Testing of the Salmon Welfare Index Model (SWIM 1.0) as a computational welfare assessment for sea-caged European sea bass

Abstract

The overall fish welfare in sea-caged European sea bass (Dicentrarchus labrax) was quantitatively assessed by adapting the Salmon Welfare Index Model (SWIM 1.0). In the model, a total of 16 operational welfare indicators in three segments (i) individual fish-based; (ii) fish-group specific; and (iii) sea cage environment-specific indicators were evaluated. In this study, the welfare indicators for salmon aquaculture which are incompatible with the characteristics of European sea bass were modified. Differently from SWIM 1.0, the welfare indicators of smoltification and salinity were eliminated; however, gill integrity and pH were added in the modified model of this study while the water temperature attributes were also changed in the model proposed. The modified model was tested for two sea cage farms of European sea bass (Farm A and Farm B) in two different locations of Mediterranean Sea for the first time. The overall welfare scores were expressed by a scale from 0-poor to 1-good welfare. The overall welfare assessment calculated by the model yielded the value of 1.0 and 0.81 for Farm A and Farm B, respectively. Based on the scores, Farm A represented the conditions of ‘good welfare’ while Farm B gave fair warning about welfare status. The methodology developed in the SWIM 1.0 model can be applied to European sea bass in Mediterranean aquaculture with small modifications.HIGHLIGHTS Salmon Welfare Index Model (SWIM 1.0) was utilised for E. sea bass welfare evaluation SWIM 1.0 was tested in sea-caged fish from two farms located in Mediterranean Sea SWIM 1.0 model can be applied to E. sea bass with small modifications

Keywords

• fish welfare
• quantitative modelling
• dicentrarchus labrax