Genotype-by-environment (GxE) interaction is the phenomenon that occurs when different genotypes perform differently in different environments. If GxE exists, selection strategies need to be adapted or separate environment-specific breeding programmes need to be developed. Annual temperature regimes vary across the Mediterranean basin. To estimate the GxE, gilthead seabream from the experiment described in Deliverable 2.4 (Estévez et al, 2021) were genotyped and phenotyped at the time of harvest in a real-scale case study, conducted simultaneously in Greece and in Spain. In order to produce comparable data and test the interaction with the environment between sites, apart from the husbandry practice, fish batches, feed and feeding regimes were the same in both sites. Also, sea cages were of the same size (16 m diameter). Low genetic correlations (< 0.7) point to the existence of GxE.
Differences were observed between local environmental conditions, particularly the temperature profile, at the two sites during the growing period. Growth rate (thermal growth coefficient, TGC) and harvest weight were found to have moderate to strong heritabilities in both sites and the same was true for the quality traits of fillet weight and fillet fat percentage. These heritabilities indicate that important improvements can be made with selective breeding in those traits. Harvest weight, growth rate, and fillet weight all showed strong GxE interactions, with genetic correlations below 0.5. This means that breeding for improved production efficiency across a range of environments needs to account for this strong GxE and cannot rely on measurements in a single environment. The GxE observed for fillet fat percentage was very limited (high genetic correlation of 0.9), which indicates that for this specific trait the local environmental conditions have limited effect on the genetic ranking of fish. These estimates are important to allow genetic improvement for production across different environmental conditions of the many sites where gilthead seabream are produced. In addition, the results from this deliverable also indicate the need to breed fish with an improved ability to deal with rapidly changing environmental conditions, i.e. caused by climate change.Continue reading
This report is part of MedAID Work Package 3 on Genetics and Breeding. In particular, it describes the application of the MedFish SNP array (developed through collaboration between the MedAID and PerformFISH projects – see Deliverable 3.1) to determine population structure and genetic variability in European seabass and gilthead seabream.
Knowledge on population structure and genetic diversity within and between wild and farmed populations is of paramount importance to achieve sustainable aquaculture production of Mediterranean seabream and seabass. In particular, the success of any breeding programme critically depends on the way in which the base population of breeders is built, as the genetic variability initially available in the founders will determine the subsequent genetic progress. These base populations can be created from wild or farmed populations and it is thus necessary to determine the relatedness between them in order to optimize their creation. Also, once genetic improvement programmes are running, the control of inbreeding and effective population size (a parameter inversely related to the loss of genetic variability) is needed to ensure their sustainability.
Fish escapes from aquaculture facilities are perceived as a major threat to natural biodiversity in marine waters as they may cause undesirable genetic effects in native populations through interbreeding. Thus, knowledge on the relatedness between wild and farmed populations will help to assess the risk of the genetic impact on wild populations from escapes of cultured fish.Continue reading
Innovation and development of new products for exisiting and new markets is clearly needed for a long-term competitive supply-demand equilibrium of Mediterranean marine aquaculture. As in the rest of the food industry, the improvement of the competitiveness and sustainability of the sector is governed by current consumer trends, which translates into the need to transform aquaculture species to offer consumers the safe, quality and convenience products they demand.
MedAID’s WP5 aims to explore and validate the technical and market feasibility of developing different product alternatives of main Mediterranean aquaculture marine fish, by identifying the best market solutions, transforming fish into new value-added and tailor-made products to satisfy the needs of different consumer profiles (children, senior, gourmet/premium, ethnic etc.), while adapting to the needs of diverse food and fish market channels.
The aim of the work developed in Task 5.3.4. ”Food fish prototypes pre-scale-up needed for market validation”, and reported in this report (Deliverable 5.4) was to determine the optimum production process for product technical quality and safety and to elaborate the food prototypes needed for market validation with consumers in Spain, France and Germany (Task 5.4.1.). Four prototypes out of the eight new products previously designed in the Task 5.3 (Deliverable 5.3. ”Development of new added value fish prototypes at pilot-scale for different fish market channels” [Peral et al., 2020]), were selected for optimization and production at pre-industrial scale at AZTI´s plant through short production runs, followed by a market validation step so as to study the sensory acceptability, consumer preferences, food packaging and purchase intention among other parameters.Continue reading
Within the Blue Growth Strategy, aquaculture is perceived and quoted as a sector that has a high potential for sustainable employment and growth and that has to be developed. Despite a strong initial growth at the beginning of the Blue Revolution, European aquaculture, and in particular marine fish farming, began to stall and stagnate. The new drivers initiated by the Blue Growth Strategy seem to have great difficulty in reversing that trend and progressing towards the stated objectives in terms of production volumes, in the light of the production statistics over the last decade. Marine socio-ecosystems are complex systems, they demonstrate non-matching scales, surprises (non-linearities), interconnection with other systems, memory effects, choke points and so on. This complexity calls for more integrated assessment through integration of existing knowledge: integration of sciences (among disciplines), integration of sciences and society, integration of sciences and policy and integration of uses. Even though some integrated assessment frameworks were developed such as the Ecosystem Approach to Fisheries, and its counterpart for aquaculture the Ecosystem Approach to Aquaculture, in practice they never really reached the required level of integration. In particular, these approaches focused on the ecological carrying capacity and left aside the social and institutional dimensions, especially the governance issues of these socio-ecosystems.Continue reading
Aquaculture in the countries bordering the Mediterranean and the Black Sea has grown substantially over the past decades, helping meet the rising demand for fishery products and contributing to increasing food security, employment and economic development in the region. However, this rapid expansion in some cases not well planned, has caused concerns about environmental impact, competitions with other local activities, human health and social issues.
Social acceptability refers to the degree to which aquaculture activities are accepted or precluded by the public at large. Social acceptability is also a key driver for sustainable aquaculture development and understanding the drivers that influence it could help unlock the aquaculture development potential and establish sustainable models that could contribute to the building of consensus around aquaculture activities.Continue reading
The evaluation of aquaculture performance is a difficult task as full-scale aquaculture production is affected by numerous parameters, such as structure and size of culture units, environmental conditions (temperature, water flow, winds, fouling, etc.), husbandry (feed and feedig pracices, fish handling, monitoring, etc.), which are very difficult to be mimicked at reseach scale. The evaluation of performance should be addressed with a multidisciplinary approach, difficult to be mimicked at research scale, and very expensive at a pilot or commercial scale. Consequently, the evaluation of causes behind a poor zootechnical performance is a very difficult objective for aquaculture managers, as the above mentioned parameters are interrelated and the sector operates with low profitability margins and on a highly competitive international scale.
There is a need for the sector to develop methodologies for the comparison of zootechnical performance among fish farms, which could facilitate decision making towards the implementation of more efficient and sustainable management practices. Considering the information previously gathered by MedAID regarding feeding practices designed along different tasks in WP2, a large case study was designed in two different sites located along the Mediterranean basin.Continue reading
The goal of MedAID is to increase the overall competitiveness and sustainability of the Mediterranean marine fish-farming sector throughout the whole value chain. In this context, the MedAID Project Work-package 6 (Improving business performance and development of strategic marketing plans), through the Task 6.5 “Estimation of the economic impact of improvements in production and marketing” aims to analyze the economic impact at the micro (firm/farm) level of some specific measures in the production and marketing areas to improve the financial performance of the European seabass and gilthead seabream aquaculture industry.
To carry out this analysis, we have designed a deterministic static model programmed with the spreadsheet Excel, which we have named MedAID Model for Economic Simulation (MMES), to simulate the annual income statement of an aquaculture facility (firm or farm). The model simulates in an independently way a grow-out facility for growing up seabass and seabream as well as a hatchery-nursery facility to culture seabass and seabream fry and larvae in the Mediterranean Sea. To obtain the baseline values of model parameters, we have used data from representative facilities from six European countries (Croatia, Cyprus, France, Greece, Italy, and Spain) collected in the survey conducted in MedAID’s WP1.Continue reading
MedAID Work Package 2 (Improving Zootechnical Performance) starts from the current context of knowledge in fish nutrition, and considers work on improvement in rearing conditions and feeding strategies fundamental to improve their related Key Performance Indicators (KPIs). This is a multidisciplinary WP that looks for correlations among different parameters related to rearing conditions, environmental factors, feeding, growth, fish health and fish quality. Furthermore cultured fish are often exposed to stresses of different nature, which can cause a wide range of physiological alterations, reducing overall performance and fish welfare. Handling operations (e.g. vaccinations, treatments, grading or transport) can involve fish crowding during short times; fasting periods are a consequence of bad weather conditions, when feeding can be impossible, or to voluntary restrictions before harvesting and slaughtering fish; cold water temperature during winter periods can also challenge fish ability to feed and impose long fasting periods. Task 2.3 of MedAID has investigated different options for reducing fish stress by optimizing feed formulation or using functional feeds.
Deliverable 2.3. reports the results from WP2 Task 2.3. Optimize feeding strategies during unfavourable farming conditions, which aims to reduce feed conversion rate (FCR), improve health and stress tolerance by better rearing and feeding strategies for seabass and seabream juveniles.Continue reading
MedAID Work Package 2 (Improving Zootechnical Performance) starts from the current context of knowledge in fish nutrition, and considers work on improvement in rearing conditions and feeding strategies that are fundamental to improve their related Key Performance Indicators (KPIs). This is a multidisciplinary WP that looks for correlations between different parameters related to rearing conditions, environmental factors feeding, growth, fish health and fish quality.
Task 2.2 (Assessment of the optimal rearing conditions to improve quality and fish health) addresses the problem of rearing conditions from a multidisciplinary approach in European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata). Considering the different factors involved, this task has focused on the Effects of temperature in seabass during larval development (Subtask 2.2.1); Effect of optimal water current inducing swimming behaviour (Subtask 2.2.2) and Effects of fish density and daily feeding frequency on KPIs (Subtask 2.2.3).Continue reading
The MedAID project (Mediterranean Aquaculture Integrated Development) aims to improve the key performance indicators (KPIs) of Mediterranean mariculture and considers health and welfare prerequisites for sustainable and profitable aquaculture in the Mediterranean area. Work Package 4: “Health management and diseases and fish welfare” addresses health issues and aims to provide tools and common strategies for the prevention and diagnosis of major diseases by creating an operative and collaborative Mediterranean platform. Task 4.1 aims to assess the risk of introduction and spread of emerging diseases at farm level, and to describe biosecurity measures to improve disease biosecurity management in seabass and seabream production in the Mediterranean basin.
A questionnaire survey was executed during the period 2018-2019. A convenient sample drawn from the MedAID database of farms/companies covering the Mediterranean basin included a total of 88 farms producing seabass and/or seabream from Croatia, Egypt, France, Greece, Italy, Spain, Tunisia, and Turkey. The purpose of this survey was to obtain an overview of farm and health management, biosecurity measures, fish health monitoring and disease diagnostics of Mediterranean marine fish farms. The questionnaire contained 19 different themes and was performed as face-to-face interviews. A univariate statistical analysis was run to test for significant association between farm mortality and various variables. Major findings were the significant association between farms reporting no major mortality due to pathogens and farms with good biosecurity practices.Continue reading