Municipalities brace for another Spanish slug season

Spanish slugs are becoming an increasingly big problem in Latvia – in some places they are just starting to appear, but in others the infestation is already spreading rapidly. Although this species was recently officially recognized as invasive, obliging municipalities to contain it and giving them the right to fine landowners who don't try to tackle the pests, at least for now Riga, Bauska and Talsi municipalities do not plan to impose penalties. 

"If in 2022 we were able to mark individual points taken over by the invasion in the city of Talsi, then practically over the past three or four years the spread of the Spanish slug has occurred to such an extent that we can put a big fat dot on Talsi, because they are everywhere," said Jānis Pauliņš, head of the Talsi County Environmental Management Department, adding that in recent years the slug invasion has become uncontrollable. 

"They are in municipal areas, public areas, and private homes. They don't discriminate, they spread at a tremendous speed." 

Spanish slugs have spread beyond the borders of the city of Talsi in recent years, and last year the fight to contain them took place throughout the entire district. 

"So there they are in Kolka, Roja, and Dundaga. In previous years, they weren't there. At the end of last year, we suddenly had a couple of places in Lauciene. So we will continue [fighting] this year," said Pauliņš. 

How is the municipality itself fighting invasive slugs? 

"We have treated municipal properties with iron phosphate limicides. We have educated the public, there have been various lectures, seminars on the spread of Spanish slugs and containment measures. There have been workshops. I will say frankly that they do not bring any real results, because it must be understood that the Spanish slug becomes active in the evening hours - around nine, ten in the evening, so the workshops must be held at a time when many people are already starting to think about going to bed," Pauliņš explained. 

He shared his experience of how the enthusiasm of the volunteers waned over time. 

"Initially, there were ten to fifteen of us, each time it became fewer and fewer, and in the end, in the last meetings we organized, there were two or three representatives of the municipality. But collecting [slugs] is the method that is most effective [in educating the public] – you can see how many you collect, because if the area is treated with iron phosphate, then there is no visual representation of how many have died," said Pauliņš. 

In Bauska, rapid spread was observed last summer 

While the fight against Spanish slugs has been going on in Talsi for several years, it is still at its very beginning in Bauska. Although the slugs have been detected there before, their particularly rapid spread was observed last summer. 

"We experienced an almost explosive invasion last year, when it was one of the most pressing topics for many residents of the Bauska region,"  admitted the deputy chairwoman of the Bauska Regional Council, Linda Abu Meri.

"It seems like there's no place where you can't find slugs. After the rain, the footpaths are full of slugs - just go ahead, step on them and they'll just squirm. And that's pretty scary. But, of course, we have to take into account that Bauska region is a very agricultural region, and for farmers, not only vegetable growers - it turns out that slugs are a big problem for grain growers as well, because it turns out that slugs like both the new rapeseed that has just sprouted and even wheat. So it's a very serious problem," admitted Abu Meri. 

However, there has not been a unified, systematic approach to combating Spanish slugs in Bauska County so far. 

"In previous years, such systematic control has not been implemented. There are four association boards in the Bauska region – Rundāle, Iecava, Bauska and Vecumnieki, and each association board has experimented and done something. There have been experiments with poison, with the so-called blue grains, but it has not proven to be a very effective method," revealed the deputy chairwoman of the Bauska district council. 

This year's budget also does not include separate funding for this. However, as Abu Meri said, Bauska region, together with several Lithuanian regions, has applied for a cross-border project, the aim of which will be to apply systematic methods to combat this species, for example, collecting snails by organizing work groups, as Talsi has already done several times. 

Rīga to begin experimenting with invasive species control 

Rīga will also begin experimenting with limiting this invasive species this year, because the problem is not yet so widespread in the capital, according to the municipality.

"In Rīga, we only received signals about their significant increase last season," said Evija Meģe, Head of the Environmental Department of the Housing and Environment Department of the Riga City Council (RD). "In principle, last year, residents began to be interested in this topic, asking what to do, or what the municipality was going to do."

Meģe said that in Rīga, Spanish slugs could be found in the Mārupīte Forest Park last year. 

"There are also many private houses around there. The slug was also seen in the Mežaparks territory, and "Rīgas meži" as the territory manager also started trying to combat this problem, how to form groups, place containers where volunteers could throw them if they found them while visiting the park," Meģe explained. 

Meģe pointed out that, at least for now, the city has not developed a systemic plan to control Spanish slugs.

"This year we plan to start experimenting in our own territories. Not through outsourcing, but through our own employees who will take courses to be able to purchase restrictive chemical agents and test how they work," said the representative of the municipality. 

At the same time, the municipality promises to follow up on reports from residents about Spanish slugs' distribution areas. "An action plan to eradicate the Spanish slug in the entire city is probably not realistic. Most of the methods are mechanical and manual. Hand picking, which works well for protecting a small area," said Meģe. 

This means that the Riga Municipality will have to evaluate priorities, determining which areas to protect from invasive slugs. 

"Where are there any established green spaces that we would like to protect, where both funds and work have already been invested to create such an environment? These will probably be parks, gardens, squares. Well-maintained green areas," the city council representative explained. 

Currently, the Riga Municipality budget does not provide additional funding for the control of Spanish nudibranchs. 

No plans to impose 'slug fines'

Although the Spanish slug has recently been officially recognized as an invasive species, giving municipalities the right to also fine landowners for not restricting the snails, the Riga, Bauska, and Talsi municipalities surveyed by Latvian Radio do not plan to impose penalties for now. 

"This year, we will most likely not set such explicit criteria. It must be understood that all municipalities must work together. There must be uniform standards for how much is controlled and how much a municipality can do," said Pauliņš, head of the Talsi Municipality Environmental Management Department.

Speaking about penalties for landowners, Pauliņš pointed out that the situation is not as simple as with another national problem – invasive giant hogweed plants. If they grow on private property, the police can establish the fact and impose a fine, but with slugs it will be more complicated. 

"A snail is mobile. One day it is in the ownership of the municipality, the next day it will be in private ownership," Pauliņš pointed out. 

Is the fight in Latvia already lost, given the rapid proliferation of Spanish slugs? 

"That first moment, when they just, just arrived and there were few of them, is long past, and we have to accept that these snails are here to stay, but that, of course, does not mean that nothing needs to be done," said Aiva Bojāre, an invasive species expert at the Nature Conservation Authority (DAP). 

"In principle, the Spanish slug is already present throughout Latvia. It is most widespread in the central part of Latvia. This is Riga, Pieriga, Jelgava, Sigulda. There is a significant concentration there." 

"But in principle, they have also been found in many other places, more so in Kurzeme. The fewest are currently in the eastern part of Latvia, in Latgale," Bojāre said. 

This season is not promising. Although the winter was cold, the snow cover protected the soil from freezing, creating favorable conditions for the Spanish slugs to hibernate. They will emerge soon and wreak havoc.

"Try not to have places in your territory that are suitable for them to live - piles of branches, piles of leaves, some kind of stacks of boards, under which they can very successfully hide and accordingly live and reproduce. Of course, also start mowing the grass in a timely manner and keep your territory in order," advised the DAP expert.