Public Reporting on Aquaculture - Marine Mammals

Fisheries and Oceans Canada (DFO) is the agency responsible for the management, including conservation and protection, of marine mammals in Canada. Provisions in the Pacific Aquaculture Regulations allow for the Department to license fish farms to undertake predator control of marine mammals that pose an imminent danger to the aquaculture facility or human life, should reasonable deterrent efforts fail.

Fish farming in British Columbia has increased substantially over the past few decades, both in the number and their spatial distribution. Over this same period, seal and sea lion populations have also increased.

The relative density and abundance of fish found in aquaculture facilities can attract marine mammals such as seals and sea lions, which may come to identify these facilities as potential sources of food. The resulting interactions that arise can lead to losses of fish and damage to facilities and equipment. In some instances, the safety of facility personnel can also be jeopardized.

The Conditions of Licence for aquaculture site in B.C. require facility operators to have a Predator Management Plan in place, including measures to deter and minimize marine mammal interactions at fish farms. In addition to protecting farmed stocks and facility infrastructure, these measures aim to protect marine mammals by reducing the number of accidental drownings that can occur when these animals attempt to feed on the farmed fish and become entangled in lines and nets.

DFO is working with industry towards the development and improvement of mitigation measures to prevent interactions and control predators that do come into contact with fish farms. At present, the most common system includes anti-predator netting, surrounding the entire facility structure on all sides and from below. DFO biologists conduct site audits and inspections to ensure that licence holders are complying with their licence conditions and implementing elements of their predator management plans in an effort to minimize interactions between marine mammals and aquaculture facilities.

In the event that mitigation measures and deterrence efforts fail, and in instances where California sea lions or harbour seals represent an imminent danger to the aquaculture facility or to human life, they may, by regulation, be lethally removed in a humane manner. Under special circumstances, additional licences can be obtained to lethally control other species. These instances are reviewed on a case by case basis by DFO biologists and the outcomes are carefully monitored.

Historical information on Nuisance Seal Licences

Prior to December 19, 2010, the authorization to humanely destroy marine mammals that were interacting in a dangerous manner with marine aquaculture facilities was issued through a Nuisance Seal Licence, pursuant to subsection 4(1) of the Marine Mammal Regulations.

On December 19, 2010, aquaculture sites were issued licenses under the Pacific Aquaculture Regulations and the Nuisance Seal Licenses for aquaculture facilities were discontinued. The Conditions of Licence that accompany finfish aquaculture licences issued by Fisheries and Oceans Canada include provisions similar to those previously contained in the Nuisance Seal Licenses, and outline the circumstances under which a marine mammal may be humanely destroyed at an aquaculture facility.

In 2003, the Steller sea lion was designated by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as a Species of Special Concern which includes those species that are particularly sensitive to human activities or natural events but are not endangered or threatened. Steller sea lions were included in the Nuisance Seal Licences until 2003; however, in response to the COSEWIC listing, the licenses issued in 2004 were modified to remove Steller sea lions. Aquaculture facility operators must apply for special permission to lethally remove any marine mammal species other than harbour seals or California sea lions.

The chart below shows the annual numbers of marine mammals killed in B.C. at aquaculture facilities from 1990 to 2010, prior to the introduction of the Pacific Aquaculture Regulations.

The data shows a generally declining trend in the number of marine mammals that were killed annually. From a high of 577 harbour seals in 1995, numbers decreased by more than 90 percent to 56 in 2010. California sea lion kills peaked in 2000 at 243 and declined steadily until 2008.  

Fisheries and Oceans Canada has established a working group, including members of Aquaculture Management staff and industry representatives, to review aquaculture practices as they relate to marine mammal interactions, and to explore suitable, non-destructive deterrent measures to reduce potentially harmful interactions at aquaculture sites.  

It is anticipated that new deterrence methods and improvements to facility infrastructure will result in a significant decline in the number of lethal interactions in the near future.