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Wang Cai - One of the best experts on this subject based on the ideXlab platform.
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using edna to detect the distribution and density of invasive Crayfish in the honghe hani rice terrace world heritage site
PLOS ONE, 2017Co-Authors: Chunyan Yang, Lin Wang, Wenzhi Wang, Guigang Zhao, Wang Cai, Yupeng GengAbstract:The Honghe-Hani landscape in China is a UNESCO World Natural Heritage site due to the beauty of its thousands of rice terraces, but these structures are in danger from the invasive Crayfish Procambarus clarkii. Crayfish dig nest holes, which collapse terrace walls and destroy rice production. Under the current control strategy, farmers self-report Crayfish and are issued pesticide, but this strategy is not expected to eradicate the Crayfish nor to prevent their spread since farmers are not able to detect small numbers of Crayfish. Thus, we tested whether environmental DNA (eDNA) from paddy-water samples could provide a sensitive detection method. In an aquarium experiment, Real-time Quantitative polymerase chain reaction (qPCR) successfully detected Crayfish, even at a simulated density of one Crayfish per average-sized paddy (with one false negative). In a field test, we tested eDNA and bottle traps against direct counts of Crayfish. eDNA successfully detected Crayfish in all 25 paddies where Crayfish were observed and in none of the 7 paddies where Crayfish were absent. Bottle-trapping was successful in only 68% of the Crayfish-present paddies. eDNA concentrations also correlated positively with Crayfish counts. In sum, these results suggest that single samples of eDNA are able to detect small Crayfish populations, but not perfectly. Thus, we conclude that a program of repeated eDNA sampling is now feasible and likely reliable for measuring Crayfish geographic range and for detecting new invasion fronts in the Honghe Hani landscape, which would inform regional control efforts and help to prevent the further spread of this invasive Crayfish.
Trude Vrålstad - One of the best experts on this subject based on the ideXlab platform.
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environmental dna edna monitoring of noble Crayfish astacus astacus in lentic environments offers reliable presence absence surveillance but fails to predict population density
Frontiers in Environmental Science, 2020Co-Authors: Stein Ivar Johnsen, Johannes Rusch, David A. Strand, Trude VrålstadAbstract:Noble Crayfish is the most widespread native freshwater Crayfish species in Europe. It is threatened in its entire distribution range and listed on the IUCN- and national red lists. Reliable monitoring data is a prerequisite for implementing conservation measures, and population trends are traditionally obtained from catch per unit effort (CPUE) data. Recently developed environmental DNA (eDNA) tools can potentially improve the effort. In the past decade, eDNA monitoring has emerged as a promising tool for species surveillance, and some studies have established that eDNA methods yield adequate presence-absence data for Crayfish. There are also high expectations that eDNA concentrations in the water can predict biomass or relative density. However, eDNA studies for Crayfish have not yet been able to establish a convincing relationship between eDNA concentrations and Crayfish density. This study compared eDNA and CPUE data obtained the same day and with high sampling effort, and evaluated whether eDNA concentrations can predict relative density of Crayfish. We also compared two analytical methods (qPCR and ddPCR), and estimated the detection probability for eDNA monitoring compared to trapping using occupancy modelling. In all lakes investigated, we detected eDNA from noble Crayfish, even in lakes with very low densities. The eDNA method is reliable for presence-absence monitoring of noble Crayfish, and the probability of detecting noble Crayfish from eDNA samples increased with increasing relative Crayfish densities. However, the Crayfish eDNA concentrations were consistently low and mostly below the limit of quantification, even in lakes with very high Crayfish densities. The hypothesis that eDNA concentrations can predict relative Crayfish density was consequently not supported. Our study underlines the importance of intensified sampling effort for successful detection of very low-density populations, and for substantiating presumed absence, inferred from negative results. Surprisingly, we found a higher likelihood of eDNA detection using qPCR compared to ddPCR. We conclude that eDNA monitoring cannot substitute CPUE data, but is a reliable supplement for rapid presence-absence overviews. Combined with eDNA analyses of alien Crayfish species and diseases such as Crayfish plague, this is a cost-efficient supplement offering a more holistic monitoring approach for aquatic environments and native Crayfish conservation.
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Microcystins in European Noble Crayfish Astacus astacus in Lake Steinsfjorden, a Planktothrix-Dominated Lake.
Toxins, 2020Co-Authors: Ingunn A. Samdal, David A. Strand, Andreas Ballot, Johannes Rusch, Sigrid Haande, Kjersti E. Løvberg, Christopher O. Miles, Trude VrålstadAbstract:Lake Steinsfjorden, an important Norwegian location for noble Crayfish (Astacus astacus), is often affected by cyanobacterial blooms caused by microcystin (MC)-producing Planktothrix spp. The impact of MCs on noble Crayfish as a food source and Crayfish health is largely unknown. We investigated the quantities and correlations of MCs in noble Crayfish and lake water during and after a cyanobacterial bloom peaking in June-July 2015. Noble Crayfish and water samples were collected monthly from June to October 2015 and in October 2016. The content of MCs was analysed by ELISA from tail muscle, intestine, stomach and hepatopancreas. PCR analysis for Planktothrix gene markers was performed on Crayfish stomach content. Water samples were analysed for phytoplankton composition, biomass and MCs. PCR-positive stomach contents indicated Planktothrix to be part of the noble Crayfish diet. Concentrations of MCs were highest in the hepatopancreas, stomach and intestine, peaking in August-September. Tail muscle contained low concentrations of MCs. Similar levels of MCs were found in Crayfish from 2016. Except in September 2015, a normal portion of boiled noble Crayfish tails was below the tolerable daily intake (TDI) for MCs for humans. Removing the intestine more than halved the content of MCs and seems a reasonable precautionary measure for noble Crayfish consumers.
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absence of the Crayfish plague pathogen aphanomyces astaci facilitates coexistence of european and american Crayfish in central europe
Freshwater Biology, 2013Co-Authors: Anne Schrimpf, Trude Vrålstad, Torsten Maiwald, Holger K Schulz, Przemyslaw śmietana, Ralf SchulzAbstract:SUMMARY 1. Most European Crayfish species are strongly threatened, mainly as a result of the introduced pathogen, Aphanomyces astaci, transmitted by invasive North American Crayfish. Long-term coexistence of American and European Crayfish species is therefore regarded as almost impossible, even though some coexisting populations have been observed. 2. In this study, Crayfish were collected from presently coexisting populations of the introduced spiny-cheek Crayfish (Orconectes limosus) and the native noble Crayfish (Astacus astacus) from nine standing waters in central Europe. Our aim was to resolve whether the coexistence resulted from reduced virulence in local strains of A. astaci, increased immunity in the native Crayfish or an absence of the pathogen in these populations. We used highly sensitive A. astaci-specific real-time PCR to evaluate the Crayfish latent carrier status, combined with transmission experiments to further validate the molecular results. 3. From the total of 523 Crayfish tested (490 spiny-cheek Crayfish, 33 noble Crayfish), none positive for A. astaci was detected. Transmission experiments confirmed these results: No abnormal mortality or behavioural changes were seen in noble Crayfish kept together with American Crayfish from the coexisting populations. If we assume a very low prevalence of A. astaci of 10% in a carrier population, there is a 98% probability of disease being absent in five of the nine coexisting populations tested. Hence, a consistent absence, or an extremely low prevalence, of A. astaci seems to allow the coexistence of European and American Crayfish in these central European populations. 4. The results are important for native Crayfish conservation and management and demonstrate that disease transmission risk may vary substantially between the different populations of spinycheek Crayfish in central Europe.
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monitoring the spore dynamics of aphanomyces astaci in the ambient water of latent carrier Crayfish
Veterinary Microbiology, 2012Co-Authors: David A. Strand, Harri Kokko, Japo Jussila, Jenny Makkonen, Satu Viljamaadirks, Arne Holstjensen, Hildegunn Viljugrein, Trude VrålstadAbstract:Abstract The specialized Crayfish parasite Aphanomyces astaci causes the devastating Crayfish plague in European Crayfish. Even though A. astaci sporulation has been thoroughly studied under pure culture conditions, little is known about the sporulation dynamic from its live host. Our purpose was to investigate the A. astaci spore dynamic in its native parasite–host relationship by monitoring the sporulation from carrier Crayfish into the ambient water using agent specific qPCR. American signal Crayfish (Pacifastacus leniusculus) with known positive carrier status were housed individually and communally in two experimental set-ups using multiple replicates and different temperatures. Water samples were collected weekly, and spore numbers were quantified. We demonstrate here that live latent carrier Crayfish continuously released a moderate number of A. astaci spores (∼2700 spores per Crayfish/week) in the absence of death and moulting events. In contrast, a pronounced sporulation increase was seen already one week prior to death in moribund Crayfish, suggesting a Crayfish plague-like condition developing in weakened or stressed individuals. Significantly more spores were produced at 18 °C compared to 4 °C, while a negative correlation was detected between spore numbers and temperatures rising from 17 to 23 °C. This study is the first attempt to quantify the spore release from carrier Crayfish on the basis of qPCR applied on water samples, and demonstrate that the approach successfully unravel A. astaci sporulation patterns. The results emphasize that carrier Crayfish pose a constant infection risk to highly susceptible Crayfish species regardless of Crayfish life cycle state.
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Non-indigenous signal Crayfish Pacifastacus leniusculus are now common in Danish streams: preliminary status for national distribution and protective actions
Biological Invasions, 2011Co-Authors: Christian Skov, Trude Vrålstad, Finn Sivebæk, Stig Pedersen, Kim Aarestrup, Sören BergAbstract:North American signal Crayfish ( Pacifastacus leniusculus ) are invasive in Europe and pose a serious threat to indigenous European Crayfish such as the noble Crayfish ( Astacus astacus ). This is mainly because signal Crayfish is the carrier of Crayfish plague agent, Aphanomyces astaci, which freshwater Crayfish from all other continents are highly susceptible to. Until recently, the distribution of signal Crayfish in Danish streams has been considered local and restricted to a small geographical area. Here we present data demonstrating that signal Crayfish are now widespread in Denmark, including the largest Danish river, River Gudenå. For one of the rivers where co-existing signal Crayfish and indigenous noble Crayfish were documented, sensitive molecular tests could not detect the Crayfish plague agent Aphanomyces astaci in either species. Hence, it seems that not all signal Crayfish are chronic carriers of the disease. For the remaining freshwater systems with the introduced signal Crayfish, the infection status is presently unknown. Large areas of the freshwater systems in Denmark also remain unexplored with respect to presence/absence of signal Crayfish and noble Crayfish. Nevertheless, our preliminary data that covers about 14% of the Danish rivers, strongly suggests that signal Crayfish should be considered as a common invader that poses an increased threat to the biota in Danish streams, in particular for the indigenous noble Crayfish.
Michael J. Lannoo - One of the best experts on this subject based on the ideXlab platform.
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breeding migrations in crawfish frogs lithobates areolatus long distance movements burrow philopatry and mortality in a near threatened species
Copeia, 2012Co-Authors: Jennifer L Heemeyer, Michael J. LannooAbstract:Movements are risky behaviors to animals, and amphibians are no exception, yet most species of amphibians exhibit cyclic annual movements. Crawfish Frogs (Lithobates areolatus) are a relatively understudied species of North American amphibian considered to be “Near Threatened” globally. To better understand the biology of this species, and in particular to assess the role that movements play in affecting survivorship, we radio tracked 48 Crawfish Frog adults in 2009–2010. Our study encompassed a total of 7,898 telemetered-frog days; individual frogs were tracked for up to 606 days. These data demonstrate two behaviors previously undocumented in this species: 1) migration distances that averaged nearly 0.5 km, and for one frog was approximately 1.2 km; and 2) philopatry to upland burrows excavated by Crayfish. Together, these findings indicate that Crawfish Frogs have a remarkable ability to home to distant upland burrow sites. Burrow fidelity in Crawfish Frogs involves, in part, following similar migratio...
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seasonal pattern of batrachochytrium dendrobatidis infection and mortality in lithobates areolatus affirmation of vredenburg s 10 000 zoospore rule
PLOS ONE, 2011Co-Authors: Vanessa C Kinney, Jennifer L Heemeyer, Allan P Pessier, Michael J. LannooAbstract:To fully comprehend chytridiomycosis, the amphibian disease caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), it is essential to understand how Bd affects amphibians throughout their remarkable range of life histories. Crawfish Frogs (Lithobates areolatus) are a typical North American pond-breeding species that forms explosive spring breeding aggregations in seasonal and semipermanent wetlands. But unlike most species, when not breeding Crawfish Frogs usually live singly—in nearly total isolation from conspecifics—and obligately in burrows dug by Crayfish. Crayfish burrows penetrate the water table, and therefore offer Crawfish Frogs a second, permanent aquatic habitat when not breeding. Over the course of two years we sampled for the presence of Bd in Crawfish Frog adults. Sampling was conducted seasonally, as animals moved from post-winter emergence through breeding migrations, then back into upland burrow habitats. During our study, 53% of Crawfish Frog breeding adults tested positive for Bd in at least one sample; 27% entered breeding wetlands Bd positive; 46% exited wetlands Bd positive. Five emigrating Crawfish Frogs (12%) developed chytridiomycosis and died. In contrast, all 25 adult frogs sampled while occupying upland Crayfish burrows during the summer tested Bd negative. One percent of postmetamorphic juveniles sampled were Bd positive. Zoospore equivalents/swab ranged from 0.8 to 24,436; five out of eight frogs with zoospore equivalents near or >10,000 are known to have died. In summary, Bd infection rates in Crawfish Frog populations ratchet up from near zero during the summer to over 25% following overwintering; rates then nearly double again during and just after breeding—when mortality occurs—before the infection wanes during the summer. Bd-negative postmetamorphic juveniles may not be exposed again to this pathogen until they take up residence in Crayfish burrows, or until their first breeding, some years later.
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strong site fidelity and a variety of imaging techniques reveal around the clock and extended activity patterns in crawfish frogs lithobates areolatus
BioScience, 2010Co-Authors: Andrew S Hoffman, Joseph R. Robb, Jennifer L Heemeyer, Vanessa C Kinney, Nathan J Engbrecht, Perry J. Williams, Daryl R Karns, Michael J. LannooAbstract:Crawfish frogs (Lithobates areolatus) base their nonbreeding activities in and around the entrances of Crayfish burrows. This site preference allows individual crawfish frogs to be monitored using still and video imaging techniques. We used three camera types offering different continuities, scales, and resolutions of data to observe the frogs' activity patterns and nonbreeding behaviors. Together, these techniques allowed us to observe two behaviors in crawfish frogs previously unreported for amphibians: (1) circumdiel activity patterns, and (2) long periods (days) of surface activity. Although these behavioral findings are at this time specific to crawfish frogs, we suspect that they may not be unusual activity patterns for other frogs, as well. The use of imaging techniques that take advantage of these frogs' dependence on burrows and use of burrow entrances has allowed us to observe these patterns for the first time.
Yupeng Geng - One of the best experts on this subject based on the ideXlab platform.
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using edna to detect the distribution and density of invasive Crayfish in the honghe hani rice terrace world heritage site
PLOS ONE, 2017Co-Authors: Chunyan Yang, Lin Wang, Wenzhi Wang, Guigang Zhao, Wang Cai, Yupeng GengAbstract:The Honghe-Hani landscape in China is a UNESCO World Natural Heritage site due to the beauty of its thousands of rice terraces, but these structures are in danger from the invasive Crayfish Procambarus clarkii. Crayfish dig nest holes, which collapse terrace walls and destroy rice production. Under the current control strategy, farmers self-report Crayfish and are issued pesticide, but this strategy is not expected to eradicate the Crayfish nor to prevent their spread since farmers are not able to detect small numbers of Crayfish. Thus, we tested whether environmental DNA (eDNA) from paddy-water samples could provide a sensitive detection method. In an aquarium experiment, Real-time Quantitative polymerase chain reaction (qPCR) successfully detected Crayfish, even at a simulated density of one Crayfish per average-sized paddy (with one false negative). In a field test, we tested eDNA and bottle traps against direct counts of Crayfish. eDNA successfully detected Crayfish in all 25 paddies where Crayfish were observed and in none of the 7 paddies where Crayfish were absent. Bottle-trapping was successful in only 68% of the Crayfish-present paddies. eDNA concentrations also correlated positively with Crayfish counts. In sum, these results suggest that single samples of eDNA are able to detect small Crayfish populations, but not perfectly. Thus, we conclude that a program of repeated eDNA sampling is now feasible and likely reliable for measuring Crayfish geographic range and for detecting new invasion fronts in the Honghe Hani landscape, which would inform regional control efforts and help to prevent the further spread of this invasive Crayfish.
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using edna to detect the distribution and density of invasive Crayfish in the honghe hani rice terrace world heritage site
bioRxiv, 2017Co-Authors: Chunyan Yang, Lin Wang, Wenzhi Wang, Guigang Zhao, Yupeng Geng, Douglas W YuAbstract:The Honghe-Hani landscape in China is a UNESCO World Natural Heritage site due to the beauty of its thousands of rice terraces, but these structures are in danger from the invasive Crayfish Procambarus clarkii. Crayfish dig nest holes, which collapse terrace walls and destroy rice production. Under the current control strategy, farmers self-report Crayfish and are issued pesticide, but this strategy is not expected to eradicate the Crayfish nor to prevent their spread since farmers are not able to detect small numbers of Crayfish. Thus, we tested whether environmental DNA (eDNA) from paddy-water samples could provide a sensitive detection method. In a mesocosm experiment, Real-time Quantitative polymerase chain reaction (qPCR) successfully detected Crayfish, even at a simulated density of one Crayfish per average-sized paddy (with one false negative). In a field test, we tested eDNA and bottle traps against direct counts of Crayfish. eDNA successfully detected Crayfish in all 25 paddies where Crayfish were observed and in none of the 7 paddies where Crayfish were absent. Bottle-trapping was successful in only 68% of the Crayfish-present paddies. eDNA concentrations also correlated positively with Crayfish counts. In sum, these results suggest that single samples of eDNA are able to detect small Crayfish populations, but not perfectly. Thus, we conclude that a program of repeated eDNA sampling is now feasible and likely reliable for measuring Crayfish geographic range and for detecting new invasion fronts in the Honghe Hani landscape, which would inform regional control efforts and help to prevent the further spread of this invasive Crayfish.
Brian M Roth - One of the best experts on this subject based on the ideXlab platform.
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changes in the distribution of michigan Crayfishes and the influence of invasive rusty Crayfish faxonius rusticus on native Crayfish substrate associations
Biological Invasions, 2019Co-Authors: Kelley R Smith, Brian M Roth, Michael L Jones, Daniel B Hayes, Seth J Herbst, Nicholas PopoffAbstract:Invasive Crayfishes have a strong negative effect on multiple trophic levels, including other Crayfishes. However, documentation of the spread of non-native Crayfish species and their impact on native Crayfishes could be improved, particularly over large spatial scales in stream ecosystems. We collected Crayfish and quantified habitat at 461 stream sites throughout Michigan in 2014–2016 and compared our collections to a historical account of Crayfish collections published in 1975. Our objectives were to: (1) quantify the change in non-native rusty Crayfish (Faxonius rusticus) and native species distributions from 1975 to 2014–2016; (2) quantify how rusty Crayfish affect the habitat associations of native species in Michigan streams; and (3) determine the effectiveness of dipnets, our primary sampling method. We found all species in more watersheds compared to 1975, likely due in part to increased sampling. However, we found rusty Crayfish in 22 more HUC-8 watersheds than in 1975, a larger increase than all other species. Habitat associations of native species also shift in the presence of rusty Crayfish. In instances where native species co-occurred with rusty Crayfish, most obligate aquatic native species were found in less-preferred habitat such as sand or macrophytes compared to cobble substrate when the species is in isolation. Our results indicate a broad range expansion by rusty Crayfish over the last 40 years, suggesting that surveys of Crayfish diversity and habitat occupancy should be more routine to inform management of native Crayfish species.
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predation by native sunfishes centrarchidae on the invasive Crayfish orconectes rusticus in four northern wisconsin lakes
Ecology of Freshwater Fish, 2011Co-Authors: J C Tetzlaff, Brian M Roth, Brian C Weidel, James F KitchellAbstract:Tetzlaff JC, Roth BM, Weidel BC, Kitchell JF. Predation by native sunfishes (Centrarchidae) on the invasive Crayfish Orconectes rusticus in four northern Wisconsin lakes. Ecology of Freshwater Fish 2011: 20: 133–143. © 2010 John Wiley & Sons A/S Abstract – Introduced rusty Crayfish (Orconectes rusticus) often establish abundant populations in lakes where they negatively impact native food webs. However, rusty Crayfish do not become abundant in all lakes. Fish predation has been posed as one potential mechanism limiting rusty Crayfish density, but there is limited empirical evidence to support this hypothesis. Using a case study approach, we quantified the extent and timing of predation on nonnative rusty Crayfish by three native centrarchids in four northern Wisconsin lakes with contrasting Crayfish densities. We estimated population-level predation effects on rusty Crayfish using bioenergetics models in combination with fish and Crayfish abundance estimates. Bluegill (Lepomis machrochirus) and pumpkinseed (Lepomis gibbosus) consumed young-of-year Crayfish exclusively whereas rock bass (Ambloplites ruspestris) consumed a wide size range of Crayfish. Rusty Crayfish were found in Lepomis diets primarily in late June and early July while rock bass consumed Crayfish throughout the summer. Per individual, rock bass consumed more Crayfish biomass than Lepomis, but at the population-level, higher Lepomis densities resulted in greater numbers of Crayfish and more Crayfish biomass consumed by Lepomis than rock bass. Lepomis populations consumed 8 × , 14 × , 22 × and 120 × more individual Crayfish than rock bass populations in the four study lakes. Bioenergetics simulations revealed that dense populations of Lepomis were capable of consuming a large percentage of the juvenile Crayfish population in two of our study lakes. In systems with high Lepomis densities, Lepomis consumption of juvenile rusty Crayfish may play a significant role in the invasion and establishment dynamics of rusty Crayfish.
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reciprocal relationships between exotic rusty Crayfish macrophytes and lepomis species in northern wisconsin lakes
Ecosystems, 2007Co-Authors: Brian M Roth, Jakob C Tetzlaff, Mara L Alexander, James F KitchellAbstract:The non-native rusty Crayfish (Orconectes rusticus) has invaded many lakes of northern Wisconsin, profoundly changing littoral zones in the process. There are other lakes that have been invaded, but do not exhibit these changes. We hypothesized that endogenous feedbacks could form involving rusty Crayfish, the macrophytes they destroy, and Lepomis species whose abundance is positively related to macrophyte abundance and also consume juvenile Crayfish. We assessed this proposal with long-term data from one lake, a regional comparative study, and a case study of Lepomis predation on Crayfish. Through time and across lakes, abundances of rusty Crayfish, littoral macrophytes and species of the genus Lepomis were related in a fashion that indicated a set of feedbacks that regulate the abundance of all three. Intense predation on juvenile Crayfish by abundant Lepomis is capable of maintaining some Crayfish populations at low abundance. Thus, some lakes display profound ecological changes where Crayfish achieve high abundance, and others sustain Crayfish at low abundance. Consequently, lakes invaded by rusty Crayfish may take on the appearance of alternative ecological regimes. Direct experimentation is necessary to determine if, and under what conditions, a lake can exist in either regime.
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fish predation and trapping for rusty Crayfish orconectes rusticus control a whole lake experiment
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Catherine L Hein, Brian M Roth, Anthony R Ives, Jake Vander M ZandenAbstract:Improved methods are needed for the prevention and control of invasive species. We investigated the potential to control a rusty Crayfish (Orconectes rusticus) population in an isolated lake in northern Wisconsin by trapping adult Crayfish and restricting fishing, thereby increasing fish populations and predation on small Crayfish. Over a 3 year period, traps and predatory fishes removed substantial portions of the rusty Crayfish population. We used an age-structured population model to determine which removal method had the largest effect on Crayfish population growth rates. Because more Crayfish were vulnerable to and removed by fish predation than by trapping, fish predation caused a larger decline in the population growth rate. However, trapping removed Crayfish with the highest reproductive value and caused the largest decline in population growth rate per individual Crayfish removed. Consideration of density-dependent responses to removal is necessary to predict long-term effects on rusty Crayfish p...