Aquatic Conservation: Marine and Freshwater Ecosystems

Sharks play a crucial role in the structure of marine ecosystems but are heavily threatened by overfishing globally. Due to their slow life history traits, even low fishing pressure can have an extreme influence on shark populations. The Mediterranean Sea, which has had historical overexploitation over the course of many centuries, is considered a hotspot for elasmobranchs. One particular species is the bluntnose sixgill shark, Hexanchus griseus, which has recently become more prominent in sightings and landings. Because of its deep range, H. griseus is difficult to study in situ so we used opportunistic data from sharkPulse, a crowd-sourcing platform that collects and organizes image-based shark occurrence records from all over the world, to better understand the abundance and distribution of H. griseus over the past decade. Additionally, we explored historical data to create a baseline of the species abundance starting from the late 1800s. We found that H. griseus underwent a quadratic-shaped change in their abundance where they started out as a rare catch, became increasingly more prominent in fisheries data, and now is declining like many other cartilaginous fishes in the Mediterranean Sea. This work is important because H. griseus is not yet threatened according to the IUCN so research is not heavily focused on this species but the decreasing trend we detected here is concerning while in line with the degree of exploitation of one of the most exploited regions of the world, as well as illustrative of a broader ecological process that will likely occur in many other large marine ecosystems worldwide.

The shorthead anchovy Encrasicholina heteroloba is a small pelagic species of significant economic and nutritional importance in Tanzania. However, reliable stock assessment remains challenging because of limited data. This study evaluates the status of E. heteroloba in Tanzanias coastal waters and provides management insights for sustainable exploitation. A total of 32,324 specimens were sampled between July 2023 and December 2024. Length-frequency data were cleaned, bootstrapped, and analyzed using the ELEFAN routine to estimate von Bertalanffy growth parameters and mortality rates. Stock biomass and abundance were estimated through virtual population analysis. Estimated parameters were asymptotic length (L{infty}) = 8.42 cm total length, growth coefficient (K) = 2.08, growth performance index ({emptyset}') = 2.19, current fishing mortality (Fcurr) = 0.85, exploitation rate (Ecurr) = 0.40, and length at first capture (Lcurr) = 6.10 cm total length. Natural mortality (M) was 1.25 and total mortality (Z) was 2.10. Overall biomass and stock abundance were 72,725 metric tons and 4.37 x 1010 individuals, respectively. Estimates of biological reference points were F0.1= 1.57, F0.5 = 1.06, and Fmax= 3.34. The results indicate that the stock of E. heteroloba in this region is currently underexploited. Fishing mortality could be moderately increased to enhance yield-per-recruit sustainably.

In Bangladeshs marine waters in the Bay of Bengal, sharks and rays face grave threats from unsustainable fishing practices and habitat degradation. Findings from our taxonomic assessment of elasmobranchs landed at the two most important marine fish landing stations in Bangladesh bring new information and insights about the nature of the Threatened elasmobranch bycatch. This study presents findings from a taxonomic assessment at Coxs Bazar and Chattogram, two crucial landing stations in Bangladesh where most shark bycatch landings happen. Over two years, 525 fish were sampled; 206 samples were of sharks, 91 of rays, and 64 of rhino rays, representing over 29 species across 12 families. Among them are 4 families of sharks, 5 rays, and 3 rhino rays. The predominant families observed were Carcharhinidae, Glaucostegidae, and Rhinopteridae. The most frequently landed species were Sphyrna lewini, Glaucostegus younholeei, Carcharhinus leucas, Gymnura poecilura, and Mobula mobular. Out of the 525 samples, 65% (n=340) were female, 35% (n=183) were male, and the rest (n=2) were unidentified. Finding one sample of Pristis pristis indicates the severity of the decline. Additionally, for Glaucostegus granulatus, 12 among the 13 studied specimens were adult females. A significant proportion of the sampled specimens, 45%, were juveniles, while only 24% were adults. This is likely because these fishing boats bringing the catch operate in inshore water and nearshore seas, which are potential nursery grounds. The overlapping of fishing grounds and these critical habitats poses a significant challenge in elasmobranch conservation and hinders population recovery. The high number of juveniles and female adults in the catch reminds us of the necessity of integrating threatened bycatch reduction measures into the countrys fisheries management.

EXECUTIVE SUMMARYUpdated population viability analyses, incorporating the latest abundance and bycatch data indicate that: O_LIThe estimated population decline for Maui dolphin is 2% per year C_LIO_LIThere is a 68% probability that the population is continuing to decline C_LIO_LIAfter 30 years (6 more surveys) statistical power of detecting this rate of decline would be < 15% C_LIO_LIOnly very large declines (37%) and recovery (45%) would be detectable with 80% statistical power after 30 years (6 more surveys) C_LIO_LIThe level of conservation threat for Hectors dolphin remains high despite a recent, larger population estimate off the east coast of the South Island C_LIO_LIIncreased overlap between dolphins and fisheries, due to more extensive offshore distribution of dolphins off the South Island east coast, more than offsets the apparently higher population size C_LIO_LIThe Hectors dolphin population has declined 70% over the last 3 generations, exceeding the 50% threshold for Endangered C_LIO_LIPopulation declines are predicted to continue under current protection levels C_LIO_LIThe results of this research are consistent with: {bigcirc}NOAA proposal to list Hectors and Maui dolphins under the US Endangered Species Act {bigcirc}IWC recommendation to ban gillnets and trawling throughout Maui dolphin habitat {bigcirc}IUCN recommendation to ban gillnets and trawling throughout Hectors and Maui dolphin habitat C_LI

The northern Adriatic Sea is an important foraging ground for the loggerhead sea turtle Caretta caretta (Linnaeus, 1758) within the Mediterranean Sea. Here, spatial-temporal patterns of loggerhead sea turtles strandings along a short portion ([~]18 km) of the coast south of the Po River delta (Italy) during a three-year period (2019-2021) were investigated. A total of 244 records (alive, n=7; dead, n=237) were analysed and the curved carapace lengths (CCL, notch to tip, cm) mainly reflected sub-adults (average CCL=55.2 cm; 95% CI= 53.3-57). The month of July was identified as the critical month with the highest number of strandings, mirroring migratory processes toward this area during warmer months. Interaction with the trawl fishery was hypothesized as the main cause of mortality and a small fraction of deaths (6%; n=16) could be linked to boat strikes and net entanglement. The number of stranded turtles*km-1 as well as the absolute number of strandings along the short portion of monitored coast confirmed this area as the most impacted in Italy and perhaps in the whole Mediterranean Sea. This study provides valuable information to improve conservation efforts for this species and highlight that, with all due caution, monitoring stranding events can offer useful insights into the geographic ranges, seasonal distribution, and life history of marine species of conservation interest such as the loggerhead sea turtle.

We determined fisheries management reference points for three major fish stocks in Lake Victoria (Nile tilapia, Nile perch and Dagaa) for Uganda and the whole lake. The aim was to ascertain stock status and define reasonable objectives and targets for rebuilding to sustainable levels. Dagaa was found to be healthy in Uganda and the whole lake but tending to overfished status. In Uganda, the stock status of Nile tilapia and Nile perch was recruitment impaired but tending more towards collapsed and overfished status respectively. In the whole lake, the stock status of Nile tilapia and Nile perch was collapsed and overfished respectively with the latter tending more towards recruitment impaired. Estimates of maximum sustainable yield (MSY) showed that catches could be increased under good management. Rebuilding the Nile tilapia and Nile perch stock biomasses to MSY level (Bmsy) could respectively increase the catches above the current level by 9.2% and 29.5% in Uganda and by 72.8% and 15.1% in the whole lake. The immediate objective for fisheries management should be to rebuild biomass for the Nile tilapia and Nile perch stocks to Bmsy. Elimination of illegal fishing practices has proved to be effective. In addition, management needs to keep catches at low levels until biomass for the stocks is [&ge;]Bmsy for at least three consecutive years.

The oceans are in a state of rapid change - both negatively, due climate destabilization and misuse, and positively, due to strengthening of policies for sustainable use combined with momentum to grow the blue economy. Globally, more than 121 million people enjoy nature-based marine tourism -- e.g., recreational fishing, diving, whale watching -- making it one of the largest marine sectors. This industry is increasingly threatened by ocean degradation and management has not kept pace to ensure long-term sustainability. In response, individuals within the industry are taking it upon themselves to monitor the oceans and provide the data needed to assist management decisions. Fiji is one such place where the dive tourism industry is motivated to monitor the oceans (e.g., track sharks). In 2012, 39 dive operators in collaboration with eOceans commenced the Great Fiji Shark Count (GFSC) to document sharks (and other species) on 592 dive sites. Here, using 146,304 shark observations from 30,668 dives we document spatial patterns of 11 shark species. High variability demonstrates the value of longitudinal data that include absences for describing mobile megafauna and the capacity of stakeholders to document the oceans. Our results may be used to guide future scientific questions, provide a baseline for future assessments, or to evaluate conservation needs. It also shows the value of scientists collaborating with stakeholders to address questions that are most important to the local community so that they have the information needed to make science-based decisions.

Alien freshwater crayfish have been widely introduced worldwide for aquaculture and the pet trade. Despite providing societal benefits, crayfish introductions are also known to cause adverse impacts in areas of introduction. This study used the recently developed Risk Analysis for Alien Taxa (RAAT) framework to assess the risk associated with 14 alien freshwater crayfish introductions in South Africa. Thirteen of the 14 species were assessed as high risk because they are likely to be introduced to South Africa and have the potential to cause major environmental impacts. Eight of these species are listed under the South African National Environmental Management: Biodiversity Act (NEM: BA) Alien and Invasive Species (A&IS) Regulations, which implies there is an obligation to manage them. This notion was supported by the recommendations from the risk analyses for Cherax cainii, C. tenuimanus, and C. quadricarinatus. The two marron species (C. cainii and C. tenuimanus) have no known naturalised populations and are likely confined to aquaculture facilities. Cherax quadricarinatus is already widespread and control methods should focus on minimising spread, as eradication is no longer feasible. The recommendations from some of the risk analyses do not agree with the current listing under the A&IS Regulations. Procambarus clarkii is already known to be invasive but is not listed and there is anecdotal evidence that C. destructor, Faxonius limosus, F. rusticus, Pacifastacus leniusculus, and Pontastacus leptodactylus are present in the pet trade and their presence needs to be verified. Crayfish can become conflict-generating alien species because they have both major negative impacts and socio-economic benefits. Therefore, the recommended management options aim to preserve benefits while limiting negative impacts by restricting the importation of high-risk species for new introductions and implementing interventions to prevent spread and minimise impacts for established introductions.

The Chinese sleeper (Perccottus glenii) has invaded European freshwaters and we present evidence of its first documented occurrence in the Elbe River basin in Czechia. The individual fish was caught by a fisherman and posted on social media. After immediately contacting the person in question, we obtained a live fish from him. The Chinese sleeper appears to have been present in interconnected ponds and streams for ten years and may have spread over a larger area. We recommend that eradication measures be implemented to prevent further spread. Statement of SignificanceThe Chinese sleeper has invaded many European countries in the last 50 years, and it is expected to invade western Europe because of the favourable conditions for its establishment. This finding indicates that it could spread in the Elbe River Basin, which could have serious impacts on floodplain and wetland ecosystems. To prevent this scenario, eradication measures should be implemented.

Conservation outcomes in the socio-economically disadvantaged regions are strongly influenced by human behaviour, social norms, and existing governance mechanisms. This study examined stakeholder attitudes, perceptions, values, norms and decision-making processes associated with the conservation of freshwater fishes in two neighbouring states in Eastern India - Jharkhand and Bihar. An approach integrating the Conservation Planning Framework (CPF) with the Theory of Planned Behaviour (TPB) and Social Values (SV) enabled the development of four interlinked themes: "livelihood and economic prioritisation over conservation", "constraints on participation", "values and conservation willingness" and "erosion of social and cultural memories of mahseer", indicative of a process of dual extinction faced by these iconic freshwater fishes. Despite the widespread positive attitudes of the stakeholders towards native fishes and freshwater ecosystems, conservation intentions and actions in both states were found to be negatively influenced by feeble communication, prioritisation of aquaculture, institutional rigidity, inadequate conservation education, limited actual behavioural control (ABC) and subjective norms-driven livelihood pressures. However, the presence of active fishermen cooperative societies and stronger relational values among the local communities makes Jharkhand better equipped to implement participatory governance and stakeholder-involved conservation engagement plans. By strategically linking CPF, TPB, and SV, this study demonstrates how human attitudes, behaviour, social norms, and institutional structures interact to shape freshwater fish conservation outcomes in regions where livelihood needs intersect with conservation priorities, thereby offering actionable insights for managing the native freshwater fish diversity.

The marine aquarium trade is a significant global industry harvesting millions of live coral reef fishes annually. Wild-caught fish dominate public and private aquaria markets in the USA and Europe, supporting fisher livelihoods in the Indo-Pacific. This diverse and species-rich trade is considered data-limited, creating barriers to quantify the sustainability of this fishery to the net benefit of the coral reef socio-ecological system. We present a revised and expanded productivity-susceptibility analysis (PSA) framework to assess the vulnerability to overharvesting of the top 258 traded species, an estimated 92.5% of all import volume into the USA in 2011. Vulnerability was calculated based on various productivity and susceptibility factors, tailored to the unique life-history and fishery selectivity characteristics of the marine aquarium trade. We present novel factors that improve model accuracy, methods to overcome missing data for individual factors, and apply an improved Gaussian mixture model clustering algorithm to objectively classify species as least, moderately, or most vulnerable. Our results show that an overwhelming 85% of species evaluated fall into the least or moderately vulnerable classification, with the remaining species designated as high priority for localized assessment and management initiatives. A comparative case study between our PSA and the popular FishBase Vulnerability assessment illustrates how it is ill-suited to handle data limitations of non-food fishes. The results of our PSA, at a species and family level, provide useful information to stakeholders and serves as a robust and accessible risk assessment tool to prioritize species for management based on their vulnerability scores.

Microplastics (MPs) pollution is a worldwide issue in the marine environment. There is growing concern of consuming MPs through fish, yet the current contamination status of fish collected from the deep sea surrounding Japan remains limited. We present baseline data on MPs in commercially important fishes from the coastal and offshore waters near Kyushu, Japan (East China Sea). We examined the MPs in the digestive tracts of two pelagic (n = 150 in total) and five demersal species (n = 235 in total). The fish were caught by pole and line, and bottom trawl at different geographical positions. The MPs in pelagic fish (39.1 %) were higher than demersal fish (10.3 %) and of larger sizes. The MPs correlated with habitat depth and type. There was species variation in the shape and polymer composition of MPs. These results increase our understanding of the heterogeneous uptake of MPs by fishes.

The red lionfish (Pterois volitans), native to the Indo-Pacific, is recognized as one of the most harmful invasive species in the marine ecosystems of the Western Atlantic. Since its accidental introduction, the species has rapidly expanded across the Caribbean, Gulf of Mexico, and Brazilian coast, reaching marine protected areas with high ecological value. This study documents the first confirmed occurrence of P. volitans in the reef environment of the Parcel de Manuel Luis Marine State Park, located on the Brazilian Equatorial Margin. The record was based on underwater footage collected during a scientific expedition in June 2025. Two individuals were observed near the wreck of the ship Ana Cristina at a depth of five meters. The specimens exhibited typical morphological features and behavioral patterns associated with foraging and habitat exploration. Physicochemical variables measured at the site confirmed stable tropical marine conditions, including high salinity and temperature, compatible with the ecological tolerance of the species. Additional measurements at eight surrounding stations revealed minimal stratification, reinforcing the environmental suitability for the species. Statistical analysis detected no significant differences in salinity or dissolved oxygen between surface and bottom waters, and a slight variation in temperature. The presence of P. volitans in a conservation unit raises concern about its potential expansion into other reef and coastal environments. Given its high reproductive capacity, absence of natural predators, and ecological plasticity, the species poses a serious threat to native biodiversity and trophic dynamics. The results highlight the urgency of establishing systematic monitoring programs and early-response strategies for invasive species in Brazilian reef systems.

The long-term monitoring of long-lived animal populations often requires individual identification. For cetacean populations, this identification is mostly based on morphological characters observable from a boat such as shape, spots and cuts of the back, caudal and dorsal fins. This is well suited for species easily displaying their caudal fins, such as the humpback whales Megaptera novaeangliae, or those whose skin pigmentation patterns enable individual identification. However, for elusive or shier species such as the sperm whales Physeter macrocephalus, this approach may be more challenging as individuals display a rather uniform skin pigmentation. They also do not show very often their caudal fin that must be photographed perpendicularly to the water surface, vertically and fully emerged, uneasing the individual identification from a boat. Immature sperm whales that usually have a caudal fin without any distinctive marks may sometimes be excluded from photo-identification catalogues. Within the framework of the Maubydick project, focusing on the long-term monitoring of sperm whales in Mauritius, passive underwater observation and video recording were used to identify long-lasting body markers (e.g., sex, ventral white markings, cut outs of fins) to improve individual identification. A catalogue of individual identity cards was developed and 38 individuals were recorded (six adult males, 18 adult females and 14 immatures). This catalogue was used in the field and enabled observers to record some nearly-daily and yearly recaptures. Advantages and disadvantages of this method are presented here. Such catalogues represent a robust baseline for conducting behavioural, genetic and acoustic studies in marine megafauna social species. Benefits of such newly acquired knowledge are of first importance to implement relevant conservation plans in the marine realm.

Understanding migratory connectivity is important for the conservation of highly mobile marine species that face escalating threats across the globe. Establishing baseline information on migratory connectivity is therefore needed to identify regions of conservation focus. Despite efforts to track migratory sharks and rays, information on transboundary movements is limited and often inaccessible to managers and policymakers. Here, we synthesised multimethod movement data for migratory Australian shark and ray species, investigating which species require international engagement to support their population recovery. Based on data from a systematic literature review, we built connectivity networks from telemetry and mark-recapture studies that provide a first baseline for transboundary migratory connectivity for Australian sharks and rays. Of the 31 shark and ray species reviewed, we identified 6 species that link the Australian Exclusive Economic Zone to other national jurisdictions via multispecies migratory connections through the Tasman Sea to New Zealand, through the Tasman and Coral Sea to New Caledonia, and north across the Timor Sea and Torres Strait to Indonesia and Papua New Guinea. White sharks (Carcharhinus carcharias) and whale sharks (Rhincodon typus) were the most data rich, whereas 14 shark and ray species had no movement information. There is a grave deficiency in available information for endangered or critically endangered migratory shark and ray populations, with 76% having only one or no published studies. This work supports future conservation strategies for migratory sharks that require robust international collaboration and the adoption of integrated and dynamic management approaches.

In recent decades, the Mediterranean Sea has experienced a marked escalation in the introduction of non-native and invasive marine species. The global expansion of aquaculture, coupled with the increased movement of commercial species, has raised concerns about the potential for introducing parasites into new environments, posing a growing threat to marine ecosystems. Polydora websteri is a shell boring polydorin worm that induces the formation of mud-filled blisters within the shells of molluscs. The annelid is considered indigenous to the Asian coasts and has been documented in various locations across the globe. In the present work, we report a massive presence of P. websteri in several sites of the North Adriatic costline and we provide some diagnostic features that are useful to identify the species. Polydora websteri can be distinguished of a lateral flange on chaetiger 5. Moreover the palps are characterized by continuous black lines along the margins of the ciliated groove. The combined findings of this study provide compelling evidence that P. websteri is expanding its range within the Mediterranean coast. Given the potential for severe ecological and economic impacts associated with this invasive polychaete, this study serves as an urgent call to action for increased monitoring of P. websteri in both farmed and wild Pacific oysters in the Mediterranean Sea. Identification key of Mediterranean Polydora is provided.

New Zealands Ministry for Primary Industries (MPI) developed a risk analysis for Hectors and Maui dolphins, in order to inform protection options being considered by the Ministers of Fisheries and Conservation. Unfortunately, MPIs risk analysis combines several estimates that are biased, and the biases consistently act together to underestimate the level of bycatch and overestimate the species ability to sustain impacts. In essence, the approach uses abundance estimates that are likely biased high, multiplies them by a reproductive rate that has been arbitrarily raised, multiplied by an assumed figure for calf survival, to reach a number of dolphins that would be added each year if the population were to remain stable. From this number, they subtract their estimates of bycatch, which are almost certainly biased low. The remaining number of dolphins is apportioned a cause of death according to autopsy data from 55 Hectors and Maui dolphins found dead on beaches. This is then compared to estimates of what level of takes would be sustainable, calculated using a formula that is not well understood and less conservative than the international standard (PBR, developed by the US National Marine Fisheries Service). This is a poor basis for rational management of an endangered, endemic marine mammal. A key problem with the MPI approach is that its definition of "risk" does not relate to the risk of population decline or extinction, and is inconsistent with the modern understanding of the behaviour of meta-populations. The approach defines risk as the likelihood of capture, which is apportioned to different areas according to fishing effort and the habitat models outputs for dolphin distribution. The protection options are therefore targeted where high densities of dolphins and high fishing effort coincide. Large populations are allocated the highest level of protection, while small populations remain poorly protected. This approach is likely to increase the risk of local extinctions, contractions of dolphin distribution, population fragmentation, loss of genetic variability and result in increased risk to the species as a whole. Many of these points were made by an International Expert Panel in 2018. MPI have failed to provide a list of recommendations from the Expert Panel Report with their responses (if any) to those recommendations. This standard step in scientific practice, following peer review (e.g. response to reviewers comments) has not been followed.

Animal imagery uploaded on social media has been identified as an important tool in wildlife research and conservation and has been used in a variety of recent studies. Here a case study is presented, where a detailed analysis of social media content revealed a shift of a long-term foraging habitat for a juvenile loggerhead sea turtle (Caretta caretta) in Greece. In particular, this individual was a long term resident of Zakynthos island, Greece, from 2016 until 2020 (5 consecutive summer seasons), regularly foraging on a nearshore reef, with no observations of it being made during the 2021 season. However regular social media image mining combined with photo-identification, detected this individual foraging in the Gulf of Corinth in August 2021, more that 200km away from his previous foraging habitat. This case study (i) shows the possibility for juvenile loggerheads to shift their foraging site even after long term use, with implications in capture-mark-recapture studies and (ii) once more highlights the usefulness of social media mining and citizen science in diverse aspects of sea turtle studies.

Conservation of exploited fish populations is a priority for environmental managers. Spatio-temporal knowledge on reproductive sites is mandatory for species and habitat conservation but is often difficult to assess, particularly over vast geographic areas. Regular and long-term standardized surveys are necessary to identify reproductive sites, assess population trends and their distribution. Here we emphasize the utility of Passive Acoustic Monitoring (PAM) for the survey and management of a depleted vulnerable Mediterranean fish species, the brown meagre, Sciaena umbra. Acoustic surveys of reproductive calls were conducted combining 1) spatial data from standardized surveys within three MPAs and from 49 unprotected sites throughout the Northwestern Mediterranean basin, as well as 2) temporal data from a two-year-long survey at a presumed spawning location. The MPA surveys, which rapidly scanned ~30-50 km of the rocky coastlines per MPA, unveiled maps of distribution and reproductive activity of the brown meagre, including potential spawning sites. They were also effective in emphasizing effects linked to management actions: Full-protection zones had a higher number of vocalizations (70% of the listening sites) compared to less protected zones (30% of the sites) or sites outside MPAs (45% of the sites). This was also reflected in the number of singers that was generally low (< 3 individuals) in less protected zones and outside MPAs, implying lower fish densities. Highest calling aggregations were observed in potential spawning areas that represented only 0.04% of all listening sites, and were almost all in older, fully protected MPAs, which thus play a key role for fish stock recovery. The two-year survey revealed a 5-month reproductive season (from May to October) with a strong positive correlation between calling activity and temperature. Overall this study confirms the role of PAM as an efficient, replicable and standardized non-invasive method for population management that can identify functional sites and key protection zones, provide valuable information on reproduction, spatial and temporal occurrence, but also on population trends and climate-driven changes. HighlightsO_LIMonitoring of threatened species and their key habitats is critical for environmental managers. C_LIO_LIManagement requires methods to assess population trends at large spatial and temporal scales. C_LIO_LIPassive acoustics (PA) is efficient in mapping and monitoring vulnerable fish species. C_LIO_LIDistribution, reproductive sites and population dynamics can be assessed over vast geographical areas. C_LIO_LIWe show the utility of PA to identify key conservation zones and assess effects of management actions. C_LI

The current study reports the first occurrence and the spread of the European catfish Silurus glanis (Family: Siluridae) in the Portuguese section of the Douro River, suggesting a potential expansion of its distribution in Portugal either via westward dispersal across international rivers and/or human-assisted introductions into new reservoirs and drainages. European catfish has unique features (e.g., opportunistic predator, hunting, and aggregation behaviour) that make it highly suitable for establishing self-sustaining populations in new areas and likely contribute to its invasion success. The species may severely affect native prey communities and modify food web structure and ecosystem functioning. Efficient and sustainable management actions are needed to prevent further introductions in the future.