LACK OF KNOWLEDGE DOES NOT JUSTIFY MISSING ACTION: ASSESSING THE STATE OF WELFARE IN FARMED FISH

Today already 50% of the world's food fish originate from aquaculture farms. Predictions indicate that this number will increase to approximately 65%, equivalent to 90-100 million metric tons/year, by 2030.   Increasing production is often associated with increased intensification and greater environmental footprints, putting aquaculture into the center of public debates regarding sustainability and animal welfare. These debates are often controversial , emotional, and lack a solid, data-based line of argumentation.

According to German federal law, a regular corporate self-monitoring on the state of welfare is required from every fish farmer. Nevertheless, at the federal level, there is still no profound reporting structure established , and until now there is no approved set of indicators available to comprehensively implement this in an equivalent way to terrestrial livestock. We reviewed the current guidelines for the assessment of welfare in terrestrial farm animals as well as the methodology used to develop these, in order to adopt a strategy for fish welfare indicators. We collect and evaluate parameters and welfare indicators for rainbow trout (Oncorhynchus mykiss) and common carp ( Cyprinus carpio) which are the most important species in the traditional, pond- based aquaculture in Germany. Despite this long tradition, little is known about the state of animal welfare of the two species, which differ fundamentally both in their biological requirements and in the husbandry systems used for rearing.

We identified several areas of activity, where welfare might be impaired or improved.

Our results enable farmers and farm managers to routinely assess the status of animal welfare on their farms. This will also enable individual farms to survey the development of their husbandry conditions and to detect trends in husbandry at an early stage. Additionally, they can check the success of changes and implemented measures immediately.