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Grand River - Raising Rainbows

Rehabilitating a tired, industrial river

More on the Grand River:
Grand River:
Ontario’s historic heartland

Bloom Town:
The flowering of an old-style Ontario town

The Grand’s Canyon:
Tourism powers an old mill town

Grinding Along the Grand:
Stone mills lined the riverbanks

High-Rise Herons:
Big swamp birds thrive in a wetland haven

Home and Native Land:
Homestead of the Six Nations

Old Order:
Mennonites set their own pace of change

Plaster of Paris:
A town arises from gypsum and cobblestones

Raising Rainbows:
Rehabilitating a tired industrial river

Sausages to Software:
The Industrial Evolution

Grand Stand:
Survival of a river valley forest

Fat, robust, brown trout and rainbow trout are now caught by fly fishers in riffles and pools that once were poisoned with industrial and domestic sewage.

The people who live along rivers pollute them, often with little regard for the river's health. The water quality of the Grand has suffered over the years, and the Grand River Conservation Authority has spent the last decade trying to improve it. One of the main goals is to increase habitat diversity, because any cold water stream that can support a wide diversity of aquatic life is a healthy one. Cold water streams are those with temperature ranges of 18 to 20 degrees Celsius. The survival and health of trout are one of the best indicators of a stream's condition.

There are three consecutive steps in rehabilitating of a stream to make it suitable for trout. The first involves removing accumulated debris, whether natural or human made. Vegetation along the banks may be cut back to let the water flow faster and to encourage root growth which stabilizes the banks. Beaver dams and obsolete man-made dams are removed. Such dams collect silt, increase the water temperature and slow the stream's natural rate of flow.

The second step involves enhancing the stream's natural flow. When the natural channel of the river takes shape after flushing the sediment and exposing gravel beds, the channel can be stabilized by building flow deflectors of rocks, brush, or log cribs to guide and maintain the natural flow. Sometimes cedar "sweepers" are installed along weak parts of the bank. The cedar branches trap waterborne silt, and this starts to rebuild the bank. Grasses and trees are planted along newly re-established banks to stabilize them.

The third and final step involves improving the habitat for trout, which need clear, clean water that is rich in dissolved oxygen. Trout like to shelter under overhanging banks, so artificial overhangs are created where needed. Often rocks are added to the stream so that fish can rest behind them, out of the direct force of the current.

Gravel is added to the stream to provide fish with a place to spawn. Fish build nests for their eggs by swishing their tails over the gravel beds to make small depressions called redds. The eggs are deposited in the redds, fertilized by milt from the male, and then dropped into the gravel where they are protected against predators until they hatch.

Today, brown and rainbow trout can now reproduce naturally in sections of the Grand River and its tributary streams. However, the river has become well known to anglers in Canada and the United States, and is now heavily fished. Most fly fishers are encouraged to release their catches alive, through special angling regulations and education programs.

Trout stocking continues, however, and wild strains are now being introduced to supplement stocked fish.



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