Currently, farmed salmon are raised in coastal net pens, where they’re in direct contact with the surrounding marine environment. This open access results in at least five distinct problems when farming salmon, that often aren’t native to the area:A 2006 study by The Fraser Institute, Escaped Farmed Salmon: A Threat to BC's Wild Salmon?, came to some starkly opposite conclusions:
When farmed salmon escape from ocean pens, they threaten wild salmon and other fish by competing with them for food and spawning grounds.
- There is little risk of Atlantic salmon establishing viable populations in the Pacific northwest;
- The number of escaped salmon has not increased radically as the production of Atlantic salmon has increased;
- Cross breeding of Atlantic salmon and Pacific salmon is highly unlikely, as they are different species (Onchorynchus vs Salmo)
- The numbers of public hatchery releases far exceed the accidental release of farmed Pacific salmon and will have a great impact; and
- The transfer of disease between escaped farmed salmon and wild salmon is unlikely.
The authors noted that even with the fallowing that occurred in 2003 the biomass of farmed salmon in the Broughton during this period was consistent with levels in the preceding years. Climate regime shift and environmental conditions may have contributed to increased sea lice production as well. Their overall conclusion: conditions in the marine ecosystem around salmon farms in the study area in 2003 suggest that it is possible to have sustainable wild and farmed salmon in a common ecosystem.
Finally, Escaped Farm Salmon: Environmental and Ecological Concerns, a report compiled by Natural Resources Consultants Inc. for the Salmon Aquaculture Review (SAR) concluded:
- The potential establishment of Atlantic salmon populations in Pacific rivers and streams as a result of reproductive success and survival of progeny in a series of years is considered unlikely.
- Existing farm technology and practices have probably contributed to the recent reduction in the number of reported fish escaping from farms. Nevertheless, a standard process for preventing escapes, recapture or escaped fish, and more comprehensive reporting could lead to further escape reductions.
Next up, fish poop:
As the result of a study completed for the Salmon Aquaculture Review, the province of British Columbia enacted the Finfish Aquaculture Waste Control Regulation (FAWCR). The regulation acts to mitigate and monitor the impacts of wastes from salmon farms:
Waste from most salmon farms is released directly into the ocean.
The regulation includes provisions for farm registration, pre-stocking sampling, domestic sewage handling, best management practices, monitoring and reporting, remediation, offences and penalties.That's certainly a lot different than the picture Monterey Bay painted of salmon farms directly releasing waste into the ocean and not caring. Instead, the province relies on scientifically-derived regulation to protect the environment.
Farm registration under the regulation has been completed, and compliance and inspection programs conducted by MOE and MAL are underway.
The standards are “performance-based,” meaning that specific thresholds for defined chemical and biological indicators should not be exceeded at any time during production (previously, production levels and feed usage were regulated, rather than their actual impact on the environment).
Farmers must carry out specific monitoring/remediation activities on the farm if the indicator levels are exceeded.
Indeed, this is a concern (and it can go both ways). That's why all salmon culture operations both public and private must have a Fish Health Management Plan (FHMP) which is reviewed by the Ministry of Agriculture and Lands. Upon return to the company, the fish health staff of each are trained using the procedures developed in the manual and enforce its use across the organization.
Parasites and diseases from farmed salmon can spread to wild fish swimming near the farms.
The majority of culture operations in BC maintain a broodstock program where all milt and egg donor fish are screened for pathogens and disease to ensure that any possible illnesses are not passed to the next generation. Fish are vaccinated prior to seawater entry against common fish disease – this not protects the farmed fish from getting infections from the environment and wild fish but also obviously protects the wild fish from getting infected from the farmed salmon.
Additional protection against introduction of exotic pathogens is provided for in the National Code on Introductions and Transfers of Aquatic Organisms.
To answer this question, we consulted with Dr. Sonja Saksida at the Centre for Aquatic Health Sciences. She passed the following onto us in a note.
Salmon farmers may use pesticides and antibiotics to control outbreaks of disease among the fish. When consumers eat this fish, the residues from the chemicals may affect their health or interfere with medicines they’re taking.
"In BC we don't use pesticides - we just use medicines - all currently used products in Canada (antibiotics and sea lice products) are licensed and regulated by the Veterinary Drug Directorate (VDD) of Health Canada, not the Pest Management Regulatory Agency which regulates pesticides," Saksida wrote in a note to BC Salmon's Mary Ellen Walling.
SLICE® is an approved drug in most other major salmon aquaculture countries including Norway, Scotland, Ireland and Chile. In Canada SLICE® has been in the drug registration process since 2000 and as of mid-2008 is still unregistered. As a result, access to the therapeutant has only been available under a special release (an emergency drug release - EDR) from the Veterinary Drug Directorate (VDD) - a branch of Health Canada. The veterinarian responsible for a particular fish farm must submit a written request to VDD for an emergency drug release to Ottawa. The veterinarian must specify the location of the farm, the number of fish to be treated, the size of the fish and the amount of drug required. After verifying the information, VDD evaluates the request and upon approval authorize the manufacturer of the drug to sell a specified quantity of a drug (e.g., SLICE®) to the veterinarian to medicate the infested fish. Only veterinarians can access veterinary drugs through the EDR program. The treatment regime for SLICE® is the same as that used in other regions (seven day treatment at 0.05 mg/kg fish/day).The following is from the Health Canada website:
Health Canada has recently amended its policy on permitted SLICE residues after completing a reassessment of available data. SLICE continues to be approved for limited use under the EDR program. Under the program, the modified Maximum Residue Limit (MRL) of 42 parts per billion (ppb) has been established. This compares to established MRLs in the European Union of 100 ppb. In addition, a revised WP has been established at 68 days from the latest treatment when used at a water temperature of 5 °C or greater."So in Canada the permitted residue levels is lower than in Europe, and withdrawal periods are longer," wrote Dr. Saksida. "For comparison, withdrawl levels in Europe for SLICE are 0 days (Scotland and Ireland), 175 degree days (i.e. 7.5days at 10C water temperature). In Canada the withdrawal period is 68 days," she wrote.
"With regard to antibiotic usage – all antibiotics used in aquaculture are only available through prescriptions obtained by a veterinarian. There are stringent withdrawal periods associated with all antibiotics used in aquaculture in Canada. The Canadian Food Inspection Agency (CFIA) closely monitors and routinely tests fish to ensure that they are clear of residues."
Thanks to Dr. Saksida for that clarifying information.
Simply put, that figure is old news. Currently, farmed salmon operations are converting fish meal to edible protein at a rate closer to 1.2:1. Due to protein substitutes, this will soon be less than 1:1, which means salmon farms will be a net protein producer -- a detail that has escaped Monterey Bay's Seafood Watch program since they last looked at the industry in 2004. Lastly, this feed is only taken from sustainable sources.
It takes three pounds of wild fish to grow one pound of farmed salmon. As a result, farming salmon actually uses more fish than it produces, which puts more pressure on wild populations.
We've passed research buttressing these claims onto MBA, but we've yet to get a response. When and if we do, we'll pass it on.