DFO marine finfish aquaculture audit activities in British Columbia

Fish health audits at salmon farms in British Columbia

Our specialized aquaculture veterinarians determine the overall health status of salmon farms based on input from our biologists, independent laboratories, and information provided by licence holders.

Every 3 months, our biologists visit a random selection of salmon farms and ensure that half of all active farms are visited in each aquaculture management zone. During these audits, they check the health of farmed salmon by taking samples to test for diseases and pathogens of concern, make observations, and check on-site records. They also make sure farm employees are following health management plans and the legal conditions set out in their licences.

Fish health testing, including checks for viruses, bacteria, and changes in fish tissue, is carried out by an accredited third-party animal health laboratory. The results of these tests, combined with information gathered by our biologists during their visits, are reviewed by our veterinarians, who then determine the health status of the farm.

Health categories

Veterinary diagnoses resulting from fish health audits are assessed based on the following categories:

Non-infectious environmental disease

These are health conditions that farmed fish can contract from their surrounding environment. They can include exposure to environmental toxins, fungal infections, or gill problems linked to environmental stressors. These conditions are not spread to wild fish populations.

Bacterial disease

Most infectious fish health issues are caused by common bacterial diseases that can be treated. About two-thirds of these cases are due to mouth rot, a condition often seen in farmed Atlantic salmon, usually soon after they move into seawater. While mouth rot or tenacibaculosis (caused by the same bacteria) has been found in farmed Pacific salmon, it is extremely rare. Other bacterial diseases that can affect farmed salmon include Bacterial Kidney Disease (BKD), Salmonid Rickettsial Septicemia (SRS), and furunculosis. These bacteria all exist naturally in Pacific Northwest waters.

Parasitic disease

These are diseases that are caused by parasites, which are naturally occurring organisms that live on or inside farmed fish and feed on them. Examples of common parasites include flukes and microscopic organisms called protozoans.

Reportable disease

Some diseases are especially important because they can affect aquatic animal health or impact the Canadian economy. These diseases are closely monitored and managed by the Canadian Food Inspection Agency (CFIA). Fish farming companies are required by law to report any signs of these diseases to the CFIA. If a reportable diseases is suspected, the CFIA will investigate and decide what actions are needed. This could include testing fish, restricting movement, controlling the spread, or removing infected fish if necessary. You can find the full list of these reportable diseases on the CFIA website.

Undetermined

In some cases, it’s not possible to identify a single cause of fish morality on a farm. This can happen when there aren’t enough samples to test, or when deaths are higher than usual but testing does not point to a specific disease.

Other

This category includes diseases that are not listed by the CFIA, are uncommon, or don’t fit any of the other categories. For example, this category includes jaundice syndrome.

Data

The graph below shows the veterinary diagnoses resulting from fish health audits conducted at salmon farms in British Columbia, based on the above categories. Diagnoses represent the presence or absence of disease in a group of fish, not in individual fish. In some cases, more than one diagnoses may be found during an audit. When this happens, only the most significant is shown on the graph.

Detailed results of each fish health audit, including laboratory test results and information specific to each farm, are available at Results of DFO fish health audits of British Columbian marine finfish aquaculture sites, by facility.

Long text version

DFO fish health audits at salmon farms in B.C., 2011 to 2023

	No significant disease(s)	Undetermined	Non-infectious environmental disease(s)	Bacterial disease(s)	Parasitic disease(s)	Reportable disease	Other	Number of active farms	Number of audits
2011	44	7	0	13	0	0	1	91	65
2012	91	12	0	14	0	0	0	79	117
2013	83	12	0	22	0	0	2	72	119
2014	90	7	1	12	1	0	0	77	111
2015	83	8	0	26	3	0	0	79	120
2016	75	17	1	24	0	0	0	77	117
2017	92	9	5	14	0	0	0	78	120
2018	78	5	8	26	2	0	1	77	120
2019	103	3	1	17	0	0	0	81	124
2020	71	4	5	11	0	0	1	75	92
2021	107	6	0	13	2	0	1	72	129
2022	99	13	1	7	0	0	0	59	120
2023	79	9	3	11	0	0	0	46	102

Sea lice audits

This graph shows the outcomes of Fisheries and Oceans Canada (DFO) audits of industry sea lice counting methodology at marine finfish aquaculture facilities in BC. DFO’s conditions of licence for marine finfish aquaculture contain sea lice monitoring, reporting and sampling requirements to determine sea lice abundance on farms. DFO audits industry’s sampling methodology and counting sensitivity to ensure that industry-reported counts are reliable and accurate.

The various licence conditions around sea lice on farmed fish seek to minimize the potential exposure of wild and farmed fish to sea lice from farms. DFO biologists and veterinarians conduct regular assessments throughout the year to verify the accuracy of licence holders’ procedures and reporting.

DFO’s random quarterly sea lice audits coincide with one of the licence holder's numerous scheduled counts. During an audit, farm staff count lice on half of the sampled fish and DFO staff count lice on the other half. In 2020 and 2021, due increased safety protocols in response to the Covid-19 pandemic, side by side counts were not completed. Audit counts were completed only by DFO and these results were assessed against industry reporting and record keeping to determine compliance.

A statistical comparison is performed to determine the level of agreement between DFO counts and industry counts. If there is agreement between the counts, and DFO staff observed counting methodology that meets requirements outlined in licence conditions, then the licence holder is in compliance. If DFO staff observed counting methodologies that do not meet requirements outlined in licence conditions and/or there is not agreement between the counts, then follow-up actions may be required.

In some cases, where there is not statistical agreement between counts but DFO staff observed counting methodology that meets requirements outlined in licence conditions, it is assumed that the difference in counts can be attributed to sample selection, or chance, and no compliance follow-up actions are required.

Detailed information on specific sea lice audits can be found in the report, DFO sea lice audits of BC marine finfish aquaculture sites.

Long text version

Year	Statistical agreement	Statistical difference, methodology meets requirements	Statistical difference, follow-up action taken	Statistical comparison not possible (Covid-19)
2011	34	1	0	NA
2012	39	2	0	NA
2013	37	0	1	NA
2014	32	3	0	NA
2015	39	3	4	NA
2016	37	3	1	NA
2017	39	2	5	NA
2018	42	7	0	NA
2019	47	4	0	NA
2020	7	3	0	18
2021	0	0	0	50
2022	26	2	1	11
2023	26	2	0	0
2024	24	6	0	0
2025	34	2	0	0

Benthic audits

This graph shows the results of benthic audits that are conducted at marine finfish aquaculture sites in British Columbia. To ensure that acceptable levels of environmental impact are not exceeded, monitoring of the sea floor is conducted during peak production, when the level of impact is expected to be highest.

Industry conducts benthic surveys and submits results to the Department. DFO biologists audit a portion of these facilities and compare the results to industry-submitted data. If there is disagreement between DFO and industry results, then DFO results are used and additional industry monitoring may be required. To better understand seasonal and long- term trends, DFO also conducts information-gathering surveys throughout the production cycle and at times when industry is not required to monitor.

Detailed information on specific benthic audits and industry surveys can be found in the reports, Results of industry benthic monitoring of British Columbia marine finfish aquaculture sites and Results of DFO benthic audits of British Columbia marine finfish aquaculture sites.

Long text version

Year	Agreement between DFO and industry results	Disagreement, DFO results used
2011	3	1
2012	9	1
2013	8	1
2014	12	1
2015	9	2
2016	15	0
2017	11	1
2018	14	0
2019	12	1
2020	12	0
2021	13	1
2022	11	0
2023	5	5
2024	9	1
2025	9	2