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Big Rideau Lake Association - BRLA

Environmental Programs | Past Programs | Lake Trout Tracking Program

The BRLA in cooperation with the Ontario Ministry of Natural Resources and the Ontario Federation of Anglers and Hunters initiated a three-year study of Lake Trout in Rideau Lake. The objective of the study was to determine the extent of optimal lake trout habitat and spawning area in the lake by monitoring the movement of trout throughout the study period.

This program ended in 2002.

trout Photo: BRLA

TRACKING STUDY
 

The BRLA in cooperation with the Ontario Ministry of Natural Resources and the Ontario Federation of Anglers and Hunters has initiated a three-year study of Lake Trout in Rideau Lake. The objective of the study is to determine the extent of optimal lake trout habitat and spawning area in the lake by monitoring the movement of trout throughout the study period.

Of special interest is the behaviour of mature fish during the spawning season in late October and early November when they gather in shallow water on gravely shoals to lay and fertilize their eggs. Since the lake trout population is made up of both native and stocked fish, the study hopes to determine if the stocked fish are reproducing in the lake or possibly interbreeding with the native species. The results may help to identify shoal areas, which may be enhanced or improved for the future. The study information will also be used as a baseline for future habitat monitoring programs.

To accomplish these goals, the study will rely on sonar tracking of selected fish. In late October of 1998, ultrasonic transponders were surgically implanted in five mature lake trout by a team of BRLA workers and volunteers. The fish were captured during the annual egg-gathering program conducted by MNR hatchery personnel.
   
The fish are first sedated by placing them in a special solution for a short period. A small incision is made on the underside of the fish just to the rear of the pectoral fins. The transponder is then carefully inserted into the body cavity. The incision is closed with six to eight stainless steel surgical staples.
   

Incision being made on the underside of the fish.

Transponder being inserted.
The incision is closed with stainless steel surgical staples.
   
The fish is revived by manually moving it in the lake water until it can swim away on its own. Fall and winter tracking has shown that all have survived to date.
 

The tracking is accomplished by employing a direction sensitive hydrophone attached to an ultrasonic receiver transported by boat or snowmobile as the season dictates.

Each fish transmits a unique sonic signal. In addition to location, the transponder can provide water temperature or depth information. The exact location of each tracked fish is then recorded by a global positioning system, which is then entered into a computer for analysis.
   
In the spring of 1999, the BRLA implanted an additional 10 fish with transponders. Each of these 10 fish will be tracked several times per week over the study period.
 

ANGLER DIARY REPORT
 

A group of volunteer anglers who regularly fish the Rideau for lake trout have been recruited to keep a dated diary of the fish that they catch throughout the trout season, June to September. The anglers will record the date and time, the weather conditions and the size and weight of the fish. By observing which, if any, fins have been clipped from the fish, the anglers will be able to determine whether the fish is a true native, a stocked fish from eggs from another lake or a hatchery fish reared from eggs culled from the Rideau.

Further details about the Angler Diary are available.
 

OTOLITHS
 

During the 2000 season, a lake trout ageing study was implemented to determine the validity of the stocking data, as there have been some discrepancies in the MNR stocking data. Anglers were asked to collect and submit heads and scales from fish they caught. Fisheries staff removed the otoliths from the collected heads. In, October of 2000, fisheries staff aged 140 fish by the otoliths and scales that were collected. See the attached Angler Diary report for the results of the ageing study.

Further details about otoliths are available.

 
last updated:
04/06/05 2:27 PM 		Big Rideau Lake Association - BRLA | PO Box 93 Portland, Ontario K0G 1V0 Canada
Telephone: 1-613-272-3629 | E-mail: