Category Archives: Carp; European carp

Seinning_carp

Carp weaknesses & vulnerabilities

CPFS10_coverKnowing your enemy is important to any defence strategy, including the management of invasive fish species. Analysis of the biology of the species is therefore an essential part of an integrated pest management plan.

A lot is known about the biology and population structure of carp in Australia and certain stages in its life cycle are regarded as weaknesses that present opportunities for management. This fact sheet explains these weaknesses and the implications for managing carp.

Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

AuthorInvasive Animals CRC
Year2014
PublisherInvasive Animals CRC
Pages2
ISBN/ISSNPestSmart code: CPFS10
Control methodIntegrated Pest Management
RegionAustralia - national
Documents

CPFS10 PestSmart factsheet: Carp weaknesses & vulnerabilities   [430 kb PDF]

Links

Native fish predators as a biological control method for carp

CPCS6_coverIn the last 40 years, carp have become widespread and abundant in Australia’s river systems, becoming a potential food source for birds, fish, reptiles, invertebrates and mammals. Relative decreases in numbers of native prey fish coupled with increasing carp numbers means that carp are now a readily available food for Murray cod and possibly other native fish predators. However, the extent to which these predators influence carp populations is not well understood.

One study found Murray cod (Maccullochella peelii peelii) predation on carp was relatively common as carp were found in 35% of Murray cod gut samples. Golden perch (Macquaria ambigua) were also reported to consume carp as a small proportion of their diet. It has been suggested that stocking native fish predators known to prey on carp,  combined with conventional control methods, may be a potential carp management option.

A case study on the the utility of using native fish predators in controlling carp. Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

AuthorInvasive Animals CRC
Year2014
PublisherInvasive Animals CRC
Pages2
ISBN/ISSNPestSmart code: CPCS6
Control methodBiological Control
RegionAustralia - national
Documents

CPCS6 PestSmart Case Study: Native fish predators as a biological control method for carp   [475 kb PDF]

Links

PestSmart Toolkit carp page:   www.pestsmart.org.au/pestsmart/carp/

OLYMPUS DIGITAL CAMERA

Radio tracking as a support tool of carp control methods

CPFS9_coverCommon carp (Cyprinus carpio L.) are a freshwater pest fish in Australia. To efficiently plan and implement an integrated carp management program, we need to understand when, where and why carp move. This allows control efforts to be targeted and more efficient.

Direct observation of fish by divers or video provides information on habitat use, movements and biotic interactions, but it is not possible to record physiological data. Diving and video observations are restricted to shallow waters with adequate light and/or small areas.

Telemetry is a step forward in the study of animal behaviour in the wild. Telemetry involves the wireless transfer of information by radio, digital, ultrasonic/acoustic or infrared signals from transmitters attached or implanted into animals to a remote receiver system. Telemetry improves our understanding of carp distribution, habitat preferences, home ranges and migration requirements by allowing us to monitor their location, behaviour and physiology continuously and individually in uncontrolled environments.

This factsheet explores the use of radio telemetry in supporting carp control programs.

Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

Documents

CPFS9 Radio tracking as a support tool of carp control methods   [800 kb PDF]

AuthorInvasive Animals CRC
Year2014
PublisherInvasive Animals CRC
Pages4
ISBN/ISSNPestSmart code: CPFS9
Control methodJudas Technique
RegionAustralia - national
Links

PestSmart Toolkit carp page:  www.pestsmart.org.au/pest-animal-species/european-carp/

Pile of carp from cage trap - Invasive Animals CRC

Pathways to adoption of Cyprinid herpesvirus 3 as a biological control agent for carp in Australia

KHVPathtoAdoption_coverThis report outlines the approval process required  for Cyprinid herpesvirus 3 (CyHV-3) to be used as a biological control agent for carp in Australia. It discusses the relevant legislation, safety and efficacy assessments, registration process and recommendations. There are a number of statutory processes that need to be satisfied to obtain approval for the release of a biological control agent in Australia. The course to be followed also depends to some degree on the nature of the control agent and also the target organism. The use of a virus as the control agent will require approvals under the Quarantine Act 1908 (for importation and release of the virus) and the Environment Protection and Biodiversity Conservation Act 1999 (EPBC) (for release of the virus into the environment). It would also be appropriate to seek approvals under the Biological Control Act 1984 (BA) because of the structured public consultation and indemnity provisions that this legislation contains. The latter legislation has not always been used for biological control agents, particularly for plants. However in cases where it is likely that there will be conflicts of interest it would appear most appropriate to use this legislation. For example, it was used for assessment of Rabbit Haemorrhagic Disease (RHD) in the 1990’s and was particularly valuable in terms of the structured public consultation process. Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

Secondary titlePestSmart
AuthorWayne Fulton
Year2013
Place publishedCanberra
PublisherInvasive Animals CRC
Pages53
ISBN/ISSNWeb ISBN: 978-1-921777-70-7
Control methodBiological Control
RegionAustralia - national
Documents

Pathways to adoption of Cyprinid herpesvirus 3 as a biological control agent for carp in Australia   [840 kb PDF]

Links

PestSmart toolkit: Carp - www.pestsmart.org.au/pestsmart/carp/

PearlCichlid

Rapid response to new fish incursions

PFFS4Some introduced freshwater fish species have had devastating impacts on Australia’s native freshwater fish species and other aquatic life and ecosystems. Introduced or ‘alien’ fish usually have a high rate of reproduction, broad environmental tolerances, and are difficult to manage. Prevention, preparedness, and incident response activities, (including quarantine/border control, risk assessments, training, containment, eradication) help stop new fish species from establishing populations in the wild. Waterway, biosecurity or fisheries managers can take a risk assessment approach to guide their decisions about how and when to respond to the discovery or an ‘incursion’ of a new fish species.

Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

AuthorInvasive Animals CRC
Year2014
PublisherInvasive Animals CRC
Pages2
ISBN/ISSNPestSmart code: PFFS4
Control methodIntegrated Pest Management
RegionAustralia - national
Documents

PFFS4: Rapid response to new fish incursions  [400 kb PDF]

Links

Exploitable biological vulnerabilities of common carp

CarpVulnerabilities_coverThis project synthesises the outputs of various projects supported by the Freshwater Products and Strategies Program of the Invasive Animals Cooperative Research Centre (IA CRC) in order to assess weaknesses of carp that can be exploited for their control.
Some of the key vulnerabilities identified that may contribute to carp management in Australia include:

Limited number of carp spawning sites:
It was found that although adult carp populations were widespread and abundant across the MDB; these populations were supported by a limited number of areas where juveniles were presen. This suggests carp reproduction is localised and restricted to a relatively small number of ‘hotspots’ within the MDB. Such identification of hotspots allows carp  control to be targeted at a key number of recruitment sources rather than scattered over tens of thousands of river kilometres.

Limited carp movement:
It was found that adult carp move at relatively small scales between sub-catchments in the MDB, particularly in low-flow conditions. Limited adult carp movement suggests there is strong potential for using cost-effective, targeted physical, chemical and/or biological control strategies at local and regional scales since control of adult carp may be sustained in certain areas by consistent methods that prevent either re-colonisation of juveniles or the reproduction of new colonisers.

Innate behaviours:
Research confirmed that carp have innate behaviours. Juvenile and adult carp migrate annually between river and wetland habitats for spawning from early August onwards. During spawning times, carp were attracted to flowing water and moved upstream towards the source of the flow. Carp also had an innate ability to push past or jump over barriers, even in shallow waters < 40 cm. Therefore carp control strategies that focus on intercepting and harvesting carp at wetland entrances are particularly desirable as migrating carp are vulnerable to trapping.

Genetic structure:
Within the Murray-Darling Basin, three discernible strains of carp were identified descendant from the European/central-Asian subspecies Cyprinus carpio carpio. Most importantly the three strains were found in distinct locations within the regional scale. The identification of specific locations for carp strains within catchments builds upon the evidence that there are discrete management units that could be routinely targeted at the local scale for carp control programs.

Secondary titlePestSmart
AuthorGehrig SL and Thwaites LA
Year2013
Place publishedCanberra
PublisherSARDI Aquatic Sciences
InstitutionInvasive Animals CRC
Pages75
ISBN/ISSNWeb ISBN: 978-1-921777-71-4
RegionAustralia - national
DocumentsExploitable biological vulnerabilities of common carp  [2.4 Mb PDF]
LinksPestSmart toolkit: Carp - www.pestsmart.org.au/pestsmart/carp/

Carp removal in Tasmania

CPCS5_coverCarp were first detected in Tasmania in 1975 when they were found in more than 30 small farm dams on the northwest coast. Specific noxious fish legislation was enacted in response and an eradication campaign using the fish poison rotenone was initiated. The populations in these dams were successfully eliminated. In 1995, carp were again found in Tasmania in two popular recreational trout fishing waters (lakes Sorell and Crescent), most likely introduced by people illegally using carp as live bait.

A case study on the attempted eradication of carp from Tasmanian lakes. Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

AuthorInvasive Animals CRC
Year2014
PublisherInvasive Animals CRC
Pages4
ISBN/ISSNPestSmart code: CPCS5
Control methodIntegrated Pest Management
RegionTAS
Links

PestSmart Toolkit carp page

Documents

CPCS5 PestSmart Case Study: Carp removal in Tasmania   [580kb PDF]

Carp pheromone attractant trials

CPCS4_coverPheromones are chemicals produced naturally by fish to trigger a social response in other fish of the same species,  such as a spawning aggregation. Scientists at the University of Minnesota have been working on identifying carp pheromones and developing products containing these chemicals, which can be used to manipulate carp behaviour and potentially assist in controlling carp populations.

The Invasive Animals Cooperative Research Centre (IA CRC) funded research that found the male carp sex  pheromone to be sex-specific and powerful. The research also found that ovulating female carp release a  prostaglandin-based attractant for males and that non-ovulating females can be primed with a synthetic dose of prostaglandin to release the attractant. This synthetic prostaglandin can be implanted in a slow-release capsule in the  fish, causing the female carp to produce their attractant pheromone for a longer period than usual (up to two weeks).

Case study on trials to investigate using carp pheromone attractant for carp control in NSW and Tasmania. Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

AuthorInvasive Animals CRC
Year2014
PublisherInvasive Animals CRC
Pages4
ISBN/ISSNPestSmart code: CPCS4
Control methodIntegrated Pest Management
RegionAustralia - national
Links
Documents

PestSmart Case Study: Carp pheromone attractant trials  [700 kb PDF]

StuartMitchell_carp1

Pheromone attractants as a means of carp control

CPFS8_coverCarp (Cyprinus carpio) are one of the most damaging invasive fishes in Australian shallow lakes, wetlands and rivers. Techniques currently available to control this species are generally labour intensive and unlikely to have long-term benefits unless persisted with longterm.

An important strategy for the control of carp is to enhance our understanding of their behaviours and vulnerabilities  to improve the efficiency of control methods. For example, the success of existing control methods, such as trapping, can  be increased by ‘baiting’ traps using various carp-attracting options.

This factsheet explores chemical-based environmental and sensory attractants, which may potentially direct carp  behaviour and movements.

Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

AuthorInvasive Animals CRC
Year2014
PublisherInvasive Animals CRC
Pages2 pp
ISBN/ISSNPestSmart code: CPFS8
Control methodIntegrated Pest Management
RegionAustralia - national
Links
Documents

PestSmart Factsheet: pheromone attractants as a means of carp control  [450kb PDF]

Carp surveys of the Logan and Albert Rivers Catchment, 2006-2009

CarpSurvey_coverIn 2006, a benchmarking fisheries assessment survey found that the Logan and Albert rivers catchment was heavily infested with carp. Benchmarking entailed electrofishing surveys at 28 sites across the catchment. The purpose was to document the status of carp and native fish species in the rivers before implementing carp management actions.

In 2007, research began into the cost effectiveness of a range of carp management strategies in parts of the catchment. As part of this research, we repeated electrofishing surveys at 18 of the 28 benchmarking sites in 2007. Heavy rains and a series of high-flow events prevented repeat sampling at the remaining ten sites. The repeated surveys were designed to detect changes in fish assemblages and habitat conditions due to both environmental variables and carp management actions. Treatment and control sites were sampled to assess the role of these factors.

In 2009, the research program on carp management strategies was completed and we assessed changes in the fish assemblages based on a final fisheries assessment survey. We electrofished at 17 sites encompassing areas where there had been intense carp removal, control areas where there had been no carp removal, and areas where carp had been removed in previous years. The survey results, presented in this report, detail the distribution, biomass and density of carp in the catchment and enable the impact of carp management activities to be assessed.

Secondary titlePestSmart Toolkit - Carp
AuthorAndrew Norris, Keith Chilcott, Michael Hutchison and Danielle Stewart
Year2011
PublisherInvasive Animals CRC
DepartmentInvasive Animals Cooperative Research Centre
Pages31 pp
ISBN/ISSNWeb ISBN: 978-1-921777-35-6
Control methodFishing
RegionQLD
DocumentsCarp surveys of the Logan and Albert Rivers Catchment, 2006-2009 [ 770kb PDF ]
LinksPestSmart Toolkit for carp:  www.pestsmart.org.au/pestsmart/carp/

Social drivers behind participation in pest fish-out competitions

SocialDrivers_coverIt is now widely accepted that it is important to understand the ‘human dimensions’ of wildlife management issues to achieve management goals (Conover 2002; Miller 2009). One of the key areas of interest within human dimensions is participation and uptake of management initiatives by the community. A clearer understanding of the drivers behind community participation will lead to better engagement with stakeholders and ultimately increase the uptake and success of management actions.

Many community groups are concerned about the impacts of pest fish, particularly carp, (Cypinus carpio) in their local waterways and want to actively address the issue. To combat the impacts and spread of these pest fish some groups have organised community ‘fish-out’ events.

The objectives of this project were to investigate the drivers, or reasons, behind participation in carp fish-out competitions and how participants perceive the presence of carp in the rivers. Competitors at six competitions were asked to complete a survey looking at their drivers behind participation, perceived impacts of carp and demographics.

Published by the Invasive Animals CRC as part of the PestSmart Toolkit series.

DocumentsSocial drivers behind participation in pest fish-out competitions [ 630kb PDF ]
LinksPestSmart Toolkit for carp:  www.pestsmart.org.au/pestsmart/carp/
Secondary titlePestSmart Toolkit
AuthorAndrew Norris and Guy Ballard
Year2013
PublisherInvasive Animals CRC
DepartmentInvasive Animals Cooperative Research Centre
Pages39 pp
ISBN/ISSNISSD: 978-1-921777-66-0
Control methodFishing

The role of fishing competitions in pest fish management

Carp (Cyprinus carpio) are one of at least 34 freshwater fish species introduced into Australia that have established self-sustaining populations (Lintermans 2004). Carp are now the most abundant large freshwater fish in the Murray–Darling Basin, comprising up to 90% of fish biomass in some locations, and are the dominant species in many fish communities in south-eastern Australia (Reid and Harris 1997, Brown et al 2003).

Many community groups are concerned about the detrimental impacts carp are having in their local waterways, and some groups have organised ‘fish-out’ events to actively address the issue. It is well known that fishing pressure can run down fish stocks in a river (Templeton 1995), but it remains unclear as to whether community-based fish-out events have a significant impact on their target species. This project quantified the percentage of carp population removed in three ‘fish-out’ competitions in the Queensland portion of the Murray–Darling Basin.

At each competition, a series of monitoring sites were established. Before the events began, carp were captured at these sites via electrofishing, marked with dart tags and released. The competition catch and post-event electrofishing enabled the carp population size at each site to be estimated from tag return rates using the Lincoln–Peterson method. Population reductions from both the competition angling and the subsequent electrofishing were calculated. A total of 1006 carp were tagged with an overall tag return of 12% for the whole project.

The results demonstrated that carp angling competitions are not very effective as a direct form of carp management. The removal efforts occurred over large areas, resulting in low angling pressure and removal rates. Population reductions were observed in the range of 0.5%–1.8% across the competition areas. In comparison, removal via boat electrofishing resulted in a carp population reduction of 8.3%–16.1%. When compared to electrofishing, the catch per unit of effort (CPUE) of competition angling was found to be nearly 100 times less in terms of carp caught per man hour. We conclude that the way these events are currently run, they are unlikely to have any significant impact on local carp population numbers.

Carp fishing competitions do, however, have a range of less tangible management benefits. The events help educate the wider community on the detrimental impacts of pest fish, raise awareness and ownership of the pest fish issue and provide a social focal point for smaller regional communities. The competitions can also generate money, which can be directed into native fish restocking, river restoration or funding contractors to remove carp in high-value areas.

Secondary titlePestSmart Toolkit
AuthorAndrew Norris, Keith Chilcott and Michael Hutchison
Year2013
PublisherInvasive Animals CRC
DepartmentQueensland Department of Agriculture, Fisheries and Forestry
Pages45 pp
ISBN/ISSNISSD: 978-1-921777-65-3
Control methodFishing
RegionQLD
DocumentsThe role of fishing competitions in pest fish management [ 960kb PDF ]
Links  
murrayriver

Reclaiming our rivers from the stronghold of feral fish

Nicknamed ‘river rabbits’ due to their ability to multiply and reach huge numbers, carp are one of the most invasive and damaging pests of our freshwater ecosystems. Just as biocontrol agents have been successfully used to control rabbits in Australia, we’re confident that a virus that has been killing carp overseas could do a similar job in our waterways.

Carp herpes virus

The virus, once known as koi herpesvirus, is now formally known as Cyprinid herpesvirus 3 (CyHV-3). Seven years of CSIRO research, supported by the Invasive Animals-Cooperative Research Centre (CRC), has shown that the use of CyHV-3 as a biocontrol agent could significantly reduce the number of common carp (Cyprinus carpio) in our rivers.

Naturally with any talk of a biocontrol agent, there is public debate and speculation. In particular, four key questions constantly arise.

1. Is it really necessary to control carp in Australia?

First introduced in Australia in 1859, carp became a major pest in the 1960s after the accidental release of a strain that had been adapted for fish farming. Within a few years they established themselves throughout the entire Murray-Darling Basin.

Carp now comprise up to 90% of the fish biomass in parts of the Basin. This is largely attributed to female carp producing up to a million eggs per year, and to the omnivorous fish’s tolerance for a wide range of habitats including degraded water. While we may not be able to ‘prove’ that carp directly caused the degradation of our rivers, their dominance must certainly contribute to the problem. It is unlikely that the Murray-Darling Basin could ever return to its previous glory while carp remain in such high numbers.

Our views in Australia are supported by research from the US. This showed that carp muddy their waters resulting in flow-on effects on plants, invertebrates, bird-life and native fish in shallow lakes. Researchers concluded that common carp damage the ecology of shallow lakes, particularly when carp density reaches levels similar to those in parts of the Murray-Darling Basin.

2. Will CyHV-3 be effective as a biocontrol agent?

CyHV-3 first appeared in Israel in 1998 and quickly spread throughout the world, killing-off common and koi carp. Ironically carp are farmed in many countries and are an important food source. So, while CyHV-3 has devastated carp farming, the overseas experience has demonstrated how it could be used successfully as a biocontrol agent here.

Testing of CyHV-3 in the high-security Fish Diseases Laboratory at CSIRO’s Australian Animal Health Laboratory (AAHL), in Geelong, Victoria, has proven that the same virus does in fact kill Australian carp, and it kills them fast.

The flip side is our rigorous testing to ensure that the virus won’t affect native Australian or important introduced species of fish. It has been shown to pose no danger to 13 native species such as Murray cod, various species of perch, eel and catfish, as well as a crustacean (yabbies) and a non-native fish species, the rainbow trout. Our work has shown that there are no clinical or pathological changes in these non-target animals, nor is there any evidence that the virus multiplies in these species.

Chickens, mice, frogs, turtles and water dragons have also been tested as representatives of a wider community of birds, mammals, amphibians and reptiles. Again the virus has shown no effect on them which also makes us confident that it won’t affect that other major group of mammals – humans.

Based on lessons learnt from past use of viral biocontrol agents for invasive vertebrates, we expect that CyHV-3 will have the greatest impact in the first couple of years after release. After that, its effectiveness may be diminished, but not lost, as virus and host adapt to each other.

Therefore, we need an integrated pest management program that utilizes other methods to complement our virus. These include new broad-scale technologies such as ‘daughterless’ technology to create male-only populations, as well as traditional regional methods such as trapping, the commercial collection of carp, and controlling access of carp to breeding grounds.

3. What happens to the dead carp?

courtesy Nigel Harriss
Juvenile carp aggregated below the Menindee Main Weir on the Darling River. Image: Nigel Harriss, NSW Office of Water.

If an image of rivers full of large dead carp floating on the surface is what springs to mind, rest assured that our research includes careful planning and modelling before release and follow-up strategies are recommended.

Carp breed in well-mapped specific sites along the Murray-Darling Basin. The virus is likely to be released in these sites where most carp are juveniles. Not only would this wipe out large populations of carp before they become mature, but bird life will probably clean up large numbers of the immature carp.

Study tours of Japan and Indonesia are part of the Invasive Animals-CRC program to study natural outbreaks of CyHV-3. Researchers will be reviewing the significance of dead mature fish, and strategies for dealing with them.

4. How can we be sure that widespread distribution of the virus is safe for people?

CyHV-3 has devastated carp farming around the world yet despite the large numbers of people working on these affected farms, there has been no evidence of any effect of the virus on them.

We have also exposed mice to CyHV-3, and found no evidence of disease. Mice were chosen as being a representative mammal, just like a human.

And finally, a report to the European Commission by the Scientific Committee on Animal Health and Animal Welfare stated that there is no evidence for ANY fish virus causing disease in humans.

The verdict

Given our very good understanding of both the biology of CyHV-3 and of carp in Australia, we are optimistic that this carp virus will make a significant impact on carp in this country. And for that, our river systems and native fish will be very grateful.


About the Author

KenMcColl

Dr Ken McColl, Senior Research Veterinarian at CSIRO’s Australian Animal Health Laboratory, Geelong. Ken is a veterinary virologist and pathologist specialising in diseases of aquatic animals.

Links

Eurpoean carp main page:   www.pestsmart.org.au/pest-animal-species/european-carp/

carp_boat_Tas

A manual for carp control: The Tasmanian model

TasCarp_coverThe Carp Management Program (CMP) was established within the Inland Fisheries Service (IFS) in 1995, in response to an incursion of Cyprinus carpio (carp) found in Lake Crescent, at Interlaken, in the central highlands of Tasmania. The incursion was contained to Lake Crescent and the upstream Lake Sorell. The integrated pest management strategies used have resulted in the successful eradication of carp from Lake Crescent and are ongoing in Lake Sorell.

This manual describes the progressive and integrated approaches that were employed to control/eradicate carp in Tasmania and that are likely to be of relevance elsewhere.

AuthorDiggle J, Patil J and Wisniewski C
Year2012
PublisherInvasive Animals CRC
Pages34
ISBN/ISSNWeb ISBN: 978-1-921777-52-3
Control methodIntegrated Pest Management
RegionTAS
Documents

A manual for carp control: The Tasmanian model [2Mb PDF]

Links

PestSmart toolkit: Carp - www.pestsmart.org.au/pestsmart/carp/

Containment as a method for pest fish control

Containment and exclusion are critical actions in a rapid response to new pest fish incursions and in the ongoing management of established pest fish populations. Effective containment and exclusion limits the scale of potential environmental, social and economic impacts and reduces the area of management, thus reducing associated costs and resources. Physical and behavioural barriers can be used for fish containment and exclusion and their use is often an integral part of pest fish eradication and control programs.

Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

DocumentsPestSmart Factsheet: Containment as a method for pest fish control
Links
AuthorInvasive Animals CRC
Year2012
PublisherInvasive Animals CRC
Pages2 pp
ISBN/ISSNPestSmart code: PFFS2
RegionAustralia - national

Feral Photos 2011

These images were entries in the first-ever Invasive Animals CRC’s Feral Photos photography competition held in 2011. The competition was initiated to help improve levels of awareness among members of the community, who have observed the presence of pest animals in their environment. The photos illustrate the significant diversity of pests we have in Australia and entries were received from across each State & Territory.
WARNING: Some people may find some of the following images confronting or distressing.

Click on the thumbnails to view a larger image.

See the website www.invasiveanimals.com/feral-photos for more information.

Validating the age of carp from the northern Murray-Darling Basin

Being able to accurately age carp is important for modelling population dynamics and potential response to various control strategies. This study examined the use of oxytetracycline (OTC) and otolith (ear bone) sampling to determine the formation of bone growth rings and in turn estimate the age of carp populations in the northern Murray–Darling Basin (MDB).

OTC leaves a mark in bony tissue that can be used as a reference point to analyse the formation of subsequent growth rings, known as ‘check marks’. The number of check marks that appear over a known time period can then be used to determine the age of the fish. In carp populations in the southern MDB, check marks are known to form annually. However, whether this occurs in the subtropical environment of the northern MDB had not been examined before this project. Validating this ageing method will enable population modelling to be applied to the whole MDB and assist in carp management.

Secondary titlePestSmart toolkit - carp
AuthorHutchison M, McLennan M, Chilcott K, Norris A and Stewart D
Year2012
Place publishedCanberra
PublisherInvasive Animals Cooperative Research Centre
InstitutionInvasive Animals CRC
DepartmentFreshwater Products and Strategies
Pages24 pp
ISBN/ISSNWeb ISBN: 978-1-921777-48-6
RegionAustralia - national
DocumentsValidating the age of carp from the northern Murray-Darling Basin [1 Mb PDF]
Linkshttp://www.pestsmart.org.au/pestsmart/carp/
carp_aggregation

Carp herpesvirus as a biological control for carp in Australia

CPFS7coverIntroduction

Carp (Cyprinus carpio) are not native to Australia, but they now dominate fish communities throughout many inland waterways. Widespread  eradication of these established populations would be difficult, costly and complicated. Recently, cyprinid herpesvirus, commonly known as carp herpesvirus (CyHV-3), has been proposed as a potential biological control method for carp in Australia. It has the potential to substantially reduce Australian carp populations, with impacts likely to be increased when used in an integrated carp management control program.

About CyHV-3

Common carp, Cyprinus carpio, the species-specific target of carp herpesvirus CyHV-3
Common carp, Cyprinus carpio, the species-specific target of carp herpesvirus CyHV-3

CyHV-3 is highly specific to carp, including the ‘koi’ ornamental variety, and only causes death in carp, with no other fish known to be affected, even the closely related goldfish. Carp-goldfish hybrids appear to be much less susceptible to CyHV-3 than pure carp. Australia does not have any native fish species that are closely related to carp, so they are not susceptible to CyHV-3. There are approximately 100 other known herpesviruses in other species, with at least one herpesvirus for each species studied. Most people would have been infected by at least one of the eight known human herpesviruses, such as the one that causes common cold sores. CyHV-3 does not affect humans.

CyHV-3 first appeared in Israel in 1998, although it may have appeared in the United Kingdom or Germany a little earlier. It spread rapidly to other parts of the world including Japan, Indonesia and North America. Mortality (death) rates of 70–100% were recorded in all age groups of carp in several countries. It now has a worldwide distribution with the exception of South America, Australia and New Zealand.

CyHV-3 is a water-borne virus and is highly contagious. Viral particles in water may be active for up to three days. New outbreaks of the disease can be expected when fish are stressed or in large aggregations. Clinical signs of disease, including mortality, are most common when water temperatures are 18°–28°C. There is little, or no disease above 30°C or below 15°C.

The first clinical signs of CyHV-3 infection are reddening of the gills, excess mucus on the gills and skin, darkening of the skin, and eventually patches of skin necrosis (tissue death). Signs of disease occur within 7-14 days of infection (depending on water temperature), and death then occurs within a day or so.

Carp that survive infection are infected for life, and, when stressed, may die or show signs of disease again. These fish are capable of spreading CyHV-3 to other carp. There is no evidence that the virus can multiply in other fish, although virus may be inadvertently transported on the surface of other fish for a short period of time.

Current research

The use of CyHV-3 as a potential carp biological control agent is being assessed by researchers at CSIRO’s Australian Animal Health Laboratory with funding from the Invasive Animals Cooperative Research Centre. This research has a number of objectives:

  • confirming that CyHV-3 is lethal to carp in Australia
  • confirming that CyHV-3 does not threaten Australian native species (thirteen native species of fish have been tested, along with rainbow trout, and a variety of other animals that might live in, or drink, virusinfected water. None of these animals are affected, or infected, by the virus)
  • confirming that CyHV-3 acts on all sizes of carp (although it is known that young carp are extremely sensitive to the virus)
  • confirming that the virus is transmitted directly from infected carp to non-infected carp
  • investigating the effect of environmental conditions (eg changes in water temperature) on the potency of the virus
  • investigating any possible cross reactions due to other related viruses that may already be present (such as cyprinid herpesvirus CyHV-1 or CyHV-2)
  • investigating characteristics of the likely spread of the virus to help plan a program for its release into the environment.

Planning for CyHV-3 release

CyHV3_quoteCyHV-3 has the potential to be an effective biological control agent for carp. However, before CyHV-3 can be released it must go through a formal evaluation process coordinated by the Australian Pesticides and Veterinary Medicines Authority (APVMA). This will require more detailed scientific assessment and the development of a release and monitoring strategy. The plans for further work to begin in July 2016 are as follows:

  • Science to support the release of CyHV-3 in Australia — CSIRO will test a few further native species for susceptibility to CyHV-3. CSIRO will also develop methods to monitor the spread of the virus if it is eventually released into natural waterways. It will also be important to develop other control methods to complement the activity of the virus. These may include genetic strategies for carp control, but new generations of CyHV-3 will also be required.
  • CyHV-3 release and monitoring strategy — A release strategy will be designed to take advantage of known vulnerabilities of carp. For example, the onset of the disease is related to temperature and to stress levels in the fish, so it will be important to choose the right time and the right site for release of the virus. Fish massing in large numbers for spawning would be an ideal target for the virus. A monitoring and evaluation strategy will be designed to track the spread and impact of the virus.
  • CyHV-3 registration application package — through close liaison with the APVMA, the information requirements for registration of CyHV-3 will be determined. All of the information needed will be assembled and the package will go through the APVMA risk evaluation and consultation process. Approval for CyHV-3 release in Australia will depend on funding and research progress. If approvals are granted, the target for release of CyHV-3 is within the 2017-2019 time-frame.

Further information

  1. Saunders G, Cooke B, McColl K, Shine R and Peacock T (2007). Modern approaches for the biological control of vertebrate pests: An Australian perspective. Biological Control 52:288–295.
  2. McColl, KA, Sunarto A, Williams LM and Crane M (2007). Koi herpesvirus: Dreaded pathogen or white knight? Aquaculture Health International 9:4-6.
  3. Bretzinger A, Fischer-Scherl T, Oumouna M, Hoffman R and Truyen U (1999). Mass mortalities in koi carp, Cyprinus carpio, associated with gill and skin disease. Bulletin of the European Association of Fish Pathologists 19:182-185.
  4. McColl KA, Cooke BD, and Sunarto A (2014). Viral biocontrol of invasive vertebrates: lessons from the past applied to cyprinid herpesvirus 3 and carp (Cyprinus carpio) control in Australia. Biological Control 72:109- 117.
Documents

Download:  PestSmart Factsheet: Carp herpesvirus as a biological control for carp  [ 300kb PDF ]

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AuthorInvasive Animals CRC
Year2012
PublisherInvasive Animals CRC
Pages2 pp
ISBN/ISSNPestSmart code: CPFS7
Control methodBiological Control
RegionAustralia - national
Cyprinus carpio

Cyprinid herpesvirus 3, CyHV-3: its potential as a biological control agent for carp in Australia

CyHv3Rept_coverCarp (Cyprinus carpio), members of the cyprinid family, were probably introduced to Australia in the 19th Century,  but they did not become a problem until the 1960s when a strain adapted for European aquaculture, known in  Australia as the Boolara strain, was imported. Floods in the mid 1970s resulted in the escape of these fish from  isolated farm dams into the Murray-Darling River system, triggering a major environmental problem. In the mid-2000s, work began on developing an integrated carp control program (Fulton, 2006), including an investigation of cyprinid herpesvirus 3 (CyHV-3), also known as koi herpesvirus, as a potential biological control agent.

There have been only three instances around the world where viral pathogens have been used successfully to counter vertebrate pest species. These include two rabbit viruses, the myxoma virus  and the calicivirus known as rabbit haemorrhagic disease virus, both used in Australia, and feline panleukopaenia virus, a DNA parvovirus that was used as part of a program to eradicate feral cats that were devastating wild seabird colonies on sub-Antarctic Marion Island in the southern Indian Ocean.

In developing a biological control program with CyHV-3 for carp, it is important to consider what can be learned from both the experience with the three previous viruses used in successful biological control programs of vertebrates, and from the epidemiology of the disease in natural populations of wild carp (McColl et al, 2014). Determining the host specificity of a viral biological control agent is clearly important, as is an understanding of the pattern of mortality in the target species. Familiarity with the clinical course of disease in the target species will allow an assessment of the suitability of the agent based on animal welfare considerations, and an understanding of the transmissibility of CyHV-3 from infected to uninfected fish is required in order to assess its suitability as a control agent. The susceptibility of the target species to CyHV-3 must be considered, and it may be dependent on a number of factors, e.g., age-related immunity; passive immunity; the presence of cross-reactive viruses in the target population; ambient temperatures; and the proportion of hybrid individuals in the target population. In summary, the success of a viral biological control
agent is likely to depend upon an intimate knowledge of the biology of the target species, and of the epidemiology of the virus.

While the literature contains a great deal of information on many of these topics, this project aimed to address many of the issues, particularly in an Australian context. In the process, we hoped to provide a solid base of knowledge that would allow a rational decision to be made about the potential use of CyHV-3 as a biological control agent for carp in Australia.

To begin the work, CyHV-3 reference strains and the KF-1 and CCB cell lines were imported into AAHL, and CyHV-3 strains were grown in both cell lines. Eventually, an Indonesian strain of CyHV-3 was also introduced to the lab, and this was chosen for all subsequent experimental work.

In order to work with the virus, assays for the detection of CyHV-3 infections of carp were introduced to AAHL. These included: (i) virus isolation and growth of CyHV-3 in carp cell lines; (ii) several PCRs used by international aquatic animal disease diagnostic laboratories; (iii) development of a generic cyprinid herpesvirus PCR with the potential to differentiate CyHV-1 (carp pox virus), CyHV-2 (goldfish haematopoietic necrosis virus) and CyHV-3; and, (iv) immunoassays for localisation of CyHV-3 in infected fish tissues and in cell cultures.

A crucial step in the project was to test the virulence of CyHV-3 for carp in Australia. In vivo infectivity trials were  undertaken to determine if 4-10 cm carp in Australia are susceptible to infection by CyHV-3, and whether they develop disease and die. The susceptibility of older fish was also examined. Knowledge of the temporal pattern of excretion of virus from infected fish was necessary for an understanding of the epidemiology of the disease caused by CyHV-3 (koi herpevirus disease, KHVD).

The specificity of a potential biological control agent for the target species is, of course, critical. Therefore, a number of non-target species of fish were also tested in susceptibility trials. Furthermore, given that mortality in carp-goldfish hybrids challenged with CyHV-3 is lower than in pure carp, a system to allow differentiation of carp from goldfish and hybrids was considered essential.

In order to ensure that there were no cross-reactive cyprinid herpesviruses in the Murray-Darling Basin (M-DB) that might compromise the efficacy of CyHV-3 were it to be released into the M-DB, an extensive survey of carp from the M-DB was also conducted.

Produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

Secondary titlePestSmart
AuthorKenneth A McColl and Mark St J Crane
Year2013
Place publishedCanberra
PublisherInvasive Animals CRC
Pages63 pp
ISBN/ISSNWeb ISBN: 978-1-921777-38-7
Control methodBiological Control
RegionAustralia - national
Documents

Cyprinid herpesvirus 3, CyHV-3: its potential as a biological control agent for carp in Australia    [1.2 Mb PDF]

Links
CarpPic

Forum Proceedings: Carp management in Australia — state of knowledge

coverCarp were first introduced to Australia more than 100 years ago. Several stains of carp, originating from both Europe and Asia can now be recognised from wild populations. Carp are now widely established throughout the Murray-Darling Basin and can also be found in all states and territories except the Northern Territory. Carp are very common in parts of this range in Australia and are considered to be one of our major pest fish species.

Many of the claims regarding carp’s environmental effects are difficult to confirm because of the lack of information on waterway health before their introduction. For many waterways the decline in habitat quality took place before the presence of carp — due to activities such as catchment clearing, removal of bankside vegetation, de-snagging, stream channelisation, pesticide use and overfishing of native species. However, when a species makes up more than 80% of the biomass at some sites, as has been recorded for carp in Australia, it is difficult to believe that their environmental impact will not be significant.

This document presents contributed papers from speakers at the Forum Carp management in Australia – state of knowledge, held in Melbourne, 19-20 June 2012. The forum was hosted by the Invasive Animals Cooperative Research Centre and the Murray-Darling Basin Authority. Proceedings produced by the Invasive Animals Cooperative Research Centre as part of the PestSmart series.

Secondary titleCarp management in Australia — state of knowledge
AuthorWayne Fulton and Kylie Hall (eds)
Date19-20 June 2012
Year2014
Place publishedMelbourne
InstitutionInvasive Animals CRC
RegionAustralia - national
ISBN/ISSNWeb ISBN: 978-1-921777-79-0
Documents

Forum Proceedings: Carp management in Australia — state of knowledge   [3 Mb PDF]

Links

PestSmart toolkit for carp:   www.pestsmart.org.au/pest-animal-species/european-carp/