"Not as Dramatic as the COVID Pandemic, but a Major Problem": Invasive Species Numbers Growing Rapidly

One of the most significant environmental stories in recent weeks has been the appearance of nutria in the Kis-Balaton region. Recognised as one of the world's most impactful invasive mammals, this species is spreading rapidly across Hungary. Its presence can cause serious ecological and economic damage, as its activities can drastically alter aquatic habitats. However, this is not the first time Hungary has faced such an invasion.

"The spread of invasive species is an accelerating global trend, but from an ecological perspective, it is a well-known phenomenon. Many species rely on others to transport them to distant areas, while others spread via wind or water. The key shift occurs when humans take on this role as carriers," explains László Zsolt Garamszegi, Director-General of the HUN-REN Centre for Ecological Research.

In addition, the world's population is growing, and we travel and trade extensively—human-mediated dispersal has only accelerated the spread of invasive species. Furthermore, we are constantly reshaping our environment, creating new habitats and ecological niches through climate change, agricultural practices, and urbanisation, to which invasive species readily adapt. According to the ecologist, this trend is intensifying worldwide, and Hungary is no exception.

"The challenge is that this phenomenon is not always as dramatic as a COVID pandemic," the researcher points out, adding that the COVID pandemic itself can also be viewed as an invasive process.

This is partly because invasive species and their impacts are often hidden; we only notice those that are conspicuous—"either very biting, very colourful, very smelly, or very cute." However, when a tiny pest or pathogen enters the system, it is often only noticed once it causes problems," explains the Director-General of HUN-REN CER. "Twenty per cent of the scale insect fauna in Hungary consists of introduced species; the average person is unaware of them, but agriculture is constantly battling against them."

Another problem is that there is no realistic understanding of the scale of the invasion. The list of invasive species continues to grow, which in turn increases the ecological challenges, as each species has a unique story. Researchers need to continuously monitor the spread of these species, uncover their pathways of introduction, and understand their impacts on nature, agriculture, and public health. "There are not enough ecologists in the world to assess this meaningfully. Furthermore, these processes must be studied locally; it is not enough to know what is happening in other countries, as ecological conditions vary everywhere," says László Zsolt Garamszegi.

The complex nature of the problem requires a multifaceted solution. As with epidemic management, the most effective approach seems to be early intervention, as this greatly increases our chances of preventing drastic consequences. "If we could identify these species at an early stage and control their entry into the country, we could establish an early barrier to the process at a relatively low cost," explains the expert. However, prevention strategies often fail due to various logistical constraints. Typically, there are no monitoring systems linking several countries, we do not fully understand the pathways of individual species' spread, and we cannot make accurate predictions about the appearance of a particular species due to a lack of adequate data. In addition, the available control measures are not effective enough, notes László Zsolt Garamszegi. "It is a mission impossible. There are practically no good examples of this working," he adds.

According to the researcher, we can only mitigate the effects and take steps to slow down the process. "Clearly, we need to take action against them, but we should also focus on preparing people for sustainable coexistence with invasive species in the long term. With the increase in tourism and trade, we should expect a growing number of alien species to be introduced."

A great example of coexistence is the black locust tree, which, despite being an invasive species in Hungary, has been recognised as a Hungarikum since 2014. Introduced in the early 18th century, it was initially planted to stabilise the sandy soils of the Great Hungarian Plain. Over the past century, however, it has spread dramatically, making eradication virtually impossible and causing significant ecological damage to native forests and grasslands. On the other hand, it has considerable value in forestry, as firewood, and in beekeeping. "Over time, we have learned to resolve this conflict—the black locust has gained social acceptance, and we can now manage the situation from a conservation perspective as well. Today, this species accounts for 25 per cent of our forests."

"You can fight like Don Quixote, but you won't achieve much because invasive species tend to be highly resistant to physical or chemical control, while their pathways of spread remain beyond our control," says László Zsolt Garamszegi. According to the researcher, rather than focusing on prevention, we should aim to slow the process down to mitigate its impact and give nature and society time to adapt. "There will undoubtedly be adverse effects, but I believe we are better off recognising them and preparing accordingly. Take the tiger mosquito, for example—many claim that it is causing such-and-such epidemics in Hungary. At present, this is not the case, but it is important to make this statement with the awareness that a continuous monitoring system is operating in the background."

"Of course, just as defining the problem is challenging, so are finding solutions and preparation, as effective communication and cooperation among multiple stakeholders are essential. While epidemic prevention requires the coordinated efforts of ecologists, virologists, and public health authorities, tackling invasive species calls for the involvement of an even broader range of disciplines," says the Director-General of HUN-REN CER.

Invasive species pose a threat not only to human health but also to the health of plants and animals, as well as the overall well-being of ecosystems. This makes it even more important to involve a broader range of stakeholders in awareness and action programmes. "When it comes to practical considerations, the issue extends beyond a purely scientific task—decision-making on these matters requires the involvement of multiple actors. The challenge becomes even greater when stakeholders have conflicting interests and interpret the situation differently."

"The aim of preparing for adaptation is not to stand by and watch invasions accelerate simply because we cannot prevent them. It is about shifting priorities. There is much we can do proactively to mitigate the harmful effects of these species, even if we cannot stop them," concludes László Zsolt Garamszegi.

"We need to incorporate the accelerating spread of invasive species into public awareness. Just as we discuss climate change, we must also address this issue. Invasions are not as prominent in public consciousness as global warming, even though they present a challenge of similar magnitude. This, too, can be a ticking time bomb set in motion by human activity," adds the Director-General of HUN-REN CER.