Non-native Freshwater Fish Species Research Articles

Isotopic diversity and niche patterns reveal contrasting resource use among co-occurring non-native fishes within a flow-altered African river system

AbstractClassic and contemporary trophic ecology-based studies have shown that most non-native freshwater fish species (NNS) that integrate into novel environments have the potential to influence the recipient ecosystems’ structure and function. However, the interspecific trophic interactions amongst co-occurring NNS within invaded systems remain poorly studied. Here, we used carbon (δ13C) and nitrogen (δ15N) stable isotope analyses to examine general fish trophic diversity patterns (native and non-native fishes) and to explore trophic niche patterns amongst co-occurring NNS within a flow-modified river system, the Great Fish River (South Africa). The system was characterised by isotopic variation, which revealed spatial differences in trophic complexity from uninvaded headwater tributaries to invaded mainstem and downstream sections. Two of the invaded sections, the upper mainstem of the Great Fish River (UGFR) and the Koonap River, had low isotopic overlaps between NNS and the native fish assemblages. Furthermore, co-occurring NNS in these two invaded sections had variable isotopic niche sizes and low interspecific isotopic niche overlaps, suggesting the potential for trophic differentiation. By comparison, there was evidence of high resource use patterns among NNS within the lower mainstem section of the Great Fish River (LGFR), which likely reflected trophic plasticity. Overall, results of this study provided evidence of both trophic niche differentiation (UGFR and Koonap River) and niche overlap (LGFR) as probable mechanisms of co-occurrences of the non-native fishes within different invaded sections of the Great Fish River system, and underscores the difficulties associated with predicting their trophic impacts.

Invasiveness Risk Assessment of Non-native Freshwater Fish Species (Order: Siluriformes)for Lake Taal, Philippines

Biological invasions caused by the introductions of non-native species (NNS) into their non- native ecosystems have long been a global environmental concern. In the Philippines large-scale importation of non-native freshwater fish species for the aquarium and aquaculture industry have been documented as early as 1940s. However, little invasiveness assessment has been done in the past, which resulted to the invasion of some of these exotic species. Thus, in this paper, 25 NNS (Order: Siluriformes) were assessed using the Aquatic Species Invasiveness Screening Kit (AS-ISK) to determine their potential for becoming invasive in the chosen risk assessment (RA) area, as well as their ecological and socioeconomic potential impacts on the Philippines. Based on the comprehensive ROC Curve, with the use of the Youden-J index, overall threshold values of ≥ 35 for basic risk assessment (BRA) and ≥ 47 for BRA + climate change assessment (CCA) were established to categorize the potential invasiveness of each species as low-, medium-, or high-risk. According to BRA, 10 (40%) NNS were screened as highly invasive, 14 (56%) with medium risk, and one (4%) with low risk. For BRA + CCA, 10 (40%) NNS were categorized as highly invasive, 12 (48%) with medium risk, and three (12%) with low risk. These findings highlight the need for more RAs of the non-native fish species that enter the country through the ornamental industry, as well as improved public educational campaigns and comprehensive regulatory and management policies to prevent their future invasion.

Increased geographical distribution and richness of non-native freshwater fish species in Argentina: evidence from a literature review

Increased geographical distribution and richness of non-native freshwater fish species in Argentina: evidence from a literature review

Non-native freshwater fish species in the Lena River basin

Non-native freshwater fish species in the Lena River basin

Evaluating establishment success of non-native fishes introduced to inland aquatic habitats of tropical Pacific islands

An information-theoretic approach was used to evaluate non-native freshwater fish species introduced to insular habitats of Hawaii and Guam comparing successful establishments vs. failures. Since the late 1800s, as many as 81 non-native freshwater fish species have been recorded as introduced to Hawaii and Guam (combined) and 50 (62%) of these are documented as having one or more established populations. We examined eleven independent variables to investigate establishment success by creating 21 a priori logistic regression models ranked using Akaike's Information Criterion adjusted for small sample size. An additional eight post-hoc models were included that comprised the best a priori model and various combinations of individual variables. The best overall model of establishment probability included effects of taxonomic affinity (family membership), prior establishment success on other tropical islands, and hypoxia tolerance. Establishment success in Hawaii and Guam was highest for those species established on many other islands, and according to our best model air-breathing fishes were more likely to become established. Six fish families, each with from three to 18 species introduced to Pacific islands, were highly successful at establishment: Cichlidae (16 established of 18 species introduced), Poeciliidae (seven of eight), Cyprinidae (four of seven), Centrarchidae (four of four), Clariidae (three of three), and Loricariidae (three of four). Those that successfully established include both small and moderately large-bodied taxa, while representing a diverse array of other morphological and life-history traits. Pathways and motives associated with fish introductions in the Pacific have been linked to desires to develop aquaculture, enhance wild stocks of food, sport, and bait fishes, for use as biological control agents, or are linked to the ornamental fish trade. We found that many established species were introduced via multiple pathways (up to eight) and our analyses suggest that the combination of prior establishment success on other tropical islands and presence of non-native fishes in multiple pathways was indicative of high propagule pressure. Our study results and conclusions on Pacific tropical island introductions are in general agreement with previous studies on non-native freshwater fishes in other regions of the world and similar to observations in continental ecosystems and temperate zones.

Ecological and biological traits of non-native freshwater fish species differentiate them from native species in China

China’s freshwater ecosystems are gradually invaded by an increasing number of non-native fish species. However, to date, some controversy about the number of native and non-native freshwater fish species in wild habitats and very limited information on ecological or biological traits mediating fish introduction success at a national scale have prevented the proposal and implementation of targeted conservation and management strategies. To address these urgent issues, first we compiled an up-to-date inventory of 1,797 fish species (1,597, 84, and 116 native, exotic (originating from outside China), and translocated (originating from within China) species, respectively) along with 13 traits encompassing various ecological and life-history strategies for each species, which is the most comprehensive freshwater fish database in China as we know. Here, we found that non-native species mainly belonged to three orders (Perciformes, Siluriformes, and Cypriniformes) and three families (Cichlidae, Cyprinidae, and Salmonidae). Native species were significantly (P < 0.001) different from both exotic and translocated species according to their quantitative traits, while no remarkable differences between exotic and translocated species were detected (P = 0.93). Specifically, G-tests of independence, Similarity Percentage Analysis (SIMPER), and Mann-Whitney-Wilcoxon rank sum tests showed that compared to native species, species with relatively higher vulnerability (intrinsic vulnerability of fishes to fishing), trophic level, and pectoral fin vertical position, but less resilience and lateral body shape were deemed as potential candidates for introduction and dispersal in China.

Possible impacts of non-native plant, pathogen, invertebrate and fish taxa on the indigenous ichthyofauna in South African estuaries: a preliminary review

We review the possible impacts of non-native biota on the indigenous fishes of South African estuaries, including macrophytes, algae, pathogens, invertebrates, and fishes. Freshwater macrophytes are one of the primary non-native groups in the oligohaline reaches of some predominantly open estuaries, lake and river mouth type estuaries, as well as the entire area of certain low salinity, temporarily closed estuaries. Anoxia and hypoxia in the water column below Salvinia molesta and Pontederia crassipes floating mats have caused fish kills in certain temporarily closed estuaries. Mass mortalities of fish in estuaries have arisen from harmful algal blooms (HABs) and a catchment-derived pathogenic water mould, Aphanomyces invadans. Non-native invertebrate species in local estuaries are derived from freshwater, estuarine and marine sources. The freshwater gastropod Tarebia granifera has invaded many subtropical estuaries and may be negatively impacting their food webs, with estuarine zoobenthivorous fishes not appearing to consume this mollusc. The marine polychaete Ficopomatus enigmaticus has invaded many South African estuaries and, in some of them, changed the zoobenthic food web by encrusting on hard surfaces and filtering particulate matter from the water column. This species also does not appear to be eaten by zoobenthivorous fishes within these systems. No non-native marine or estuarine fish species have been recorded in South African estuaries but non-native freshwater fish species now occur in 25% of estuaries in the region. Degraded estuaries in particular are more vulnerable to colonisation by non-native and translocated fish species than unimpacted systems. During the 1990s, a fish survey of 191 estuaries revealed that only 0.04% of the catch comprised non-native or translocated species but this percentage has increased in many estuaries in recent decades. Non-native and translocated freshwater fish species have successfully colonised the oligohaline and mesohaline reaches of many systems and there may be an impact due to predation on the eggs and larvae of resident estuarine taxa and the recruitment success of catadromous and some estuarine-associated fish species. However, most non-native fishes have a limited tolerance for the salinity regimes found in the lower and middle reaches of many South African estuaries, with an even larger threat to the indigenous estuarine ichthyofauna coming from non-native plant, invertebrate and pathogen invaders. Based on this review, and other similar global studies, there is a developing paradigm that non-native invasions by fishes and other organisms into South African and global estuaries are driven primarily from freshwater taxa and not estuarine or marine species.

Identifying threats from introduced and translocated non-native freshwater fishes in Croatia and Slovenia under current and future climatic conditions

Introduced and translocated non-native species are a major threat to biodiversity, especially in aquatic habitats. Efforts aimed at the mitigation of impacts and the implementation of preventative measures for the conservation of native biota must rely upon an accurate evaluation of the risks posed by non-native invasive species and are expected to be strengthened by international collaboration. In this study, 76 non-native freshwater fish species of which 48 extant (both introduced and translocated) and 28 horizon were screened for their risk of invasiveness in the neighbouring countries of Croatia and Slovenia under current and future climatic conditions. Using the Aquatic Species Invasiveness Screening Kit (AS-ISK), threshold scores for the Basic Risk Assessment (BRA) and for the combined BRA and Climate Change Assessment (BRA + CCA) allowed to distinguish with a high level of accuracy between low-, medium- and high-risk species – the latter representing ≈70% of the screened species. Brown bullhead Ameiurus nebulosus, round goby Neogobius melanostomus, topmouth gudgeon Pseudorasbora parva and Wels catfish Silurus glanis were the highest-scoring species for Croatia, and Ameiurus nebulosus, snakehead Channa argus and Pseudorasbora parva for Slovenia. There were discrepancies in medium- and high-risk rankings between Croatia and Slovenia for 12 species. Upon comparison of the BRA outcomes with those based on the Freshwater Fish Invasiveness Screening Kit (the predecessor of the AS-ISK), the risk changed for six species in Croatia and five in Slovenia. After accounting for predicted climate change conditions, the BRA + CCA risk scores increased for ≈50% of the species, with western mosquitofish Gambusia affinis, channel catfish Ictalurus punctatus and black carp Mylopharyngodon piceus achieving the highest score increment for Croatia, and round goby Neogobius melanostomus and Chinese (Amur) sleeper Perccottus glenii for Slovenia. The present outcomes will assist decision-makers in the implementation of appropriate measures for the management of extant non-native species and the potential introduction of horizon species. This is important for the regulation of pet trade and aquaculture as well as for management strategies aimed at the conservation of native biodiversity, which in the case of neighbouring countries/jurisdictions will benefit from joint efforts relying on a full risk assessment for the species classified at higher risk of invasiveness.

Distribution of Lessepsian Migrant and Non-Native Freshwater Fish Species in Mediterranean Brackish Waters of Turkey

The introduction of invasive fish species is considered to be one of the major causes of species endangerment in aquatic ecosystems. More than 30 non-native freshwater fish species which are introduced for the different purpose were reported in Turkey. In addition to the freshwater non-native fish species, the brackish water systems are also affected by the fish species that enter the Mediterranean Sea through the Suez Canal. This study aimed to identify non-native fish species introduced in the Mediterranean brackish water systems of Turkey. Thirteen non-native species from eleven families were identified from 15 localities along the entire Mediterranean Coast of Turkey between 2014-2017. These species are Carassius gibelio (Bloch, 1782), Pseudorasbora parva (Temminck &amp;amp; Schlegel, 1846), Coptodon zillii (Gervais, 1848), Oreochromis niloticus (Linnaeus, 1758), Gambusia holbrooki Girard, 1859, Oncorhynchus mykiss (Walbaum, 1792), Chelon carinatus (Valenciennes 1836), Equulites klunzingeri (Steindachner, 1898), Upeneus moluccensis (Bleeker, 1855), Upeneus pori Ben-Tuvia &amp;amp; Golani, 1989, Siganus rivulatus Forsskål &amp;amp; Niebuhr, 1775, Sillago suezensis Golani, Fricke &amp;amp; Tikochinski, 2013 and Sphyraena chrysotaenia Klunzinger, 1884. The most widely distributed non-native fishes were Gambusia holbrooki, Chelon carinatus, and Carassius gibelio. Of the 15 localities surveyed Lessepsian fish species were sampled from 9 localities.

Invasive fish threat in Manyas Lake (Turkey)

Two non-native freshwater fish species, Gambusia holbrooki Girard, 1859 and Pseudorasbora parva (Temminck & Schlegel, 1846) were recorded for the first time for the Manyas Lake, and the number of the non-native fish species living in the lake has increased to three. These non-native fish species described as invasive were considered as new threats to the lake, which is already threatened by eutrophication and habitat degradation.

Interaction between non-native predatory fishes and native galaxiids (Pisces: Galaxiidae) shapes food web structure in Tasmanian lakes

ABSTRACT Non-native fish invasions threaten native fauna and ecosystem functioning, not least in isolated island lakes. In Tasmania, where the native fish are mostly galaxiids, 9 non-native freshwater fish species have been introduced over the past 150 years, with uncertain ecological outcomes. We evaluated the effects of non-native predatory fishes (NNPF) and various environmental and biological variables on the trophic niche of native fish (galaxiids) and potential cascading effects. We analysed Layman’s food web metrics based on both stable isotope (δ 15N and δ 13C) values and fish stomach contents in 14 shallow Tasmanian lakes along a NNPF abundance gradient. The food web metrics calculated were (1) range of δ 13C (CR) and δ 15N (NR) centroid distance (CD) and (2) standard ellipse area. Our results showed that NNPF relative abundance in the fish catch per unit effort was negatively related to the galaxiids’ trophic niche metrics (e.g., CRG, NRG, and CDG), trophic position, and the pelagic contribution to the diet. Moreover, the proportion of galaxiids in the diet of NNPF was higher in turbid lakes. The zooplankton standard ellipse area was negatively correlated with the pelagic contribution to the NNPF diet, and NNPF relative abundance was positively correlated with the maximum body size of calanoid copepods. While our results suggest a negative effect of NNPF on the trophic niche of galaxiids, the cascading effect on phytoplankton biomass was weak. Non-native predatory fish affect native fish prey, and the outcome of these interactions should be considered for conservation purposes, particularly for island lakes, such as those in Tasmania.

PiSCES: Pi(scine) stream community estimation system

The Piscine Stream Community Estimation System (PiSCES) provides users with a hypothesized fish community for any stream reach in the conterminous United States using information obtained from Nature Serve, the US Geological Survey (USGS), StreamCat, and the Peterson Field Guide to Freshwater Fishes of North America for over 1000 native and non-native freshwater fish species. PiSCES can filter HUC8-based fish assemblages based on species-specific occurrence models; create a community abundance/biomass distribution by relating relative abundance to mean body weight of each species; and allow users to query its database to see ancillary characteristics of each species (e.g., habitat preferences and maximum size). Future efforts will aim to improve the accuracy of the species distribution database and refine/augment increase the occurrence models. The PiSCES tool is accessible at the EPA's Quantitative Environmental Domain (QED) website at https://qed.epacdx.net/pisces/

Non-native fishes in the Indian Himalaya: an emerging concern for freshwater scientists

ABSTRACTAnthropogenic activities impose major threats to global biodiversity, compounded by changing climatic variables. Freshwater ecosystems are amongst the most vulnerable habitats, integrating multiple pressures across catchment landscapes. Introduction of non-native fish species exerts multiple direct and indirect impacts on native species and the ecosystems of which they are part, with further impacts on the socio-economic wellbeing of communities. Field studies and an in-depth literature survey have recorded 15 non-native freshwater fish species from the Indian Himalaya. Three of these species (common carp, brown trout and rainbow trout, all highly invasive fish species globally) were documented from multiple locations between 2010 and 2017, raising environmental concern among scientists. In the wake of changing climatic variables and a range of linked population, land use and river impoundment and conversion pressures across the Indian Himalaya, there is an urgent need to understand the behaviour of these non-native fish species and identify factors which provide them an ecological advantage over native fish species. This can support a case for cessation of stocking with alien species. Further collection of long-term field data, integrative quantitative models, public awareness and education programmes could greatly assist in addressing these knowledge gaps and identification of effective control measures.

A global database on freshwater fish species occurrence in drainage basins

A growing interest is devoted to global-scale approaches in ecology and evolution that examine patterns and determinants of species diversity and the threats resulting from global change. These analyses obviously require global datasets of species distribution. Freshwater systems house a disproportionately high fraction of the global fish diversity considering the small proportion of the earth’s surface that they occupy, and are one of the most threatened habitats on Earth. Here we provide complete species lists for 3119 drainage basins covering more than 80% of the Earth surface using 14953 fish species inhabiting permanently or occasionally freshwater systems. The database results from an extensive survey of native and non-native freshwater fish species distribution based on 1436 published papers, books, grey literature and web-based sources. Alone or in combination with further datasets on species biological and ecological characteristics and their evolutionary history, this database represents a highly valuable source of information for further studies on freshwater macroecology, macroevolution, biogeography and conservation.

Native freshwater species get out of the way: Prussian carp (Carassius gibelio) impacts both fish and benthic invertebrate communities in North America.

Prussian carp (Carassius gibelio) are one of the most noxious non-native species in Eurasia. Recently, Prussian carp, a non-native freshwater fish species, were genetically confirmed in Alberta, Canada and have been rapidly expanding their range in North America since establishment. Given their rapid range expansion, there is an increasing need to determine how Prussian carp may impact native species. We assessed the severity of the Prussian carp invasion by (i) determining their impact on fish communities, (ii) assessing their impact on benthic invertebrate communities, (iii) evaluating if Prussian carp alter abiotic conditions, and (iv) identifying where we find higher abundances of Prussian carp. When Prussian carp were established, we found significant changes to the fish community. Correspondingly, the degree of impact to benthic invertebrate communities was related to the stage of invasion (none, early or recent), where changes in fish communities were significantly concordant with changes in benthic invertebrate communities. Finally, we found that higher abundances of Prussian carp were significantly associated with lower abundances of a majority of native fish species. Altogether, using three lines of evidence, we determine that Prussian carp can have wide-ranging impacts on freshwater ecosystems in North America, pressing the need for management intervention.

Global test of Eltonian niche conservatism of nonnative freshwater fish species between their native and introduced ranges

Despite growing evidence that biotic interactions limit the distribution of species and their potential redistribution under climate change, the recent surge of interest in niche conservatism has predominantly focused on the Grinellian (abiotic) niche, whereas few studies have attempted to quantify potential lability in the Eltonian (biotic or trophic) niche. Here, we test for conservatism in the Eltonian niche of 32 freshwater fish species between their introduced and native ranges from 435 populations across the globe. We used stable isotope data to quantify niche shifts along the horizontal (δ13C: indicating the origin of the resources consumed) and vertical (δ15N: describing the trophic position) dimensions of the isotopic niche, as well as shifts in overall isotopic niche breadth. Using an assemblage centroid standardized isotope vector analysis and controlling for phylogenetic relatedness among species, we demonstrated that introduced freshwater fishes exhibited flexibility in both resource use and trophic position that was beyond levels of natural variability observed in their native ranges. By contrast, niche breadth showed variability only within the limits recorded in native populations and varied independently from shifts in mean isotopic niche positions. Across all species and introduction histories, we found a consistent shift towards more balanced acquisition of resources with mixed origins and at intermediate trophic positions, suggesting a general mechanism by which fish species successfully establish into recipient communities. The mechanisms that promote or inhibit species from shifting their Eltonian niche remains unknown, but trophic flexibility is likely to contribute to both the success and the ecological impacts of invasive species and range shifts of native species under future global change.

Non-native freshwater fish species in China

Non-native fishes are regarded as a serious threat to freshwater biodiversity. However, little information exists about non-native freshwater fish in China. This study compiled an inventory of non-native freshwater fish species in China based on various sources. The inventory includes a total of 439 freshwater fish species belonging to 22 orders, 67 families, and 256 genera. The four most dominant orders were Perciformes, Characiformes, Siluriformes, and Cypriniformes, accounting for 38.50 14.81 13.90, and 11.16 % of the non-native freshwater fish in China, respectively. Over one-third of non-native freshwater fish species were of South American origin (35.54 %), followed by Asian (23.01 %), and African (21.41 %) origins. The aquarium and aquaculture industries are the two main vectors responsible for the introduction of non-native fish species into China. The status and potential impacts of most non-native fishes are uncertain. This study summarizes the known ecological and economic effects of non-native freshwater fishes in China. The results demonstrate that there are enormous positive and negative impacts of non-native fishes on the economy, and that some non-native species are potential threats to humans and biodiversity in China. Therefore, more attention should be focused on non-native fishes in China in the future.

Detection of invasive freshwater fish species using environmental DNA survey

Invasive species are one of the most significant problem in freshwater ecosystems. Most common non-native freshwater species in Turkish freshwater fish fauna are Prussian Carp (Carassius gibelio), North African Catfish (Clarias gariepinus), Nile Tilapia (Oreochromis niloticus) and Topmouth Gudgeon (Pseudorasbora parva).Recent studies showed that environmental DNA could be used to detect target species inhabiting the ecosystem with higher precision and less effort compared to traditional field surveys. In this study, eDNA approach was used to investigate non-native freshwater fish species from fifteen different locations of Upper Sakarya Basin. eDNA was successfully extracted from the water samples of locations where the species were visually observed. Mean amplification rate of eDNA was calculated as 77.03%.This study is the first environmental DNA study used in detection of four of the most common invasive freshwater fish species. Results clearly indicating that eDNA surveys could be used as an important molecular tool to monitor invasive fish species in freshwater ecosystems.

DNA barcoding common non-native freshwater fish species in Turkey: Low genetic diversity but high population structuring

Negative impacts of introduced non-native freshwater species on native species have been increasingly recognized in the world as well as in Turkey. However, there has been relatively little attention on genetic characterization of alien freshwater fishes in their non-native distribution range and virtually no study has been conducted in Turkey despite its crucial importance in invasion biology. The purpose of this study was to elucidate genetic diversity of common non-native freshwater fish species (Carassius auratus, Carassius gibelio, Gambusia holbrooki, Lepomis gibbosus, and Pseudorasbora parva) using mitochondrial Cytochrome c oxidase subunit I (COI) sequences; known as DNA barcodes. Through the whole dataset, seventeen haplotypes (haplotype diversity = 0.8908) were found containing 145 COI sequences. Mean Kimura two-parameter genetic distances were calculated as 0.209 for interspecific distance and 0.009 for intraspecific variation. COI barcode diversity among populations of the same species was found to be low, especially for C. gibelio, G. holbrooki, and L. gibbosus populations which were 0.5%, 0.6%, and 0.3%, respectively. Our results clearly demonstrate the effectiveness of the DNA barcoding approach both for identifications at species level and revealing intraspecific variation among populations, which could be used for effective management measures for invasive species and conservation strategies for indigenous and endemic species.

Distribution history of non-native freshwater fish species in Germany: how invasive are they?

Distribution patterns of non-native fishes in Germany have been analysed starting from their first introductions reported, with the objectives to determine indicators of their invasiveness, to identify the most important distribution pathways, and to predict their further development. In Germany, 14 out of 93 non-native freshwater and migratory fish species ever registered are established today, a further six are possibly established, eight have failed to establish, and the rest were single records. Five of the established and three potentially established species were restricted to single locations. Of the remaining species, only the gobiid species are actually spreading throughout the waterway network, whereas other stocks rather tend to decline or did not change. The most wide-spread species is rainbow trout Oncorhynchus mykiss, with 5,872 records in open waters being the most important fish for German’s commercial inland fisheries with an annual yield of > 21 000 tons. But rainbow trout is widely stocked and its establishment status is a subject of debate. Inland fisheries management has contributed most to the recent distribution of non-native fishes, but it became also the best regulated pathway. Therefore, it is expected that ornamental fish trade and aquaculture will become most important for introducing new non-native fishes in the near future, even if unintentionally. Every single fish escaping from a garden pond or holding facility is a potential founder of an invasive species stock and in particular raising water temperatures in winter might promote the establishment of ornamental fish. Once established, there are nearly no legal means to remove a non-native species successfully from a water body.