In 2016, the Canadian province of Ontario installed its first Riverwatcher fish counter to monitor salmonid passage at Corbett’s Dam on the Ganaraska River. The Lake Ontario Management Unit (LOMU) of the Ontario Ministry of Natural Resources and Forestry (OMNRF) funded the purchase and installation of the equipment to collect data on the population dynamics of native Atlantic salmon, which had been extirpated from the lake and are now the subject of a reintroduction effort. The Riverwatcher can also provide information on non-native Coho salmon, Chinook salmon, and steelhead that have been introduced into the lake. A primary goal is to determine whether Atlantic salmon reintroduction efforts are resulting in natural spawning in the tributaries of Lake Ontario, which can help inform restoration goals for the Ganaraska River.
The Riverwatcher provides an automated solution to help LOMU biologists document counts of fish passing upstream and downstream, fish condition, species, size, presence or absence of adipose fins (with clipped fish suggesting hatchery origin), presence or absence of external tags, passage timing, and sex. This information had previously been collected by hand using an upstream trap that agencies also used to collect Chinook salmon for hatchery spawning activities. However, the infrequency of trapping events left gaps in the fish count data. Furthermore, an electronic fish counter used previously could not differentiate between the various salmonid species passing through the Corbett’s Dam fish ladder. In contrast, the Riverwatcher can collect the needed information continuously without the need to handle fish, and can provide species-specific data that are crucial for Atlantic salmon restoration efforts. Following the installation of the Riverwatcher, FISHBIO staff traveled to Ontario to provide training on Riverwatcher operation and data analysis.