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The Cap Santé fishway
The first case study is a fine example of what the IchtyoS system has to offer. During the final phase of its development, a test of its effectiveness in actual conditions of use was conducted at the Cap Santé fishway on the Jacques Cartier River, near Québec City. To validate the information recorded by the system, it was placed for several days downstream from a point where fish were already counted and measured by hand. The IchtyoS system recorded a high number of passages, a number of which were downward migrations. The sum of these events (upward minus downward migrations) nonetheless corresponded to the manual counts performed upstream. These data revealed that each time the elevator of the manual counting system was activated, a change in water flow resulted, leading to the downward migration of salmon which had already entered the fishway. Based on this observation, it was possible to correct the problem. In this example, the IchtyoS system revealed an unsuspected problem which was greatly reducing the fishway's effectiveness.
The Gouffre River
The Gouffre River is a natural stream with no fishway, in which salmon migration had not yet been monitored. It is particularly capricious, making it difficult to install a conventional counting fence, since emergency removal of a cage is a delicate operation. In this context, the IchtyoS system had two major advantages: the lightness and relative mobility of the installed structure in the event of flooding, and the fact that the fish are not caged, but circulate freely through the system. Indeed, because salmon often migrate at night, when the operators are not present, they would spend hours in the cage, increasing the likelihood of poaching. With the IchtyoS system, the natural timing of fish migrations is respected, thereby reducing stress and the risk of poaching.
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The Ouelle River
The Ouelle is another temperamental river, with highly variable flow. Its average depth is also low and the water temperature is at the limit of what salmon can tolerate. These conditions pose extreme constraints for monitoring fish migrations. Indeed, given the high temperature, the use of a traditional counting cage results in significant stress, since the salmon are kept for hours in water containing little oxygen. Moreover, the shallow water limits the possibility of installing passageways at a reasonable distance from the bank, complicating counting operations and increasing the risk to operators. When we installed the IchtyoS system, we first modified the cage that had been used previously, to make a protective structure against the copious debris that comes down this river. Because the system is automated, risks to operating personnel are considerably lower. Moreover, it poses no obstacle to fish migration, allowing fish to pass through it day and night, and thereby greatly reducing the risk of poaching.
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The Denil type fishway at the McDougall Dam
The installation of the IchtyoS system in the Denil type fishway at the McDougall Dam on the Jacques Cartier River helped in understanding another problem. At this site, there is a complex of three dams and a rapids considered to be at the limit of what salmon are capable of climbing. The downstream dam is equipped with a fishway where fish are hand-counted. Then come the rapids, followed by the McDougall Dam and, farther upstream, the last dam, also equipped with a manual counting station. But only a few fish are counted at this station, whereas the station below the rapids records a greater number. When the McDougall Dam fishway was equipped with an IchtyoS system, it was observed that below a certain water flow, salmon cannot climb rapids and thus do not reach fishways located upstream.
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