Portage Creek is a small spring-fed tributary located on the Sibley Peninsula, near the hamlet of Pass Lake (40 km east of Thunder Bay). This stream has long been recognized for its quality steelhead fishery. The main branch of Portage Creek is 11 km in length and drains a 6000 ha watershed. Numerous tributaries of the creek drain both the Sibley escarpment and adjacent wetland areas. A small waterfall, located approximately one km from the mouth, slows upstream movement of adult steelhead during their spring migration. Portage Creek sustains its steelhead population by natural reproduction.
During the 1980's, anglers noted that adult steelhead were smaller in size and fewer in number. Over-harvest by recreational fishing was thought to be the most likely cause. From 1991 to 1994, a steelhead assessment study was conducted on the Canadian tributaries of Lake Superior. Portage Creek was found to have an adult steelhead population that showed all the signs of over-fishing.
Anglers (from the NSSA) and Ontario Ministry of Natural Resources (OMNRF) fisheries specialists work in partnership to collect and biologically sample adult steelhead during the spring spawning migration. Each day, over a six-week period (mid-April to the end of May), one or two anglers and an OMNRF specialist catch steelhead using normal angling practices.
The adult steelhead population in Portage Creek has undergone significant fluctuations since the study began in the early 1990s. The estimated adult population size went from 500 in 1992 to over 2000 in 2004 and back down to 400 in 2013.
The spawning migration of Portage Creek steelhead begins in early to mid-April, peaks during early May, and is usually completed by mid-June. Timing of the migration and upstream movement is influenced by flow regimes and water temperature.
Additional notes on conditions that can generate a strong year class of steelhead and resident Brook Trout and Coaster.
The Portage Creek steelhead study hopefully will continue on an annual basis. This data will be used to monitor climate change on a cold water fish community, to evaluate steelhead year class strength, and to utilize Portage Creek as an Index Stream for managing Black Bay's steelhead populations.