Introduction Of Non-native Species Research Articles

Coexistence or extinction: Dynamics of multiple lizard species with competition, dispersal and intraguild predation.

Biological invasions significantly impact native ecosystems, altering ecological processes and community behaviors through predation and competition. The introduction of non-native species can lead to either coexistence or extinction within local habitats. Our research develops a lizard population model that integrates aspects of competition, intraguild predation, and the dispersal behavior of intraguild prey. We analyze the model to determine the existence and stability of various ecological equilibria, uncovering the potential for bistability under certain conditions. By employing the dispersal rate as a bifurcation parameter, we reveal complex bifurcation dynamics associated with the positive equilibrium. Additionally, we conduct a two-parameter bifurcation analysis to investigate the combined impact of dispersal and intraguild predation on ecological structures. Our findings indicate that intraguild predation not only influences the movement patterns of brown anoles but also plays a crucial role in sustaining the coexistence of different lizard species in diverse habitats.

Distinct resource utilization by introduced man-made grouper hybrid: an overlooked anthropogenic impact from a longstanding religious practice

AbstractAnthropogenic activities, such as the introduction of non-native aquaculture species, have significantly altered trophic interactions in marine ecosystems. The hybrid grouper (TGGG), an aquaculture product originating from an artificial F1 crossbreed between Epinephelus fuscoguttatus and E. lanceolatus, has been released into the wild through religious activities, raising concerns about the ecological implications of this man-made species. With its carnivorous diet and large body size inherited from the parental species, TGGG could pose significant impacts to the marine ecosystem. Yet, little is known about the diet composition of TGGG upon release into the natural environment as well as its dietary overlap or partitioning with closely related species. Here, we deployed gut content DNA metabarcoding to determine the prey richness and dietary niche of wild-caught TGGG and compared it to four native grouper species (Epinephelus awoara, E. bleekeri, E. coioides and E. quoyanus). Our results indicate that the TGGG exhibited five unique prey taxa, with teleosts being the predominant prey, followed by crustaceans and cephalopods. Notably, the TGGG displayed a significantly lower mean number of prey taxa compared to the other groupers, suggesting a distinct diet composition that may reflect a transition in feeding behaviour. This study provides a comprehensive analysis with high taxonomic resolution on the diet of artificial hybrids in the wild, indicating the potential for successful establishment if release events persist. Finally, these findings provide new insights into how local trophic dynamics are impacted by the under-investigated release of animals through religious practices.

From Firestick to Satellites: Technological Advancement and Indigenous Cultural Practice in Managing Forest Fires in Australia

ABSTRACT Australia’s interaction with forest fires highlights the interplay of geography, climate, and ecosystems. This research explores the evolution of fire management practices, from ancient Indigenous ‘firestick farming’ to modern strategies using remote sensing and predictive modelling. For millennia, Indigenous Australians used controlled burns to manage landscapes, promoting ecological health and reducing wildfire risks. The disruption of these practices by European settlers in the late 18th century, through land clearing and the introduction of non-native species, led to increased fuel loads and more severe wildfires. The 20th century brought significant technological advancements to fire management, including motorised fire trucks, aircraft, and improved communication systems. However, the real revolution came with the introduction of remote sensing and early warning systems. These technologies enabled real-time monitoring and predictive insights, significantly enhancing fire management. Today, predictive modelling and machine learning further improve fire management by enabling precise forecasting and efficient resource allocation. This research underscores the crucial role of integrating Indigenous knowledge and community engagement with modern strategies for sustainable fire management. As climate change increases wildfire risks, adapting to these challenges is more important than ever. Australia’s approach, which blends traditional wisdom with modern science, serves as a global model for effective wildfire management.

Detection of human enteric viral genes in a non-native winter crane fly, Trichocera maculipennis (Diptera) in the sewage treatment facilities at Antarctic stations

BackgroundThe Antarctic environment is susceptible to the introduction of non-native species due to its unique ecosystem, which has evolved under geographical isolation and extreme climatic conditions over an extended period. The recent introduction of the non-native winter crane fly, Trichocera maculipennis, to maritime Antarctica may pose a potential threat to the Antarctic ecosystem. In this study, we evaluated the possibility of the mechanical transmission of viruses by T. maculipennis.MethodsWe assessed the potential for the mechanical transmission of viruses using next-generation sequencing (NGS), quantitative PCR (qPCR), and virus isolation methods from T. maculipennis (Tm)-related samples (Tm body-wash fluid and Tm body-ground samples) collected from habitats and sewage treatment facilities located at three research stations in Antarctica.ResultsVirome analysis detected the genomic fragments of human adenovirus (AdV) and human endogenous retrovirus (HERV) in Tm-related samples. These viruses are commonly found in human feces. In addition, plant viruses, such as pepper mild mottle virus (PMMoV) and cucumber green mottle mosaic virus (CGMMV), both known indicators of enteric viruses, were identified in all Tm-related samples, likely originating from wastewater. However, the low quantities of AdV and HERV genomes detected in Tm-related samples through qPCR, coupled with the non-viability of AdV in virus isolation tests, indicate that T. maculipennis has limited potential for mechanical transmission under the conditions in the studies.ConclusionsOur study represents the first evaluation of the potential risk of non-native species serving as vectors for viral pathogens in Antarctica. Although the viruses detected were in relatively low quantities and non-viable, this study highlights the importance of further evaluating the risks associated with non-native species, particularly as the likelihood of their introduction increases to Antarctica due to climate change and increased human activity.Graphical abstract

Cities Shape the Diversity and Spread of Nonnative Species

The globalization of trade and increased human mobility have facilitated the introduction and spread of nonnative species, posing significant threats to biodiversity and human well-being. As centers of global trade and human populations, cities are foci for the introduction, establishment, and spread of nonnative species. We present a global synthesis of urban characteristics that drive biological invasions within and across cities, focusing on four axes: (a) connectivity, (b) physical properties, (c) culture and socioeconomics, and (d) biogeography and climate. Urban characteristics such as increased connectivity within and among cities, city size and age, and wealth emerged as important drivers of nonnative species diversity and spread, while the relative importance of biogeographic and climate drivers varied considerably. Elaborating how these characteristics shape biological invasions in cities is crucial for designing and implementing strategies to mitigate the impacts of invasions on ecological systems and human well-being.

Hurricanes threaten species and alter evolutionary trajectories on tropical islands

Hurricanes are natural phenomena, but anthropogenic climate change will cause hurricanes to be stronger and more frequent in the future. It has long been known that hurricanes impact plants and animals, but only recently has the impact on biodiversity been mapped globally, showing that species at risk of extinction due to hurricanes are largely restricted to tropical islands. Tropical islands harbor many plants and animals found nowhere else, many of which are currently threatened, and tropical islands have already suffered a disproportionate number of species extinctions due to human activity and introductions of non-native species. The big question is whether species on tropical islands are adapted to hurricane disturbance and will be able to cope with stronger and more frequent storms, or whether tropical islands will see a wave of hurricane-induced extinctions in the future. Here, we discuss this question and how hurricanes will reshuffle interactions between species - such as those between nectarivorous birds and their flowers - and will alter evolutionary trajectories for coadapted species. Moreover, we discuss the role of life history and other taxa-specific traits, such as diet preferences and dispersal ability, both to survive the direct and indirect impact of hurricanes and to recolonize islands when local populations have been eliminated. We also highlight how topographic complexity and island area may buffer against hurricanes; thus, biodiversity on small and low-lying islands should be more impacted than biodiversity on large and mountainous islands. We end by discussing conservation efforts to diminish the detrimental ecological and evolutionary effects of stronger and more frequent hurricanes on tropical islands.

The critical need for long-term biomonitoring: The case study of a major river system in Anatolia.

The long-term monitoring of freshwater ecosystems has been globally recognized for its critical role in preserving natural biodiversity and human well-being over the past century, yet monitoring efforts remain heterogeneously distributed. The Anatolia region in Turkey is known to host three out of the world's 34 biodiversity hotspots, boasting high biodiversity, but is increasingly threatened by anthropogenic effects and invasive freshwater fish species. Although the introduction of non-native fish species and pollution has detrimental effects on different river catchments in this area, long-term biomonitoring studies in Anatolia remain scarce and inconsistent. Collecting information of the Gediz River basin, a major Anatolian river catchment as a model that has been significantly impacted by human activities, published between 1971 and 2023, a total of 21 fish species from 12 families were identified. The spatial and temporal occurrences of these species fluctuated significantly due to heterogeneous sampling efforts that did not follow a clear pattern, indicating a complex ecological and conservation scenario characterized by both spatial and temporal variability in species prevalence, endemism and abundance. The presented results emphasize the need for comprehensive long-term biodiversity monitoring for anthropogenically impacted catchments like the Gediz River basin. Only with a coherent basis of high-resolution monitoring data can the multiple stressors threatening Anatolia's freshwater biodiversity be disentangled and, subsequently, be mitigated. Using the Gediz River basin as an example, this study emphasizes the urgent need for comprehensive, long-term biodiversity monitoring in understudied regions worldwide to protect regional biodiversity and ensure ecosystem health.

Native and non-native unionids respond differently to the presence of fouling dreissenid mussels

Unionid mussels are globally threatened by several human disturbances, including the introduction of non-native species. Among these, biofouling zebra and quagga mussels of Ponto-Caspian origin are considered to be especially detrimental to unionid locomotion, filtration and physical condition. The aim of our study was to determine and compare the impact of dreissenid fouling and/or presence on locomotion and burrowing of the native Unio tumidus and invasive Sinanodonta woodiana, a novel invader expanding its range in Europe in recent decades. We tested unionids collected from Lake Balaton (central Europe) that were fouled by dreissenids (zebra and quagga mussels mixed), cleaned of fouling or non-fouled (collected without any signs of dreissenid fouling). Moreover, unionids were tested in the presence or absence of other fouled individuals and dreissenids isolated in mesh bags to determine the influence of direct fouling and presence of dreissenids in the environment on unionid behaviour. Movement initiation time, locomotion distance and burrowing level were retrieved from videos recorded for 24 hours. Direct fouling affected only the behaviour of U. tumidus, limiting their burrowing and delaying movements. After removal of fouling, movement timing returned back to normal, but mussels still burrowed less than the control non-fouled individuals, indicating persisting effects of fouling on physical condition. Moreover, U. tumidus reduced their locomotion in the presence of fouled unionids. Sinanodonta woodiana responded to the presence of dreissenids (especially quagga mussels) with increased burrowing. These different responses of the two unionid species to Dreissena spp. indicate that biofoulers may influence biotic interactions between the unionids by promoting the invasive species (less susceptible to negative effects of fouling). Moreover, S. woodiana may indirectly affect U. tumidus through apparent competition, constituting an environmental reservoir of biofoulers exerting a stronger impact on the native species.

Native and non-native winter foraging resources do not explain Pteropus alecto winter roost occupancy in Queensland, Australia.

Anthropogenic land use change concurrent with introductions of non-native species alters the abundance and distribution of foraging resources for wildlife. This is particularly concerning when resource bottlenecks for wildlife are linked to spillover of infectious diseases to humans. Hendra virus is a bat-borne pathogen in eastern Australia. Spillovers align with winter food shortages for flying foxes and flying foxes foraging in agriculture or peri-urban lands, as opposed to native forests. It is believed the increased abundance and spatiotemporal reliability of non-native species planted in anthropogenically modified areas compared to native, ephemeral diet species may be a key draw for flying foxes into urban and peri-urban areas. We investigate the explanatory power of environmental factors on the winter roost occupancy of the reservoir for Hendra virus, the black flying fox Pteropus alecto, from 2007-2020 in Queensland, Australia. We measured the extent, spatial aggregation, and annual reliability of typical (i.e. native) and atypical (i.e. non-native) winter habitat species in 20km foraging areas around roosts surveyed by the National Flying Fox Monitoring Program. We find that neither the extent nor the spatial distribution of winter habitats explained black flying fox winter roost presence. Although the establishment of roosts was associated with high reliability for typical winter diet species, the reliability of frequently listed winter diet species surrounding surveyed roosts was not different between roosts that were occupied versus unoccupied in the winter. Significant interactions between lagged weather conditions and winter habitats identified by the best model did not reflect observable differences in patterns of occupancy upon scrutiny. Static measures of winter habitat and weather conditions poorly explained the winter roost occupancy of black flying foxes. Understanding the drivers of flying fox movement and presence requires further investigation before they can be thoughtfully integrated into Hendra spillover prevention efforts and flying fox management.

Ruderal Plant Diversity as a Driver for Urban Green Space Sustainability

Urban development in south-eastern Europe has significant ecological consequences, such as a reduction in native plant diversity, the introduction of non-native species, and increased maintenance costs of urban green spaces. Achieving sustainable urban development requires a thorough understanding of the inventory of native plant species to better manage and conserve these areas. This study analyzed 806 vegetation surveys conducted in rural and urban areas over a 30-year period, identifying 450 plant species from 39 distinct plant communities. Our findings revealed generally low dominance index values in all communities, while Shannon diversity index values were particularly high, indicating rich species diversity despite urbanization pressures. Equality index values varied slightly, reflecting differences in species distributions. Principal component analysis (PCA) identified a substantial group of species with low abundance, which is essential for understanding and managing urban biodiversity. These findings have significant implications for urban planning and plant species conservation. Low dominance and high diversity suggest opportunities to improve urban green spaces by integrating diverse native species. In addition, the ecological and practical value of ruderal species, plants that thrive in disturbed environments, was emphasized, as well as their potential in medicine, phytoremediation, green roof design, and pollination services. Through directly correlating biodiversity indices with urban sustainability goals, our study provides useful insights for urban biodiversity management and the strategic integration of native plant species into urban landscapes.

Baseline data and recommendations to decrease the introduction and spread of invasive non-native species in federal and state protected areas in Brazil

Baseline data and recommendations to decrease the introduction and spread of invasive non-native species in federal and state protected areas in Brazil

Future invasion risk assessment of the peacock bass in Neotropical ecoregions: A conceptual and testable model

Protecting freshwater biodiversity from non-native invasive species and their impacts is crucial for minimising both regional and global deterioration of ecosystem services. The yellow peacock bass Cichla ocellaris, a predatory freshwater fish endemic to the Amazon region, has been translocated within several Neotropical ecoregions, exhibiting harmful effects on biodiversity. In order to facilitate the prioritization of management efforts, which are essential for defining conservation actions in extensive and diverse areas, we propose a risk assessment index that integrates multiple ecological and environmental variables within a comprehensive framework, here applied for C. ocellaris. By considering fish species richness, occurrence frequency, and climate suitability, our index provides a more nuanced understanding of invasion risks. Within regions categorized as high and very high risk, where ecological impacts of C. ocellaris have been extensively documented (e.g., the Southern and North-East Brazilian regions, as well as Central American and Caribbean ecoregions), numerous environments are increasingly conducive to the establishment of this invasive species, exacerbated by a surge in dam constructions. Our analysis projects a significant increase in suitable habitats by 5% to 6.5%, with Southern and Northeastern Brazil and Central America identified as critical zones. Thus, our reproducible risk assessment framework, which considers freshwater ecoregions as conservation units, not only directs effective resource allocation for control measures but also enhances our ability to predict and mitigate the ecological impacts of non-native species introductions, providing a valuable tool for both policymakers and conservationists.

Investigation of the distribution patterns in moinids (Crustacea: Cladocera: Moinidae) forming ephippia with two resting eggs.

During last two decades, morphological and genetic studies of the microcrustaceans from the family Moinidae Goulden, 1968 (Crustacea: Branchiopoda: Cladocera) were intensified. However, species diversity within this family remains underestimated. It refers to both subtropical and tropical areas of different continents that have traditionally been less studied compared with Central Europe and some other Palaearctic regions. In addition to this, only a restricted set of morphological characteristics is used for the discrimination of species within the genus Moina Baird, 1850. Most common moinid taxa are considered species complexes rather than single species, making any biogeographic reconstruction difficult. Here, we present an investigation of distribution patterns in moinids that form ephippia with two resting eggs based on both a reexamination of data from the literature and from specimens in museum and personal collections. Also, we redescribed morphology of poorly known taxa from the arid regions of the Old World-Moina belli Gurney, 1904 and M. kaszabi Forró, 1988 and clarify their diagnostic morphological characters and distributional ranges. We found that M. belli and M. kaszabi are morphologically very similar. In both species, setae 1 and 2 of thoracic limb I are armed bilaterally by fine, densely located short setulae. Reliable differences between M. belli and M. kaszabi concern armature of the valve posteroventral portion. Among the moinids with two resting eggs in the ephippium, M. belli and M. kaszabi are morphologically closer to M. macrocopa (Straus, 1820) and M. americana Goulden, 1968. All these species have: (1) a dorsal head pore; (2) fine long hairs on head, valve and preanal margin of postabdomen; (3) thoracic limb I of male with a long exopodite. In general, an investigated group of moinids includes both species with relatively compact and very broad distributional ranges. We concluded that maximum diversity of the moinids forming ephippia with two resting eggs is characteristic of southern portions of Palaearctic and Nearctic zoogeographical regions and approximately corresponds to subtropical climate zone. We need to underline that M. macrocopa and M. americana have a great invasive potential. Both species were anthropogenically introduced in South America and have been successfully naturalized there. Their distribution in tropical regions of the Old World and Australia requires new precise investigations. A group of moinids forming ephippia with two resting eggs can be considered as a convenient model for biogeographical reconstructions, including studies on changes in aquatic ecosystems due to global climate warming, eutrophication and the introduction of non-native species. There is no doubt that subsequent joint application of morphological and genetic data will shed more light on the global phylogeographic structure of the entire family Moinidae.

The urban island: climatic suitability of Linepithema humile (Hymenoptera: Formicidae) and the role of cities in the invasion of the Western Palearctic

AbstractUrban environments often present environmental conditions that facilitate the introduction and establishment of nonnative and invasive species. These can expand their range into areas with unfavorable climates by taking advantage of the ecological and climatic homogenization of cities, bypassing the ecological barriers presented by the surrounding environment. One way to monitor the expansion of these species is using potential distribution models. We used as a model species the Argentine ant, Linepithema humile (Hymenoptera: Formicidae) whose invasion has caused serious consequences for biodiversity and economic losses worldwide. We used the average result of six different algorithms and used climatic variables and population density as a proxy for the urbanization level in the Western Palearctic to build the predictive model. The model indicates this ant prefers to inhabit areas with Mediterranean and Temperate Oceanic climates and that its suitability depends on two main factors: the continentality (temperature annual range) and the degree of urbanization. The species is predicted to be absent in areas with large temperature contrasts throughout the year, particularly in rural and peri‐urban areas (i.e. adjacent to urban areas) of inland regions. Conversely, the species has a predilection for coastal and urban areas where environmental conditions are attenuated by the influence of the sea or the “urban heat island” effect in the case of inland cities. In this sense, cities act as “bioclimatic islands” facilitating the establishment of the Argentine ant as a reservoir, enlarging its distribution into climatically nonoptimal areas, and promoting its future expansion in a scenario of global warming and socioeconomic change.

Ladybird Beetle Diversity in Natural and Human-Modified Habitats in the San Cristóbal Island, Galapagos, Ecuador.

This study investigates the species richness and distribution of ladybird beetles (Coccinellidae) across various habitats on San Cristóbal Island in the Galápagos Archipelago, Ecuador. Through extensive field surveys, we catalogued nineteen species, including four previously known species (two endemics, Psyllobora bisigma and Scymnobius scalesius, and two natives, Cycloneda sanguinea and Tenuisvalvae bromelicola). We also identified nine possibly native species reported for the first time in the Galapagos islands in this study or correspond to the first voucher specimens for the island. We collected three previously reported non-native species: Cheilomenes sexmaculata, Novius cardinalis, and Paraneda guticollis. Three species belonging to the genera Stethorus, Calloeneis, and Delphastus remain undetermined, pending further taxonomic analyses. Our findings reveal a rich and complex community with notable differences in species abundance and habitat preference. Endemic species were found to be particularly scarce and restricted mainly to crops undergoing forest regeneration and deciduous forests, emphasising their vulnerability and specialised habitat requirements. The native Cycloneda sanguinea emerged as the most prevalent species, exhibiting broad ecological adaptability. Non-native species, like Cheilomenes sexmaculata, were predominantly found in disturbed habitats, with some showing early signs of spreading into more natural environments, raising concerns about their potential impact on local biodiversity. These findings contribute valuable knowledge to understanding Coccinellidae diversity on San Cristóbal Island and highlight the importance of continued monitoring, particularly in the face of ongoing environmental change and the introduction of non-native species. This study underscores the need for targeted conservation efforts to protect the unique and fragile ecosystems of the Galápagos Archipelago.

Invisible dynamics: exploring the genetic diversity of peacock bass in Brazil

In Brazil, the introduction of non-native species into freshwater environments, such as peacock bass (Cichla spp.), was driven by aquaculture and sport fishing. These Amazonian fish possess phenotypic plasticity and resilience that facilitate their invasion and establishment in new habitats. Due to the taxonomic complexity of cichlids, studies on intraspecific variation are essential to mitigate the impacts of biological invasions. This study aimed to analyze the genetic diversity of peacock bass, assessing how invasive populations have diversified over time and across different regions in Brazil. Samples were collected from different invasive populations in Maranhão, São Paulo, Paraná, and Goiás. DNA was extracted and the 16S and COX1 genes were amplified. Ninety-seven specimens of the genus Cichla Schneider, 1801 were identified as Cichla monoculus Agassiz, 1831 (n=12); Cichla kelberi Kullander and Ferreira, 2006 (n=75); and Cichla piquiti (Kullander and Ferreira, 2006) (n=10). Sixteen 16S haplotypes (445bp) were identified, with haplotype diversity and nucleotide diversity values of Hd: 0.830 and Pi: 0.03777, respectively. The results showed proximity between the invasive populations from Maranhão and São Paulo, with haplotype sharing among Parque Nacional dos Lençóis Maranhenses, Baixada Maranhense, and Ilha Solteira. This highlights the fragility of species delimitation and definitions within the group, based solely on morphological data. By evaluating the set of morphological and genetic data, we found significant intraspecific variations, despite expecting population homogeneity due to the founder effect and bottleneck commonly observed in invasive populations. This underscores the adaptive potential of these cichlids.

First Record of the invasive Banded jewel cichlid Hemichromis elongatus (Guichenot, 1861) (Teleostei: Cichlidae) on Bangka Island, Indonesia

Abstract The introduction of non-native species into an ecosystem has been found to have a notable detrimental effect on the environment. Hemichromis elongatus, in particular, is recognized as one of the more problematic invasive species. In fact, Hemichromis elongatus introductions are linked to human activities, primarily associated with the aquarium trade. This study examines the presence of Hemichromis elongatus on Bangka Island, where it was inadvertently introduced into the aquatic environment by the indigenous population. During the field trip that we undertook between the months of August and September 2023, in the Jebus River, West Bangka Regency, we discovered at least one hundred live specimens of Hemichromis elongatus in a single round of sampling using the fish trap. This is a significant number that represents a significant level of invasion. However, invasive alien species are most harmful to freshwater ecosystems, which are prone to biodiversity loss. Due to this fact, it is strongly advised that the foreign fish and the effect they have on the ecology be continuously monitored.

Evidence of Climate Change and the Conservation Needed to Halt the Further Deterioration of Small Glacial Lakes

Although somewhat debated, it is generally agreed in Europe that small water bodies comprise lentic ecosystems that are shallow (less than 20 m) and have a surface area of a few hectares (less than 10 ha). In Albania, 84 glacial lakes constitute a substantial portion of the aquatic ecosystems that sustain high levels of biodiversity, metabolic rates, and functionality. This paper discusses the integration of ecological sustainability into ecosystem services (i.e., cultural, regulatory, and sustaining services) and the national ecological networks of protected sites. This integration is particularly important in light of recent advancements regarding European integration. It is also important due to the catchment continuum, which addresses biodiversity values and gradients that, in this work, are considered using rotifer communities and aquatic plant species. The main causes of the stressors on small ecosystems are inappropriate land use, water pollution, altered habitats, non-native species introduction, resource mismanagement in basins, inadequate planning, and a lack of sector integration. The glacial lakes reflect climate change elements through: an increased number of dried glacial lakes, so only 84 remain functioning; the water level is slowly being reduced; the oscillation of the water level is steadily increasing; and the eutrophication process is rapidly advancing.

Hybridization in the Anthropocene - how pollution and climate change disrupt mate selection in freshwater fish.

Chemical pollutants and/or climate change have the potential to break down reproductive barriers between species and facilitate hybridization. Hybrid zones may arise in response to environmental gradients and secondary contact between formerly allopatric populations, or due to the introduction of non-native species. In freshwater ecosystems, field observations indicate that changes in water quality and chemistry, due to pollution and climate change, are correlated with an increased frequency of hybridization. Physical and chemical disturbances of water quality can alter the sensory environment, thereby affecting chemical and visual communication among fish. Moreover, multiple chemical compounds (e.g. pharmaceuticals, metals, pesticides, and industrial contaminants) may impair fish physiology, potentially affecting phenotypic traits relevant for mate selection (e.g. pheromone production, courtship, and coloration). Although warming waters have led to documented range shifts, and chemical pollution is ubiquitous in freshwater ecosystems, few studies have tested hypotheses about how these stressors may facilitate hybridization and what this means for biodiversity and species conservation. Through a systematic literature review across disciplines (i.e. ecotoxicology and evolutionary biology), we evaluate the biological interactions, toxic mechanisms, and roles of physical and chemical environmental stressors (i.e. chemical pollution and climate change) in disrupting mate preferences and inducing interspecific hybridization in freshwater fish. Our study indicates that climate change-driven changes in water quality and chemical pollution may impact visual and chemical communication crucial for mate choice and thus could facilitate hybridization among fishes in freshwater ecosystems. To inform future studies and conservation management, we emphasize the importance of further research to identify the chemical and physical stressors affecting mate choice, understand the mechanisms behind these interactions, determine the concentrations at which they occur, and assess their impact on individuals, populations, species, and biological diversity in the Anthropocene.

Floating debris and organisms can raft to Antarctic coasts from all major Southern Hemisphere landmasses.

Antarctica's unique marine ecosystems are threatened by the arrival of non-native marine species on rafting ocean objects. The harsh environmental conditions in Antarctica prevent the establishment of many such species, but warming around the continent and the opening up of ice-free regions may already be reducing these barriers. Although recent genomic work has revealed that rafts-potentially carrying diverse coastal passengers-reach Antarctica from sub-Antarctic islands, Antarctica's vulnerability to incursions from Southern Hemisphere continents remains unknown. Here we use 0.1° global ocean model simulations to explore whether drift connections exist between more northern, temperate landmasses and the Antarctic coastline. We show that passively floating objects can drift to Antarctica not only from sub-Antarctic islands, but also from continental locations north of the Subtropical Front including Australia, South Africa, South America and Zealandia. We find that the Antarctic Peninsula is the region at highest risk for non-native species introductions arriving by natural oceanic dispersal, highlighting the vulnerability of this region, which is also at risk from introductions via ship traffic and rapid warming. The widespread connections with sub-Antarctic and temperate landmasses, combined with an increasing abundance of marine anthropogenic rafting vectors, poses a growing risk to Antarctic marine ecosystems, especially as environmental conditions around Antarctica are projected to become more suitable for non-native species in the future.