Experts Weigh in on Farmed Salmon Escape in Washington State

A few weeks ago in Puget Sound, a net pen used for farming Atlantic salmon broke and allowed over 150,000 salmon to escape. Fear of these non-native fish interfering with native salmon have led to questions on potential impacts and a call to reevaluate salmon farming policy in Washington State. In particular, many Native American and First Nation Tribes (most of which are reliant on wild salmon fishing) have called for an end to farming salmon in Puget Sound.

Below we feature five comments on the situation. The first, by Casey Ruff, gives a Tribal perspective on the situation; the second, by Jim Seeb, traces the history of salmon farming in Washington State; Mike Lapointe then talks risks, insurance, and consequences; finally, Carl Walters focuses on the scientific implications.

Comment by Casey Ruff, Skagit River System Cooperative

While there is certainly some very compelling evidence from previous work quantifying negative effects of Atlantic salmon net pen aquaculture via transfer of parasites, from my limited knowledge of existing literature, I am aware of only one instance where there was evidence of successful natural spawning of escaped Atlantic salmon in the wild. There have been accidental releases of Atlantic salmon from net pens in the past, and individual adult Atlantic salmon associated with these releases have been observed in tributaries in the Skagit River during the fall time frame. To be clear, these fish weren’t observed spawning. Unfortunately, there wasn’t any coordinated monitoring effort that occurred as a result of these earlier accidental releases, so nothing was really learned in terms of the potential impact of those earlier release groups on wild populations. Therefore, while I am generally concerned about the potential risks of accidental escapements of Atlantic salmon to threatened populations of Puget Sound salmon stocks via interbreeding, competition/predation, or disease transfer, unfortunately we just don’t know a lot about the long term effects of escaped adult Atlantic salmon on wild Puget Sound salmon stocks.

For this incident, both state and tribal agencies are coordinating existing monitoring efforts to include sampling protocol for any adult or juvenile Atlantic salmon encountered. The sampling metrics include collection of diet samples, scales and otoliths for aging purposes and identifying the origin of the fish, kidney and spleen samples, pathology samples, length and weight for condition factor, and tissue samples for DNA confirmation of species which will be important should any juveniles be encountered.

Luckily, there are a number of River systems in the Puget Sound such as the Skagit River with existing adult and juvenile monitoring frameworks including nearshore, estuary/delta, smolt traps and spawning ground surveys. I would hope that the existing monitoring frameworks would allow some inference to be made regarding the long term impact of this particular release. Specifically, spawning ground surveys in the fall should allow the detection of any spawning activity by Atlantic salmon and subsequent smolt trapping and juvenile monitoring in the delta/estuary and nearshore would hopefully enable the detection of successful reproduction. As of Tuesday, September 5, there were approximately 186,000 Atlantic salmon unaccounted for; they are being encountered in river systems throughout the Puget Sound. In the lower Skagit River for example, at least 50 adult Atlantic salmon have been caught in tribal net ceremonial subsistence fisheries targeting Chinook salmon and coho salmon test fisheries. Thus far, all of the Atlantic salmon sampled in Skagit River have had empty stomachs which would indicate that these fish aren’t feeding at all. Hopefully we can learn something from this coordinated monitoring effort that will help inform the assessment of risk of Atlantic salmon aquaculture to Puget Sound salmon stocks.

Regarding actions that could reduce the risk of accidental adult escapement in the future, it seems that the existing net pens in Puget Sound are placed in areas with significant tidal exchange to help minimize the risk of the risk of disease transfer of parasite colonization. However, this increases the risk of accidental escapement of adults as a result of the combined effect of a compromise in the net pen structure and a large tidal event as occurred with the current escapement incident from the Cooke net pens. So in effect, they are trading one risk, which has been quantified to some degree, for a lesser understood risk.

In Puget Sound, wild Chinook salmon stocks area threatened under the Endangered Species Act and therefore have the potential to limit both terminal and mixed stock fisheries coast wide on any given year. It seems that given the present unknowns regarding the risks of escaped adult Atlantic salmon to native salmon stocks, my preference would be that regulatory actions require existing Atlantic salmon net pen operations in Puget Sound marine areas be discontinued or at a minimum not be allowed to expand, as was being evaluated by state agencies up until the recent accidental release incident. Land-based aquaculture programs would certainly be preferable, although my knowledge of different possibilities is extremely limited.

Casey Ruff is the Director of Harvest Management for the Skagit River System Cooperative.

Comment by Jim Seeb, University of Washington

I applaud the governor and state regulators for moving quickly to attempt to address the recent escape of Atlantic salmon from the Cooke Aquaculture pens. Over a month has passed since the escape, public debate is waning, and I find that I’m left with more questions than answers. How well are the Washington farms regulated? Are the pens engineered to standards necessary to withstand Puget Sound currents? Do the farmers pay their fair share to the state for costs of regulation and environmental costs of farming? What will the final regulatory response be?

Not many are aware of the bankrupt thinking that originally led to the farming of Atlantic salmon in Washington. In the 1970s and 1980s NOAA devised a poorly-thought-out scheme to raise adult Atlantic salmon in net pens at their Manchester facility, west of Seattle, in order to provide an egg source to use for restoring depleted runs of fish in New England. This sounds really silly, but this is not a joke. Up until 1983 NOAA imported Atlantic salmon eggs from many sources in order to develop broodstock for their Manchester pens. But in 1984 a panel of other federal and New England state officials recognized that that the operation of an Atlantic salmon hatchery in Puget Sound, to produce eggs for enhancement of stocks in rivers of the US Northeast, posed a great risk of introducing diseases into the Atlantic Ocean drainages. The eggs produced at Manchester were determined to be unfit for transfer to the East Coast.

NOAA should have scrapped the useless Manchester program, but they didn’t. Instead NOAA determined that now they had millions of Atlantic salmon eggs that could be distributed to salmon farmers in Puget Sound! Where were the Washington State regulatory agencies at the time? Probably underfunded and understaffed and challenged to provide the critical regulatory framework needed to promote the responsible development of a farm program in Washington.

NOAA helped the state regulators by publishing reports (not peer-reviewed) that promoted the positive elements of Atlantic salmon culture while at the same time minimizing any consideration of risk. I have two that detail the original thinking (NMFS-NWFSC 49 and 53), and I suspect that there are many more. While the reports do contain some useful background information, they too often fall back on alternative thinking. Example include: the state already moves and stocks local Pacific salmon in Washington, walleye and other exotics established in Washington waters are more predatory on Pacific salmon that are exotic Atlantic salmon, no detrimental effects of Atlantic salmon have been found yet, so Atlantic salmon farming must be OK.

The escape of 165,000 of Atlantic salmon from Cooke Aquaculture is in itself not an environmental nightmare. There is no risk that this batch fish will hybridize with Pacific salmon. There is a low (but uncertain) risk to Pacific salmon due to competition, predation, and disease. But are these uncertain risks a reasonable burden to be borne by Washington stakeholders who prize native salmon and the Puget Sound ecosystem? Fish farming and the long-term farming of Atlantic salmon may be a Puget Sound nightmare that requires careful scrutiny.

I hope that the state regulators capitalize on this opportunity to bring less bankrupt thinking to evaluate and regulate fish farming, especially the farming of Atlantic salmon, in Washington.   What are the economic benefits of fish farming to the State? What are the environmental costs? Not all exotic species become invasive, and the single release of Atlantic salmon at Cypress Island is not likely to become invasive. But the results of such releases through time present an opportunity for Atlantic salmon to take root, with uncertain consequences.

Jim Seeb is a Research Professor in the School of Aquatic and Fishery Sciences at the University of Washington. Take a look at his lab here.

Comment by Mike Lapointe, Pacific Salmon Commission

I suspect the varied reactions to the escape of Atlantic Salmon from the fish farm at Cypress Island are analogous to folks’ considerations in buying insurance.  Like insurance decisions, these reactions have two main parts: (1) the probability or likelihood that something bad will happen, and (2) the consequences should something bad actually happen.   With respect to the former, history suggests the likelihood of something bad arising out the Atlantic salmon escape is very low.  The predecessor agency to the Pacific Salmon Commission (PSC), the International Pacific Salmon Fisheries Commission (IPSFC) made numerous attempts to establish a pink salmon return to the Fraser on even years (only an odd year run exists) and introduced sockeye from various Fraser River donor populations to a number of Fraser tributaries that lacked established runs.   The pink salmon attempts were an abysmal failure and only a small fraction of the attempts at introducing sockeye succeeded.   This history suggests that even deliberate efforts to introduce Pacific Salmon have been largely unsuccessful with the implication that hap hazard establishment of a sustaining population of maladapted Atlantic Salmon is very unlikely to occur as a consequence of the recent escape from Cypress Island.

With respect to the latter, the potential consequences, should Atlantic salmon successfully invade Pacific Salmon streams, clearly that is undesirable, and could be catastrophic in the long term, especially for species of Pacific salmon that rear as juveniles in streams (e.g. Coho, some populations of Chinook, and Steelhead) where competition with juvenile Atlantic salmon would occur.  The severity of such impacts would be particularly important to those folks for which Pacific Salmon are integral to their existence (e.g. Tribes in the United States, First Nations in Canada).

Of course the best insurance against a bad event is removal of the threat.  Whether one believe that threat posed by Atlantic Salmon aquaculture outweighs any potential benefits, likely relates, in part, to differing views about likelihoods and consequences.

Mike Lapointe is the Chief Biologist at the Pacific Salmon Commission

Comment by Carl Walters, University of British Columbia

We have been farming Atlantic salmon in B.C. since the mid-1980s, and there have been many escapes but little evidence of successful reproduction.

There remains a legitimate concern about diseases. There have been repeated warnings in B.C. about sea lice. More worrisome are viral diseases: Infectious Salmon Anemia (ISA) has been found in B.C., and so has Heart and Skeletal Muscle Inflammation (HSMI). Fortunately, there is as yet no clear evidence that these diseases have persistently impacted survival of native salmon species. There have been various attempts to correlate the declines that we have seen in marine survival rates of some salmon stocks with fish farming, and this worked about as well as other correlative studies of salmon survival—the rule seems to be publish quickly, before your correlation breaks down.

For a good review of the history of Atlantic deliberate introductions and escapes in Washington and BC, and lack of evidence of their establishment in any of our streams, see here.

Carl Walters is a Professor Emeritus at the Institute for the Oceans and Fisheries at the University of British Columbia.
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