Lake State opens Sea Grant office
Sault Ste. Marie Evening News (6/29)
Lake Superior State University officially welcomed its new Michigan Sea Grant office to campus with a ribbon cutting ceremony Monday morning.

Stone Lab hosts series of experts to discuss lake
Port Clinton News Herald (6/28)
In Ohio, people looking to learn more about the issues facing Lake Erie will have several opportunities this summer to hear firsthand from the experts in the field who deal with those issues every day.

TEACH Calendar of Events
What's going on in your neighborhood this month? Meet other people and learn together at recreational and educational events! Our new dynamic calendar is updated daily with current educational events.
TEACH Questions & Answers

If the St. Lawrence River connects the Great Lakes to the Atlantic Ocean, why aren't the Great Lakes saltwater instead of freshwater?
from Billie Rae in Summerville, South Carolina, Age 12

Great question!

The St. Lawrence River can be divided into three broad sections: the freshwater river, which extends from Lake Ontario to near the city of Quebec; the St. Lawrence estuary, which extends from Quebec to Anticosti Island; and, the Gulf of St. Lawrence, which leads into the Atlantic Ocean.

View a map of the St. Lawrence river region
View a map of the entire Great Lakes-St. Lawrence River system

Originating from Lake Ontario near the Canadian town of Kingston, the St. Lawrence River is freshwater until near the Canadian town of Donnacona in Quebec. In this section, the river is always freshwater and flowing in the direction of the Gulf, or downstream. There are many tributaries that flow into the river, such as the Ottawa and Chateauguay Rivers. Because the water flow is quite fast in this part of the river, the water from the tributaries is kept from entering the center of the St. Lawrence River; this phenomenon creates two separate water masses that flow beside one another for a long distance before mixing completely.

After Donnacona, the river widens considerably and enters the brackish water zone, the area where freshwater and saltwater meet. In this section, the salinity of the water rises from zero to twenty percent! Tidal influences from the Atlantic start to affect the river, and the river becomes an estuary, with one of its main tributaries being Saguenay River. An estuary is where a freshwater river current meets an ocean tide, and is often abundant in wildlife. The St. Lawrence estuary is over 300 miles long, and is one of the most productive marine ecosystems along the Canadian coast. Over 718,000 seabirds of 19 species, such as the Atlantic puffin, the red-throated loon, and the Artic tern, and several different species of whales, such as finback, minke, Beluga, sperm and blue whales, are found in the St. Lawrence estuary.

The estuary deepens considerably as it heads toward the ocean, with the depth increasing from around 80 feet (25 meters) to 1,145 feet (358 meters). Once the waterway passes by Anticosti Island, the estuary becomes known as the Gulf of St. Lawrence. The Gulf extends 250 miles from the St. Lawrence River estuary to Newfoundland, where it becomes the Atlantic Ocean, and at its greatest width the Gulf is 500 miles (800 km) wide.

St. Lawrence River and Seaway, Encyclopedia Britannica
The Hydrology of the St. Lawrence Basin, Canada's Digital Collections
The Seabirds of the St. Lawrence, Environment Canada

St. Lawrence Region, College of Communication, University of Illinois
St. Lawrence Hydrographic System, Encyclopedia Britannica

Thank you for your question!

Answered on September 1, 2000

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