Genetically Engineered Fish and Seafood

CRS Report for Congress
Genetically Engineered Fish and Seafood
July 1, 2005
Rachel Borgatti
Resources, Science, and Industry Division
Eugene H. Buck
Specialist in Natural Resources Policy
Resources, Science, and Industry Division

Congressional Research Service ˜ The Library of Congress

Genetically Engineered Fish and Seafood
Genetic engineering techniques allow the manipulation of inherited traits to
modify organisms. Genetically modified (GM) fish and seafood products are
currently under development and may offer potential benefits such as increasing
aquaculture productivity and addressing human health concerns. However, some
critics of this rapidly evolving field are concerned that current technological and
regulatory safeguards are inadequate to protect the environment and ensure public
acceptance of these products.
To date, there has been little legislative activity in Congress on GM fish and
seafood issues, but as commercialization moves closer, pressures may build for
oversight of industry developments and the appropriate role of federal regulation.
This report will be updated as circumstances warrant.

Background ..................................................1
Domestic Regulation...........................................2
Environmental Concerns........................................4
International Developments......................................6
Possible Benefits and Disadvantages of GM Fish and Seafood..........7

Genetically Engineered Fish and Seafood
Through selective breeding, farmers and scientists have a history of modifying
animals to maximize desirable traits. In the broadest sense, genetic modification
refers to changes in an organism’s genetic makeup not occurring in nature, including1
the production of conventional hybrids. With the advent of modern biotechnology
(e.g., genetic engineering or bioengineering), it is now possible to take the gene (or
genes) for a specific protein either from the same species or from an entirely different
one and transfer it to create an organism expressing a novel trait or a trait outside the
normal range of variation for the species. This technique can add both speed and
efficiency to the development of new foods and products. Genetically engineered
plant varieties, such as herbicide-resistant corn and soybeans, have already been
widely adopted by U.S. farmers, and genetically engineered fish or seafood may
similarly be adopted by the aquaculture industry.
Potential issues include the impacts of genetically modified (GM) fish and
seafood on the environment and food safety, and whether GM foods should be
specially labeled. Underlying these issues is the question of whether U.S. regulation
and oversight of biotechnology — with responsibilities spread primarily among the
U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA),
and the Environmental Protection Agency (EPA) — remain appropriate, particularly
as newer applications emerge that did not exist when the current regulatory regime
was established. For additional background on broader concerns, see CRS Report
RL32809, Agricultural Biotechnology: Background and Recent Issues.
Scientists are seeking ways to genetically engineer fish and other seafood
species to introduce or amplify economically valuable traits. Fish are of particular
interest to researchers since many fish produce large quantities of eggs; those eggs,
being external to the animal (as opposed to mammals that produce fewer eggs
internally), make it relatively simple to insert novel DNA.
Research on GM strains is currently under development for at least 35 species
of fish worldwide, as well as for a variety of mollusks, crustaceans, plants, and
marine microorganisms, for various purposes. Fish are being modified to increase
food for human consumption, to produce pharmaceuticals, to test water
contamination, and for other uses.2

1The term hybrid is used by geneticists to describe the offspring of two parents differing in
any genetic characteristics, such as the offspring of a cross between different species,
subspecies, strains, or inbred lines of animals or plants. An example of a common
aquaculture hybrid is the sunshine bass, the result of the fertilization of white bass eggs with
striped bass sperm.
2For a list of genetically engineered organisms under research, see Table 2-2 in National

One GM fish has been marketed to date. Glofish™, a genetically altered
version of the popular aquaria zebrafish (Danio rerio), fluoresce after the insertion
of a sea anemone gene into the zebrafish egg.3 This fish is currently legal to be sold
in all states except California. Since Glofish™ were determined not to “pose any
more threat to the environment than their unmodified counterparts,” and because they
are not meant for human consumption, the U.S. Food and Drug Administration
(FDA), which is responsible for regulating GM foods, determined the Glofish™
posed no clear risk to human health or the environment and should not be formally
regulated by the FDA.4 However, the FDA made clear that this decision applied only
to this specific line of fish, and that the FDA maintained jurisdiction over these and
any other GM fish.
Another private research company has taken the promoter5 from an antifreeze
protein gene found in ocean pout (an eel-like, edible fish) to regulate expression of
a salmon growth hormone gene and drive its expression throughout the cold season,
when growth normally slows, to create an Atlantic salmon that grows to market size
twice as fast as its non-GM counterparts. The company is currently seeking
regulatory approval from the Food and Drug Administration to sell its fish in the
United States for human consumption.6 Other examples of GM fish that have been
developed, but for which regulatory approval is not yet being sought, include fish that
would produce a blood-clotting factor to treat hemophiliacs7 and disease-resistant
channel catfish.8
Domestic Regulation
A National Research Council study maintains there is a low to moderate food
safety risk from GM seafood.9 Since genetic engineering can introduce new protein

2 (...continued)
Research Council, Animal Biotechnology: Science-Based Concerns, (Washington, DC:
National Academies Press, 2002), at [
pagetop], visited Sept. 27, 2004.
3Yorktown Technologies, L.P., at [].
4For the FDA statement regarding Glofish, see [
NEW00994.html], visited Oct. 6, 2004.
5The DNA region, usually upstream to the coding sequence of a gene or operon, which binds
and directs RNA polymerase to the correct transcriptional start site and thus permits the
initiation of transcription.
6Aquabounty Technologies, Inc., at [].
7Amitabh Avasthi, “Can Fish Factories Make Cheap Drugs?” New Scientist, v. 183, no. 2464
(Sept. 11-17, 2004): 8, at [].
8See Pew Initiative on Food and Biotechnology, Harvest on the Horizon, Future Uses of
Agricultural Biotechnology, at [].
9National Research Council, Safety of Genetically Engineered Foods: Approaches to
Assessing Unintended Health Effects, (Washington, DC: National Academies Press, 2004)
at [].

into a food product, there are concerns that this technique could introduce an
allergen, known or previously unknown, into the food supply.
Within FDA, the Center for Veterinary Medicine (CVM) regulates GM (i.e.,
transgenic) animals intended for human consumption under the same authority it uses
to regulate new animal drugs.10 In addition, GM fish must adhere to the same
standards of safety under the Federal Food, Drug, and Cosmetics Act (FFDCA)11 and
the seafood inspection program overseen by FDA’s Center for Food Safety and
Applied Nutrition12 that apply to conventionally bred fish. Under the adulteration
provisions in §402(a)(1) of the FFDCA, the FDA has the power to remove a food
from the market or sanction those marketing the food if that food poses a risk to
public health. In addition, other laws might elicit federal oversight of GM fish and
seafood by federal fisheries management agencies — the Fish and Wildlife Service
and the National Marine Fisheries Service, whose expertise and credibility could
address multiple concerns and issues.13 No federal law specifically addresses GM
fish and seafood.
Since states have the primary authority for fishery resources within their
boundaries and offshore to the outer limit of state waters (generally 3 miles), several
states have taken steps to regulate the use and transport of GM fish.14 For example,
Maryland,15 Washington,16 Oregon,17 and California18 have passed laws banning the
release of GM fish in some or all state waters.

10FDA Center for Veterinary Medicine, “Questions and Answers about Transgenic Fish,”
at [].
1121 U.S.C. §§301, et seq.
12FDA’s Center for Food Safety and Applied Nutrition administers the agency’s seafood
inspection program; see [].
13Eric M. Hallerman and A.R. Kapuscinski, “Transgenic Fish and Public Policy: Regulatory
Concerns,” Fisheries, v. 15, no. 1 (1990): 12-20; Council on Environmental Quality and
Office of Science and Technology Policy, “Case Study No. 1: Growth-Enhanced Salmon,”
Case Studies of Environmental Regulation for Biotechnology, 2001 (available at
[], visited Mar. 8, 2005); Pew Initiative on Food
and Biotechnology, Future Fish: Issues in Science and Regulation of Transgenic Fish, 2003
(available at []).
14S. Stenquist, “Federal and State Regulations Relevant to Uncontained Applications of
Genetically Engineered Marine Organisms,” in Genetically Engineered Marine Organisms:
Environmental and Economic Risks and Benefits by R. A. Zilinskas and P.J. Balint, eds.
(Boston, MA: Kluwer Academic Publishers, 1998), p. 139-180.
15Maryland Natural Resources Code Ann. §4-11A-02 (2003).
16Washington Administrative Code 220-76-100 (2003).
17Oregon Administrative Code 220-76-100 (2003).
18California Fish & Game Code § 15007 (2003) and Dept. of Fish and Game § 671.1. This
law prohibits all “unpermitted” import, possession, transport, and sale of GM fish. Because
permit requirements are extremely stringent — permits can essentially only be issued for
bona fide research use — this law essentially bans any commercial GM fish.

Environmental Concerns
Under the National Environmental Policy Act of 1969 (P.L. 91-190; 42 U.S.C.
§§4321-4347), the FDA must assess the potential environmental impacts of newly
engineered fish. To fully assess these potential impacts, FDA consults with the Fish
and Wildlife Service and the National Marine Fisheries Service (popularly called
“NOAA Fisheries”). However, critics question whether the FDA has the mandate
and sufficient expertise to identify and protect against all potential ecological effects
of transgenic fish.19 Under the FFDCA’s provisions on new animal drugs (21 U.S.C.
§321), the FDA must keep all information about a pending drug application
confidential, except for information publicly disclosed by the manufacturer. This
approach limits the opportunity for public comment before approval. Consumer
advocates are calling for more transparency in this process and for more authority to
be given to environmental and wildlife agencies.20
The possible impacts from the escape of GM organisms from aquaculture
facilities are of great concern to some scientists and environmental groups.21 A
National Research Council report states that transgenic fish pose the “greatest
science-based concerns associated with animal biotechnology, in large part due to the
uncertainty inherent in identifying environmental problems early on and the difficulty
of remediation once a problem has been identified.”22 Critics and scientists predict
that GM fish could breed with wild populations of the same species and potentially
spread undesirable genes. In addition, they argue that transgenic fish, especially
organisms that have been modified so as to enable them to withstand wider ranges
of salinity or temperature, could be more difficult or impossible to eradicate, similar
to an invasive species. Escaped transgenic fish could harm wild fish through
increased competition or predation. Critics maintain that an indication of this
potential problem may be noted where non-GM salmon from nearshore net pens in
the northwest United States,23 British Columbia,24 Norway, and Scotland25 have
escaped and entered streams, in some cases outnumbering their wild counterparts.

19Andrew Martin, “One Fish, Two Fish, Genetically New Fish; Firm Seeks OK for Altered
Salmon,” Chicago Tribune, Nov. 13, 2003.
20Union of Concerned Scientists, “Genetically Engineered Salmon,” at [http://www.ucsusa.
org/ food_and_environment/biotechnology/ page .cfm?pageID=327].
21Pew Initiative on Food and Biotechnology, Future Fish (see note 13, above).
22National Research Council, Animal Biotechnology: Science-Based Concerns (Washington,
DC: National Academies Press, 2004) at [

73.html#pagetop], visited Sept. 27, 2004.

23Washington Dept. of Fish and Wildlife, “Atlantic Salmon in Washington State: A Fish
Management Perspective,” at [].
24The Alaska Fish and Game Dept. reports statistics on escaped and recovered Atlantic
Salmon in Washington State, British Columbia, and Alaska at [
25Eric M. Hallerman and A.R. Kapuscinski, “Ecological Implications of Using Transgenic
Fishes in Aquaculture,” ICES Marine Science Symposia, v. 194 (1992): 56-66.

However, it is not known whether GM fish could survive in the wild in
sufficient numbers to inflict permanent population damage. One study indicated that,
when food supplies were low, GM fish might have the ability to harm a wild
population, although the authors caution that laboratory experiments may not reflect
what would happen in the wild.26 Biotechnology proponents argue that GM fish
would be unlikely to survive in the wild since they would likely be less adept at
avoiding predators.
A predictive model — popularly termed the Trojan gene model — was put
forward after observing that GM Japanese medaka, a fish commonly used as an
experimental model, were able to out-compete non-altered fish for mates. The
resulting offspring were less fit, resulting in the eventual demise of the modified
population.27 Even if fast-growing GM fish do not spread their genes among their
wild counterparts, critics fear they might disrupt the ecology by competing with
native fish for scarce resources. The consequences of such competition would
depend on many factors, including the size of the wild population, the number and
specific genetic strain of the escaped fish, and local environmental conditions.
Other potential safeguards also exist. For example, FDA could require that only
sterile GM fish be approved for culture in ocean pens. Fertilized fish eggs that are
subjected to a heat or pressure shock retain an extra set of chromosomes. The
resulting triploid fish do not produce normal eggs or sperm, and females do not
exhibit maturation of the ovary or reproductive behaviors.28 Thus, all-female lines
of triploid fish are the best current method to ensure non-breeding populations of GM
fish. Nonetheless, there are batch-to-batch variations in the efficacy of triploidy
induction, and it is uncertain whether this method could be effective for all species
of fish; it has not been successful for shrimp.29 Also, critics question whether
escaped male triploid fish, which in some species have sufficient sex hormone levels
to enable normal courtship behavior, could mate with wild individuals, lowering
reproductive success of the wild population.30 The ecological risks of stocking GM
shellfish in the wild have not yet been thoroughly considered, but confinement of

26Robert H. Devlin, et al., “Population Effects of Growth Hormone Transgenic Coho Salmon
Depend on Food Availability and Genotype by Environment Interactions,” Proceedings of
the National Academy of Sciences, v. 101, no. 25 (June 22, 2004): 9303-9308, at
[ cgi/cont ent/abstract/101/25/9303].
27Richard D. Howard, et al., “Transgenic Male Mating Advantage Provides Opportunity for
Trojan Gene Effect in a Fish,” Proceedings of the National Academy of Sciences, v. 101, no.

9 (March 2, 2004): 2934-2938, at [].

28Gary H. Thorgaard and Standish K. Allen, “Environmental Impacts of Inbred, Hybrid and
Polyploid Aquatic Species,”in Dispersal of Living Organisms into Aquatic Ecosystems,
(Univ. of Maryland Sea Grant, 1992), pp. 281-288.
29National Research Council, Bioconfinement of Genetically Engineered Organisms,
(Washington DC: Nat. Academies Press, 2004), at [
30Eric M. Hallerman and A. R. Kapuscinski, “Potential Impacts of Transgenic and
Genetically Manipulated Fish on Wild Populations: Addressing the Uncertainties Through
Field Testing,” in Genetic Conservation of Salmonid Fishes, by J. G. Cloud and G. H.
Thorgaard, eds. (New York, NY: Plenum Press, 1993), pp. 93-112.

these organisms is likely to be even more difficult than confinement of fish, due to
their methods of reproduction and dispersal.31 Other sterilization methods are
currently under study, and it is likely that research in this area will increase options
for containment. Critics of GM fish speculate that the risks to native fish
populations, however small, may outweigh the potential benefits of this technology,
especially where native fish populations are already threatened or endangered.
To be most effective in reducing ecological risk, the National Research Council
report on the Bioconfinement of Genetically Engineered Organisms recommends that
each individual organism have its own bioconfinement32 plan. Guidelines for
designing and implementing confinement of a GM aquatic species have been
developed by a U.S. Department of Agriculture-sanctioned working group.33 Also,
since no single method is likely to be 100% certain, bioconfinement redundancy is
crucial, especially if it will not be combined with physical confinement. Growing
GM fish in isolated onshore tanks rather than in offshore or nearshore pens may
minimize the risk of escape into the wild.
International Developments
Many countries and international institutions have promulgated policies for
oversight of GM organisms, including aquatic species.34 Notably, Canada — where
development of GM salmon is progressing — has regulations that are more
prescriptive and restrictive than those in the United States. Nations that are party to
the United Nations Convention on Environment and Development adhere to the
Cartegena Protocol regarding international transfer of GM organisms; each such
nation has designated an oversight authority and a permitting process. Cuba is such
a nation; it has regulations, and seems poised to approve commercial production of
transgenic tilapia. Cuba, like much of the world, seems to be waiting to see whether
the United States will approve commercialization of the GM salmon. This decision
may prove to be a tipping point in commercialization of GM fish and GM farm
animals, more generally. Alternatively, should Chile, a major producer of Atlantic
salmon, approve production of GM salmon, this could provide the tipping point. The
Organization for Economic Cooperation and Development and the Food and
Agriculture Organization-World Health Organization have held several workshops
on GM fish, and published working papers. The international dimension of issues

31Many shellfish, such as oysters, broadcast their eggs and sperm into the water column and
have larvae that have a planktonic or swimming form, making them very difficult to contain
in an open water pen.
32Bioconfinement refers to biological methods, such as induced sterilization, used to confine
GM organisms and their transgenes to their designated release setting.
33Agricultural Biotechnology Research Advisory Committee, Performance Standards for
Safely Conducting Research with Genetically Modified Fish and Shellfish (U.S. Dept. of
Agriculture, 1995), available at [].
34Eric M. Hallerman, Public Policies Regulating the Use of Genetically Modified Aquatic
Organisms: Current and Future Needs Internationally, VSG-94-168R (Charlottesville, VA:
Virginia Sea Grant College Program, 1994); D. M. Bartley and Eric M. Hallerman, “A
Global Perspective on the Utilization of Genetically Modified Fishes in Aquaculture and
Fisheries,” Aquaculture, v. 137 (1995): 1-7.

pertaining to GM aquatic organisms has important bearing on how technical and
policy issues may be resolved.
Possible Benefits and Disadvantages of
GM Fish and Seafood
Biotechnology proponents maintain that genetic modification has many
advantages over traditional breeding methods, including faster and more specific
improvement of beneficial traits. Because scientists are able to directly manipulate
the traits they wish to create or amplify, the desired change can be achieved in very
few generations, frequently making it faster and cheaper than traditional methods,
which may require many generations of selective breeding. Genetic modification
allows scientists to precisely select traits for alteration, enabling them to create an
organism that, for example, grows larger or faster or has a different nutritional
content. Proponents claim that faster-growing fish could make fish farming more
productive, increasing yields while reducing the amount of feed needed, which in
turn could reduce waste. Shellfish and finfish, genetically modified to enhance
disease resistance, could reduce the use of antibiotics. Increased freeze resistance in
fish could lead to the ability to grow freeze-resistant species in previously
inhospitable environments, allowing aquaculture to expand into previously unsuitable
areas. Research efforts are also under way to address selected human health
concerns, such as genetically modifying fish to produce human drugs like a blood
clotting factor and creating shellfish that will not provoke allergic reactions.
Biotechnology proponents claim these advantages could translate into a number of
potential benefits, such as reduced costs to producers, lower prices for consumers for
edible fish and pharmaceuticals, and environmental benefits, such as reduced water
pollution from wastes. Food scientists and the aquaculture industry may support the
introduction of genetic engineering, provided that issues of product safety,
environmental concerns, ethics, and information are satisfactorily addressed.
On the other hand, while the majority of consumers in the United States appear35
to have accepted GM food and feed crops, it is uncertain whether consumers will
be as accepting of GM fish. Although such fish may taste the same and some are36
expected to be less expensive than other farmed fish, ethical concerns over the
appropriate use of animals, in addition to environmental concerns, may affect public37
acceptance of GM fish as food. Ongoing campaigns by environmental and
consumer groups have asked grocers, restaurants, and distributors to sign a pledge38

to not sell GM fish products, even if approved by the FDA.
35Thomas Hoban, “Trends in Consumer Attitude About Agricultural Biotechnology,”
AgBioForum, v. 1, no. 1 (1998): 3-7, at [
htm], visited Oct. 6, 2004.
36GM fish with traits to enhance efficiency of production would be expected to be less
expensive. However, GM fish that offer added nutritional benefits or some other consumer-
oriented trait might actually command a premium price in the marketplace.
37National Research Council, Animal Biotechnology (see note 22, above).
38The Center for Food Safety, “Genetically Engineered Fish Campaign,” at [http://www.

In addition, the commercial fishing industry says that it has successfully
educated the public to discriminate among fish from different sources, such as wild
and farmed salmon. It is possible that a publicized escape of GM fish could lead to
reduced public acceptance of both the wild and the non-GM aquacultured products.
Many environmental and consumer groups are asking that genetically engineered
products be specially labeled. However, industry groups are concerned that such
labeling might lead consumers to believe that their products are unsafe for
To date, there has been little legislative activity in Congress on GM fish and
seafood issues,40 but as commercialization moves closer, pressures may build for
oversight of industry developments and the appropriate role of federal regulation.

38(...continued) page241.cfm].
39See CRS Report RL32809, Agricultural Biotechnology: Background and Recent Issues.
40In the 109th Congress, an amendment was offered to an agriculture appropriations bill, and
subsequently withdrawn, that would have prohibited the use of FY2006 funds for the
approval or process of approval of an application for an animal drug for creating transgenic
salmon or any other transgenic fish.