ae 2015 rotterdam special session diversify
During the Aquaculture Europe 2015 conference, DIVERSIFY project had a special session day, Thursday 22th October. Major achivements in grey mullet culture obtained during 2014 and 2015 were presented by the species leader Bill Koven, (IOLR), with results from the work of H. Rosenfeld, C. Fauvel, O. Nixon, A. Tandler, I. Meiri-Ashkenazi, A. Bitan, E. Gisbert, A. Estévez, Y. Kotzamanis, R. Robles, G. Shafran, N. Papaioannou,
justification for the selection of grey mullet
Farming of grey mullet has been practiced for centuries, but production of this potentially invaluable source of animal protein in Europe has been small and non-intensive (Nash & Koningsberg, 1981; Pillay, 1993). It is a euryhaline species, found throughout the world (Oren, 1981) and is a rapid-growing, herbivorous species that can be reared over the wide geographical and temperature range of the Mediterranean basin. As it is detritivorous in the wild, it has been stocked in fish ponds to improve sediment quality and avoid oxygen depletion (Milstein et al., 1991). Therefore, it can be an excellent candidate for the enhancement of aquaculture in earthen ponds, coastal lagoons, "valli" and deserted Salinas that exist throughout the EU Mediterranean countries. Hatchery produced juvenile females have been grown to 1.9 kg in 2 years on a fishmeal-containing pelleted feed (P4. HCMR). The development of fishmeal-free feed will reduce the cost of fish production, and will be more sustainable and environmentally friendly. In this way, grey mullet would be more acceptable to an increasingly aware consumer public that demands sustainability and lower environmental impact. Moreover, grey mullet aquaculture has the advantage of providing not only affordable whole fish and fillets, but also fish roe (“bottarga” in Italian), a high value product (>100 € kg-1), whose market is expanding around the Mediterranean. Therefore, grey mullet has a great biological and economical potential for fish species and product diversification, and development of value added products.
A market for grey mullet is well established, though a niche one, in the Mediterranean. Even without any marketing effort by the aquaculture industry, the European market demand for grey mullet is likely to increase in the coming years, due to the demand from established and newly immigrant families originating from North Africa, Middle East and Asia. Currently, the industry is a capture-based aquaculture, relying exclusively on capture of wild fry (ca 1,000,000,000) that are subsequently grown out to market weight (600-1200 g) in captivity, in lagoons or earthen ponds. The sustainability of such an activity is, of course, questionable, and the future growth of the grey mullet aquaculture is limited by a number of bottlenecks, which will be addressed in DIVERSIFY. Firstly, controlling the reproductive cycle and improving egg quality via broodstock management and nutrition is necessary not only for the production of robust larvae, but also for producing high value bottarga. Secondly, development of a larval rearing protocol is necessary to reduce early mortalities, size dispersion as well as increasing metamorphic synchrony, which will lead to a supply of high quality juveniles. Finally, development of a sustainable, economical, fishmeal-free grow out feed is needed, which would perform well under different environmental conditions of temperature, pond type, and water quality, thus broadening the geographical range of grey mullet aquaculture in Europe.
A market for grey mullet is well established, though a niche one, in the Mediterranean. Even without any marketing effort by the aquaculture industry, the European market demand for grey mullet is likely to increase in the coming years, due to the demand from established and newly immigrant families originating from North Africa, Middle East and Asia. Currently, the industry is a capture-based aquaculture, relying exclusively on capture of wild fry (ca 1,000,000,000) that are subsequently grown out to market weight (600-1200 g) in captivity, in lagoons or earthen ponds. The sustainability of such an activity is, of course, questionable, and the future growth of the grey mullet aquaculture is limited by a number of bottlenecks, which will be addressed in DIVERSIFY. Firstly, controlling the reproductive cycle and improving egg quality via broodstock management and nutrition is necessary not only for the production of robust larvae, but also for producing high value bottarga. Secondly, development of a larval rearing protocol is necessary to reduce early mortalities, size dispersion as well as increasing metamorphic synchrony, which will lead to a supply of high quality juveniles. Finally, development of a sustainable, economical, fishmeal-free grow out feed is needed, which would perform well under different environmental conditions of temperature, pond type, and water quality, thus broadening the geographical range of grey mullet aquaculture in Europe.
