By Lauren Stoot, Field Biologist, Canadian Wildlife Federation
The 2014 Ottawa River eel project, led by Canadian Wildlife Federation, marked the 3rd year of the program. Throughout previous years, the focus has been aimed at adult barrier passage and habitat to better understand the biology of American eels in the Ottawa River. For the 2014-2015, we switched focus to juvenile upstream passage. Together with partners, the Arnprior & District Fish and Game Club and the Ontario Ministry of Natural Resources we were able to complete a variety of objectives this season.
Throughout this summer, our team of researchers tested a variety of tactics to catch juvenile American eels in areas near barriers. Baited eel traps were deployed around Chats Dam near Fitzroy and below Chaudière Falls in downtown Ottawa. In addition, we also continued to operate our temporary eel ladder, located in the Fleet St. Pumphouse channel. Although intensive effort, we did not catch any eels throughout these reaches.
The highlight of the season was a successful trap and transfer program which resulted in the addition of over 400 juvenile American eels being transferred into the Ottawa River. A collaborative effort between Hydro Quebec, Ontario Ministry of Natural Resources and Forestry (Pembroke and Kemptville Offices), Quebec Ministry of Natural Resources and Wildlife, Arnprior and District Fish and Game Club, Algonquins of Ontario, Milieu Inc. and Canadian Wildlife Federation pit tagged 420 juvenile American eels, taken from the Beauharnois Generating Station eel ladder and released them in the Ottawa River above the Carillon Dam, near Chute-A-Blondeau,Ontario. The transfer of eels above the Carillon dam was the first of its kind in the Ottawa River and allows these individuals a successful upstream passage to the reach between Chaudière Falls complex and Carillon dam.
As part of a two year study in which we will use acoustic telemetry to track juvenile eels as they move up the Ottawa River, specifically in and around hydro facilities, the acoustic array network and various tag options were tested at locations between Ottawa and Carillon dam. Various acoustic telemetry tags were tested to best determine the optimal tag for this project and detection range of the receivers. Throughout the 2015 field season, juvenile eels will be implanted with acoustic tags in order to determine their movement in the river and passage attempts at Chaudière Falls in order to help inform potential passage solutions.
We continued to monitor radio-tagged adult American eels in the Lac des Chats region. Through both boat and aerial surveys we were able monitor the presence of individuals and assess timing of downstream passage along with passage success.
Our work was also presented at many local outreach events including Ottawa’s Fish Migration Day and a presentation to the Macoun Club of the Ottawa Field Naturalists Club. Work will continue throughout the 2015 field season with a focus on determining the upstream passage options and preference at Chaudière Falls complex which can help researchers better understand the difficulties of upstream passage and improve upstream passage options.