The Wetland World of Netley Marsh
Falling no more than 70 metres during its entire 870 kilometre length, the Red River is in no big hurry to send its waters north. As it prepares to empty into the southern tip of Lake Winnipeg, it gets downright sluggish, ending in a vast deltaic wetland known as Netley Marsh.

Part of a low-lying area that characterizes the southern basins of both Lake Winnipeg and Lake Manitoba, Netley Marsh covers 24,000 hectares north of the cities of Winnipeg and Selkirk. It is a key spawning, feeding and nursery area for Red River and Lake Winnipeg fish species, as well as the site of the Netley Marsh Game Bird Refuge.

Cattail Colonists: Amidst the dense vegetation of the Marsh, diving birds such as Great Blue Herons, Black-Crowned Night-Herons and Western Grebes build their nests and raise their young. Nocturnal and noisy, the stocky, black-capped Night Herons feed on fish, frogs and crustaceans, while colonies of much larger, long-legged Great Blue "day" Herons roost high up in their oversized nests of reeds, sticks and twigs.

In contrast to the ungainly, primeval appearance of the wading herons, the jaunty, duck-like Western Grebes bob and swim in pursuit of their underwater prey. Like the herons, however, they share three physical characteristics which are well-suited to the dive-and-capture foraging method:
• small, narrow heads,
• slender, forward-thrusting necks,
• long, sharply-pointed bills.

The Legacy of Lake Aggasiz
Imagine it's 11,000 years ago, and imagine that you are high above midwestern North America. All you see below you is a lake — a giant lake, born of a massive, continental glacier.

Bigger than Lake Superior, larger than any freshwater body on the earth today, ancient Lake Aggasiz extended from northern Saskatchewan in the west to northeastern Ontario in the east, and from southern Minnesota in the south to northern Manitoba in the north.

Rising and Falling: Glacial Lake Aggasiz (named for Louis Aggasiz, 19th century Swiss naturalist and glaciation theorist) began to form about 12,000 years ago, as the Laurentide Ice Sheet retreated northward. Over the next 5,000 years, it changed its boundaries several times, as glacial ice advanced and retreated. At the peak of its coverage, the lake drained to the south through the Minnesota River Valley, west through northern Saskatchewan to Alaska, and east to the Great Lakes. About 8,500 years ago, the southern part of the lake drained for the last time, and about 1,000 years later, it was gone from northern Canada.

Today, the Red River Valley exists in what was the southwestern portion of Lake Aggasiz, extending just over 500 kilometres from Lake Traverse in the south to Lake Winnipeg in the north.

Big Cats of the Red
You won't easily forget your first sight of a Red River channel catfish. You will notice its distinctly whisker-like barbels, its sharply-pointed head, and its deeply-forked tail. But, most of all, you will be impressed with its size — these monster fish often weigh in at 10 kilograms or more. Native to much of eastern and north central North America, the channel catfish is particularly well-adapted to the Red River.

The channel catfish is both a bottom feeder and a piscivorous fish, feeding on crayfish, insects, minnows and other fish. (Goldeye are a particular target.) In comparison to other catfish species, channel catfish have well-developed eyesight. They also use their barbel "whiskers" to find food.

Mr. Mom: When channel catfish spawn in the spring, males build the nests, keep them fanned with their fins, and defend them at all costs. When the tiny golden eggs hatch after a week, the male channel catfish cares for the young until they can fend for themselves.