Management of fish discards and by-products on board

In the framework of the future application of a zero-discard policy in EU fisheries, this thesis aims to develop and implement an efficient and integral waste management both on board the fishing vessels and in land (fish auctions and fish processing industry). To this end, it proposes a compaction operation able to reduce the volume and the water activity of the fish wastes, thus favouring their handling and reducing the economical costs associated to their transport and storage. To assess the viability of a waste compaction operation, the main operation factors governing the process were identified, and their influence upon the performance of a prototype at pre-industrial scale was investigated by a statistical approach. The main drawback associated to fish waste compaction is the generation of a variable amount of wastewaters, which cannot be directly discharged without a suitable depuration treatment. To this regard, the proposed wastewater treatment comprised two series filter cartridges, able to remove most of the fine solids followed by a membrane batch concentration unit able to produce a final permeate meeting the current environmental regulations.