S.J. Kaushik

UMR NuAGe “Nutrition Aquaculture & Genomics »

Unité Mixte INRA-IFREMER-Univ. Bordeaux I

Station d’Hydrobiolgie, 64310 St-Pée-sur-Nivelle, France

Email : kaushik@st-pee.inra.fr

The meeting started with an introductory lecture by European deputy Mr Hugues Martin, who is also the vice-president of the Fisheries Commission of the EU parliament and author of the 2002 report on « Strategies for sustainable aquaculture development in the European Union».

Session I : EU instruments and actions

The first session was devoted to the description of EU research priorities and the specific instruments of potential interest to those involved in Aquaculture. The representatives of the DG FISH (Mario Lopes dos Santos (Research Unit) and Alessandro Piccioli (Aquaculture Unit) made it clear that under the 6^th Framework Programme, the general approach adopted is from “fork to farm”, meaning that the assurance of human food quality and safety is of prime importance. It was also made clear that EU would support the co-ordination of research efforts at the national levels, although the precise instruments were not yet clear. Mention was made of the forthcoming call devoted to sustainability and possibly also on “aquafeed and human health”. Speakers from the EAS (European Aquaculture Society) and Aqua-TT (Alistair Lane and David Murphy, respectively) also stressed the strong benefits withdrawn from networking projects which have been quite efficient in terms of disseminating results from R&D efforts. It was suggested that actions such as “Aquaflow” should continue to be supported and pursued for the benefit of the aquaculture industry at large.

Session 2 : Market Issues

Market issues for hatcheries were treated from different angles. In the first instance, the constraints and needs of producers (marine and freshwater) of already established aquaculture systems were presented. As regards the potential new species of interest; the views of an economist and of the producer were presented.

With regard to marine hatcheries, the efforts made by the industry to ensure the quality of juveniles were stressed by Mr. Gustavo Larrazábal (Tinamenor). He also made it clear that this improvement in quality has a price to be paid but that the dividends are hard to obtain. (“Quality Costs - Make Sure it Pays”). Given the differences between EU Member States with regard to establishing and monitoring quality and sanitary standards, distortions in trade and payments, specific stress was given to the “need for harmonisation of rules at the EU level” on such matters.

As regards salmonids, the report by Torben Nielsen made it clear that there was a need for a change in paradigm. He also stressed the importance of relevant breeding strategies devoted to the improvement of feed utilisation efficiencies and the need for understanding the process of domestication and adaptation to the varied husbandry practices that are currently in use.

The presentation by Alan Jones dealt with another aspect of juvenile production, that of producing juveniles for restocking purposes. Presenting diverse attempts in different areas with different species, he insisted that although the success stories were few, this area should not be ignored from the mainstream of activities connected with aquaculture hatchery technology. The questions raised were whether this is tantamount to “seeding the sea” or whether this kind of aquaculture will rescue some of the declining fisheries. However, the possible social roles played by such activities (i.e. recreational fisheries, rural stability) also have to be taken into account. The research areas identified were at the biological level: evaluation of fitness, assuring broodstock and juvenile quality, preservation of genetic diversity; at the ecosystem level: carrying capacity and habitat quality.

At this stage, it is worth pointing out that the Commission representatives stated that restocking does not fall under the current priorities.

As regards “New species”, the analysis made by P. Paquotte, from an economist’s point of view, explained that there is a clear market segmentation even between closely-related species and that there is a clear need for big fish (> 1 kg) which strongly favours the selection of species with fast growth rates. The consumer’s perception is rather volatile and which is also changing relatively fast: there are both positive and negative aspects in the perception of farmed fish. Apart from the UK, there is no image ‘bonus’ for farmed fish in other countries. A nice point which was made was that of a confused consumer who wants products that are “natural but totally under control”. A mention was also made that one should recognise that the market is global and that fish is a commodity. Another point made was that a pro-active attitude would be to create the market rather than pushing products through channels. The needs here hence are besides improving the image/perception of farmed fish, a standardisation of econometric and market analyses procedures. 

From the producers’ viewpoint, (Larrazabal), embarking on the production of “New Species” is a long and expensive process. An ideal situation is that this should be engaged only when there is market viability. R&D efforts of companies would not be sufficient to strengthen efforts towards new species and that there is definitely a need for more and more support from the EU.

Pascal Divanach, addressing the issue from a scientist’s point of view, explained that already about 30 million (5%) of the +/-600 million juveniles produced correspond to those other than European sea bass, gilthead seabream and turbot. Research priorities should go towards choice of species which have an inherent potential for fast growth, reaching big sizes in a short time and, better still, if they belong to a low trophic level.

During the discussion, questions arose as to whether “vaccination”, for instance, was well perceived as against the use of therapeutic agents. The question also rose as regards cultural differences which might make it difficult to extrapolate situations from one market to another. Commission officials stated that the economy governs and benchmarking work on selected species and then application/extension to other species of interest would be most appropriate. They also mentioned that there have already been substantial contributions for projects on new species (e.g. bluefin tuna, colouration…) and that it is mandatory that there is more and more SME involvement in pursuing efforts in this area.  

From the foregoing, it appeared that there is definitely a need for an integrated set of indicators for selection of «New» species. A suggestion was also made to avoid «Wild» as a reference point and to strengthen the positive aspects of fish in human nutrition and use reference endpoints based on the Consumer’s food basket.

Session 3. Production Issues

The cost of production of juveniles has really gone down. This point was explained by Didier Leclercq by making a comparative analysis of the costs of production of juveniles of turbot, European seabass, gilthead seabream, Siberian sturgeon and rainbow trout in France. In all cases, labour represented almost 40 to 50% of the total cost. He also stated that a significant gain can be made by substituting artemia and the related labour costs in the marine hatcheries. He also mentioned the importance of improving and standardising quality of both seed and feed. Techniques for micro-vaccination procedures need to be developed for all species.

Addressing the issue of artemia use, Eamonn O’Brien presented the current situation as regards global availability and the efforts with regard to tapping yet-unexploited sources. The major issues concerning artemia are those of predictability of supply, standardisation and quality of products delivered. Leaving aside the sustainability issues related to artemia, studies on cost-effectiveness of artemia replacers need to be undertaken, giving proper attention to quality of larvae and juveniles, especially with regard to deformities. Mention was also made of resilience to change (“used to, simple vs difficult, novel technical challenges”)

How far automation and mechanisation of hatchery practices can improve overall quality was dealt with by Roberto Menegatti. He made the point that, given the evolution of production systems which at all stages are getting more and more mechanised (involving sophisticated equipment), there is more than ever a strong need for the standardisation of quality control practices at all stages of the production chain. This can, on the one hand, lead to product certification and, on the other, provide bases to strengthen confidence through better transparency between producer and consumer.

From the scientific perspective, the first presentation dealt with the reproduction and conservation of gametes (A. Fostier) and the second with environmental and genetic basis of malformation in salmonids (Grete Baeverfjord). The major objectives as regards the mastery of reproduction are to obtain eggs of good quality, in sufficient number, in a predictable manner and with the desired characteristics which can ensure species preservation. This can be achieved through the proper management of broodstock (nutrition, environment, hormonal control…) throughout the gametogenetic period and through understanding factors which are connected to fertilisation events. Alternatives to steroid treatments, modification of sex ratios, cryo-preservation of male and female gametes are further areas of research where a comparative approach is definitely warranted. Special mention was made of efforts towards the initiation of basic research on the genomics of rainbow trout supported in part by professional organisations (CIPA).

Grete Baeverfjord explained that malformation of juveniles is also a major issue in salmonids and this is a complex issue affected by multiple parameters.  She presented results from a series of studies devoted to analysing the effects of genetics, incubation temperature, dietary factors etc affecting skeletal, jaw, or soft tissue deformities. High temperatures experienced during early development seem to induce significant levels of deformities. There appears to be a ‘window’ of temperature stress which needs to be determined for the different species. How far this susceptibility to malformation is genetically determined is again another question of interest. Another point worthy of note is that errors and problems encountered/solved in salmonids can serve other species, again emphasising the need for a comparative approach.

The major issues which arise in the production side are finding the means to reduce labour costs, possibly through increased automation and reliability of entrants and inputs. There is a definite need for the standardisation and predictability of seed quality, larval survival and quality. Problems related to deformities and malformations appear to concern all species, including salmonids and the governing factors are multiple (environment incl. feeds, husbandry, management…). There is a need for developing techniques to apprehend biologically sensitive ‘windows’ during early embryogenesis. We have to define sound bio-management practices for ensuring quality and confidence in hatchery operations. An integrated approach is needed both to understand the basic potential of organisms as well as at the system level to analyse such multifactorial issues.

Session 4. Health & Sanitary Issues

This session started with a survey of problems encountered with regard to the management of health in hatcheries. Other aspects which were dealt with included: water quality control, quality in live feed production, vertical transmission of disease and diagnostic tools. According to Alain LeBreton, the problems are related to varied husbandry and management practices. As regards pathogens, there are several entry points (water, seed, feeds…) and control of sanitation is the main issue. How far the microbial environment of the hatchery system as a whole contributes to either the pathogenicity or the protection against pathogens needs some elucidation: reduction of pathogens and selection of protective flora can increase disease resistance in larvae and juveniles.

According to Prof Sorgeloos, recirculation systems are more predictable in terms of ensuring the quality of live prey. For instance, ozone treatment improves rotifer production by improving the physico-chemical as well as the microbial environment. The addition of specific antimicrobials has been shown to be beneficial. Efficient, non-destructive washing and cleaning methods can have far reaching consequences in terms of bacterial load. The potential of probionts has to be fully analysed in an objective manner avoiding possible pitfalls in terms of pathogenicity to non-target organisms. As regards rotifer culture, he also presented some of the outcomes of some of the recent EU projects. The green water techniques indeed benefit from such controlled environments. He also stressed the importance of standardisation of techniques for live food production.

Dealing with vertical transmission of diseases, Guirec Dewavrin made a point as regards the need for a clear distinction between true vertical transmission inside the fertilised egg and those due to surface contaminations. After presenting a list of putative vertically-transmitted diseases, he insisted on the need for establishing clear zoo-sanitary regulations at the EU level. He insisted on the need for more research to bring clear evidence of vertical transmission of diseases. According to him, a total aquaculture quality concept should be developed to include measures for broodstock screening and quarantine and gamete disinfection procedures. He also suggested a creation of a centralised European broodstock improvement centre (as already mentioned by Cachelou, in his initial speech).

Prof. Sandra Adams, in her speech, explained the complementary nature of conventional testing procedures and the more rapid diagnostic tools. The relative merits and inconveniences were explained. Development of specific antibodies is a long process and need specific work for almost each species. Nevertheless, it is clear that the range of commercially available antibodies, serological tests are expanding rapidly and new developments are under way. She insisted on the need to develop adequate non-stressful, non-invasive and reliable diagnostic tools with standardised protocols, reagents and test protocols to ensure pathogen-free certification of broodstock.

From a technical side, the critical points in controlling water quality were described by Jean-Philippe Caillères.   As regards water quality management in hatcheries, industrial water treatment methods can be applied, involving physcico-chemical barriers to prevent infection. Different available techniques were presented and how such techniques can be useful in preventing pathogens and for disinfection. 

The research priorities identified are : ensuring total broodstock quality and gamete innocuity, control and management of microbial environment, development of efficient and reliable diagnostic tools. For hatchery management, the needs are standardised procedures for assessment of broodstock health status, sanitary procedures and maintaining high water quality in hatcheries. A specific need expressed was to create a centralised broodstock improvement centre at the European level.

Session 5. Genetic Improvement

It is clear that significant progress has been made in terms of the genetic improvement for some finfish species, but much less in others. Marc Vandeputte, in his introductory speech, gave precise examples and said that margin of progress is potentially high. Increasing productivity along with product quality improvement remains the major challenge in all the current genetic improvement programmes. Different strategies have been applied by different groups to achieve such progress, the strategies depending upon both technical as well as biological considerations. In terms of cytogenetics or transgenesis, although the former has become acceptable, the negative perception of transgenesis by the general public remains an issue. The needs are towards phenotyping of traits of interest with regard to sustainability issues and research on “clean/targeted transgenesis”.

Progress achieved in Atlantic salmon is indeed significant and the contribution of consistent selection programmes supported both by institutional research and industry is worth mentioning. Recent progress concerns at least 8 different traits of interest to improved flesh quality. Although there are a number of genetically determined traits, it was clear from the presentation of Morten Rye that in terms of heritability, the more subjective the traits are (less precise are the measurements), less are the corresponding heritability values. He also stressed the importance of developing non-destructive tests in live fish and QTLs for quality traits.

As regards marine finfish, research is under way in different lines: sex control, maturation and selection. Beatrice Chatain reported on the different methods currently available in these lines. It is clear that a better control of artificial fertilisation techniques is needed in order to demonstrate similar benefits as has been obtained with salmonids. In particular, understanding factors involved in sex determinism (sea bass) and sex reversal (seabream) are needed. Induction of long-term “sterility” is another issue of interest to the farmers, given the growth dimorphism and the interest for bigger fish in the market.

Mark Henryon dealt with selection for genetic resistance and gave examples of heritability values for resistance to different diseases in Atlantic salmon. It was interesting to note some negative genetic correlations between two disease resistance traits. Problems related to non-invasive diagnosis and the needs for development of reliable immune system indicators were brought forth. Here again, the creation of a breeding station for research purposes was considered necessary.

Overall, the success seems to depend upon the total control of « domestication », broodstock, larval culture etc, Artificial fertilisation techniques have to be developed for marine finfish. Definition of phenotypic traits of interest for sustainable breeding practices such as quality criteria, immune response criteria, and improved nutrient/energy utilisation efficiencies will require development of precise non-invasive tests in live fish. As regards tools, development of specific quantitative trait loci (QTL), marker assisted selection (MAS) strategies and basic work on targeted transgenesis are needed. From a structural point of view, European aquaculture will definitely benefit from a common platform/research centre for genetic improvement.

Recommendations of the Commission

As part of concluding remarks, Mario Lopes dos Santos requested that there should be a ranking of research priorities, in line with the Common Fisheries Policy. He also insisted that structural funds which exist be exploited thoughtfully for the benefit of the aquaculture industry. As regards market issues, it is for the profession to develop and implement strategies and protocols. Benchmarking has been already made for new species. With regard to production issues, he suggested that fish can be a model and participate in other integrated projects dealing with puberty and sex. If malformations are considered as part of the welfare issue or linked to quality aspects, there is a possibility for collective research (where SMEs play the major role) under priority 8 of the 6^th framework. Automation and other aspects related to improved hatchery technologies will have to be an in house activity, where possible involvement of structural funds can be sought. As regards health issues, prevention will have to prevail and best management practices have to be jointly developed. In terms of diagnosis and detection, coordinated actions between reference laboratories is a possibility. Genetics has been supported by several projects funded under priority 8, especially as regards functional genomics and so are projects related to stress and disease resistance. Quality aspects have been taken care of under priority 5.

Listed Priorities

Following presentation by Rosa Flos on a prospective European Masters degree in Aquaculture, the overall summary of the two-day events was made by S. Kaushik.

Three major areas were pinpointed : (i) Improvement of Broodstock & Egg Quality, (ii) Strategies to decrease malformation and deformities in juveniles and (iii) development of a scheme for “Best Hatchery Management Practices”.