Cold-tolerant traits that favour northwards movement and establishment of Mediterranean and Ponto-Caspian alien aquatic invertebrates

Embargo until 26 July 2023Over recent decades, many Mediterranean and Ponto-Caspian aquatic invertebrate species have dispersed northwards and established as non-native species in colder regions. We hypothesized that these species have cold-tolerant traits, which facilitate dispersal into colder climates. Thanks to these traits, Southern European aquatic species are able to cross biogeographic boundaries. We downloaded the list of all alien invertebrate species that were fully aquatic (i.e. lacking terrestrial adults) from the GRIIS database and picked out those Mediterranean and Ponto-Caspian species that have undergone northwards range expansion. We identified traits that may facilitate dispersal to colder climates including the following: small size; capacity for behavioural thermoregulation; feeding habit (omnivorous, filter-feeders, food generalists); quiescence and dormancy (or diapause); freezing avoidance (presence of cryoprotectants); tolerance to low temperatures or eurythermicity; active dispersal; and enhanced reproduction. We statistically tested the null hypotheses that Mediterranean and Ponto-Caspian alien aquatic invertebrate species that dispersed into the north have all of these traits. We used contingency tables populated with raw frequency data with χ2—tests and assessed statistical significance at α of 0.05. We identified 95 Mediterranean and Ponto-Caspian alien aquatic invertebrate species that have shown northwards range extension, 10 (10%) of which were of Mediterranean origin and 85 (90%) of Ponto-Caspian origin. We found that this northwards dispersal from Southern Europe is mainly limited to a few following groups of aquatic invertebrates: small crustaceans, molluscs, cnidarians and annelids. Ability to go to diapause, hibernation or resting period, temperature tolerance and small size were the traits most commonly shared by these organisms. We conclude that Mediterranean and Ponto-Caspian aquatic invertebrate species showing northwards range expansion have cold-tolerant strategies. The traits analysed can favour the establishment of the species.acceptedVersio

Nuclear power and coastal birds: predicting the ecological consequences of warm-water outflows

Local alteration of species abundance in natural communities due to anthropogenic impacts may have secondary, cascading effects on species at higher trophic levels. Such effects are typically hard to single out due to their ubiquitous nature and, therefore, may render impact assessment exercises difficult to undertake. Here we describe how we used empirical knowledge together with modelling tools to predict the indirect trophic effects of a future warm-water outflow on populations of shorebirds and wildfowl. Of the main potential benthic prey used by the birds in this instance, the clam Macoma balthica was the only species suspected to be adversely affected by a future increase of temperature. Various scenarios of decreases in prey energy content, simulating various degrees of temperature increase, were tested using an individual-based model, MORPH, in order to assess the effects on birds. The survival and body condition of eight of the 10 bird species modelled, dunlin, ringed plover, turnstone, redshank, grey plover, black-tailed godwit, oystercatcher and shelduck were shown to be not influenced even by the most conservative prey reduction scenarios. Most of these species are known to feed primarily on polychaete worms. For the few bivalve-feeding species, the larger size-classes of polychaete worms were predicted to be a sufficient alternative food. Only knot was predicted to have a lower survival under the two worst case scenario of decreased M. balthica energy content. We believe that this is the first time such predicted cascade effects from a future warm-water outflow have been shown

Are Ponto-Caspian species able to cross salinity barriers? A case study of the gammarid Pontogammarus maeoticus

Recently, Ponto-Caspian species (i.e., area of Azov, Black, and Caspian Seas) have invaded brackish and freshwater habitats of the North and Baltic Seas and the Laurentian Great Lakes in much higher numbers than expected based on shipping frequency and environmental conditions among these regions. Therefore, it has been suggested that Ponto-Caspian species may have inherent advantages over other species in colonizing new habitats, or that they are of freshwater origin. Artificial selection offers the possibility to investigate phenotypic plasticity, shifts in environmental tolerance, and heritability of environmentally sensitive traits; therefore, in this study, we conducted artificial selection experiments on Ponto-Caspian amphipod Pontogammarus maeoticus collected from 10 PSU to evaluate adaptation capacity of this species to different salinities, and to shed additional light on a possible freshwater origin of Ponto-Caspian invaders. Our results indicated that selection to lower salinity than that of the population's ambient salinity is possible within few generations due to a likely existence of standing polymorphic variation for selection to act on. In contrast, selection to higher salinity was unsuccessful because the phenotypic variation was mainly caused by environmental variance and therefore might depend on new mutations. Consequently, the results of our study suggest that the tested species might be of freshwater origin and lacks necessary genetic background for adaptation to fully marine conditions. Further selection studies using more species and populations, as well as molecular techniques, should be conducted to elucidate if other Ponto-Caspian invaders are of freshwater origin as well

From chitin to chitosan – a potential natural antimicrobial agent

Chitin is a naturally occurring polymer. Together with its derivatives such as chitosan, it has a wide spectrum of application possibilities, and many properties not yet exploited. Chitosan possesses many features desirable in an ideal antimicrobial polymer. It shows activity against multidrug-resistant bacterial and fungal strains that pose a challenge to modern medicine. Chitosan also shows activity against certain viruses, such as SARS-CoV-2. It might be used as a drug or a vaccine delivery system, is biodegradable, bioavailable and considered safe for medical use. It is important to continue exploring the potential of chitosan, as well as to investigate its sources. Indeed, many sources of this polymer are still not or have been poorly described. In this paper, we compile the current state of knowledge on the antimicrobial properties of chitosan, list alternative sources of chitin to highlight the potential of these two polymers and encourage further research

New data on the non-indigenous gammarids in the Vistula Delta and the Vistula Lagoon

This communication reports on the occurrence of non-indigenous gammarid species of Ponto-Caspian and of North American origin – in the lower course of the River Vistula, in its Delta and in the Vistula Lagoon

The Baltic Sea under Anthropopressure—The Sea of Paradoxes

The Baltic Sea is a unique ecosystem that is especially sensitive to anthropogenic pressure. We analysed human pressure in this sea, which may be considered as paradoxes. One of these, is paradox of “marine” pollution. The Baltic Sea is almost totally surrounded by land and therefore sources of marine pollution are located mainly on the land. Another paradox is connected with shipping traffic intensity and maritime accidents. The Baltic Sea is characterised by the large shipping traffic, but the last decades’ data show only more than 100, usually insignificant and minor, accidents and incidents at the Baltic Sea every year. Although the Baltic Sea is characterised by a relatively low native species number compared to most marine systems, it is home to alien species. Moreover, despite the common opinion that a sea is a source of living marine resources, available riches in the Baltic Sea under anthropopressure are limited and the sea does not give expected benefits—it is the next paradox. The fact that the Baltic Sea is warming rapidly due to climate change and more suitable for bathing when the weather is favourable, massive algae growth often prevents it. Therefore, strong human impact on the Baltic Sea should be limited and sustainable use of this sea should be prioritised

The Baltic Sea under Anthropopressure—The Sea of Paradoxes

The Baltic Sea is a unique ecosystem that is especially sensitive to anthropogenic pressure. We analysed human pressure in this sea, which may be considered as paradoxes. One of these, is paradox of “marine” pollution. The Baltic Sea is almost totally surrounded by land and therefore sources of marine pollution are located mainly on the land. Another paradox is connected with shipping traffic intensity and maritime accidents. The Baltic Sea is characterised by the large shipping traffic, but the last decades’ data show only more than 100, usually insignificant and minor, accidents and incidents at the Baltic Sea every year. Although the Baltic Sea is characterised by a relatively low native species number compared to most marine systems, it is home to alien species. Moreover, despite the common opinion that a sea is a source of living marine resources, available riches in the Baltic Sea under anthropopressure are limited and the sea does not give expected benefits—it is the next paradox. The fact that the Baltic Sea is warming rapidly due to climate change and more suitable for bathing when the weather is favourable, massive algae growth often prevents it. Therefore, strong human impact on the Baltic Sea should be limited and sustainable use of this sea should be prioritised

The ditch through the Vistula Spit or the interference in biodiversity of the Vistula Lagoon?

Budowa kanału łączącego Zalew Wiślany z Morzem Bałtyckim to ogromna inwestycja, która może mieć wpływ na środowisko, zarówno w trakcie budowy, jak i w czasie jej użytkowania. Idea tego kontrowersyjnego przedsięwzięcia wciąż odżywa. Artykuł podejmuje dyskusję różnych aspektów hipotetycznego wpływu przekopu na ekosystem Zalewu Wiślanego, a szczególnie na jego różnorodność gatunkową w bezpośredniej lokalizacji inwestycji.The ditch through the Vistula Spit, connecting the Vistula Lagoon with the Baltic Sea is the huge investment, which may effect on the environment during the building and exploitation. Idea of this controversial investment still revives. Hypothetical effects of the ditch through the Vistula Spit on the ecosystem of the Vistula Lagoon and especially on its biodiversity of macrozoobenthos near the onvestment are discuss

A new horizon-scanning tool to identify potential aquatic invasive alien species introduced into the Baltic Sea by shipping

2023 descuento MDPISome invasive alien species (IAS) may constitute an important threat to global biodiversity due to major ecological impacts. In 2014, the European Union (EU) introduced a regulation (EU) No 1143/201 on the prevention and management of the introduction and spread of IAS. EU member states are required to carry out an analysis of the introduction and spread of potential IAS in their territories. In the case of aquatic alien species, shipping is considered as the main pathway for their introduction. In this study, a horizon-scanning tool was applied for identifying potential aquatic IAS introduced by shipping into the EU Baltic Sea Region (BSR) countries. This tool has mostly been applied on a country level, but it is more reasonable to study the invasive potentiality at a regional scale, especially for aquatic species that generally disperse over long distances. Individual Baltic countries may also benefit from the results of this study. The result of the horizon-scanning method that we applied produced a list of 27 potential aquatic invaders for the EU BSR countries introduced by international marine and inland shipping. In order, Asia (34% of the species), North America (27% of the species), and Indo-Pacific (23% of the species) were the most frequently listed geographical origins of concern. Marine habitat was the most frequent of the potential IAS, accounting for 41% of the species. Fish (26% of the species), Mollusks (18% of the species), and Crustacea (15% of the species) were the most frequent taxonomic groups. The list of potential IAS was prioritized from highest to lowest probability of invasion (establishment, spread, and impact). Eight species reached the highest probability of invasion. One of the potential IAS, Mytilus galloprovincialis, is native to the Mediterranean Region. These results provide valuable information that policy makers can use to develop more efficient prevention strategies for IAS introduced by shipping into the Baltic Sea.Unidad Docente de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpubDescuento UC