Fisheries Act

The Fisheries Act is legislation enacted by the Parliament of Canada, governing the powers of government to regulate fisheries, and to protect fish bearing water. Let us help make sure your project navigates the Fisheries Act today!

What is the fisheries act?

The Fisheries Act regulates the protection of fish and fish habitat. It has specific provisions aimed at preventing the death of fish, and avoiding harmful alteration, disruption, or destruction of fish habitat (commonly referred to as HADD). This legislation applies to all projects that have a potential to result in the death of fish or HADD.

As defined by the Fisheries Act, “Fish” includes all parts of fish, shellfish, crustaceans and marine animals, in all life stages (eggs, sperm, spawn, larvae, spat, juvenile and adult stages). “Fish habitat” is defined as “water frequented by fish and any other areas on which fish depend directly or indirectly to carry out their life processes, including spawning grounds and nursery, rearing, food supply and migration areas”.

Under this legislation, proponents are required to avoid the death of fish and/or HADD by incorporating avoidance and mitigation measures into their projects. If these impacts are unavoidable based on the nature of the proposed works, proponents are required to seek an Authorization from the Minister (or a prescribed authority).

There are two additional provisions in the Fisheries Act that specifically apply to new construction: Fish Passage and Deposit of Deleterious Substances.


Fish passage

The Fisheries Act requires the safe passage of fish. Where the Minister determines it to be necessary for the public interest, they can require the construction of a fish-way or canal to permit the free passage of fish around obstructions across or in any stream. Any projects that have the effect of blocking the stream channel require the construction of a fish-way in a portion of the channel to allow for fish passage. For some projects (such as bridges), a fish-way may be required only during the construction phase; for projects that result in the permanent blockage of streams (such as dams), the fish-way would be a permanent structure requiring ongoing maintenance. A fish guard or screen must be placed at the entrance of water intakes, ditches, channels or canals that are constructed for conducting water from any Canadian fisheries waters for irrigating, manufacturing, power generation or domestic purposes.

Deposit of deleterious substances

The Fisheries Act prohibits any person from depositing or permitting the deposit of a deleterious substance of any type in water frequented by fish or in any place under any conditions where the deleterious substance may enter such water. “Deleterious substance” means any substance that degrades or alters the water and makes it harmful to fish or fish habitat. Common types of deleterious substances are: silt, nutrient imbalances, acid rain, toxic contaminants, pesticides, industrial and municipal waste discharges, and other chemical, physical and biological agents. The Fisheries Act also places a duty on a person to report the deposit of a deleterious substance and to take steps to remedy or mitigate any adverse effects.

Projects near water

Fisheries and Oceans Canada (DFO) has developed several guidance documents intended to assist proponents with the implementation of the Fisheries Act. These guidance documents identify:

  • Types of water bodies where DFO review is not required;
  • Those project activities and criteria where DFO review is not required;
  • Measures to protect fish and fish habitat; and
  • Instructions on how to apply for a DFO project review or Fisheries Act

These guidance documents can be found online at: