Frequently Asked Questions

Q. What is a transgenic fish and how is it created?

A. Transgenic or genetically engineered animals are developed by inserting single or multiple genes from one species into the DNA of another species.(1) Transgenic procedures rely on three basic steps:

1. Researchers isolate and identify the genes that posses the desired trait. Genes may come from similar fish species, plants, bacteria, animals, and even humans.
2. The isolated genetic material is inserted into the intended target fish’s eggs.
3. When the genes have been successfully inserted, the new transgenic fish are raised like other farm fish in holding tanks or other confinements.(1)
   

Q. Is there a difference between genetically engineered, genetically modified, and transgenic animals?

A. The terms genetically engineered, genetically modified, and transgenic are used synonymously. The term transgenic arises from the procedure of transgenesis, one method in which scientists have successfully inserted genes from one species to another. Throughout this package, the terms are used interchangeably to describe the same type of altered aquatic species.

Q. What is a triploid fish?

A. Triploidy and triploid fish refer to fish that possess three instead of the normal two sex chromosomes. Transgenic fish can be rendered sterile by applying heat and or pressure to females’ eggs to generate the extra chromosome. Proponents of genetically engineered animals often suggest that by creating triploid fish the environmental risks associated with their release into open water would be rendered harmless. However, many scientists caution that there is no such thing as a 100% guarantee of sterility given the great possibility for human error and natural variation.(2) Research has shown that even successfully sterilized fish can pose threats to native species populations by reducing availability of food resources and disturbing the existing food chain.

Q. Why is the regulation of transgenic animals important to me?

A. Transgenic fish and shellfish pose a variety of potential threats to natural ecosystems and food safety. Researchers believe that genes added to promote disease resistance may cause fish to absorb higher rates of toxic substances, like mercury, and those high levels could be passed on to human consumers.(2) Roughly 90 percent of food allergies can be attributed to consumption of eggs, fish, shellfish, milk, peanuts, soybeans, tree nuts, and wheat.(1) If proteins used in the production of transgenic species originate from one of these eight sources, transgenic fish could provoke an allergic reaction in a consumer. The majority of transgenic fish have been inserted with genes to promote rapid growth. Large doses of growth hormones may pose health risks if consumed in raw and uncooked foods like sushi. Because of the lack of research, the potential health risks associated with transgenic animals are not well documented and warrant a closer examination.

It is estimated that millions of farmed fish escape from open water facilities each year and contaminate native populations.(3) Genetic alterations in transgenic fish may give them competitive advantages over native species. Because of faster growth rates, transgenic fish reach sexual maturity quickly allowing them to breed earlier and at faster rates than their native counterparts. Thus, transgenic genes are more likely to be spread throughout the native population reducing the genetic diversity of the population. The “Trojan gene” scenario suggests that transgenic fish will grow at a faster rate, but die out earlier than native species as a result of the genetic modification. Eventually, this would lead to dramatic decreases and may even cause the extinction of entire fish species.

Q. Doesn’t the federal government regulate transgenic species?

A. No. No single federal law or agency is charged with regulating transgenic species. Responsibility is spread between several agencies; the U.S. Army Corps of Engineers oversees navigable waters, the Department of Commerce regulates marine resources, the Department of Agriculture regulates marine aquaculture, and the Food and Drug Administration regulates animals intended for human consumption. In the absence of clear governing authority at the federal level, the burden of establishing a clear regulatory framework is left to states and their legislators.