Great Lakes Fishery Commission

Updated 2026-08-20 15:01:48

Lake Huron -> 1.0 Salmonine (Salmon and Trout) -> Juvenile Lean Lake Trout Catch Rate

1.2.5. Average catch of wild juvenile lake trout during annual surveys greater than or equal to one individual per 305 m of gillnet per night

The final recovery indicator for Lake Trout is the relative abundance of wild juvenile individuals, which was expected to equal or exceed one individual per 305 m of gillnet per night by 14-24 years after the initiation of stocking.  The preceding threshold was found to result in continued increases in abundance and eventual replacement of stocked fish in Lake Superior (Ebener et al. 1998). An increasing trend in juvenile catch would be an indication of successful spawning by stocked adults and survival of young lake trout.

Catch-per-effort (CPE) of wild juvenile Lake Trout in Lake Huron has only sporadically reached the target threshold of one individual per 305 m of gillnet per night.  During the current reporting period, wild juvenile catch met or exceeded target during 2018-2021 at Drummond Island (Figure 1) but elsewhere rarely exceeded 0.5 fish per 305 m of gill net per night (Figures 2-4).  Considering the entire time series, wild juvenile CPE met the target catch 6 times at Drummond Island (2013, 2014, 2018-2021; Figure 1); once at the Yankee Reef/Six-Fathom Bank offshore reef complex (2002; Figure 1); twice in Michigan waters of the northern main basin (2014, 2015; Figure 2), and once in Ontario waters of the southern main basin (2014; Figure 3).  Wild juvenile CPE has not reached the target catch rate in Georgian Bay or the North Channel since monitoring began in 1987 (Figure 4); however, the second highest catch in each time series occurred in the current reporting period (2018 in Georgian Bay and 2020 in the North Channel).  Catch rates of wild juveniles in the North Channel also increased substantially after 2010 (Figure 4). 

Despite significant spatial and temporal variation in catch rates of wild juvenile Lake Trout in Lake Huron, evidence exists that natural recruitment is occurring across the entire lake.  Continued monitoring will be required to determine if wild production can be sustained and if it can reach levels sufficient to sustain populations in all areas of the lake.

Figure 1. Catch-per-effort (number per 305 m of small mesh gillnet per night) of wild juvenile Lake Trout (total length < 532 mm) in Drummond Island Refuge and Offshore Reefs (6-Fathom/Yankee Reef) in Lake Huron. The horizontal line denotes the target catch-per-effort of 1 fish per 305 m of small mesh gillnet in overnight sets. (Assessment Survey(s): Sault Tribe Gigoonh (fish) community survey andUnited States Geological Survey spring Six Fathom Bank-Yankee Reef gillnet survey ).

Figure 2. Catch-per-effort (number per 305 m of small mesh gillnet per night) of wild juvenile Lake Trout (total length < 532 mm) in Michigan waters of the Northern and Southern main basin, Lake Huron. The horizontal line denotes the target catch-per-effort of 1 fish per 305 m of small mesh gillnet in overnight sets. (Assessment Survey(s): Michigan Department of Natural Resources spring gillnet survey).

Figure 3. Catch-per-effort (number per 305 m of small mesh gillnet per night) of wild juvenile Lake Trout (total length < 532 mm) on the midlake reef complex of Lake Huron. The horizontal line denotes the target catch-per-effort of 1 fish per 305 m of small mesh gillnet in overnight sets. (Assessment Survey(s): Ontario Ministry of Natural Resources offshore index gillnet survey).

Figure 4. Catch-per-effort (number per 305 m of small mesh gillnet per night) of wild juvenile Lake Trout (total length < 532 mm) in Georgian Bay and the North Channel, Lake Huron. The horizontal line denotes the target catch-per-effort of 17 fish per 305 m of large mesh gillnet in overnight sets (Assessment Survey(s): Ontario Ministry of Natural Resources offshore index gillnet survey).