Summary of the 6th EPFC Workshop, 17th October 2017, Dubrovnik/Croatia
“As a sector we can only grow, if we expand.”
Research and improvements in the field of percid fish culture are progressing at a fast pace. New protocols have been developed or adapted to fit specific requirements of percids. Still, the lack of stable (re)production is requiring intensive knowledge exchange and further improvements. Consequently, the 6th EPFC workshop was geared towards exchange of practical knowledge under the title “New skillsets in Percid Fish Culture” in close connection with the EAS Aquaculture Europe 2017 in Dubrovnik. Building upon the success of preceding EPFC events, over 50 international participants attended the workshop and the six presentations and contributed to a fruitful discussion. The EPFC workshop again proved to be an ideal place to network and for knowledge transfer connecting attendants from research and industry.
Stefan Meyer (KNAQ, GMA) welcomed the participants, as well as the speakers and opened the workshop with a brief presentation of the EPFC achievements since the founding of this thematic group in 2012. The number of contacts within the EPFC list has increased to above 1900. Furthermore, he announced the launch of a new EPFC website (www.epfc.net), which will help to further improve the communication and outreach serving as a platform for the EPFC activities. Stefan Meyer then gave the floor to Stefan Teerlinck (INAGRO), who was moderating the workshop.
RISK MANAGEMENT TO MINIMIZE DISEASE ASSOCIATED ECONOMIC LOSSES IN AQUACULTURE OF PERCIDS - Melanie Rupp, University Bern, CH
Knowledge of critical time points during the production cycle and potential risk factors are undoubtedly the foundation for a successful disease management in aquaculture, including diagnosis, prophylaxis and treatment. As the first speaker, Melanie Rupp presented initial results of a new project (start in February 2017) targeting these important issues in perch and pikeperch. In both species, elevated mortalities were observed during the summer months, which have possibly been caused by the feeding regime and subsequent change in critical water parameters. Transportation could also be identified as critical point during the production cycle, with mortalities peaking at around day 4 (pikeperch) and 9 (perch) post-transport. Fish health condition was classified by body weight and evaluated (macroscopy, parasitological, bacteriological and virological examination, histopathology). Liver inflammation could be observed in 61% of the samples. Furthermore, muscle necrosis was frequently detected (36% perch; 43% pikeperch). Of 120 bacteriological samples, 13 showed growth in one or several organs. Lactococcus garvieae and Shewanella putrefaciens could be identified as possible fish pathogens. Available results of the virological examination showed no positive results in either species. The initial outcomes of this project highlight the need for a prophylaxis and treatment concept. Melanie Rupp presented preventive measures, including regular control of the fishstock, as well as staff training and basic hygiene measures. It will be worthwhile to follow this three year project, since it will deliver more results in the near future.
PRACTICAL INSIGHT IN ARTIFICIAL REPRODUCTION AND LARVAL REARING METHODS AT RESEARCH INSTITUTE FOR FISHERIES AND AQUACULTURE NARIC HAKI - Uros Ljubobratovic, NARIC HAKI, HU
Reproduction of pikeperch is still laborious, unreliable and complicated. Improvements are therefore needed targeting every aspect of the protocols. Since Uros Ljubobratovic could unfortunately not make it to the workshop, Daniel Zarski jumped in to give this application-oriented presentation on pikeperch hatchery practice based on the practical experience of his Hungarian colleagues. Regarding the maturation temperature, a generally often discussed topic, it was recommended to apply 12 °C, which should result in ovulation after ~6 h. As hormone treatment, sGnRHa delivered better results than hCG. This improvement however comes at the cost of synchronization. Yet it is not clear what the effects of hCG on the timing of ovulation might be. The detailed description of suturing, gamete collection and the in vitro fertilization protocols (using milk during the swelling period finished with a kaolin bath) initiated a lively discussion after the talk comparing nest and the so called artificial spawning technique.
FIRST RESEARCH RESULTS OF PERCH SPERM CRYOPRESERVATION AT THE RESEARCH FACILITY BORN (DARSS, GERMANY) - A PILOT EXPERIMENT - Frederik Buhrke & Sebastian Rakers, LFA MV & FhG EMB, GER
Undoubtedly, cryopreservation of sperm has a great potential for the improvement of hatchery practice by delivering gametes when needed and allowing for comparison of e.g., egg quality across farm sites. Frederik Buhrke presented the results of a pilot project on perch sperm, which was conducted in cooperation with Sebastian Rakers. Perch sperm was sampled during in- (ponds) and off-season (RAS). Cryopreservation trials featured the comparison of two different extenders and cryoprotectants. Motile sperm (only 12%) could be detected in one extender (carp extender) and fertilization rate post-cryopreservation ranged up to 50%. However, no embryonic development until hatch could be observed. Frederik Buhrke then put up some questions for discussion and received valuable input from attending experts, an ideal example of the EPFC potential.
BUILDING THE FOUNDATION FOR A SUCCESSFUL PIKEPERCH (SANDER LUCIOPERCA) BREEDING PROGRAM - Stefan Klenke, ETZH, CH
To the present day, no breeding programs have been published in the commercially valuable pikeperch. Using the EPFC network, Stefan Klenke conducted a survey among experts and visited farms to identify the most promising breeding traits to deliver suggestions for a possible breeding program. A total of 53 participants from 19 countries with an average experience of 10 years in pikeperch farming or research took part in the online survey. As most important traits, growth rate, stress tolerance, disease resistance, robustness against handling, reduced cannibalism, larval survival and feed efficiency were identified. For a fast breeding progress, Stefan Klenke suggested to focus on growth rate, according to the survey the most important trait with a high expected breeding progress, and reduced cannibalism. Currently, cannibalism is countered by size sorting, increased water turbidity and changes in stocking densities. It will need to be tested whether cannibalism is a heritable trait and/or if every pikeperch is a potential cannibal. Stefan Klenke also came up with a hypothesis to breed the fish towards a smaller mouth gap. This might also increase filet yield, which was found to be already higher (+14%) in females. Conclusively, it was suggested to step away from using wild fish as broodstock and to move towards all-female stocks while focusing on selection for growth rate related traits.
RESULTS OF THE BORD IASCAIGH MHARA (BIM) PERCID REPRODUCTION WORKSHOP 8-9 MARCH 2017 - Damien Toner, BIM, IRE
Within the last block of the event, Damien Toner presented the results of the BIM Percid Workshop held in March 2017 in Ireland. The purpose of the meeting was to allow for discussion on a range of issues surrounding reproduction in percid culture and was attended by 30 participants from 12 European countries (>55% from the industry). Besides practical insides, the workshop saw discussions on further co-operations including much favored exchange with other fields, such as fish nutrition. As important bottlenecks, development of breeding programs, cost reduction (especially in RAS) and consequently stabilization of production were identified. In order to achieve the latter, Damien Toner underlined that “it is important to talk about our failures”. Keeping precise records, developing new methods and routines, as well as sharing best practices are considered key tasks. Regarding the dependency of producers on (niche) markets, Damien Toner stated that “as a sector we can only grow, if we expand” by accessing further potential and diversifying product categories. Anyone interested should be looking forward to the announcement of a series of videos to disseminate techniques (first video to be launched in spring 2018).
RESULTS OF THE INAGRO PIKEPERCH REPRODUCTION WORKSHOP 11-15 SEPTEMBER 2017 - Stefan Teerlinck, Inagro, BE
As last speaker Stefan Teerlinck summarized the pikeperch reproduction workshop, which took place at Inagro during September 2017. During this intensive hands-on workshop, experts trained the enthusiastic participants in the entire spawning process focusing on gonad biopsies, hormone treatment, evaluation of gamete quality and in vitro fertilization followed by egg treatment and incubation. RAS-reared broodstock originated from grow out at Inagro. The applied larval rearing protocol after the end of the workshop was presented including first results on larval feeding trials. As other speakers, Stefan Teerlinck emphasized the benefits of a full and detailed documentation of the entire process for each female and highlighted the need for a “give and share” mentality among people involved in percid farming and research in order to overcome current bottlenecks. Given the success of the 2017 workshop, those who are interested should look out for another workshop announced for 2018.
This workshop summary was written by Dr. Fabian Schäfer, IGB, Berlin, Germany.
EPFC Workshop 2017, 17th October, Dubrovnik
The 6th edition of our annual EPFC workshop will be held on 17th October in Dubrovnik, Croatia in close conjunction with EAS annual Aquaculture Europe conference. The workshop title is: "New skillsets in Percid Fish Culture" and will pertain to the latest achievements in skills and competencies required for successful percid fish culture.
The workshop agenda is now ready for download: EPFC Workshop 2017 Agenda. You can find the abstracts for the talks enclosed in the Agenda table.
For further details on registration for AE17, please visit the EAS conference webiste here.
The 2017 edition of our annual EPFC workshop will be held on
17th October in Dubrovnik, Croatia
12.00 to 18.00
Meeting room RUDA
Valamar President Hotel (AE2017 conference venue)
in close conjunction with EAS annual Aquaculture Europe conference.
Confirmed speakers include colleagues from Switzerland, Hungary, Belgium, Germany and Ireland. Registration for the wortkshop will close in short due. Please register yourself by sending an email to firstname.lastname@example.org by latest 13th October. As every year, participation is free of charge for all AE conference and trade show delegates.
|13.00-13.30||Opening and Welcome|
|RISK MANAGEMENT TO MINIMIZE DISEASE ASSOCIATED ECONOMIC LOSSES IN AQUACULTURE OF PERCIDS||Melanie Rupp, University Bern, CH|
|PRACTICAL INSIGHT IN ARTIFICIAL REPRODUCTION AND LARVAL REARING METHODS AT RESEARCH INSTITUTE FOR FISHERIES AND AQUACULTURE NARIC HAKI||Uros Ljubobratovic, NARIC HAKI, HU|
|14.30-15.00||Break, 30 min, refreshments included|
|FIRST RESEARCH RESULTS OF PERCH SPERM CRYOPRESERVATION AT THE RESEARCH FACILITY BORN (DARSS, GERMANY)- A PILOT EXPERIMENT||Frederik Buhrke & Sebastian Rakers, LFA MV & FhG EMB|
|BUILDING THE FOUNDATION FOR A SUCCESSFUL PIKEPERCH (SANDER LUCIOPERCA) BREEDING PROGRAM||Stefan Klenke, ETZH, CH|
|16.00-16.30||Break, 30 min, refreshments included|
|Results of the Bord Iascaigh Mhara (BIM) percid reproduction workshop 8-9 March 2017||Damien Toner, BIM, IE|
|Results of the Inagro pikeperch reproduction workshop 11-15 September 2017||Stefan Teerlinck, Inagro, BE|
|17.45-18.00||SUMMARY & CLOSING OF THE WORKSHOP|
If you have not registered for AE2017 yet, please do so by following the link to Aquaculture Europe conference website.
We are also inviting all workshop participants to join us for a social dinner event on the evening before the workshop, Monday 16th October (18.00 pm). Please indicate your interest to join dinner in your registration Email and you will receive further details.
Looking forward to meeting you in Dubrovnik soon!