Invasive Carp Research Articles

Invasive gibel carp use vacant space and occupy lower trophic niche compared to endangered native crucian carp

Invasive gibel carp use vacant space and occupy lower trophic niche compared to endangered native crucian carp

Comparison of resource use by invasive Black Carp and native fishes using isotopic niche analysis reveals spatial variation in potential competition

Comparison of resource use by invasive Black Carp and native fishes using isotopic niche analysis reveals spatial variation in potential competition

WhoseEgg: classification software for invasive carp eggs.

The collection of fish eggs is a commonly used technique for monitoring invasive carp. Genetic identification is the most trusted method for identifying fish eggs but is expensive and slow. Recent work suggests random forest models could provide an inexpensive method for identifying invasive carp eggs based on morphometric egg characteristics. While random forests provide accurate predictions, they do not produce a simple formula for obtaining new predictions. Instead, individuals must have knowledge of the R coding language, limiting the individuals who can use the random forests for resource management. We present WhoseEgg: a web-based point-and-click application that allows non-R users to access random forests via a point and click interface to rapidly identify fish eggs with an objective of detecting invasive carp (Bighead, Grass, and Silver Carp) in the Upper Mississippi River basin. This article provides an overview of WhoseEgg, an example application, and future research directions.

Effects of an ensonified bubble curtain and a cyclic sound on blocking 10 species of fishes including 4 invasive carps in a laboratory flume

Effects of an ensonified bubble curtain and a cyclic sound on blocking 10 species of fishes including 4 invasive carps in a laboratory flume

Patterns of zero and nonzero counts indicate spatiotemporal distributions, aggregation, and dispersion of invasive carp

Patterns of zero and nonzero counts indicate spatiotemporal distributions, aggregation, and dispersion of invasive carp

Recreational angler reporting as a tool for tracking the distribution of invasive Prussian carp (Carassius gibelio)

AbstractThe recent invasion of Carassius gibelio (commonly known as Prussian carp or Gibel carp) in freshwater environments in central Canada threatens native North American aquatic species and ecosystems. Accurate distribution information is essential for targeting control efforts but is challenging given the resources necessary to continually sample the species' potential distribution. We investigated the extent to which reports by recreational anglers—key resource users—could be used in a citizen science program to generate species distribution information, and factors affecting the accuracy of reporting for C. gibelio. Comparing the location of angler reports to the known distribution of C. gibelio generated by professional biological sampling across the region revealed that anglers can be a powerful resource for tracking an invasive species' distribution; 88% of the C. gibelio angler reports aligned with invaded watersheds (HUC‐8 [hydrological unit code 8], the second finest watershed unit) identified by professional biological sampling. For every report of C. gibelio received in a HUC‐8 area, the probability that area was invaded increased by more than 10 times (odds ratio = 10.26, ±95% CI: 4.4–29.7). Anglers' fish identification abilities were positively related to likelihood of reporting Carassius spp. (odds ratio = 2.52, ±95% CI:1.51–4.45). Anglers that fished more frequently were also more likely to have reported C. gibelio accurately (odds ratio = 1.00, ±95% CI: 0.99–1.01), although the mechanism behind this relationship is unclear. Our results suggest programs that engage recreational anglers in reporting could provide a cost‐effective alternative or complimentary tool for traditional Aquatic Invasive Species (AIS) population tracking.

Analysis of per capita contributions from a spatial model provides strategies for controlling spread of invasive carp

AbstractMetapopulation models may be applied to inform natural resource management to guide actions targeted at location‐specific subpopulations. Model insights frequently help to understand which subpopulations to target and highlight the importance of connections among subpopulations. For example, managers often treat aquatic invasive species populations as discrete populations due to hydrological (e.g., lakes, pools formed by dams) or jurisdictional boundaries (e.g., river segments by country or jurisdictional units such as states or provinces). However, aquatic invasive species often have high rates of dispersion and migration among heterogenous locations, which complicates traditional metapopulation models and may not conform to management boundaries. Controlling invasive species requires consideration of spatial dynamics because local management activities (e.g., harvest, movement deterrents) may have important impacts on connected subpopulations. We expand upon previous work to create a spatial linear matrix model for an aquatic invasive species, Bighead Carp, in the Illinois River, USA, to examine the per capita contributions of specific subpopulations and impacts of different management scenarios on these subpopulations. Managers currently seek to prevent Bighead Carp from invading the Great Lakes via a connection between the Illinois Waterway and Lake Michigan by allocating management actions across a series of river pools. We applied the model to highlight how spatial variation in movement rates and recruitment can affect decisions about where management activities might occur. We found that where the model suggested management actions should occur depend crucially on the specific management goal (i.e., limiting the growth rate of the metapopulation vs. limiting the growth rate of the invasion front) and the per capita recruitment rate in downstream pools. Our findings illustrate the importance of linking metapopulation dynamics to management goals for invasive species control.

Validation of a Portable eDNA Detection Kit for Invasive Carps

Loop-mediated isothermal amplification (LAMP) is a rapid molecular detection technique that has been used as a diagnostic tool for detecting human and animal pathogens for over 20 years and is promising for detecting environmental DNA shed by invasive species. We designed a LAMP assay to detect the invasive carps, silver carp (Hypophthalmichthys molitrix), bighead carp (Hypophthalmichthys nobilis), black carp (Mylopharyngodon piceus), and grass carp (Ctenopharyngodon idella). To determine the sensitivity of the LAMP assay, we determined limit of detection (LOD) for each invasive carp species and compared with the performance of a grass carp quantitative PCR (qPCR) assay in LOD and in a mesocosm study. We used two grass carp densities, 3 juvenile grass carp in one mesocosm and 33 juvenile grass carp in the other. Prior to adding grass carp to the mesocosms, we added 68 kg of fathead minnows (Pimephales promelas) to each mesocosm to simulate farm ponds used for raising bait fish. We filtered 500 mL of water per sample to compare LAMP and qPCR analysis, and we collected 50 mL grab samples that were only analyzed using qPCR to gain additional data using a higher-throughput method to monitor environmental DNA (eDNA) levels throughout the study period. No eDNA for any of the four invasive carp species was detected in water collected from the mesocosms during the three days prior to adding grass carp. Forty-eight hours after grass carp addition to mesocosms, we detected grass carp eDNA in the mesocosm containing 33 grass carp using the LAMP assay. However, we failed to detect any grass carp DNA in the mesocosm containing 3 grass carp with the LAMP assay throughout the study. We analyzed the data using an occupancy model and found that the 500 mL filter samples yielded a higher eDNA capture probability than 50 mL grab samples in the mesocosm containing three grass carp but had similar eDNA capture probability in the mesocosm containing 33 grass carp. Both LAMP and qPCR reliably detected grass carp eDNA 2 days after grass carp addition, but detections were more consistent with qPCR. The LAMP assay may have utility for certain niche uses because it can be used to rapidly analyze eDNA samples and is robust to inhibition, despite having some limitations.

The influence of the drugs “Brovermectin-granulate TM” and “Avesstim TM” on indicators of non-specific resistance of one year-old carp fish infested with monogeneans

The article presents data on the study of the influence of the drugs “Brovermectin-granulate TM” and “Avesstim TM” on indicators of non-specific resistance of one-year-old carp fish infested with monogeneans. For conducting experiments, 14 experimental groups were formed (two groups of each species of fish affected by Dactylogyrus lamellatus, Gyrodactylus hypophthalmichtіdis, Eudiplozoon nipponicum ). The fish of the first experimental group were administered “Brovermectin-granulate TM”, and the second experimental group were administerec a complex of drugs “Brovermectin-granulate TM” and “Avesstim TM”. Fish infected with various ectoparasites (Dactylogyrus lamellatus, Gyrodactylus hypophthalmichtіdis, Eudiplozoon nipponicum ) served as controls. Fish of each group were kept in separate aquariums with a capacity of 40 dm3 with artificial aeration at a temperature of 20–22 °С. Their care and feeding was carried out according to the relevant norms and rations. During the entire period of research, the behavior and clinical condition of the fish were observed. The pre-experimental period of acclimatization of annuals was 7 days. The use of the drug “Brovermectin-granulate TM” to one-year-old white carp, crucian carp and scaly carp affected by monogeneans had a stimulating effect on the resistance of their organism. At the same time, the simultaneous use of the specified drug with the immunomodulator “Avesstim TM” contributed to better activation of the humoral link of non-specific immunity in sick fish. To normalize the organism homeostasis, correct metabolism and activate the humoral link of non-specific immunity during a monogenoid invasion of carp, it is recommended to feed them with a combined feed of the drugs “Brovermectin-granulate TM” and the immunomodulator “Avesstim TM”.

Using individual‐based models to develop invasive species risk assessments by predicting species habitat suitability

Abstract Preventing invasive species establishment is a global conservation priority, yet limited management resources oftentimes restrict sites to target for prevention or monitoring. Risk assessments based on habitat suitability can identify sites most vulnerable to invasion that should be prioritized for preventative actions. Since habitat suitability is the result of interactions between environmental and organismal attributes, analyses should incorporate individual variability in demographics expected in an invasive population. Individual‐based models (IBMs) can predict habitat suitability by accounting for interactions between environmental conditions and individual‐level variability. We developed an IBM to predict suitability of rivers in the northern United States to the invasive fishes silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) and explored the projected effects of climate change on habitat suitability. All rivers supported adult survival, although complete survival of all adult demographics and positive growth only occurred in approximately 45% (17 of 38) of rivers for silver carp and 26% (10 of 38) of rivers for bighead carp. Only the largest individuals at the time of introduction survived in rivers where adult mortality occurred. Most rivers were unsuitable for young‐of‐year (89% and 92% of rivers for silver carp and bighead carp respectively). Climate change simulations had relatively little effect on adult habitat suitability but resulted in up to four times the number of rivers being suitable for young‐of‐year by the late‐21st century and greatly extended the viable spawning season by up to an additional 65 days for silver carp and 77 days for bighead carp. Synthesis and applications. Our approach of using individual‐based models as a risk assessment tool informs proactive conservation planning by identifying sites for invasive species early detection monitoring, promoting the development of contingency response plans and allowing for proactive prevention efforts. Model predictions also provide specific management guidance regarding the size and life stages to target for monitoring efforts, which capture gears to use, and the most effective time to sample for early detection monitoring.

Silver Carp (Hypophthalmichthys molitrix) (Asian Silver Carp) Presence in Danube Delta and Romania-A Review with Data on Natural Reproduction.

The Danube River has a large hydrographical basin, being the second largest river in Europe. The main channel flows through seven European countries with many species of fish inhabiting it. In this review we focused on the invasive species silver carp (Hypophthalmichthys molitrix), which plays an important ecological and economic role in its original habitat, but since introduced in Europe’s rivers, the species has posed a serious ecological risk under global warming. In this review paper, we gathered data regarding silver carp, such as when and how it entered the Danube Delta and the water temperature suitable for its growth and reproduction, mainly in the context of global warming, as well as the nature of nutrition and the ecological risk the species poses.

Policy action needed to unlock eDNA potential

Policy action needed to unlock <scp>eDNA</scp> potential

Establishment of invasive Black Carp (Mylopharyngodon piceus) in the Mississippi River basin: identifying sources and year classes contributing to recruitment

Black Carp (Mylopharyngodon piceus) was imported to the USA to control aquaculture pond snails. This species has escaped captivity and occurs in parts of the Mississippi River, several tributaries, and floodplain lakes, which is concerning due to potential competition with native fishes and predation on native mussels, many of which are imperiled. However, Black Carp captures have primarily been incidental by commercial fishers, and evidence of reproduction in the wild is limited. The objectives of this study were to assess relative abundance of aquaculture-origin and wild Black Carp using ploidy and otolith stable isotope analysis, identify spatial extent of natural reproduction using otolith microchemistry, assess age distributions of wild and aquaculture-source Black Carp to infer years in which natural reproduction occurred and timing of aquaculture escapement or introductions, and estimate size and age at maturation to assess whether recruitment to adulthood has occurred. Results revealed that Black Carp are established in parts of the Mississippi River basin based on findings that: (1) non-captive Black Carp primarily consist of fertile, naturally-reproduced fish, (2) reproduction has occurred in several rivers, (3) multiple year classes of wild fish are present, and (4) wild fish have recruited to adulthood. Multiple introductions or escapements of aquaculture-source fish into the wild, including both fertile and functionally sterile individuals, were also inferred. Individual growth appears to be rapid, although considerable variation was observed among fish. Additional study is suggested to refine understanding of where and when Black Carp reproduction is occurring in the Mississippi River basin.

How low can they go: A comparison between dog (Canis familiaris) and environmental DNA detection of invasive koi carp (Cyprinus rubrofuscus)

Carp (Cyprinus sp.) are a highly invasive fish that pose a significant threat to freshwater ecosystems worldwide. At high biomasses (i.e., ≥100 kg/ha), the benthic feeding behaviour of carp can have deleterious ecosystem effects, often changing clear, macrophyte dominant waterbodies to turbid-phytoplankton dominant ecosystems. To prevent carp from reaching ecologically harmful biomasses, early detection (i.e., before population establishment) and rapid control actions are vital. Boat electrofishing, netting, and environmental DNA (eDNA) are commonly used to survey for carp, but these methods can be expensive or time inefficient when fish densities are low. Scent-detection dogs have proven efficacious at detecting terrestrial and aquatic species and could represent an efficient method for early detection of carp invasions. Here, we investigated a dog’s sensitivity and specificity to carp scent using a multiple probe design experiment. The dog was trained to use an automated carousel independently of its handler and assessed water samples from aquaria containing either no fish scent (n = 3, non-target), goldfish (Carassius auratus) scent (n = 5, non-target) or carp scent (n = 9, target). The goldfish samples and six of the target samples were presented to the dog at a standard fish biomass concentration of 15.5 mg/L. The remaining three target samples (probes) were systematically diluted to determine the dog’s detection threshold. Results showed that the dog could detect carp housed under laboratory conditions down to a dilution equivalent biomass of 9.3 kg/ha (i.e., 0.5 mg carp/L), which is well below the likely biomass threshold of carp known to cause significant ecological impacts. The dog’s scent-detection performance was then compared with eDNA, an existing survey method. Quantitative PCR conducted on DNA extracted from laboratory aquaria filtrate revealed that the species-specific primer could detect carp at 9.3 kg/ha, but amplification rates at this dilution were low, as were all dilutions below the limit of quantification (≈160 kg/ha). These findings suggest that dogs could provide an accurate and highly sensitive method invasive fish detection. However, before deployment as a carp surveillance method, dogs’ performance on water samples collected from natural aquatic systems (i.e., lakes, ponds, rivers) needs to be evaluated. To our knowledge this is the first published study of its kind comparing a dog’s sensitivity to eDNA, and investigating the potential utility of dogs as an invasive fish detection method.

Proof-of-Concept Studies Demonstrate That Food and Pheromone Stimuli Can Be Used to Attract Invasive Carp So Their Presence Can Be Readily Measured Using Environmental DNA

The utility of environmental DNA (eDNA) as a detection tool for fisheries management is limited by dilution and degradation, especially in areas of low fish abundance. This proof-of-concept study addressed these challenges by testing whether food or pheromones might be used to attract invasive carp so they can be measured more readily using eDNA. In two experiments, PIT-tagged carp were stocked into ponds (N = 3 for silver carp; N = 1 for common carp) while one of two stimuli (planktonic food [spirulina] for silver carp and a sex pheromone [prostaglandin F2α] for male common carp) was added to determine if we could attract fish to one side while measuring both fish presence (detections) and eDNA concentrations. The addition of spirulina increased detections of silver carp by 2–3 fold, while eDNA concentrations increased by 4-fold on the test side when compared to the side without the stimulus. The addition of the sex pheromone increased detections of common carp by ~25-fold, where a 6-fold increase in eDNA concentrations was measured (p &lt; 0.05). A strong positive correlation was noted between fish presence and eDNA concentration for both species. These experiments demonstrate that food and pheromone stimuli could be used to attract invasive carp so they could be measured more easily and accurately.

Food composition and feeding strategies of an invasive species, Carassius gibelio (Bloch, 1782) inhabiting a eutrophic lake in Middle Black Sea region

Diet composition and feeding features of the Prussian carp Carassius gibelio (Bloch, 1782) were studied by analysing the stomach content of 155 fish specimens sampled from Lake Ladik during November 2009-October 2010. Five of the specimens had empty stomachs. A total of 29 prey taxa belonging to eight major groups comprising aquatic insects, Copepoda, Cladocera, Rotifera, Bacillariopyhta, Chlorophyta, Cyanobacteria and fish eggs were identified in 150 full stomachs. Diet composition showed slight seasonal variation. Cladocera was the most important prey item in all seasons, with peak abndance in spring. Feeding intensity exhibited seasonal change and was maximum in summer. Summer and autumn diets of this species showed the highest similarity. The study indicated that the Prussian carp in Lake Ladik showed both omnivorous and opportunistic feeding habits, exhibiting specialised feeding strategy on Cladocera, while they showed generalised feeding strategy on most prey items. The wide dietary plasticity of invasive Prussian carp can help their population to expand rapidly in different aquatic ecosystems. Keywords: Alien species, Diet composition, Feeding habits, Lake Ladik, Prussian carp

Evidence of alternative trophic pathways for fish consumers in a large river system in the face of invasion

Large rivers are susceptible to anthropogenic alteration, which can result in drastic changes to their functional ecology. We evaluated spatial–temporal changes in the functional fish communities of the Upper Mississippi River System (UMRS) using data from six study reaches. Species were classified into one of 14 feeding guilds and mass per unit effort (MPUE) was then calculated for each feeding guild annually per gear type. MPUE was standardized using the multigear mean standardization method (MGMS) and log-transformed. Both ANOSIM and Chi-square tests were used to determine differences in MPUE among reaches. We then estimated functional diversity by calculating the number of functional groups (N), Margalef's d, Pielou's J′, Shannon's Diversity, and Simpson's Diversity Index. An AR(1) time series model was used to investigate proportional changes in each guild over 25 years. To evaluate the effect of invasive Carp species in invaded reaches, a Chow test was applied to observations between 2000 and 2005. Analyses revealed differences in the functional fish community among reaches. We found differences in functional diversity metrics among study reaches, but there was little evidence that this differed between invaded and non-invaded reaches. Results determined that invertivore/detritivores have been consistently declining system-wide, with few groups showing a net change. There was also little evidence that invasion altered the proportion of any functional guild. Evaluating the spatial–temporal patterns of functional communities is beneficial to understanding the resilience of a system and can provide further insight into its trophic needs when considering future restoration initiatives.

Environmental Cues of Spawning Migration into a Confined Wetland by Northern Pike and Common Carp in Lake Erie: Identifying Fine‐Scale Patterns

AbstractRestoration of wetlands in the Laurentian Great Lakes is designed to improve numerous ecosystem services including nutrient sequestration, support recreational uses, augment waterfowl habitat, and provide spawning and nursery habitat for fish. These projects often use Northern Pike Esox lucius, as a sentinel species for assessing restoration success because of their obligate use of emergent and submergent vegetation by the early life stages. However, invasive species such as Common Carp Cyprinus carpio also utilize these habitats and can have negative effects. Thus, fostering the use of these wetlands by Northern Pike and limiting access by invasive carp is a common restoration management concern. Using a dual frequency sonar system to observe fish migration in a recently connected Lake Erie coastal wetland, we were able to identify fine‐scale environmental correlates to immigration by each species during early spring. Both species overwhelmingly migrated during daylight hours and against the flow of water that was generated through seiche‐driven water oscillations. However, Northern Pike predominantly immigrated during the initial increase in water temperature immediately after ice‐out; Common Carp also began to enter the wetland at low temperatures shortly after ice‐out, but immigration exhibited a slow exponentially increasing pattern, such that the primary immigration timing differed by almost 30 d. Thus, we demonstrate common fine‐scale spawning migration patterns (i.e., water oscillation effects and time of day) for both species and reinforce the temperature‐correlated differences in spawning migration. Using these results could enable managers of connected wetlands to more precisely and dynamically manage habitat accessibility for desired species like Northern Pike while better regulating invasive Common Carp spawning migration and use of these systems.

The consequences of misrepresenting feedbacks in coupled human and environmental models

Feedbacks between the ecosystem and the economy are important to consider when measuring impacts from a disturbance but are often omitted from general equilibrium bioeconomic models. These models usually focus on how humans respond to ecological change, but do not consider that in adapting to changed conditions, humans can further affect the ecosystem. We present a framework that couples a regional computable general equilibrium model with an Ecopath with Ecosim food web model with bidirectional feedbacks between the two systems. Our bioeconomic model uniquely represents a comprehensive mapping of the entire regional economy, including recreational and commercial fishing, harvest quotas, and fish biomass in the economic system. We simulate the bioeconomic impacts of a potential Asian carp invasion of Lake Erie's food web and regional economy with and without bidirectional feedbacks between the economy and the ecosystem. When feedbacks are omitted there are large ecological variations in the projected biomass levels of many target species, with differences in biomass of up to 80 percentage points. Results demonstrate the need to reflect bidirectional feedbacks between the economy and the ecosystem; omission of these feedbacks in this case may appear to be economically trivial yet have large ecological consequences.

Zooplankton community dynamics along the bigheaded carp invasion front in the Upper Mississippi River

Zooplankton community dynamics along the bigheaded carp invasion front in the Upper Mississippi River