Update on Fish Disease Situation in Italy

Abstract

In this presentation we provide a general overview of the aquatic animal health issues related to the aquaculture sector and wild environment in Italy in 2011. Considering saltwater species European sea bass (Dicentrarchus labrax) and Gilthead sea bream (Sparus aurata) are still the most widely farmed species, nevertheless some “new” candidates are employed often. The first two species represents more than 95% of the total production while the remaining is obtained by different promising candidates species, including sole (Solea solea), meagre (Argyrosomus regius), northern blue fin tuna (Thunnus thynnus) and amberjack (Seriola dumerilii) for which some breeding/reproduction plans have been attempted by some hatcheries. The farming of sea bass and sea bream is affected by the presence of several important diseases. Firstly considering Bacterial diseases, Marine Flexibacteriosis, caused by Tenacibaculum maritimum; Vibriosis, caused by Listonella anguillarum and Pasteurellosis caused by Photobacterium Damsela subsp. piscicida are considered the major bacterial diseases even though for these pathogens exists chemicals and for some of them efficacious vaccines. Considering viral diseases Viral encephalopathy and retinopathy (VER) still plays a key role in some areas where, mortalities ranging from 30-40% can be observed in sea bass rearing unit. Nevertheless in recent years, serious epizootics affecting sea bream larvae, previously considered a resistant species, have been reported. Finally the appearance of the clinical disease has been recorded also in the wild. Lymphocystis disease (LCD) represents an important disease not for its pathogenicity but for the interferences with strict production plans of farm. Finally, considering parasites, over than “old” protozoans (Cryptocarion irritans and Amyloodinium ocellatum) and gill flukes (Diplectanum aequans and Sparicotyle chrysophrii) mainly present in inland farms (earth ponds and concrete tanks based); isopods crustacea (Ceratotoa, Anylocra) and Enteromyxidiosis (Enteromyxum leei) represent a treat for offshore cages. Among the dismetabolic unknown aetiology disease Winter Syndrome, affects mainly 1-year-old sea bream causing mortalities ranging from 5-15%. The therapeutic treatment addresses great attention to the diet, especially at the end of Summer and the approaching winter season. Considering trout farming which is a well developed industry two main pathological scenarios are present. Farms with low water temperature (mainly located in the mountains) can be more affected and damaged by viral diseases (i.e. viral haemorrhagic septicaemia VHS) which is one of the most important problem. Rainbow trout fry syndrome (RTFS) is responsible for significant mortalities in salmonids, during juvenile stages, particularly if not treated promptly. Another bacterial problem that seems to be re-emerging is Enteric Red mouth (Yersinia ruckerii). Finally considering freshwater wild environment a mortality outbreak in eels is presented.