How do you feel about transgenetic technology?

Transgenic fish

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When it comes to fish, what the genetic engineering companies dream of when it comes to pigs and cattle seems to be routine: the production of super-fast-growing animals.

In the United States and Canada, authorities approved genetically engineered turbo salmon for human consumption. But scientists fear enormous ecological consequences, especially with gene fish, if they - and one has to assume - escape from the breeding enclosure into the environmental cycle.

Overfishing problem

The global hunger for fish is great. So big that the permanent overfishing of the world's oceans causes fish stocks to collapse. An average of around 90 million tons of fish go into the net every year. In view of the growing world population that needs to be fed, alternatives are now being feverishly searched for. Because an increase in fishery production is no longer possible.

Some see aquaculture and fish farms as a solution. Freshwater fish such as carp and trout but also marine fish such as Atlantic salmon, flatfish and sea bass are bred in breeding tanks or net cages. Thanks to Norwegian breeding farms, the luxury product salmon has become a mass product. This industry has been booming since 1986 with a growth rate of ten percent. At the moment around 40 million tons of fish are produced annually in aquaculture.

However, the fish species that were once wild must be adapted to the alien breeding conditions. The fish farmers want to achieve this with the help of genetic engineering. It should make the impossible possible: The mass production of fast-growing, cheap, robust and tasty fish that can survive unnatural keeping conditions.

How does the rat get in the salmon?

After the transfer of foreign genes was first successful in mice in 1982, a real boom broke out in the use of this technology in other animal species as well. 1985 saw the first publication on successful gene transfer in goldfish. Since then, genetic engineers have succeeded in making genetic modifications to around 35 different fish species. The fish is a practical test object for genetic engineering. In order to achieve a permanent change in the genetic makeup of animals, either the germ cells (eggs and seeds) or the eggs that have just been fertilized must be manipulated (see Umweltnachrichten 96/02). In the case of fish, this is relatively easy, as the scientists do not have to laboriously operate them out. The fertilization of the eggs and the entire embryonic development takes place in the fish - easily observable - outside of the body. Injecting foreign genetic material into the eggs using a cannula is easier here than with mammals.

But the genetic engineers have to struggle with the same negative effects in the fish that are caused by the untargeted massive interference in the genome of living beings: high death rates and unexpected side effects such as crippled fins, deformed gills, deformed skulls, missing body segments, reduced sperm production, changed eating behavior - to name just a few. If all goes well, maybe 80 percent of the fish embryos will survive the procedure. As a rule, however, it is only 35 percent. After all, a success rate that genetic engineers still dream of in pigs and cattle. But in a few of the surviving fish, the foreign gene has latched onto the genetic make-up and develops the desired effect. Sometimes the gene designers are even happy about a coincidental side effect and try to capitalize on it: For the Canadian company A / F Protein, a salmon with an antifreeze gene from the flounder is supposed to become a bestseller. Actually, this gene should make the salmon less sensitive to frost. Instead, however, the fish grew faster. Still not a failure for the scientists: fast-growing breeds are in great demand on the fish farms because of their possible economic gain.

What are genetically modified fish used for?

Robust fish for mass farming

Robust fish for mass farming

The main goal of all gene experiments in fish is to increase the animals' production. Similar to the other animals used for agriculture such as pigs, cattle and chickens, attempts are made to increase growth by transplanting various genes from humans, pigs, cattle or rats. In some cases with success: some of these genetically modified fish do indeed grow faster than their fellow species and have better feed conversion rates. But an increase in growth does not always succeed. As with our high-performance pigs and cows, many farmed fish can hardly improve their performance. Their growth potential has already been exhausted by conventional breeding methods. The alien keeping of the fish in large breeding tanks with high stocking density and artificial feeding brings many problems with it: Bacterial diseases, fungal or parasite infestation spread quickly. Many breeding farms therefore use high doses of drugs and antibiotics in order to be able to produce a sufficiently large amount of fish in the smallest of spaces. A condition that regularly makes headlines when fish or shrimp highly contaminated with antibiotics appear on the supermarket shelves. However, since one does not want to deviate from the principle of “quantity instead of quality”, one hopes to produce more robust fish using genetic engineering.

- Gene against cold: tropical fish in ice water

Fish that are insensitive to the cold are just as interesting for industry. So-called antifreeze genes from naturally cold-tolerant fish species such as the flounder are transferred to heat-loving fish species. The company A / F-Protein (AFP = Antifreeze Proteins) has specialized in this and is a world leader in the development of transgenic fish.

- Sterile fish

By means of genetic manipulation, attempts are made to produce fish that are unable to reproduce, for example by changing certain genes for the fish's hormonal balance. On the one hand, there is - similar to the terminator technology in cultivated plants - the possibility for industry to prevent the unauthorized reproduction of its creations protected by patent. On the other hand, sterile fish lines are supposed to prevent the alien gene constructs from crossing into wild species.

Gene against the cold: tropical fish in ice water

Fish that are insensitive to the cold are just as interesting for industry. So-called antifreeze genes from naturally cold-tolerant fish species such as the flounder are transferred to heat-loving fish species. The company A / F-Protein (AFP = Antifreeze Proteins) has specialized in this and is a world leader in the development of transgenic fish.

Sterile fish

By means of genetic manipulation, attempts are made to produce fish that are unable to reproduce, for example by changing certain genes for the fish's hormonal balance. On the one hand, there is - similar to the terminator technology in cultivated plants - the possibility for industry to prevent the unauthorized reproduction of its creations protected by patent. On the other hand, sterile fish lines are supposed to prevent the alien gene constructs from crossing into wild species.

The ecological risk

It is very likely that the fish - even if they are kept in aquaculture - will end up in the wild. Experience shows that animals regularly escape from the breeding tank. Not only a few, but sometimes hundreds of thousands of individuals escape. The breeding tanks either have direct access to the sea or are in the immediate vicinity of the waters. Here, GM fish, their sperm, eggs or fry can get outside via sewage, exchange water or via spreading by birds and other animals. Developing an escape-proof system is very costly and is not in the economic interest of the grower.

Sloppiness, human error but also unforeseen environmental events such as storms and floods also increase the likelihood that fish will escape. And the consequences can already be felt - even without transgenic fish. The problem with this is that the transgenic fish and the farmed fish are still very similar to their wild relatives and can easily survive in the wild. In addition, they can mate with their wild counterparts. The native fish species are "infiltrated" by foreign genes. Genes find their way into fish populations that would not find their way there in nature even after billions of years of evolution, such as cattle growth genes. No one can answer what kind of consequences this will have on evolutionary processes.

It is clear that once the process has started, it cannot be stopped. If the transgenic fish have a survival advantage over their wild counterparts, they take their place in nature. A problem that has long been observed with farmed salmon: For example, Atlantic salmon are increasingly displacing Pacific salmon from farms. An angler in Norway rarely catches a wild salmon in some rivers. It is assumed that in a few years the wild salmon stock will collapse completely, because farmed salmon keep escaping from the fish farms.

Proponents of genetic engineering like to say that genetic fish are inferior to their natural counterparts in terms of fitness. But amazingly, that is exactly what can lead to the death of a fish population. Namely when, for example, the less fit are more sexually active and thus spread their “worse” genes better. The American scientists Muir and Howard found an example of this in 1999 and used a computer model to calculate what happens if these gene fish escape. For their experiment they used the Japanese fish species Oryzias latipes. A gene introduced into the embryos made them grow faster and become sexually mature, and they also produced more eggs than the non-genetically modified animals. The disadvantage of these GM fish: Overall, only two thirds even reach sexual maturity. Due to the early sexual maturity and the higher number of eggs, the genes of the transgenic animals are spread more widely in the fish population than those of the wild species. The scientists calculated that in just 40 generations, 60 such fish would destroy a fish population of 60,000 fish. The ecologists classify the risk of outcrossing as very high. That is why the genetic engineers are also trying to sterilize the fish using other methods. For example, the fish eggs are subjected to high pressure so that their normally double set of chromosomes increases to three times. Such triploid fish are sterile. Attempts are also made to generate sterile fish populations by irradiating the eggs with gamma radiation or by gender conversion through hormone therapy. But the same applies here: There is no such thing as one hundred percent security. Some fish retain their fertility. And these very few can cause disaster.

Extinction of natural species

But it is not only the outcrossing into the natural species that poses a threat to the native fauna: they are also in direct competition with the wild species. Most transgenic fish are predators. Fatal if such animals - made more robust by cold resistance genes or made hungrier by growth genes - go hunting much earlier in the year. Namely when there is hardly any food in the water. An entire food chain is then interrupted right from the start: The transgenic turbo fish not only eat everything away from their wild counterparts, but at the same time destroy the livelihoods of other species or simply eat them up.

Experiences that we have already made with non-transgenic predators that are alien to the respective body of water should be a warning to us. As a result of the release of alien perch species in Lake Victoria in Africa, no less than four hundred native fish species disappeared within a decade!

Even if the actually intended change should at first glance have no consequences for the respective ecosystem, even small unwanted side effects such as changed territorial, mating or flight behavior in the interaction of the species can have fatal consequences.

Aquaculture against hunger?

As mentioned above, many see aquaculture as the only way to meet the global demand for fish and to curb the exploitation of the world's oceans. But depending on how the aquacultures are managed, they are themselves an ecological problem and consume resources from the world's oceans.

Similar to factory farming of pigs, cattle and chickens, a high concentration of organic waste occurs in a very small space. Most of the wastewater from such systems is discharged untreated into rivers or the sea. In this way, further nutrients get into the already over-fertilized waters. Most of the farmed fish are carnivores and need protein-rich food. To raise one kilo of farmed fish, two to three kilos of fish meal are required. The fish farms devour most of the fish meal, made from caught sea fish. The farmed salmon, which are mostly infested with parasites such as salmon lice, also contribute to the extermination of their conspecifics.

But there are also alternatives: The organic association Naturland has already drawn up “guidelines for natural aquaculture”. And there are already some companies that offer carp, salmon or trout from these organic aquacultures. And the demand is increasing. For this reason, an expansion of the new uniform organic seal is currently being discussed, according to which organic aquacultures must operate in an environmentally friendly manner, use organically produced feed and maintain low stocking densities. Genetic engineering and the preventive use of antibiotics are taboo.

Transgenic salmon as a food

As with the development and marketing of transgenic crops, the US and Canada lead the way in genetically modified fish. But also in countries like Great Britain, Norway and Japan, Cuba and China work is being done on the development of transgenic fish. Trout and carp as well as Atlantic salmon are of particular economic interest. Since 1999, the American Food and Drugs Administration (FDA) has received applications from A / F Protein for transgenic turbo fish. For a long time, protests by environmental organizations in the USA had an effect. The approval of the transgenic fish was postponed again and again for almost 20 years.

In November 2015, however, the authorities buckled and approved the turbo salmon for human consumption. This was the very first time that a genetically modified animal should be brought onto the market as food. However, approval is only about selling the product. Interestingly, the eggs of the transgenic fish may only be produced in a special facility in Canada and the rearing must take place in Panama. From there they are then imported into the USA. So are the US authorities themselves afraid of the fish and its uncontrollable effects on nature should it escape from the facilities?

This could confirm the decision made by the FDA in spring 2016: The authority banned the import and sale of genetically modified fish just two months after their approval. The final approval is to be postponed until the authorities decide whether to label the salmon. 60 supermarket chains had announced that they would boycott GM salmon. Regardless of this, the turbo salmon was also approved for human consumption in Canada in May 2016. It is slated to hit the Canadian market next year without a label.

What can the consumer expect?

In Brussels, AquaBounty, the manufacturer of the GM salmon, has not yet received an application for approval. In the negotiations for the transatlantic free trade agreement TTIP, however, the declared goal of the USA is to open the European market for genetically modified food. For the US food industry, the stricter approval procedures, the zero tolerance for non-approved varieties and the labeling requirement in the EU are trade barriers.

In the CETA agreement with Canada, which is also GM-friendly, the EU Commission has approved an article on the subject of "Biotechnology" which obliges them to enter into a dialogue on genetic engineering and in which the objectives of the dialogue are also laid down. We have analyzed the original CETA text for you. The result: The agreement contains many dangers for the freedom from genetic engineering in Europe and the precautionary principle in the approval process.

Agreements such as TTIP and CETA subject environmental and consumer protection to trade and the profit interests of corporations. In the future, GM salmon could also be sold in our supermarkets without labeling. And in the US, another 30 genetically modified fish and other animals are waiting for approval.

An ecosystem is a complex interplay of different organisms that have worked together over millions of years.If this interaction is suddenly disrupted, it can lead to the collapse of the ecosystem. Our waters are already weakened by environmental pollution, entry of foreign species, structural measures, overfishing, etc. Additional risks in the form of genetically modified organisms cannot be tolerated and must be prevented.