Preprint volume - SIBM
Preprint volume - SIBM
Preprint volume - SIBM
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Pre-print Volume – Posters<br />
AQUACULTURE COMMITEE<br />
G. MARICCHIOLO, T. CARUSO, G. CARUSO, L. GENOVESE, S. MIRTO<br />
Institute for Coastal Marine Environment (IAMC), CNR, Spianata S. Raineri, 86 - 98122 Messina, Italia.<br />
giulia.maricchiolo@iamc.cnr.it<br />
REARING CONDITIONS AND WELFARE IN DICENTRARCHUS LABRAX:<br />
A COMPARISON BETWEEN SUBMERGED AND SURFACE CAGES<br />
VALUTAZIONE DEL BENESSERE IN SPIGOLE (DICENTRARCHUS LABRAX)<br />
ALLEVATE IN GABBIE DI SUPERFICIE E SOMMERSE<br />
Abstract – The aim of this study is to investigates growth, haematological, biochemical and immunological<br />
parameters of European sea bass, Dicentrarchus labrax (Teleostei, Moronidae) farmed in submersible and<br />
surface cages in order to compare physiological status under different rearing conditions. Results obtained<br />
suggest mariculture in submerged cages a promising system that allows to minimize stress and that, hence,<br />
promotes fish welfare.<br />
Key-words: aquaculture, submergence, sea-cage, fish welfare.<br />
Introduction – Offshore submersible cages play an important role for Mediterranean<br />
aquaculture expansion solving several of the substantial operational challenges that<br />
exist in surface-based fish farming such as those related to heavy storms, algal and<br />
jellyfish blooms, sea lice infestations, unsuitable temperatures, and biofouling of net<br />
cages. Moreover, the high concentration of fish confined in surface net cages causing<br />
repeated attacks by predators (i.e., cormorants) determine death, injury and expose fish<br />
to a stressful condition. Therefore, we expected submergence may have a positive<br />
effect on fish welfare.<br />
Subsurface technologies have been tested in several production experiments but the<br />
growth and behaviour of fish in submerged cages relative to standard surface systems<br />
is however largely unknown; objective comparisons of fish performance in<br />
commercial-scale submerged cages vs. surface cages have only been undertaken for<br />
short-term, shallow submergences (Dempster et al., 2008, 2009), or for long-term in<br />
Atlantic salmon (Korsøen et al., 2009).<br />
The aim of this study is to investigate haematological, biochemical and immunological<br />
parameters of European sea bass (Dicentrarchus labrax) farmed in submersible and<br />
surface cages in order to compare physiological status under different rearing<br />
conditions and to validate the efficacy of submersible technology.<br />
Materials and methods – The study was conducted from January to December 2008<br />
in the Castellammare Gulf (NW-Mediterranean Sea) in four fish cages (two submerged<br />
and two surface). The fish cages (2000 m 3 ) were filled, on January 2008, with 75.000<br />
specimens of D. labrax (initial weight: 28.2±4.3 gr), for each cage. The fish were<br />
manually fed with a commercial diet twice a day according to the estimated live weight<br />
and water temperature.<br />
During the trial, fish were randomly collected on a monthly basis, and total and<br />
standard length and wet weight were immediately recorded for each specimen, to test<br />
growth performance, by calculation of the daily specific growth rate (SGRW%) and the<br />
relative condition factor (Kn, Le Cren, 1951). At three sampling time (February, June,<br />
September), samples of fish (n=40) were taken to investigate haematological,<br />
biochemical and immunological parameters. Individuals were taken from the cages and<br />
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010<br />
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