With clear sustainability benefits, ‘waste’ or solid organic residues from the fisheries sector must necessarily be our priority in biodiscovery. In Bythos, we ensure not only that the marine peptides are obtained from sustainable sources but that they also lead to increased circularity in the fisheries sector.

In 2018, the EU landed approx. 5.3 million tonnes of seafood with a reported added value of €7.7 billion (mostly created by the processing and distribution sectors); however, as the largest importer of seafood in the world, self-sufficiency stands at only 45% from own waters (Eurostat, 2019). Looking at these landing numbers from a waste stream perspective, our on-going work in this sector, confirmed by data from scientific literature all over the world, shows that conservative estimates put ‘waste’ or residues in the processing and distribution sectors as ranging between 40-50% of the weight of the living natural resource (based on yields as % of whole fish or shellfish weight, also confirmed by FAO Yearbook of Fishery Statistics, catches and landings) (FAO, 1989). Estimates on the millions of tonnes of waste produced by the fisheries sector every year vary considerably and it is of little use trying to extract an exact figure without a more systematic review; however, it is clear that the quantities of residues are considerable. A simple manipulation of the statistics reported above would put waste from the fisheries sector at over 2.5 Mt, based on annual EU landings in the EU alone. The figures are far greater if we consider waste streams from capture originating in other parts of the world which are processed/consumed in the EU or the millions of tonnes of discards (both vertebrates and invertebrates) thrown back into our waters every year as recent EC landing obligations are put into place.

The U.S Food and Drug Administration (FDA) asserts that, as a class of drugs, peptides are increasingly important in medicine. It defines a peptide therapeutic as a chain of amino acids containing 40 amino acids or less and regulates them as small molecules (U.S Food and Drug Administration, 2019). Peptides can occur naturally in a living organism or can be produced in a laboratory through chemical synthesis or recombinant DNA technology using other living systems. However, the manufacturing of generic peptide drug products that are equivalent to their brand-name counterparts (fundamental to ensure a wider public access to medication) is expensive and struggles with impurities which may be inadvertently introduced during the production process and which may affect a proposed generic drug’s safety profile (U.S Food and Drug Administration, 2019). There are currently only approximately 100 peptide drug products marketed in the U.S., Europe and Japan; these are expensive and not always available to the wider public. The sector requires new, natural and pure molecules in sufficient amounts. This will require large amounts of the source material and relatively low-cost extraction methods to ensure that the end product is both effective and financially accessible to the general public.

In addition, increasing interest is being shown in Recirculating Aquaculture Systems (RAS). These often highly technological systems (which currently largely rely on imported dry feed formulated for marine cages and not for RAS) would greatly benefit from specialised bioactive feed to mitigate stress response and stimulate the immune system of farmed animals. Typical farm management practices, such as overfeeding, netting, high stocking density, air exposure and chasing, cause permanently stressful conditions, which affect not only fish growth and reproductive output (Sneddon, Wolfenden, & Thomson, 2016) (Herrera, Mancera, & Costas, 2019) but also the immune system and increase susceptibility in the organisms to disease (Vazzana, Cammarata, Cooper, & Parrinello, 2002) (Barton & Iwama, 1991).

Bioactive ingredients with an immunostimulant action enhance defence mechanisms and increase resistance to specific pathogens (Barman, Nen, Mandal, & Kumar, 2013). Furthermore, research indicates that certain dietary additives, such as amino acids and fatty acids (sourceable from fish residues), can mitigate the negative effects of stress and disease susceptibility (Herrera, Mancera, & Costas, 2019).

The use of antibiotics is widely practised in fish farming to control the outbreak of disease (Cabello F. C., 2006). However, in the long term, antibiotics create selective pressure for the emergence of multidrug resistant pathogens (Cabello, Godfrey, Buschmann, & Dolz, 2016). Feed enriched with bioactive molecules may also help reduce the use of antibiotics in aquaculture and increase the quality of fish feed, thereby improving the nutritional value of fish (Martinez-Alvarez, Chamorro, & Brenes, 2015).

Bioactive feed would also be of interest in attempting to mitigate stress factors in near-shore farmed species caused by increasingly high sea temperatures and newly emerging disease.