When an Environment and Climate Change Canada enforcement officer becomes aware of an alleged offence under the pollution prevention provisions of the Fisheries Act, they collect information to verify compliance with the Act, or as evidence of an offence. Under the Act, it is prohibited to deposit a deleterious, or harmful, substance into fish-bearing water or any place where it can enter that water. As part of an inspection, officers may decide to collect samples of spilled substances or effluents and send them to our laboratories to perform toxicity testing.
Environment and Climate Change Canada laboratories are accredited under international quality management standards for environmental testing. From the moment a sample is collected until it is analyzed, records are kept to show the movement of the sample from collection to testing, interpretation, and results. Enforcement officers collect samples in the safest way possible; this means that sample sizes can vary, depending on how easily and safely they can be collected.
Once the laboratory receives the sample, it is logged into a database and tested within five days of sample collection to ensure accuracy of results. Toxicity tests are conducted by exposing either Rainbow Trout or Daphnia magna, a water flea, to the sample of the suspected deleterious substance. The trout are exposed for a 96-hour period, and the Daphnia magna for a 48-hour period. A sample is considered toxic to fish if it kills more than 50 percent of the fish or Daphnia magna when it is not diluted. However, a substance does not have to kill fish to be considered deleterious, or harmful, to fish.
