A Cautionary Tale: Single-Minded Efforts to Manage Nature Are Confounded by the Complexity of Ecosystems
Gayton, Don, Alternatives Journal
THERE WAS A MORNING, back in time, when this region of British Columbia they call the Kootenays changed from ice and rock to land and water, from Pleistocene to Holocene. This morning can be described neatly in multiples of ten; at the beginning of the morning, some ten millennia ago, the glaciers lay across the landscape a thousand metres thick. At the end of the postglacial morning, a thousand years later, the continental glaciers were gone.
One of the very first inhabitants of the region, arriving literally on the melt-waters of receding glaciers, is a fish. This fish is an extravagant gift from the Pacific Ocean to the interior. It is an elusive flash of molten silver, a lustful reproductive torrent of fire-engine red, a marvel of adaptation, an icon of regional culture, and a pawn of industry. Its name has cycled through various cultures as kukeni, redfish, kickininee, silver, Oncorhynchus nerka, kokanee. These cultures have depended on it, studied it, even brought it close to annihilation, but none has ever completely possessed it.
In the early 1960s, the diminutive kokanee of Kootenay Lake began a radical transformation. Once herring-sized, kokanee were now achieving lengths up to 45 centimetres and weights of 3.5 kilograms, nearly as large as their saltwater cousins, the sockeye salmon. The kokanee's fine red flesh and sportiness made them a welcome addition to the creels of both local and visiting anglers, who now could chase the bulked-up kokanee as well as fish for the world-class Gerrard rainbow trout.
This transformation was attributed to the work of biologist Peter Larkin of the BC government's Game Commission. He felt that the fishery at Kootenay Lake, in southeastern British Columbia, was not reaching its full potential, and he had an idea how to enhance it.
In the spring of 1949, Larkin made a trip to Waterton Lake, Alberta. Using a fine-meshed net, he trawled the bottom of Waterton Lake and captured a small population of a tiny crustacean called Mysis. This organism was found in Waterton and other lakes east of the Rockies, but not in BC lakes. Larkin's idea was that Mysis (also known as the "opossum shrimp," for its nocturnal habits) would be an ideal food source for the Gerrard rainbow trout.
The Gerrards fed on plankton when they were fry, then switched to a diet of kokanee once they were mature. Larkin felt that the crustacean might become an intermediate food source that would help the growing rainbows as they moved from juvenile to adult food. Accordingly, he released Mysis into Kootenay Lake in 1949, and again in 1950.
As the newcomer slowly worked its way into the lake's ecology, biologists duly included it in their periodic monitoring regime. Kootenay Lake is remarkable in many ways, but one of the unique aspects of this rather remote mountain lake is its lengthy legacy of monitoring. Beginning as early as the 1930s, scientists from as far away as Ontario have made the trek to the lake with their sample bottles and trawling nets, making the time-consuming and often tedious measurements that form the basis of limnology, the scientific study of inland waters.
For the first several years, Larkin's species introduction was written off as a failure since the monitoring found Mysis in only vanishingly small quantities. This was not unexpected. In the lengthy history of aquatic introductions around North America, certain species caught on and others didn't, and it was hard to predict outcomes in advance.
Far off in the East Kootenay community of Kimberley, another interference was taking place. In 1953, Cominco's massive Sullivan lead-zinc mine began producing phosphate fertilizer as a by-product.
In the industrial style of the day, the fertilizer plant was a messy operation, producing large quantities of phosphorous-laced wastewater, which was dumped unceremoniously into the adjacent Saint Mary River. Tumbling down the rapids of the Saint Mary and into the Kootenay River system, this concentrated pulse of phosphorous acted like an ecological steroid. …