There are two MNRF guiding documents (and a compilation* of documents) that provide direction in relation to stocking fish. These include:

  • Guidelines For Stocking Fish In Inland Waters In Ontario
  • Walleye Stocking As A Management Tool – Percid Community Synthesis
  • Ontario Lake Trout Synthesis*

These documents are consistent with MNRF’s Provincial Fish Strategy (OMNRF, 2015b) and MNRF Horizons 2020 (OMNR, 2015a) which are guiding documents that primarily promote self-sustaining naturally reproducing populations and science to support policy and management decision making. The Provincial Fish Strategy (MNRF, 2015b) also recognizes that hatchery-dependent fisheries will, to some extent, continue to play a role in providing fishing opportunities in Ontario.

Fish stocking is a fisheries management tool used for the following reasons:

  • introduce a population into a new waterbody
  • provide hatchery-dependent angling opportunities
  • rehabilitate/restore a population
  • research and assessment

In order to implement a fish stocking program for a given fishery, the waterbody to be stocked needs:

  • habitat that supports survival, growth and potentially reproduction (Aquatic Habitat Inventory Survey)
  • a good supply of forage fish
  • a simple fish community or limited fish community competition
  • to be accessible to anglers
  • to undergo an Environmental Assessment (Introduction Stockings)

PGT stocking

The type of stocking that provides hatchery-dependent angling opportunities is called Put-Grow-Take (PGT) stocking. This type of stocking is often used to divert fishing pressure away from over-fish lakes. PGT stocking should only occur on waterbodies that provide suitable habitat conditions to support growth and survival, and where there is no reliance on natural reproduction to support the fishery. If there is a natural reproducing population, then this type of stocking would not be conducted because it could negatively impact the natural reproducing population by out-competing the natural population. The stocked fingerlings are usually larger than the native fingerlings since they are raised in a hatchery under excellent conditions and can predate on or out-compete the native fish. Also the native fish have adapted to the local environment and will survive better than hatchery fish that have been raised in artificial environments.

PGT stocking should be assessed periodically to determine if habitat conditions remain suitable to ensure stocked fish survive and provide fishing and harvest opportunities.

Rehabilitative stocking

This type of fish stocking is used to help restore severely depleted naturally reproducing populations. The depleted population is augmented for a few years to enhance natural reproduction that will eventually maintain the population. Rehabilitative stocking should ensure that the most appropriate genetic stock is used to restore native populations.

The cause of the population decline must be addressed prior to stocking. Changes in habitat, fish community and fishing pressure may limit recovery and should be assessed prior to stocking. The presence of too many panfish, bass and Northern Pike may prevent recovery because of their ability to predate on the young stocked fish.

If it is determined that stocking is needed to assist in the recovery of a population, a stocking plan that outlines stocking duration, strain/source, age/size, stocking rate, marking, disease/invasive species transfer prevention, stocking methods, assessment and evaluation of project success, should be developed.

Fish stocking in FMZ 18

Six species of fish are stocked annually or biennially across FMZ 18 (Table 15). Additional information on fish species stocked in FMZ 18 waterbodies is available in the Background Information to 2014 Fisheries Management Plan for Fisheries Management Zone 18 (OMNR, 2014).

Table 15: FMZ 18 fish stocking - number of waterbodies stocked by fish species

Adapted from tabular format:

  • lake trout: 19
  • brook trout: 103
  • brown trout: 12
  • rainbow trout: 15
  • splake: 20
  • walleye: 5

MNRF and the Advisory Council reviewed the stocking program for each stocked species listed in Table 16 during the development of species specific goals and objectives. Stocking was identified as a management action in several of the species management strategies. In general, the Advisory Council recommended that the current fish stocking program in FMZ 18 be maintained.

The FMZ 18’s stocking program strategies are:


  • Consider whether rehabilitative stocking seriously degraded walleye populations is appropriate on a case by case basis.
  • Maintain existing PGT walleye lakes, where effective, and explore options for creating new PGT lakes.
  • Determine if water quality and habitat variables in potential FMZ 18 waterbodies are sufficient to provide an opportunity for stocking additional PGT coolwater lakes.

Lake trout

  • Stock PGT lakes to divert fishing pressure away from native lake trout fisheries.
  • Maintain existing PGT lake trout lakes, where effective, to provide alternate angling opportunities, as well as winter fishing opportunities.
  • Reduce angler harvest on naturally-reproducing lakes by encouraging harvest from PGT lake trout fisheries and/or from other species.
  • Consider whether rehabilitative stocking seriously degraded lake trout populations is appropriate on a case by case basis.
  • Use existing genetic stocks when considering rehabilitation stocking.

Coldwater species

  • Monitor coldwater fish populations to assess the growth and survival of stocked fish (BsM, SPIN, FWIN, BTIN, Modified Index Netting Assessments, OSAP), as required.
  • Maintain existing PGT coldwater fish lakes where effective, and explore options for creating new PGT lakes.
  • Utilize BTIN, SLIN, or a modified version of BTIN or SLIN, SPIN, BsM, OSAP, or other electro-fishing survey methods to determine the state of PGT fisheries.
  • Develop public/partner opportunities to measure fishing pressure and harvest rates via public reporting (e.g. volunteer angler diary program) for PGT fisheries.
  • Determine if water quality and habitat variables in potential FMZ 18 waterbodies are sufficient to support stocking additional PGT cold or cool water lakes.

Invasive species and fish diseases

  • Allowing walleye spawn collection from the VHS Management Zone only if the fish are stocked in the zone; or if the fish (brood stock) are tested at the receiving fish culture facility, located outside the zone.