Will terrifying robots be able to curb the spread of the gambosia fish, one of the most problematic invasive species in the world, and the environmental damage it causes?
Yonatan Sher, Angle - news agency for science and the environment
The science fiction fans among us will be happy to hear that some of the futuristic predictions of the genre are coming true: for example, it is possible that we will soon have deadly robots, which are impossible to distinguish from real living creatures except for the fact that they are faster, stronger, and do not need food or rest. True, at the moment early versions of these robots can only be found in aquariums, but this is certainly a promising start.
it's aboutA new Australian study, published in the journal iScience, examined the use of a terrifying robot fish, which knows how to attack its prey, in an attempt to instill fear in the hearts of Gambozia fish - a notorious invasive species that humans have spread around the world, and also in Israel, in order to deal with mosquito hazards and which has since become an ecological hazard of Really, which leaves environmentalists at a loss.
So are a swarm of robotic fish with flashing laser eyes and pointed metal teeth likely to save us from the danger of the Gambos? And what makes the Gambozia (a fish with a maximum length of seven centimeters) so problematic in the first place?
From a resource to a nuisance
The origin of the Gambos is in the USA and northern Mexico, but during the 20th century they were imported into countless freshwater ecosystems all over the world in an attempt to fight diseases transmitted by mosquitoes - that's why the fish are also known as "mosquitofish". "This species arrived in Israel at the beginning of the last century, so all measures were kosher to fight malaria," explains Dr. Dana Milstein, aquatic habitat ecologist at the Nature and Gardens Authority. "Biological pest control (in which one species is used in order to reduce the population of another species, Y.S.) was considered very modern during this period, because they had already begun to understand the problems that could be caused to nature and humans by the toxicity of chemical pesticides."
The great survival of the gambosia fish made them the ultimate mosquito killers, because mosquitoes tend to multiply and become a hazard in polluted water sources. "At first it seemed like a very environmental solution," adds Dr. Gal Zagron, head of the Pest and Pest Control Division at the Ministry of Environmental Protection. "Mosquito larvae know how to survive well in a polluted environment and the gambos that eat the mosquito larvae constitute a solution that seems sustainable and long-term - you can release a lot of fish at the beginning of each pest season and then there is peace, unlike chemical extermination where it is necessary to return and exterminate every few days."
However, the same qualities that made Gambosia good as mosquito repellants - high survival and an inexhaustible appetite, also made them a species that takes over ecosystems and habitats and is difficult to get rid of. In fact, the Gambosia, which for more than a hundred years have spread around the world as an "environmentally friendly solution", are now defined as one of the hundred most problematic invasive species in the world by an organization IUCN.
"Today there is a recognition of the enormous damage potential of the gambosia," says Milstein. "Most chemical pesticides, even if they are catastrophic - eventually break down, Even if it takes decades, but the gambos remain. They have a tremendous potential to reproduce so that one female can establish an entire population. In addition, they are resistant to a wide range of environmental conditions of temperature, salinity and oxygen resistance. It is a very gluttonous fish, which can eat as much as its body weight in a day, and they are not selective, so they cause damage to everything in the habitat, and even when they are not hungry, they are aggressive and attack other fish and amphibians."
stress the fish
In contrast to the methods used in the world that rely on killing the fish in order to reduce their population and thus their damage to the environment, the new development of the fish-robot is designed to demonstrate a creative solution to the danger of gambosis. The experiment tested whether Creating feelings of fear and distress In the case of the Gambosia, their activity will be reduced. Therefore, the researchers built a robot in the shape of a large-mouthed bass fish - a natural predator of the gambos, which is lacking in the environments to which they were imported, such as Israel.
In the experiment, 12 aquarium containers were used, each containing six fish and six tadpoles (food bait for the fish). The fish and the tadpoles were together in the experimental chamber for one hour, twice a week, for five weeks. For half of the groups the fish-robot was also present, which recognized and automatically attacked gambozis if they approached the tadpoles. The researchers report that fish exposed to the robot tended to cling to each other and not explore their surroundings, while the tadpoles that were free of disturbance swam more freely. In addition, fish exposed to the robot were physically smaller, and their sperm count was on average halved, compared to the control group. These effects, which were preserved even weeks after the end of exposure to the robot, the researchers attribute to the stress and fear reactions that the robot evoked in the fish.
Balanced nature - for man
Despite the successful curbing of the gambos' behavior, the researchers note that they do not intend to release hundreds of thousands of robot fish into the wild in the expectation that they will solve the problem, but rather - to demonstrate the potential of using stress and fear responses as a means of dealing with invasive species. According to the researchers, it is possible that the smell of a natural predator will cause similar results, and it may be possible to make practical use of it outside the laboratory.
Today it is already clear that in dealing with the gambos, as with other problematic invasive species, the only perfect solution is to prevent their arrival in the new habitat in the first place, but this does not mean that it is impossible to make policy changes in order to reduce the damage. Contrary to the practice in previous years, hundreds of thousands of gambozias were scattered in Israel every year (an example of this can be seen In the publication of the municipality of Hadera from 2015), last year the Ministry of Environmental Protection issued a ban on the use of gambosia as a pesticide. "Today there are far fewer polluted streams than there used to be, so the need for fish has decreased and there are other solutions to mosquito hazards," explains Zagron. "It is impossible to look at human health without also looking at natural health, because it affects one another. The aquatic habitats contribute to human health and the well-being of all of us, so we need to take care of them in return."
More of the topic in Hayadan:
