In Risk assessment and mitigation of AquAdvantage salmon I discussed exactly what Aqua Bounty was asking permission from the FDA to do, as well as the environmental, animal welfare, and human health concerns associated with the AquAvantage fish in comparison to non-transgenic farmed salmon.
The Center for Food Safety has a “new” document to bring to the discussion: an opinion (pdf) written by the National Marine Fisheries Service regarding a U.S. Army Corps of Engineers proposal about ocean net pens to raise finfish off the coast of Maine that was written in 2003. CFS talks about this letter in a blog post titled Newly Disclosed Government Documents Conclude GE Salmon Pose A Critical Threat To Marine Environments. Let’s just say there’s a few errors in the reasoning found in the blog post and indeed all over the GFS site about genetically engineered fish. Here, I’ll go over the blog post (I’ll let our excellent commenters take a look at the rest of the site) and discuss some of the errors.
The post opens with:
Adding a new twist to the controversy over genetically engineered (GE) salmon, the Center for Food Safety (CFS) revealed today that, in recent hearings on transgenic fish, the U.S. Food and Drug Administration (FDA) knowingly withheld a Federal Biological Opinion by the U.S. Fish and Wildlife Service (FWS) and National Oceanic and Atmospheric Administration (NOAA) prohibiting the use of transgenic salmon in open-water net pens pursuant to the U.S. Endangered Species Act (ESA).
The problem is that the opinion wasn’t about genetically engineered salmon. It was about the risks of any ocean farmed salmon, with a fairly small amount of discussion of transgenic fish (less than 3 pages of a document totally 101 pages, with a full 61 pages of text). Is this opinion relevant to the application by Aqua Bounty to raise transgenic salmon in two very specific land based facilities? Perhaps. Here’s everything the report says about transgenic fish:
page 27 Transgenic salmonids are prohibited at these facilities [referring to a list of permitted ocean pen fish farms]. Transgenic salmonids are defined as species of the genera Salmo, Oncorhynchus and Salvelinus of the family Salmonidae and bearing, within their DNA, copies of novel genetic constructs introduced through, recombinant DNA technology using genetic material derived from a species different from the recipient, and including descendants of individuals so transfected. This prohibition does not apply to vaccines.
page 34-35 [at the very end of the section Disease Factors, Predators, and Competitors discussing concerns of farmed salmon] Atlantic salmon and rainbow trout produced by the aquaculture industry (including non-North American strains and potentially transgenics) that escape from hatcheries or net pens also compete with wild Atlantic salmon.
page 74-75 [under the heading Transgenics]
The potential use of transgenic salmonids in the aquaculture industry has recently been identified as a possible threat to wild Atlantic salmon populations. Transgenic salmonids include fish species of the genera Salmo, Oncorhynchus, or Salvelinus in the family Salmonidae that bear, within their DNA, copies of novel genetic constructs introduced through recombinant DNA technology using genetic material derived from a species different from the recipient, and descendants of any individuals so transfected. Escaped, reproductively viable transgenic salmon could interbreed with wild fish. Research to develop transgenic fish for aquaculture increased through the 1980s and had advanced to the extent that, by 1989, production of 14 species of transgenic fish, including Atlantic salmon, had been reported (Kapuscinski and Hallerman 1990).
Transgenic fish produced for culture in marine net pens must be selected to survive under nearly natural physical and chemical environmental conditions. If they escape, therefore, it is likely that. a portion of them will survive. In a study by Sheela et al. (1999), transgenes were inherited in many progeny from transformed fish, as determined through DNA analyses and through expression of the reporter gene. If an introduced construct can find its way onto or into a chromosome before the first cell division of a newly-fertilized egg, all the cells in the developing organism, including future germ cells, will contain copies (Lutz 2000). The transmission of novel genes to wild fish could lead to physiological and behavioral changes, and traits other than those targeted by the insert gene are likely to be affected. Ecological effects are expected to be greatest where transgenic fish exhibit substantial altered performance. Such fish could destabilize or change aquatic ecosystems (Kapuscinski and Hallerman 1990).
In a study by Cook et al. (2000), growth-enhanced transgenic Atlantic salmon exhibited a 2.62- to 2.85-fold greater rate of growth relative to non-transgenic salmon, over the body weight interval examined. This study found that the transgenic experimental subjects possessed the physiological plasticity necessary to accommodate acceleration in growth well beyond the normal range for this species, with few effects other than a greater appetite and a leaner body (Cook et al. 2000). Because aquatic ecosystems function through complex interactions involving transfers of energy, organisms, nutrients, and information, it is difficult to predict the community-level impacts of releasing transgenic fishes that exhibit one or more types of phenotypic change (Kapuscinski and Hallerman 1990). At this time, more research is needed to identify the impacts that escaped transgenic salmon would have on natural populations and their habitat before use for commercial aquaculture is considered.
Research and development efforts on transgenic forms of Atlantic salmon and rainbow trout are currently being directed toward their potential for sea pen aquaculture. Emphasis has been placed on enhancement of growth and low water temperature tolerance through the transfer of genetic material from other cold-tolerant species, such as flounder. In 2002, the Food and Drug Administration received an application for approval to sell and possibly grow transgenic salmon in the United States for use by the aquaculture industry.
The prohibition on the Use of transgenic salmonids at existing marine sites off the coast of Maine (Special Condition No. 2) will eliminate the potentially adverse disease and ecological risks posed by the use of transgenic salmonids in aquaculture. The risk posed by a transgenic salmonid to wild salmon would be greatly affected by the specific gene manipulation conducted. Anyone proposing the use of transgenic salmonids in aquaculture would need to provide information on the methods used and the potential for genetic, fish health and ecological impacts on wild stocks. This information would have to be evaluated to determine the level of risk posed to wild Atlantic salmon stocks and a decision would have to be made as to whether that level of risk was acceptable or not. The use of transgenic salmonids will be prohibited under Condition No. 2 until such time as these risks can be evaluated.
A slightly better than superficial reading of this discussion of transgenic salmon reveals that the National Marine Fisheries Service is strongly recommending a ban on transgenic salmon in ocean pens due to concerns that the transgene will make the fish more fit than non-transgenic fish and that such a transgene would spread through natural populations if the accidentally released transgenic fish were reproductively viable. Anyone wanting to use transgenic salmon in aquaculture would need to provide clear information about the specific risks they may pose to wild salmon (which is exactly what Aqua Bounty did). I’m not sure if this recommendation was codified – if anyone knows, please provide that information in the comments.
CFS concludes something a little different:
“This adds further evidence that in fact GE salmon pose a serious threat to marine environments and is another compelling reason for the FDA not to approve the fish for commercial use,” said Andrew Kimbrell, Executive Director of the Center for Food Safety. “While the FDA applauded the company’s choice of land-based containment as responsible, it never revealed that it is illegal in the U.S. to grow genetically engineered salmon in open-water net pens.”
Is it actually illegal to raise transgenic salmon in open water pens? If it is illegal, is that relevant to a discussion of land based aquaculture? The differences between risks of ocean based compared to land based aquaculture are quite large, whether we’re discussing transgenic or non-transgenic fish. All ocean based aquaculture was determined by the same report to be quite risky to wild fish:
page 79 [Conclusion] Based on the close proximity of hundreds of fish pens to the GOM DPS [Gulf of Maine Distinct Population Segment] of Atlantic salmon, and the anticipated continued escapes, the best available scientific data and commercial information indicates that the continued operation of Maine aquaculture facilities poses a threat to individual wild salmon because escaped aquaculture salmon compete for food and habitat, disrupt redds, interbreed, thus disrupting breeding, feeding and sheltering of wild Atlantic salmon. Aquaculture facilities may also promote the transfer of disease and parasites to wild salmon, which may also adversely affect wild salmon.
The National Marine Fisheries Service thinks that the permit procedure and the special conditions the U.S. Army Corps of Engineers recommends will help mitigate the risk to wild fish. The special conditions (presumably applying to ocean pen aquaculture since that’s what the entire opinion is about) are:
(1) eliminating the use of non-North American strain Atlantic salmon; (2) developing containment management systems with loss control plans and audits; (3) marking aquaculture fish; (4) prohibiting the use of transgenic salmonids; and (5) requiring fish health certification before stocking alternative salmonids.
CFS thinks that this report means that transgenic fish are a great threat, but it’s clear that National Marine Fisheries Service thinks that all ocean pen aquaculture is a great threat. National Marine Fisheries Service seems to think that these conditions are enough to mitigate the risk, although I am skeptical. Anyway, the only thing that sets transgenic fish apart is that there are more unknowns, or at least there were at the time, when the literature indicated that fast-growing salmon would be better able to compete than salmon without a growth hormone transgene. Later studies have shown that the fast growing salmon have behavioral phenotypes that actually make them less likely to survive than non-transgenic salmon. For example, fast growing salmon are more fearless such that they are more likely to be eaten by predators.
An opinion (pdf) by the Environmental Protection Agency in 2001 on the same subject (whether there should be ocean pen fish farms allowed off the coast of Maine where there are a lot of wild salmon) says pretty much the same thing, with some of the text seemingly cut and pasted from the 2001 Environmental Protection Agency opinion to the 2003 National Marine Fisheries Service opinion.
Anyway, CFS thinks that since these two documents weren’t presented earlier, that must mean the FDA is keeping information from the public. Maybe, but it seems more like these documents weren’t relevant to the discussion of Aqua Bounty’s application for land based facilities rearing fish that are sterile 98% of the time or more (on average).
The CFS post concludes:
Conversations between NOAA and FWS staff in 2009 highlight a Swedish study that found that in simulated escapes, transgenic fish have a “considerably greater effect on the natural environment than hatchery-reared, non-transgenic fish when they escape.” The study further noted that genetically modified fish survive better when there is a shortage of food, benefit more than non-transgenic fish from increasing water temperatures, and can be more resistant to environmental toxins that may ultimately end up in consumers.
Why does’t anyone ever provide a proper citation? According to Web of Science, there were 2,044 papers about salmon published in 2009. Out of the subset of 28 papers that also included the word transgenic, I think the study they’re referring to is:
L. Fredrik Sundström, Wendy E. Tymchuk, Mare Löhmus, & Robert H. Devlin (2009). Sustained predation effects of hatchery-reared transgenic coho salmon Oncorhynchus kisutch in semi-natural environments. Journal of Applied Ecology, 46, 762-769 : 10.1111/j.1365-2664.2009.01668.x
This study didn’t mention toxins at all, or temperatures, but did find that transgenic fish with a growth enhancing gene ate more than non-transgenic fish, at least at first. After about two months, all fish were the same size (not significantly different sizes), including: non-transgenic fish, transgenic fish that were fed an amount of food that restricted them to approximately the same size as non-transgenic, and transgenic fish that were allowed to eat as much as they wanted. The reduced swimming capacity of the transgenic fish that were allowed to eat as much as they wanted led to higher ability of prey to swim away, leaving those prey for other fish. It wasn’t apparent from this study that transgenic fish would have a greater effect on the environment than non-transgenic farmed fish.
Finally, there wasn’t any mention in the Environmental Protection Agency or National Marine Fisheries Service documents about risks of fish bred for specific traits such as fast growth to wild fish. The natural variation in salmon populations for size, growth rate, etc is pretty wide. It’s very possible that a breeding program could develop super salmon without any genetic engineering and those super salmon could potentially be a threat to wild salmon, particularly if they were farmed as reproductively viable individuals in ocean pens near by wild salmon populations. Perhaps this is covered by special condition 1: “eliminating the use of non-North American strain Atlantic salmon”? This is unlikely to have any real positive effect, since the problem of ocean farmed salmon escaping is that they spread a) disease and b) genes that are far less diverse than those in wild populations even when they are of the same strain. I stand by my previous assertion that both ocean farmed non-transgenic salmon and fishing of wild fish are a greater risk to wild salmon than transgenic salmon in land based facilities.
Hat tip to Mark Bittman (@bittman) for creatively tweeting about the CFS blog post:
FDA hid evidence about threats posed by genetically engineered salmon. Your tax $ at work: http://bit.ly/aYJGbl
I’ve been a strong advocate of Bittman’s work. He advocates a diet that is mostly plant based for environmental and health reasons but allows meat as an indulgence. I have a lot of respect for his stepping out with this rare practical viewpoint. I love his How to Cook Everything Vegetarian and recommend it to everyone, especially if you’re not an experienced cook. But, I don’t love uncritical tweets. Mark, if you happen to read this, please, please consider some critical thinking material such as the Skeptoid podcast where Brian Dunning takes the listener through the process of claim, evidence, evaluation of claim.