Frequently asked questions: Fisheries Act pollution prevention provisions

The Fisheries Act is a federal legislation, dating back to 1868, which aims to manage and protect Canada's fisheries resources. The Fisheries Act contains requirements for preventing pollution in Canadian waters.

Fisheries Act subsection 36(3) prohibition

How does the Fisheries Act prevent pollution?

Environment and Climate Change Canada (ECCC) is the lead department responsible for the administration and enforcement of the pollution prevention provisions of the Fisheries Act. These provisions (sections 34-40) serve to protect fish as a public resource by prohibiting pollution that could be deleterious to fish.

Subsection 36(3) is the key pollution prevention provision. It prohibits the deposit of all deleterious substances:

  • into water frequented by fish, or
  • to any place, under any conditions, where it may enter water frequented by fish

This applies to all deposits whether they are made directly into water frequented by fish or indirectly, such as a roadside ditch that flows into water frequented by fish. A deposit of a deleterious substance is only authorized pursuant to, and in a manner consistent with, a Fisheries Act regulation or by a regulation under other federal legislation. Fisheries Act regulations include:

Where and to whom does the prohibition apply?

Subsection 36(3) of the Fisheries Act applies to:

  • all Canadian waters that are frequented by fish
  • deposits from Crown, private or indigenous lands into Canadian waters that are frequented by fish
  • all persons including all levels of government (federal, provincial, municipal, indigenous), as well as private sector operators and members of the public
What constitutes a deposit?

Subsection 34(1) of the Fisheries Act defines a deposit as any action that results in a deleterious substance making its way into waters frequented by fish, including:

  • discharging
  • spraying
  • releasing
  • spilling
  • leaking
  • seeping
  • pouring
  • emitting
  • emptying
  • throwing
  • dumping
  • placing
Do fish have to be harmed by the deposit for the prohibition to apply?

The subsection 36(3) prohibition of the Fisheries Act does not require an effect to occur in the receiving area in order for the prohibition to apply. In other words, for a potential violation, it is not necessary for the deposit to cause deleterious effects in fish that inhabit the receiving waters or for the receiving water to become deleterious itself. The deleterious substance needs only to have been deposited and made its way into water frequented by fish, or be deposited in a place under any conditions where it may enter water frequented by fish.

What are my responsibilities concerning the prohibition?

Everyone in Canada must ensure that their activities are managed to prevent the deposit of deleterious substances into waters frequented by fish.

In case of an unauthorized deposit which is likely to be detrimental to fish or fish habitat or of an imminent danger of such an occurrence, the person responsible for the deposit must:

  • immediately notify an inspector, a fishery officer, a fishery guardian or an authority prescribed by a regulation
  • take all reasonable measures to mitigate impacts and prevent further damage
  • submit a written report as soon as possible after the occurrence or learning of the danger of an occurrence to an inspector, fishery officer, fishery guardian or an authority identified in a regulation such as the Metal and Diamond Mining Effluent Regulations and the Pulp and Paper Effluent Regulations
How does ECCC enforce the Fisheries Act pollution prevention provisions?

The Compliance and Enforcement Policy for the Habitat Protection and Pollution Prevention Provisions of the Fisheries Act lays out the principles for application of the pollution prevention provisions of the Fisheries Act in a fair, predicable, and consistent manner.

ECCC’s enforcement officers verify compliance through inspections, gather evidence of alleged violations through investigations, and take appropriate enforcement action if they discover a possible violation.

Enforcement officers may use a range of responses to alleged violations. The following responses are available to deal with violations of the pollution prevention provisions of the Fisheries Act:

  1. issue warnings and directions
  2. recommend that the Minister of ECCC consider exercising the authority to issue an order requiring that a person provide plans or other information
  3. recommend that the Attorney General seek an injunction from a court to stop an alleged violation, or
  4. recommend a file for prosecution to the Public Prosecution Service of Canada

The Fisheries Act provides for significant penalties upon conviction for violations of the pollution prevention provisions of the Act. In the case where a decision has been made to prosecute, and the responsible party has been convicted in court, the Fisheries Act sets out minimum and maximum penalties depending on various factors, including whether the conviction was on indictment or on summary conviction.

Deleterious substances

What is a deleterious substance?

A deleterious substance can be any substance that, if added to any water would degrade or alter the water quality such that it could directly or indirectly harm fish, fish habitat, or the use of fish by humans. Regulations under the Fisheries Act, such as the Pulp and Paper Effluent Regulations, among others, identify certain deleterious substances in the effluent from the regulated facilities and authorize the deposit of limited quantities of those deleterious substances in certain circumstances.

Deleterious substances include substances that could cause lethal or sublethal effects to fish. These effects may include impacts, for example, on growth, respiration, reproduction, larval survival, or normal development.

Any substance with a potentially harmful chemical (e.g. acutely lethal), physical (e.g. water temperature), or biological effect (e.g. deformities) on fish or fish habitat may also be deleterious, including but not limited to:

  • petroleum products (oil, gasoline, diesel, grease, etc.)
  • chemicals
  • pesticides
  • heavy metals
  • industrial effluents
  • cleaning supplies such as bleach and detergents
  • wood preservatives
  • paint
  • chlorinated water
  • untreated or undertreated wastewater effluent
  • fertilizer run off
  • livestock waste
  • sediments
  • suspended solids
  • thermally altered water (cooling water)

See section 34 of the Fisheries Act for the full definition of deleterious substance.

How to determine if a deposit contains a deleterious substance?

There are a broad range of tests that can be used to determine if a deposit contains a deleterious substance. Approaches could include chemical characterizations or toxicity tests. Chemical characterizations use lab based testing to identify individual deleterious substances within a sample of the deposit.

Toxicity tests are used to determine the potential effects of a mixture of substances in an effluent. Common toxicity tests used to determine if a discharge is deleterious are the test methods titled “Biological Test Method: Reference Method for Determining Acute Lethality of Effluent to Rainbow Trout (EPS 1/RM/13)” and “Biological Test Method: Acute Lethality Test Using Threespine Stickleback (Gasterosteus aculeatus) (EPS1/RM/10)”. The tests are designed to determine whether or not the fish will die when subjected to a particular substance, or mixture of substances such as effluent, for a specified time period.

Other tests could be used as well, such as sublethal tests that measure whether an effluent affects growth or reproduction of the test species.

A substance may also be considered to be deleterious based on evidence of fish kills near a deposit or other impacts that can be linked to a deposited substance, enforcement sampling result, and/or expert opinions concerning toxicity of the substance.

Water frequented by fish

What is meant by ‘water frequented by fish’?

Water frequented by fish means Canadian fisheries waters, which includes all:

  • waters in the Canadian fishing zones
  • waters in the territorial seas of Canada
  • internal waters (waters within Canada’s landmass), including waterways such as:
    • rivers
    • lakes
    • creeks
    • canals
    • other such water bodies
What is meant by ‘fish’?

Under the Fisheries Act, the definition of fish includes finfish as well as a range of other organisms that live in water. The definition of fish also comprises all stages of the life cycle of fish (e.g. from the egg to adult) and includes all parts of fish, such as shellfish, crustaceans, and marine animals.

Do fish have to be present in the water at the time of deposit?

For the Fisheries Act to apply it is not necessary for the water to be frequented by fish on a continuous basis or for fish to be present at the time and in the location of the deposit. If fish use the water, even if only annually for a short period, then such water qualifies as “water frequented by fish.” Waters may be used by fish for, but not limited to:

  • migration
  • feeding
  • spawning
  • developing

In considering a potential deposit, it is important to take into account the fact that both water and fish move and relocate. Therefore, if there is the potential for there to be fish in waters at any time or in connected waters, such as tributaries, then the waters are considered to be frequented by fish.

What if the deposit was not made directly to ‘water frequented by fish’?

Many activities may result in deleterious substances either entering or being placed in a location where they may enter water frequented by fish; not all of which are readily apparent. For example, ditches may connect directly or indirectly to waterways, storm drains may empty into local waterways, and some floor drains in some commercial premises have outfalls which release either directly or indirectly to local waterways.

The Fisheries Act prohibition applies to any place where deposit of deleterious substances may enter waters frequented by fish, even indirectly through

  • infiltration of groundwater
  • surface runoff
  • overflow of an area or container which leads to water frequented by fish

Contact us

For specific information related to the enforcement and administration of the pollution prevention prohibitions of the Fisheries Act, contact us.


In case of an inconsistency between this page and the Fisheries Act or any of its regulations, the Act or regulations prevail.

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