St. Lawrence River Ecosystem

The Upper St. Lawrence River has a wonderfully complex ecosystem and is home to the Thousand Islands region, a globally unique archipelago.

Linking Great Lakes to the Ocean

The St. Lawrence River is one of the largest Rivers in the world, linking the Great Lakes to the Atlantic Ocean. The Great Lakes hold nearly 20% of the world's freshwater, placing the St. Lawrence River in a unique position. As the only natural outflow to the Great Lakes, the health of the St. Lawrence is forever directly tied to the health of one of the world's greatest freshwater ecosystems.

Thousand Islands

Flowing over ancient glaciated rock, the upper St. Lawrence River has formed a unique island paradise known as the Thousand Islands, consisting of 1,864 islands. The islands provide a variety of habitats supporting all kinds of plants and wildlife.


imageThe St. Lawrence River valley is teeming with wildlife throughout the year.

The River is home to several species of concern including threatened and endangered species such as Blanding's turtle, bald eagles, osprey, black tern, and the Indiana bat.

Numerous north woods mammal species find their home on the shores and islands of the River including muskrat, beaver, flying squirrels, mink, deer, porcupine, and many others. Winter ice cover on the River provides important passage for animals from the shoreline and to/from many of the islands.

Known as one of the great freshwater sport fishing grounds in the northeast, anglers travel from around the country to fish for pike, bass (particularly smallmouth bass), and muskellunge on the River.

The St. Lawrence River Valley is a key part of the Atlantic Migratory Fly-Way - the main pathway for seasonal migration of many bird species. The region has also been listed as an Important Bird Area by Audubon New York.

Bald eagles, which have not been seen in the River valley for many years, are making a comeback and can be seen frequently on the River in the winter. Visit our bald eagle page to learn more.


The St. Lawrence River is home to extensive coastal wetlands which provide filtration for runoff, flood retention, and provide wildlife with food and shelter. Wetlands also act as a nursery for the species of the River including waterfowl, numerous fish species as well as amphibians and reptiles.

For more information about the River's ecosystem visit the following:

Latest News

EPA Accepting Public Comments on Proposal to Ban the Dumping of Sewage from Boats into the St. Lawrence River
“It’s astonishing that in 2016, boaters can dump raw sewage into the St. Lawrence River. Declaring this area of the St. Lawrence a “no discharge zone” would provide cleaner water for people who use this river,” said Regional Administrator Judith A. Enck. “The EPA and New York State looked carefully at the information and agree that the St. Lawrence has enough facilities to remove treated waste from all types of vessels and keep it from entering the river.” read more

Meadow Marsh Wetlands Disappearing on the St. Lawrence River as Governments Delay
And with them, populations of species key to the River ecosystem health - Northern Pike, Black Tern, Least Bittern, King Rail and Muskrat read more

Happy Birthday Haas!
It's been a year since Save The River published Juliane Flora's hit children's book Haas the Great Blue Heron read more

Save the date! September 12th, 3-5pm
Save The River and Clarkson University are bringing the Wild & Scenic Film Festival to the River region. read more

How invasive species changed the Great Lakes forever
A primer on invasive species in the St. Lawrence River and Great Lakes. Worth a re-read this Invasive Species Awareness Week. read more

Invasive Species Awareness Week to be annually held from July 12th-18th.
The New York State Executive Chamber Proclamation instated by Governor Cuomo declaring Invasive Species Awareness Week (ISAW) to be annually held from July 12th-18th. read more

Prevent the Spread of Aquatic Invasive Species
Important steps for anyone boating on the St. Lawrence River (and not just during Invasive Species Awareness Week) from the New York State Department of Environmental Conservation website read more

Invasive Species Awareness Week
We know a little bit about invasive species here on the St. Lawrence. In fact, we've become a vector for for their movement from our waters to others in the state and provinces. The invasion of non-native, harmful species goes back to at least the construction of the Erie Canal. But it wasn't until the opening of the River and the Great Lakes to international shipping in the 1950's that the scope and pace of the invasion threatened to completely upend the natural ecosystem and species dependent on it. read more

Happy World Wetlands Day 2015!
On the River, supporting wetlands means adopting Plan 2014 – a modern water levels plan that will restore 64,000 acres of wetlands on the St. Lawrence River and Lake Ontario read more

New Data Show Multiple Asian Carp eDNA Hits Just Yards from Lake Michigan
Asian carp continue to knock on the door of the Great Lakes, based on eDNA sampling results released last week by the U.S. Fish and Wildlife Service. The sampling data, collected in October, show the presence of bighead or silver carp DNA throughout the Chicago Area Waterway System (CAWS). read more

See our blog for more news!     

About Us

Founded in 1978, Save The River is a non-profit, member-supported environmental organization whose mission is to restore, preserve and protect the ecological integrity of the Upper St. Lawrence River through advocacy, education and research. Since 2004 Save The River has been a member of the Waterkeeper Alliance as the Upper St. Lawrence Riverkeeper.

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The River

The St. Lawrence River is one of the largest Rivers in the world and a magnificent place to live, work and play. Save The River has been working for more than 35 years to protect the River for current and future generations.

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Join or Give

Over half of Save The River's budget comes from individual memberships and contributions. Supporting us with an annual membership donation will keep our River advocacy, education and research programs going strong.

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Save The River was designated the Upper St. Lawrence Riverkeeper and is a member of the international Waterkeeper Alliance. The Waterkeeper Alliance is the world’s fastest growing environmental movement, with more than 200 local Waterkeepers patrolling rivers, lakes and coastal waterways on 6 continents.

Photos from around the River

Off to the races by Pam Quimby  Resting by Pam Quimby  On the Rocks by Nick Apel  Classic Sunset by Barb Hupp  TI Park Library by Meg Kerr  Fall by Carrie Kerr  Girls by Juliane Bauer  Winter Navigation by Sherman Ward  Off on the River by Jenni Werndorf  A Seaway View by Devon Colby 
 Pictures from our Flickr photostream

409 Riverside Drive
Clayton, NY 13624

(315) 686-2010


© Save The River 2014