One warm day in 1925, a hatchery truck carrying 45,000 fingerling brown trout broke down on the Trans Canada Highway just east of Banff. The driver, fearing that his cargo would perish if left in the truck, did what seemed to be the right thing at the time - he released the young trout into a nearby stream. The brown trout eventually followed the creek down into the Bow River, and their offspring have lived there ever since.

Though probably the least planned, this was not the first incidence of fish stocking in Banff National Park. Employees of the Canadian Pacific Railway had already introduced eastern brook and rainbow trout into the Bow River as early as the turn of the century. Stories of the park's abundant fish were luring in tourists by the train-full. Fish stocking was necessary to appease the voracious appetites of Banff's early fishermen - and women. In 1906, one of these women boasted "in an hour, 13 trout varying from one-half to two pounds would be in my creel.

Such bounty could not last long. The cold and often silty waters of these mountain environments cannot support large numbers of fish. Many of the exotic species that were brought in did not survive. On the other hand, some introduced fish species did alarmingly well in their new surroundings. The native fish populations, suffering from competition for food and spawning sites, declined.

The actions of the past cannot be undone, but we can learn from them. Non-native fish are no longer being stocked into park waters. Mountain park waters are not stocked and do not naturally support large fish populations so catch and release is encouraged. The more fish are allowed to “get away” today, the more there will be for the future.

Past fisheries management programs in Banff National Park were directed at providing good fishing. To achieve this goal, massive introductions of cultured fish were made to virtually all of the park's accessible lakes and streams. These waters contained many rare genetic stocks of fish and other organisms. Introduced stocks were regarded as superior sport fish or innocuous supplements to native stocks. Fisheries managers could be reasonably sure that these fish would thrive in the wide variety of habitat conditions found in the park.

While introduced species thrive and support an active recreational fishery, there is concern over the decline in abundance of native species. The status of westslope cutthroat trout and bull trout, two species native to park waters are of concern. The Banff longnose dace, which was found no where else in the world but Banff National Park, is listed as extinct by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).

Introducing fish to previously fishless lakes has also altered the community structure of those systems. Since the early 1900s, nearly forty million fish have been introduced into the Bow watershed of Banff National Park. Stocking in Banff National Park stopped in 1988. While many of the introductions failed, a shrimp, Yellowstone Cutthroat trout, brook trout, rainbow trout and brown trout predominate the many lakes and streams where they were introduced.

Lake Minnewanka was stocked with fish from 1901 to 1972. It's estimated that over 17 million eggs and fry of lake trout, Atlantic salmon, cisco, brook trout, cutthroat trout, splake, smallmouth bass, lake whitefish and rainbow trout were introduced into the lake's waters. Studies are now being conducted on the long-term effect that stocking and angling has had on the overall health of our aquatic ecosystems.

One way you can enjoy the fish in Banff National Park is simply by watching them. Of course, it helps to know where to look. If you are hiking by the outlet or inlet of an alpine lake in June you may find cutthroat trout spawning there. As you paddle on the Bow River you might see a bull trout resting on the bottom, or a school of mountain whitefish foraging in the current.

You could even jump in for a closer look, if you're feeling very brave. Some divers in Lake Minnewanka claim to have caught sight of a giant lake trout down in the murky depths - one to rival the record 43-pounder caught there in 1889! Not surprisingly, it always manages to get away.

Fish watching is the "low impact" way to discover the world beneath the water's surface. You can watch fish swim, feed, and breed without being intrusive. Look through binoculars to bring dramas to large-scale life. Wear polarized sunglasses to reduce the reflective glare of water and let you see beyond the surface.

Like other wildlife watching, the best times to fish watch are early morning and evening when there is likely to be more activity and better visibility - less glare and calmer waters anyway. Spring and fall are great times to watch fish spawn. Stand away from the stream bank or lakeshore to avoid casting shadows and creating vibrations, which may startle and stress the fish. Never throw objects into the water to catch their attention.

Best places and times to fish watch:

• Cave & Basin Marsh: view introduced tropical fish at the fish-viewing platform.
• Beaver Pond, west end of 3rd Vermilion Lake: In October, look for brook trout spawning in shallow water close to the road.
• Johnson Lake: take the trail on the north side of the lake to the bridge that crosses the stream flowing into Muskrat Bay. In spring, look for rainbow trout spawning in the shallows, in the fall it is brook trout's turn.
• Forty Mile Creek: Look for whitefish spawning beside the Fenland trail in the fall.

N: native
I: introduced
U: unsuccessful introduction

Sculpin

• Spoonhead Sculpin - Cottus ricei (N)

Trout

• Cisco - Coregonus artedi (I)
• Lake Whitefish - Coregonus clupeaformis (I)
• Cutthroat Trout - Oncorhynchus clarki (I/N)
• Rainbow Trout - Oncorhynchus mykiss (I)
• Golden Trout - Oncorhynchus aguabonita (U)
• Mountain Whitefish - Prosopium williamsoni (N)
• Brown Trout - Salmo trutta (I)
• Bull Trout - Salvelinus confluentus (N)
• Brook Trout - Salvelinus fontinalis (I)
• Lake Trout - Salvelinus namycush (I/N)
• Atlantic Salmon - Salmo salar (U)
• Arctic Char - Salvelinus alpinus (U)

Minnow

• Goldfish - Carassius auratus (I)
• Lake Chub - Couesius plumbeus (N)
• Northern Redbelly Dace - Phoxinus eos (N)
• Finescale Dace - Phoxinus neogaeus (N)
• Fathead Minnow - Pimphales promelas (N)
• Longnose Dace - Rhinichthys cataractae (N)
• Banff Longnose Dace - Rhinichthys cataractae smithi (N) extinct
• Pearl Dace - Margariscus margarita (N)

Sucker

• Longnose Sucker - Catostomus catostomus (N)
• White Sucker - Catostomus commersoni (N)
• Mountain Sucker - Catostomus platyrhynchus (N)

Trout-Perch

• Trout-perch - Percopsis omiscomaycus (N)

Cod

• Burbot - Lota lota (N)

Livebearer

• Western Mosquitofish - Gambusia affinus (I)
• Sailfin Molly - Poecilia latipinna (I)
• Guppy - Poecilia reticulata (U)
• Green Swordtail - Xiphophorus helleri (U)

Stickleback

• Brook Stickleback - Culaea inconstans (N)

Cichlid

• African Jewelfish - Hemichromis bimaculatus (I)
• Convict Cichlid - Cichlasoma nigrofasciatum (U)
• Freshwater Angelfish - Pterophyllum scalare (U)

Bull trout are part of the "char" family which includes brook trout and lake trout. Bull trout look very similar to brook trout and the two species are often confused. As an angler you are responsible for ensuring you do not have a bull trout in your possession. If you are in doubt release the fish immediately.

• Bull trout dorsal fins do not have black spots.
• Bull trout do not have black lines following the white line on their pelvic, pectoral or anal fins.