The farming of decapod crustaceans is a key economic driver, with production reaching 11.2 million tonnes (USD 81.5 billion) in 2020. In the last decade, public interest in the welfare of decapod crustaceans has increased in many parts of the world. In the UK, for instance, decapods crustaceans are recognised as sentient. In other countries, changes in legislation on methods for stunning have occurred. Electro-stunning may have the potential for reducing noxious stimuli experienced by decapods during slaughter. However, data on activity in the central nervous system and product quality-related data are not available for most of the important decapod species. Furthermore, decapod crustaceans are highly perishable due to rapid post-harvest bacterial growth. Previous work in our group has identified multiple bacteria species that drive lobster spoilage. However, comprehensive microbiome spoilage landscape for key decapod species is missing. Therefore, the aim of this research was firstly to investigate electro-stunning in a valuable decapod species, Norway lobster (Nephrops norvegicus) as a humane slaughter method and secondly to characterise microbiome changes during the conversion of muscle to meat.
Recordings of nerve activity showed that electro-stunning can render N. norvegicus rapidly insensible qualifying it as a potential humane slaughter procedure. In contrast, placing lobsters on ice for 30 min did not suppress neural activity. Results also show that while shelf life was not affected by the electro-stunning process, this stunning method did shorten the period that the product would be considered fresh. From a microbial biodiversity perspective, results indicate a clear lag phase of up to 5 days if product is stored on ice and key representatives’ families will be discussed. This research represents an important effort towards improving decapod welfare practices and increasing our understanding on the degradome of valuable seafood products.