An assessment of disease occurrence and mortality in marine fish farming in Spain

Marine fish farming in Spain, as in most Mediterranean countries, focuses on the production of European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata). The sector has experienced performance problems that affect the industry’s competitiveness, and infectious and parasitic diseases have been described as being among the main causes of losses. Whereas companies are aware of the need to assess the impact and causes of such losses, the analysis of disease occurrence and mortality in seabass and seabream has received scarce attention from the sector and official administrations. Through information obtained from interviews and surveys, it has been possible to carry out an assessment of disease occurrence and mortality in marine fish farming in Spain. The median survival rate data for seabass and seabream was shown to be slightly higher in seabream, although no significant differences were found between species. It was not possible to further differentiate the causes of diseases or losses, as they were generally not standardized into categories and they also varied between companies. Nevertheless, the aim was to prompt producers and health management stakeholders into discussing how to improve the collection and analysis of data for relevant disease outbreaks and mortalities. Moreover, EU Regulation 2016/429 (the ‘Animal Health Law’) calls on Member States to implement disease surveillance programmes to investigate ‘increased mortality’ events in order to be alert for possible emerging diseases. Good knowledge of a disease situation and its impact on production represents a base mechanism for designing health surveillance. Therefore, the standardization of health data collection and its analysis will help countries in the implementation of surveillance programmes and rapid alert mechanisms in order to combat emerging diseases at an early stage.