Invasive amphipods are larger, reproduce more intensively and are more resistant than native species, so it is no wonder that they are replacing them. – True, just like “our” crustaceans, they can be food for fish and ducks, but at the same time they are a big threat to the ecosystem. Not only do they prey on native crustaceans and other invertebrates, but they also devour fish eggs, thus significantly affecting their reproduction. In a word, their spread in the Masurian lakes is bad news
– explains Dr Andrea Desiderato from the Department of Invertebrate Zoology and Hydrobiology, Faculty of Biology and Environmental Protection, University of Lodz.
Invasive amphipod: Dikerogammarus villosus (photo by Michał Grabowski)
Research on invasive crustacean species conducted by researchers from Lodz was initiated in the 1980s. by Prof. Jażdżewski – The invasion of crustaceans is a long-term process, but from the environmental point of view, quite dynamic – explains Krzysztof Podwysocki from the Department of Invertebrate Zoology and Hydrobiology, Faculty of Biology and Environmental Protection, University of Lodz. – In just two years, we have observed the rapid spread of amphipods in Masurian lakes.
Worryingly, crustaceans also appear in isolated water bodies that are not supplied with water from rivers or connected by canals to other lakes. It might seem, therefore, that they will not be able to get there on their own. It turns out that they use people to do this.
– These organisms behave like hitchhikers – explains Dr Andrea Desiderato. – They attach themselves to water equipment: boats, kayaks, surfboards and SUPs, scooters, as well as buoys, ropes and even diving suits, and this way, together with tourists, they move between water bodies.
– Our research shows that in a favourable, humid environment, Ponto-Caspian amphipods can survive even a few days out of water – says Krzysztof Podwysocki. – So, by transporting a boat or other floating equipment between lakes, we can also transfer these organisms. And it is happening on an increasingly larger scale. Our team has also conducted research on Alpine lakes and also found the presence of invasive amphipods in isolated water bodies. They could not have gotten there except with the help of humans.
Every year, over 100,000 tourists come to Masurian Lakeland, for most of them sailing and water sports are the main purpose of their stay. – Such mass tourism cannot remain without an impact on the natural environment – says Krzysztof Podwysocki. – We must take into account the fact that the effects of the appearance of these species in lakes are often irreversible.
– The biofouling of organisms to boats is a commonly observed phenomenon, it also happens on sea boats or ships – says Dr Andrea Desiderato. – However, those organisms are larger and clearly visible, and by biofouling boats or ships, at some point they make swimming difficult, which is why people clean sea vessels. In freshwater the situation is slightly different. Ponto-Caspian amphipods are small, inconspicuous and do not impede swimming. – Tourists are usually unaware of their existence, and as a result, they do not care about getting rid of them before transporting their water equipment – adds Krzysztof Podwysocki. – And it is this lack of awareness that is the biggest problem.
Invasive amphipod, Dikerogammarus villosus in the shells of an invasive zebra mussel (photo by Luca Desiderato)
In Western countries (USA, Canada and Great Britain) and also in some Scandinavian countries, legal regulations regarding water sports have been introduced. Boats may only be launched in designated areas, and before changing water areas they must be thoroughly cleaned and dried, and ropes and buoys must be thoroughly disinfected. There are also regulations that specify how such cleaning should look like. – In Poland, there are no regulations in this area, but we hope that our research will contribute to increasing awareness of the threat and introducing legislative changes – says Krzysztof Podwysocki. – In the meantime, it would be great if sailors and other users of water equipment were aware that equipment should be thoroughly cleaned before transport between waters. Our observations show that ordinary water under pressure, e.g. from a pressure washer, works perfectly for this purpose.
Monitoring how floating equipment is transported between lakes seems to be an important element in preventing the invasion of amphipods. – In our opinion, it is necessary to introduce a register or at least surveys among tourists: in what directions they travel, with what frequency, at what time – adds Krzysztof Podwysocki. – This way, we would have a chance to control the invasion routes and prevent it.
Source: Faculty of Biology and Environmental Protection, University of Lodz
Text: Justyna Kowalewska (3PR)
Photos: Michał Grabowski, Luca Desiderato
The results of the research by the team from the Department of Invertebrate Zoology and Hydrobiology of the University of Lodz have been published in the scientific journal NeoBiota: Podwysocki, K., Desiderato, A., Mamos, T., Rewicz, T., Grabowski, M., Konopacka, A., Bącela-Spychalska, K. (2024). Recent invasion of Ponto-Caspian amphipods in the Masurian Lakeland associated with human leisure activities. NeoBiota, 90, 161-192.