Research Article |
Corresponding author: Karolina Bącela-Spychalska ( karolina.bacela@biol.uni.lodz.pl ) Academic editor: Eric Larson
© 2024 Krzysztof Podwysocki, Andrea Desiderato, Tomasz Mamos, Tomasz Rewicz, Michał Grabowski, Alicja Konopacka, Karolina Bącela-Spychalska.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
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. https://doi.org/10.3897/neobiota.90.109221
|
Non-indigenous species (NIS) contribute to the decrease of native species’ diversity on a local and global scale. One of Europe’s most significant donors of freshwater invasions is the Ponto-Caspian Region. Following the construction of artificial canals connecting isolated waterbodies and the resulting heavy boat traffic, the Ponto-Caspian Amphipoda started to spread in Europe. Four amphipod species: Dikerogammarus haemobaphes, Dikerogammarus villosus, Pontogammarus robustoides and Chaetogammarus ischnus have invaded the Masurian Lakeland (North-eastern Poland). Based on literature and our data, we studied their distribution in 22 lakes in the region during the years 2001–2016. We analysed their distribution against several water quality parameters and levels of anthropogenic pressure. Our results also present the first records of two new invaders, D. villosus and C. ischnus, in the studied area. We show that the relative abundance and frequency of these two species rapidly increase and, simultaneously, the populations of the earlier invaders, i.e. D. haemobaphes and P. robustoides, decrease. The native species – Gammarus lacustris – seems to be negatively affected by NIS richness, as well as by the proximity of towns. The spread of NIS in the lakes appears to be facilitated by boating and the lower complexity of the shoreline. Our study shows how anthropogenic pressure, especially tourism, can facilitate bioinvasion, jeopardising native biodiversity unless appropriate regulations are implemented.
assemblage succession, biological invasions, lakes, propagule pressure, recreational boating, time series, tourist pressure
Biological invasions are perceived as the second strongest threat to biodiversity on a local and global scale, right after habitat degradation (e.g.
Even though surface freshwaters represent only 0.01% of the Earth’s water resources and constitute 0.80% of the Earth’s surface, they are inhabited by ca. 6% of the world’s species (
One of the richest European sources of species invading inland waters is the Ponto-Caspian Region (
Seven species of Ponto-Caspian gammarids (Amphipoda, Gammaroidea) have already been recorded from Polish freshwaters: Chaetogammarus ischnus (Stebbing, 1899), Dikerogammarus haemobaphes (Eichwald, 1841), Dikerogammarus villosus (Sowinsky, 1894), Obesogammarus crassus (G.O. Sars, 1894), Pontogammarus robustoides (Sars, 1894), Spirogammarus major (Cărăușu, 1943) (former European population of Echinogammarus trichiatus) and Chelicorophium curvispinum (G.O. Sars, 1895) (
Lakes seem to be particularly susceptible to biological invasions, as many of them are under high tourist pressure, resulting in a higher probability of alien species introduction, even if the lakes are not directly connected with the invasion corridor (
The aims of our study were: i) to update the knowledge on the distribution and expansion of the Ponto-Caspian amphipod fauna in the Masurian Lakeland; ii) to assess the distribution of native vs. invasive Ponto-Caspian amphipods in the context of biotic and abiotic characteristics of the lakes and anthropogenic pressure in this region, using both historical and newly-obtained data. Based on observed trends in other regions (e.g.
We tracked the distribution of invasive Amphipoda in the Masurian Lakeland since 2001, based on literature and our data. To explore the relationship between the structure of amphipod assemblages and lake characteristics, including human tourist pressure in the years 2014 and 2016, we collected data on the relative abundance of amphipods, measured basic water parameters, implemented hydromorphological data and estimated the tourist pressure.
The Masurian Lakeland (Pojezierze Mazurskie in Polish) is a lake district (macroregion) in North-eastern Poland with a surface area of 52,000 km2 including seven mesoregions, amongst others, the Land of the Great Masurian Lakes (Kraina Wielkich Jezior Mazurskich in Polish) and the Ełckie Lakeland (Pojezierze Ełckie in Polish) (
The sites in the Masurian Lakeland. Sites were divided into previously unpublished (records of this study) and published (
Our dataset consists of two types of data: (i) published, including the years between 2001 and 2007 (
To detect the potential role of biotic and abiotic factors, as well as human pressure on the presence of invasive amphipods in the lakes sampled in 2014 and 2016, we used topological and anthropogenic variables, such as the surface-volume ratio or the distance from town. As a proxy of the level of anthropogenic pressure, we used the water quality status (water QS) from
Using all unpublished records since 2008 from the lakes and the rivers, including sites outside the study area (see Suppl. material
Using samples collected in 2014 and 2016, we first explored the variability of the environmental parameters of the sites and lakes, grouping them according to their geographical position and connectivity (i.e. I: northern, II: southern, III: eastern; Fig.
A the distribution of invasive and native amphipod species in studied lakes since 2001, based on published and new data (locality codes according to Suppl. material
We recorded four invasive gammarid species from 12 lakes and the Rivers Węgorapa and Pisa and one native species (Gammarus lacustris) from 16 lakes (Fig.
Generally, the native species – Gammarus lacustris – was not found in lakes inhabited by invasive species, apart from Lake Dobskie, where the native and invasive gammarids co-occurred in 2014 with a low number of G. lacustris (two individuals vs. 194 individuals of invasive species) (Fig.
The first three components of the PCA explained 85.5% of the variance amongst the environmental variables (Fig.
Biplots displaying the first three axes of the PCA of the environmental variables of the lakes sampled in 2014 and 2016 (A PC1-2 B PC1-3). The colours refer to the different lake groups: orange circles (I), green triangles (II) and blue squares (III). The lengths of the arrows are proportional to the loading of each variable, dashed lines = 0. The acronyms of lakes are according to Fig.
The first two axes of the dbRDA fitted 90.1% of 52.1% of the total variation explained (Fig.
Canonical analysis of principal coordinates (CAPSCALE) derived from the Bray-Curtis dissimilarities of the gammarid assemblages and the environmental variables of the studied lakes in the years 2014 and 2016. The colours of the dots refer to the different lake groups: orange circles (I), green circles (II) and blue circles (III).
Our study shows that, between 2001 and 2016, the number of invasive amphipod species in the study area increased drastically from one (D. haemobaphes) to four (three more species recorded: D. villosus, P. robustoides, C. ischnus). Simultaneously, a continuous decrease in the occurrence of native Gammarus lacustris was recorded. Our study reveals that the presence of NIS in lakes is primarily facilitated by three key factors: recreational boating activities, proximity to urban areas and simplified lake shorelines.
According to our results, the presence of more than one NIS significantly affects the presence of the native G. lacustris, bringing the probability of its presence almost to zero already with three NIS (Fig.
These four lakes (three of them in the eastern group of lakes) are characterised by low tourist pressure (low number of boats, long distance from the tourist routes) (Fig.
Instead, we recorded G. lacustris in lakes characterised by a high level of shoreline development. Lakes with higher shoreline complexity may provide higher habitat diversity, resulting in lower competition rates between species on environmental resources and, consequently, promoting the possible co-existence of many species, both native and invasive amphipods (
The declining populations of G. lacustris in our studies are similar to the general tendency observed in Europe. This species seems to be one of the weakest competitors amongst European freshwater amphipods giving way to the Ponto-Caspian species of genera: Chaetogammarus, Dikerogammarus and Pontogammarus (
Similarly, we did not record another native amphipod, Pallasiola quadrispinosa, also recorded as declining in the freshwater ecosystems due to invasive amphipods (
Our findings report the set of lake features promoting the distribution of native amphipod species in the studied lakes. As the study area is highly impacted by tourist activities, our results can be useful for better comprehension of the threats to native amphipods in other regions with similar levels of anthropogenic pressure and biological invasions. Our conclusions may highlight the need to protect isolated lakes from tourism and urban area development.
Freshwater NIS can easily spread with tourist activities, including yachting and angling in particular. Our results show that the number of boats is one of the factors which best explains the distribution of D. villosus (Fig.
Similar findings were done in other tourist lakes. In Alpine lakes, with higher yachting activity than in the Masurian Lakeland, the expansion of D. villosus was caused by yachting and using diving equipment (
Overland transport of boats may explain the invasion of D. villosus in our study area. Although D. villosus was found in most of the recently studied lakes, the species was not found in the River Pisa and the River Węgorapa. These rivers connect the Masurian Lakeland with large rivers, where D. villosus is present. It suggests the possible expansion of this species in the Masurian Lakeland by overland transport apart from these rivers. In certain lakes, we did not record D. villosus. These lakes have no direct contact with the invaded lakes and low tourist activity almost excludes the possibility of overland boat transport. In contrast to the Alpine lakes, we did not expect diving and angling (using waders) equipment to play a significant role in invading isolated waterbodies by D. villosus in the studied area.
Another strong factor explaining the distribution of D. villosus is the distance from town. Our results show that this species occurs mainly in the lakes with towns nearby. Proximity to the town and tourist activities are correlated with each other. Most of the marinas are located in towns with well-developed tourist facilities. Indeed, the proximity to the ports and marinas is an important factor in promoting the expansion of D. villosus (
Distribution of other invasive species in the Masurian Lakeland, i.e. P. robustoides, D. haemobaphes and C. ischnus, concerns mainly the lakes with less developed shoreline and rather low water quality (higher class of water status). Predominantly, they are present in lakes with different conditions compared to those where D. villosus was found (Figs
Another species rapidly spreading in the Masurian Lakeland is Chaetogammarus ischnus. In the study area, this species was recorded for the first time in 2014 (Fig.
Our results constitute an important contribution to the long-term observation of expansion dynamics of Ponto-Caspian amphipods and can be part of global databases monitoring invasive species. Rapid expansions underline the importance of regular, annual samplings in lakes and watersheds connecting them with invasion corridors. We show the very important role of tourist activities in lakes in the expansion of alien amphipods, in particular of D. villosus. These findings underline the important role of permanent monitoring of yachting and shipping vessels. Our predictions can be applicable in other tourist freshwater areas and help designate protection zones limiting boating. Our results can be also valuable to studies on other biofouling taxa. The significance of the town’s proximity for the amphipod invasion is due to well-developed tourist facilities in urban areas and possibly water pollution; thus, lakes shorelines and marinas should be controlled as well. Water connections between lakes also should be regularly monitored. Our records of Chelicorophium curvispinum in the River Narew in 2014 and 2016 suggest that this species may be the next recorded invasive amphipod in the Masurian Lakeland (see Suppl. material
Although our data come from several years, it is important to indicate that the most recent data come from 2016; thus, the current invasion status in the study area can be worse than what we present here. The lack of lakes where native and invasive amphipods co-occur makes some of our findings difficult to interpret and partially speculative.
One of the crucial findings of our study is the impact of boating on the invasions. However, we need to remember that the methods we used have some limitations. We used the maximum capacity of marinas as the number of boats in use. Although on busy days the percentage of used boats in the total number of moored boats is high, as shown in
Lakes, especially those with high shoreline complexity, provide many habitats which various species can occupy. Therefore, analysing the data based on one sampling per lake may not depict the real diversity of the amphipod communities. Especially, the lack of records of amphipods in Lake Nidzkie, which has a connection with other lakes and Masurian tourist routes, suggests not enough efficient sampling. We need to be aware that the absence of a species in one sample does not exclude the possible occurrence of this species in other habitats of the same lake. Thus, our results, showing the replacement of native species by invasive species, present interesting trends, but are insufficient to conclude the extinction of certain species. Therefore, our findings should be perceived as predictions, not postulates.
Future studies would benefit from utilising a more thorough and systematic sampling to provide a more accurate and reliable picture of the invasion process.
Our results show the importance of the proximity of sampling points to towns for invasions. Although we assume that this correlation is connected with tourist facilities and pollution, implementation of more data is needed in the future. Particularly, the distance between sampling points or lake centroid and marinas should be implemented in the analyses (
Additionally, using the actual number of boats in use in the area would be advisable as was done in studies by
As far as the financial and technical situation allows, samples should be collected from a large number of points on each lake. Additionally, studying a greater set-up of lakes would allow better tracking of invasions and more accurate detection of all amphipod species in the lakes. Finally, tracking of the invasion process can be supported by molecular studies (e.g.
The rapid expansion of the invasive Ponto-Caspian amphipods observed in this study aligns with a general trend along European freshwater basins. The contraction of the range and niche of native species when faced with more aggressive (e.g. D. villosus) and/or generalist (e.g. C. ischnus) species is something expected and confirmed by our findings. Even though many lakes seem to be still free from amphipod invaders, this may be for a short time considering the abrupt increase we have registered in just two years.
Our study emphasises the need for a comprehensive approach to understanding and addressing the dispersal of alien species through human activity. Our findings highlight the important role of boats in the spread of invasive amphipods within lake systems. The invasion process of Dikerogammarus villosus especially suggests the possible impact of overland boat transport in spreading this species in new lakes.
Furthermore, it is essential to raise awareness amongst lake users about the negative consequences of biological invasions and the necessity of implementing a “check, clean and dry” policy. By educating and engaging lake users, we can foster a sense of responsibility and cooperation in preventing the spread of invasive species. Implementing these measures collectively will contribute to better biosecurity practices and safeguard the ecological integrity of lakes against invasive species.
We would like to thank Krzysztof Jażdżewski, Ewa Janowska, Mariusz Surlejewski, Olga Antczak-Orlewska, Paula Krzywoźniak, Remi Wattier, Aleksandra Jabłońska and Anna Jażdżewska for help during sampling and their valuable suggestions. We would like to thank Stephen Venn for linguistic corrections and for providing valuable suggestions that improved the overall quality of the manuscript. We are grateful to Denis Copilaș-Ciocianu for the suggestions concerning the taxonomic status of Spirogammarus major.
Metadata for each sampling site and date
Data type: xlsx
Explanation note: Sampling sites between the years 2001–2016 with a number of individuals (or +/-) for the presence/absence) of each recorded Amphipoda species (names of invasive species have been underlined). Symbols for lakes provide two-letter acronyms used on the figures. Symbols for rivers and canals provide three-letter acronyms used on the figures. Water QS: Water quality status (
Summary of the best-fitting Bernoulli GLMM for the presence of native gammarid – Gammarus lacustris
Data type: docx
Results of PERMANCOVA test using 9999 permutations
Data type: docx
Supplementary image
Data type: jpeg