By Maja Cvetkovic, Carleton University’s Fish Ecology and Conservation Physiology Laboratory (FECPL)
Reprinted with permission from www.fecpl.ca
Last week post-doctoral researcher Dr. Jon Midwood led a group of volunteers from the FECPL lab and Ottawa community on a hunt for juvenile Muskellunge and Northern Pike in the Rideau River.
Ottawa can boast about its urban muskie population in the Rideau river, which winds through the city and provides unique habitat where both muskie and pike populations exist.
There is currently an active tracking project for adult muskie and pike in the Rideau River (click here to read about the Brewer Pond project), but the last time surveys were conducted for the juvenile fish was in 1999. With the International Muskellunge Symposium fast approaching (at Carleton, August 14th & 15th) and the Brewer Park Pond habitat creation project slated to break ground in mid-August, it seemed like a perfect time to get back out there to sample.
In association with Rideau Valley Conservation Authority (RCVA) and the Ottawa Chapter of Muskies Canada, FECPL members seined 12 sites on July 21st and 22nd. The main objectives were to 1) confirm muskies are still successfully spawning by finding young-of-year (YOY) and 2) determine if habitats near Brewer Pond are being used as nursery habitat by these YOY.
The surveys were a success. In the 12 sites that were seined, we found 14 juvenile muskies (averaging 10 cm in length) and 1 juvenile pike (130 cm in length). Esocids (either pike or muskie) were found in 8 of the 12 sites. It was especially gratifying since most of the volunteers seining ended up wading past the chest wader line and becoming thoroughly wet. Luckily it was a hot week so a thorough soaking was welcome despite the damp commute home. Well worth it!
Of course numerous other species were caught, including juvenile and adult Rock Bass, Pumpkinseed, Smallmouth Bass, Largemouth Bass, Walleye, Yellow Perch, as well as Golden Shiners, Blackchin Shiners, and some adult Northern Pike (a nice surprise to find in a seine net!). It was great to see the high level of recruitment of juvenile fish, especially in some of the embayments near Bronson St. Bridge that were created a decade ago for fish nursery habitat by the Ottawa Chapter of Muskies Canada in conjunction with RVCA/City of Ottawa.
So what does this tell us? First, it seems that muskies are successfully spawning in the Rideau River, and secondly, the habitats near Brewer Park Pond are being used as nursery habitat. Armed with this knowledge, it may be possible to link the tracking data from the spawning season with the locations where muskies were found to help narrow in on potential spawning locations.
Also, the presence of YOY muskies near Brewer Park Pond means that habitat remediation and creation work slated for late this summer will take place near an existing population. This population might be able to serve as a source for colonization of the newly created habitat (fingers crossed).