Assessment
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Environmental Assessment Office |
Salmon Aquaculture | |||
As outlined in Chapter 2, commercial salmon farming in B.C. has several distinct operational stages, including egg incubation and hatching, initial rearing of young salmon in freshwater, and final grow-out in marine net-cages. At each of these stages, salmon may escape into the freshwater or marine environment. During 1994–1995, the reported annual escape was 61,996 farm salmon (57,846 Atlantic, 3,650 chinook, 500 coho).
The factors contributing to escaped farm fish include: deficient farm operations, weather (e.g., storm damage to net pens), predators, accidents (e.g., inadvertent release during transport), and vandalism. Overall, weather has been the most significant contributor to fish escapes. However, over time, the relative importance of weather has been declining and the primary factors contributing to farm salmon escapes in recent years have been farm operations and predation.
Historical changes in reported escape numbers indicate two distinct trends. First, the total numbers reported annually have declined from an average of approximately 185,000 fish per year between 1989 and 1991 to an average of approximately 27,300 fish per year during 1992 –1996. Second, the species composition of escapes has changed significantly. While the overwhelming majority (99 per cent) of escapes during 1989–1991 were chinook salmon, by 1992–1996 most (65 per cent) were Atlantics. This reflects the steadily increasing proportion of overall production represented by Atlantic salmon.
The reported number of escaped farm salmon represents a minimum number. While salmon farmers are required to report fish escapes, typically only those large enough to be deemed of economic importance are actually reported. The numbers of farm salmon getting into the wild as a result of smaller escapes or "leakage", that often go unnoticed and/or unreported, are difficult to estimate. However, the TAT noted that the number of escaped salmon resulting from chronic leakage could be equal to the number that are actually reported, thus potentially doubling the total number of escapes. An additional source of escaped Atlantic salmon is the commercial salmon farms in Washington State. Escaped Atlantics from those farms are undoubtedly entering and spending significant time in B.C. waters.
Salmon farmers are concerned about escaped farm fish. They have an economic incentive to keep their stock in the net-cages. This has led to techniques/operating practices designed to address the various underlying causes of escapes. For example, devices such as ADDs and predator nets are used to try and minimize predation and, hence, prevent escapes caused by predator damage to nets (refer to Chapter 8 for further details). Similarly, improved siting and farm design have enabled farms to reduce escapes resulting from damaged net-cages caused by storms.
Although it is in the best interests of salmon farmers to minimize or prevent escapes, and it appears that the trend is towards fewer escapes, many farm salmon still get out into the wild. As a result, there are serious concerns relating to the potential negative effects of large numbers of escaped farm salmon on B.C.'s coastal resources. This has led to specific policies and regulations that form part of the existing aquaculture management framework.
Provincial controls of escaped farm salmon are outlined in the provincial Aquaculture Regulation, and the federal controls in the Fishery (General) Regulations adopted under the federal Fisheries Act. The provincial requirements are tied to the aquaculture licence, which is necessary for all commercial aquaculture operations. Non-compliance with the aquaculture licence can result in the licence being suspended, revoked or not re-issued.
The provincial Aquaculture Regulation is administered by MAFF. It specifically prohibits the release of fish from a salmon aquaculture facility unless the release is authorized by the aquaculture licence. It also requires a licence holder to take "reasonable precautions" to prevent accidental escape of farm fish, including the period of transportation from one facility to another. Failure to comply with the regulation is punishable as an offence under the Fisheries Act. The federal Fishery (General) Regulations prohibit the release of live fish to any fish habitat, unless the release is authorized under a licence issued by the Minister of Fisheries and Oceans. However, this is aimed at addressing the intentional release of fish rather than the unintentional escape of farm fish. In practice, aside from salmon farmers' self-interest in preventing escapes, the provincial Aquaculture Regulation and the aquaculture licence are the primary management tools for the prevention of escapes.
Both MAFF and DFO require a salmon farm operator to report escape events, each from their jurisdictional perspectives. Under the Aquaculture Regulation, an aquaculture licence-holder is required to report any escape or evidence suggesting an escape to the provincial Aquaculture Manager, either verbally within 24 hours of discovery or in writing within one week of the discovery if requested by the Aquaculture Manager. Similarly, the Fishery (General) Regulations authorize DFO to require notification of any escape of farm salmon, first orally and then in writing. The written report must contain information regarding the location, the species and strain of fish, the cause of the accidental escape, the previous freshwater location of the fish, the size of the fish, and details of any medications being administered to the fish.
There are both federal and provincial requirements regarding the recovery of escaped farm salmon. The federal Fisheries (General) Regulations require that a special permit be obtained from DFO prior to attempting to recapture escaped farm salmon. The purpose of this is to ensure that efforts to recapture escaped farm fish do not negatively affect wild populations. The provincial Aquaculture Regulation requires that an aquaculture licence-holder submit a written report to the Aquaculture Manager within one week of any recapture attempt.
Other than reporting escape events, there is no requirement under federal or provincial legislation for an aquaculture licence-holder to monitor a farm's escaped fish. The only monitoring initiative relating to escapes is the Atlantic Salmon Watch (ASW). The ASW was established in 1991 and is jointly managed by MAFF and DFO. Its purpose is to monitor commercial and sport catches and observations of Atlantic salmon to help determine abundance and distribution of Atlantic salmon in the wild.
MELP's Aquaculture Policy outlines a series of salmon farm siting guidelines designed to reduce conflicts with coastal resources and coastal resource users. This includes a guideline for a 1 km buffer between salmon farms and the mouths of salmonid-bearing streams (refer to Chapter 4 for further details). This avoidance is designed to reduce the potential negative effects of escaped farm salmon on wild stocks.
Although there are federal and provincial measures designed to prevent escapes and to address the potential negative effects resulting from the escapes that do occur, concerns persist. These concerns are particularly focused on the potential negative effects on native salmonids (Pacific salmon, steelhead, cutthroat trout, etc.) and their spawning and rearing areas. Concerns about the potential effects of escaped farm salmon can be divided into three groups: those related specifically to farmed Atlantic salmon; those related exclusively to farmed Pacific salmon species; and, those related to all farmed salmon species (see Table 14).
| Concerns with farming Atlantic salmon | Concerns with farming native Pacific species | Concerns with farming any salmon species |
| Genetic Impacts | Genetic Impacts | Ecological Impacts |
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| Ecological Impacts | ||
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The salmon farming industry in B.C. gradually shifted from farming Pacific salmon species (chinook and coho) almost exclusively to farming predominantly Atlantic salmon. This shift towards Atlantics occurred for economic reasons. Atlantic salmon are found to be better suited to farm conditions, primarily, in that they grow faster and can tolerate higher stocking densities than Pacific species. Thus, they are more profitable to raise. Both the federal and provincial governments have approved of the farming of Atlantic salmon in B.C. by allowing the importation of Atlantic salmon eggs into the province and through the approval of aquaculture development plans, which must name the species being farmed.
The issue of farming Atlantic salmon in B.C.'s coastal waters is of significant concern for many people. Atlantic salmon are an introduced or "exotic" species in B.C. and some people view the introduction of any exotic species as wrong in principle. They point to the unforeseen ecological and economic problems resulting from introductions of other exotic species throughout the world to illustrate the potential for significant negative impacts. The review heard the suggestion that land-based or closed-containment culture was the only acceptable way to reduce risks to wild salmon and to prevent other potential negative externalities from farming Atlantics.
There is a detailed history of intentional human-induced introductions of Atlantic salmon throughout the world. However, with the exception of the Faeroe Isles in the northeastern Atlantic, none of these attempted introductions has ever succeeded in achieving a self-sustaining anadromous population of Atlantic salmon outside of their endemic range. The TAT concluded that in B.C., reproductive colonization by Atlantic salmon is improbable but not impossible. With continuously high levels of escapes, and low numbers of wild stocks, the potential for successful colonization could increase. However, even if Atlantics were to reproductively colonize in particular waterbodies, it would likely be possible to target that particular stock for eradication, if that action was considered appropriate.
Even if Atlantic salmon never successfully colonize in B.C., there are concerns that the mere presence of escaped farm salmon in the ocean and fresh water environments will result in significant impacts to native Pacific stocks. People have asserted that escaped farm salmon will represent serious competition to wild salmon for food and other resources. As well, predation on wild stocks by salmon escaping from farms has been raised as a concern. The conclusions of the TAT, however, found that, in terms of both predation and competition, current levels of escaped farm salmon offer no significant threat to wild stocks. At higher levels of escapes, there may be some localized increases in competition in the immediate vicinity of farm sites. These effects, however, would likely be temporary, and would decline as the escaped fish dispersed over a broader area.
Public concerns about potential genetic impacts of escaped farm salmon on native Pacific stocks through hybridization and interbreeding have also been raised. The TAT found the potential for hybridization between escaped Atlantic salmon and wild Pacific salmonid species to be extremely low. However, the risk of genetic damage due to interbreeding between escaped Pacific salmon and wild stocks is potentially high if consistently large numbers of escapes occur and successful interbreeding occurs over several years. This risk, however, must be viewed within the context of past enhancement efforts where many millions of salmon of different genetic backgrounds were intentionally mixed, with little regard to the potential long-term risks from interbreeding.
The SAR also heard serious concerns regarding the potential commercial farming of transgenic salmon. A transgenic salmon has had its genetic composition altered, usually through the injection of DNA from other salmon, other species, or combinations of the two. The purpose of transgenic research is to try and produce favourable altered characteristics in the transgenic fish (e.g., increased growth rate, or improved disease resistance). It is not known whether these favourable attributes could allow escaped transgenic salmon to successfully out-compete wild populations for resources.
Because of the uncertainty regarding how these genetically altered fish would behave in the wild, the current DFO policy is to maintain both physical and biological (reproductive) containment of transgenic organisms. There has been ongoing research into the development of transgenic salmon in B.C., but this has been done under close supervision in closed-containment, land-based facilities.
Currently, there are no transgenic salmon being farmed commercially in B.C., nor has there been any interest expressed for doing so. This is primarily related to the negative public perception of transgenics, and the potential for this to affect all farmed salmon sales. In view of the uncertain potential risks, and the serious public concern that has been expressed, it is recommended that the farming of transgenics continue to be prohibited in marine net-cage systems.
Overall, at current levels of escapes, the risk of adverse effects from escaped farm salmon on wild stocks appears to be low. A great deal of public concern has been expressed with regard to the potential adverse effects of farming Atlantic salmon, an exotic species. The TAT concluded that the potential for adverse effects is associated more with farmed Pacific species than with Atlantics. The risk is considered higher where a farm raising a Pacific species is located near a body of water with an important or vulnerable native stock. In these situations, there is an increased likelihood that due to proximity alone, escaped Pacifics might enter the stream and interbreed or exclude wild salmon from feed or habitat. For this reason, it is important to avoid locating farms raising Pacific species near sensitive wild streams. In these circumstances, it may mean siting farms beyond the 1 km siting guideline (see Chapter 4).
The conclusion of the SAR is that there is no demonstrable basis at this time for discontinuing the culture of Atlantic salmon in B.C. Arguments to do so are based primarily on "principled viewpoints," given the experiences of other species introductions in the world where the introduced species was able to competitively exploit an ecological niche. This probability does not appear likely in B.C. given that native salmonids already occupy that niche, and also given the evidence that prior intentional Atlantic introductions here and elsewhere have failed.
Moreover, the economic impacts on the current B.C. salmon aquaculture industry of a policy decision to ban Atlantic culture in the marine environment would be considerable, potentially rendering the industry uncompetitive. Since land-based technology for rearing Atlantic salmon to full grow-out is not yet considered economic (see Chapter 11), farmers would be induced to farm Pacifics, where the ecological risks of escapes are of greater concern.
As discussed above, the TAT concluded that overall, the risk of adverse effects to the province from current levels of escaped salmon is low. However, the TAT also pointed out that continued or higher levels of escapes would increase the risk of impacts in some locations. Moreover, there is a certain level of uncertainty regarding both the potential and the significance of adverse effects. Thus, maintaining vigilance over the potential effects of escaped farm salmon is justified by the need to reduce risk in the face of this uncertainty.
Although the overall numbers of escapes have decreased over time, existing measures to prevent escapes have clearly not been adequate. The existing requirement of the aquaculture licence to take "reasonable precautions" to prevent escapes is difficult to enforce, and to date there has been limited follow-up or verification of escape events by government agencies. In practice, the requirement to report escape events is most often only complied with for what farmers consider to be economically significant losses. The management system for addressing escapes has little or no enforcement, and no incentives/disincentives to prevent escapes other than the economic incentive for farmers to avoid the loss of stock. In total, there have been over one million reported farm salmon escapes into the wild from B.C. farms. The economic self-interest of salmon farm operators and existing management regulations and policies regarding escapes are not sufficiently effective in addressing this issue.
There was general agreement among all participants in the SAR that the prevention of escapes is a worthwhile goal. All of the concerns described previously in this section relate to the potential effects of farm salmon in the wild after they have escaped. Escape prevention should be the main regulatory thrust. Ultimately, the goal of management agencies should be zero escapes.
An effective mechanism to achieve this is by including escape prevention measures in the farm's management plan and establishing a threshold escape number that, when exceeded, triggers a review of the management plan and requires that any remedial measures identified by the review be implemented. The threshold number should be set as a percentage of the total number of fish stocked into the farm. Recognizing that the ultimate goal is zero escapes, it is suggested that the threshold should be initially set at 3 per cent of total fish stocked and move to zero as quickly as possible, but no later than five years. This threshold number should be treated as a starting point and should be regularly reviewed by managing agencies and reduced as technological and managerial improvements are made.
Implementing these measures will ensure that farmers act proactively by including escape prevention measures in the farm development plan. It will also allow regulatory agencies to provide advice on which technologies and husbandry practices are most effective for ensuring escape prevention. It will also provide a tool to help ensure that these same technologies and husbandry practices are implemented.
The effectiveness of the recommendation outlined above is dependent upon an accurate and up-to-date inventory system. Improvements in escape prevention are dependent upon knowing where and why losses are occurring. In order to determine if threshold numbers of escapes have been reached, both farmers and government auditors need to have an effective means of determining how many fish are being lost due to chronic leakage and/or escape events. To be accurate, the tracking system also needs to be able to separate losses due to disease and predation. Thus, this type of inventory would also be a crucial tool for ensuring the effectiveness of recommendations regarding fish health, and interactions with aquatic mammals (refer to Chapters 6 and 8 for more detailed information).
A computerized inventory tracking system has been developed and is in use on a number of commercial salmon farms in B.C. This system can track salmon stock from the hatchery through to processing and identify and separate key information, including: losses due to predation (various types), losses to disease (various types), losses to escape events, and unexplained losses (chronic leakage). This system should be used as a model for implementation throughout the entire industry. This will require up-front investment from farm owners for implementation. In order to ensure effectiveness and consistency, government also has a role to play in further developing the appropriate inventory system protocols. Establishing a standardized, computer-based system to be used industry-wide would ensure consistency and make review and auditing easier and more effective.
It should be recognized that even with this inventory system in place, there will remain a certain number of fish that go unaccounted. However, this does not diminish the need for this type of tracking system, it simply points to the need for further refinement over time as the body of information is developed. The accuracy of the information recorded is crucial to its effectiveness, as is the ability to determine if threshold numbers have been reached and to identify operating procedural or technological problems. In order to ensure this accuracy, farm operators found to be misreporting information should be penalized through fines.
Reports based on the information found in the inventory tracking system should be submitted on a regular basis. Tying this to the farm's production cycle would likely be appropriate. The inventory system itself should also be open to government inspection and audit at any time. In order to address the principle of transparency, access to data from the inventory tracking system reports should be made available to the interested public and presented in a way that addresses the proprietary nature of some of the information.
The above recommendations will reduce the potential for farmed salmon to enter the open marine environment, thus preventing adverse effects. However, the possibility of escapes, either through individual escape 'events' or through ongoing 'leakage' cannot be ruled out. The potential for farmed salmon escapes will always exist so long as fish are being reared in an aquatic environment. This suggests that contingency measures are needed to mitigate risks associated with inevitable farmed salmon escapes, even though they should become limited in number. The SAR considered a range of measures, including:
Since the proposed strategy is to place priority emphasis on escape prevention as the principal basis for reducing environmental risks of escaped farm salmon, and because the TAT concluded that the risks associated with escapes are relatively low in the first place, and given the cost implications of developing and implementing various risk mitigation strategies, the appropriate approach is to focus on remedial action to address significant escape events. Salmon farmers should be required to develop escape recovery plans which would be invoked when escapes exceed a specified numerical level. The specified number should be developed by government, in consultation with industry, taking into account feasibility and logistical considerations.
The successful development and implementation of escape recovery plans is dependent upon the cooperation and support of the DFO. Due to their mandate under the Fisheries Act to regulate Canada's fisheries, any attempts at escaped fish recovery would require their approval. Recognizing this mandate, salmon farmers and the provincial government need to work cooperatively with DFO to develop a process whereby conditional permits for attempts at escape recovery would be issued by DFO. These conditional permits would allow farmers to implement their escape recovery plan when the appropriate conditions are triggered without reapplying for DFO approval.
The effective recovery of escaped salmon will also require an ability to react quickly and efficiently. This will be compromised if salmon farmers are forced to spend time trying to locate a boat and crew that are willing and capable of escape recovery and are available with relatively no notice. In order to address this issue, this report recommends that a regional approach is used. In this respect, salmon farmers and government would develop regional "recovery teams" that would be established and available on-call under any circumstances for all of the salmon farms in a designated region. As discussed in Chapter 9, local people, especially First Nations, could provide a valuable resource to these teams. Again, since DFO, as the lead agency in fisheries management, will be required to issue catch licences to authorize these recovery teams, the participation by DFO in the development of these regional strategies will be crucial.
To facilitate the development of effective escape recovery plans, government should document appropriate escape prevention technologies and procedures as a reference guide for use by farmers when preparing their individual escape recovery plans. The escape recovery plans, linked to the numerical escape standard, should constitute part of the salmon aquaculture licence, thus ensuring their enforceability.
In addition to the requirement for an escape threshold standard and recovery plans, an appropriate and cost-effective measure for mitigating risks associated with escaped salmon is to maintain a minimum level of monitoring. To this end, the Atlantic Salmon Watch program should be maintained, with a focus on specific streams known to have Atlantic salmon and a determination of whether the fish can successfully spawn. This will provide information that enables agencies to adjust management requirements respecting escape prevention and mitigation measures.
The recommended management for escapes, as outlined above, will significantly reduce, but not eliminate, the risks associated with escapes. The remaining risk will not be enough to require the implementation of severe post-escape mitigation measures. However, the uncertainty that remains justifies the need for focused research, subject to a determination of research priorities, that looks
at means to further reduce risks associated with escaped farm salmon. Specifically, the following research should be further pursued:
These risk mitigation measures should be adopted, pending determination of their cost effectiveness through research initiatives (refer to Chapter 10 for further discussion).
In addition to actively engaging in its own research and monitoring efforts, government should commit to maintaining an ongoing review of other relevant research being conducted both in B.C. and other jurisdictions. Of specific interest should be research that investigates the behaviour and ecology of escaped farm salmon in the wild and, more particularly, their potential for successful spawning and impacts on other fish species. Two extensive research proposals are expected to proceed over the next year.2 Also the Directorate for Nature Management in Norway is developing a research program based on tagging a percentage of farmed fish. It is expected that this program will be operational in two to three years and should be monitored for its potential usefulness and application in B.C.
Managing agencies generally are aware of ongoing research, but specific agency personnel should be designated to review new relevant research and regularly report on how the results of this research may be used to improve the management of salmon farming in B.C.